Ophthalmology Review

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June 30, 2006

Intrastromal corneal ring in penetrating keratoplasty: Evidence-based update 4 years after implantation

Journal of Cataract & Refractive Surgery Volume 32, Issue 6 , June 2006, Pages 993-998

An 8 mm cobalt-titanium-molybdenum alloy ring was sutured into the PKP wounds. A prospective study compared the outcomes of PKP in 179 consecutive cases with a ring (Group 1) and 101 consecutive patients without a ring (Group 2). The ring was used in different types of endoepithelial degeneration as well as in keratoconus stage IV. Patients with macular pathology were included.
Results
The mean age of Group 1 patients was 67 years (range 9 to 96 years). Postoperative best corrected visual acuity after 1 year was almost identical in both groups (20/42 in Group 1 and 20/45 in Group 2) as were the cylinder values (Group 1, 2.64 diopters [D] ± 1.44 (SD) versus Group 2, 2.83 ± 1.52 D). There were 2 immune reactions in group I as compared to 6 (1.2% vs 7%, P value 0.02) in group II within 4 years of the procedure. Evaluation was performed by the Kaplan-Meier method.
Conclusion
Advantages of the ISCR were observed outside the targeted goals of improving the amount of astigmatism and maintaining refractive stability. Best corrected visual acuity and cylinder development were similar in Groups 1 and 2, whereas, there was a highly reduced immune rejection rate. The ring also appeared to act as a barrier to superficial vessels.

Posted by mmiraftab at 12:42 PM | Comments (0)

Intacs adjustment surgery for keratoconus

Journal of Cataract & Refractive Surgery Volume 32, Issue 6 , June 2006, Pages 986-992

Of 58 keratoconic eyes managed with Intacs, 7 had additional Intacs surgery. After the initial Intacs surgery, 6 of these eyes had UCVA ≤20/100 and 1 had UCVA of 20/50. After the final Intacs adjustment, 3 eyes achieved UCVA ≥20/40, 5 achieved UCVA ≥20/70, and 2 remained <20/200. The indications for Intacs adjustments were increased astigmatism in 4 eyes, induced hyperopia (overcorrection) in 3, and undercorrection in 1. One eye had both surgically induced astigmatism and hyperopia. Induced astigmatism and hyperopia were most often managed by removing the superior segment. The undercorrected eye, having initially received a single inferior segment, was treated by implanting a superior segment.
Conclusions
Approximately 10% of keratoconic eyes managed with Intacs may require Intacs adjustment surgery, which often has a good outcome.

Posted by mmiraftab at 12:40 PM | Comments (0)

Intracorneal ring segments for keratoconus correction: Long-term follow-up

Journal of Cataract & Refractive Surgery Volume 32, Issue 6 , June 2006, Pages 978-985

This retrospective study comprised 13 eyes operated on between April 2000 and December 2001 that had Intacs implantation for keratoconus correction. The outcomes were evaluated at 6, 12, 24, and 36 months in all eyes and at 48 months (6 eyes).
Results
Mean best spectacle-corrected visual acuity (BSCVA) increased from 0.46 (20/50) preoperatively to 0.66 (20/30) postoperatively (P≤.001). Mean decrease of inferior-superior (I-S) asymmetry was 2.81 diopters (D) (P≤.02), and the average K-value was 3.13 D (P≤.001). Mean difference between 6 and 36 months (stability) showed no significant difference regarding BSCVA (P≤.5) and I-S asymmetry (P≤.6). Although a significant increase was noticed in the average K by 1.67 D (P≤.002), at 36 months it did not reach the initial preoperative values.
Conclusion
Intacs increased the BSCVA and decreased I-S asymmetry with stability up to 36 months. In spite of the decrease of the K-values at 6 months, a further significant increase was detected 36 months after surgery.

Posted by mmiraftab at 12:38 PM | Comments (0)

Topography-guided customized laser-assisted subepithelial keratectomy for the treatment of postkeratoplasty astigmatism

Journal of Cataract & Refractive Surgery Volume 32, Issue 6 , June 2006, Pages 949-957

In this pilot study, 15 patients (16 eyes) who were intolerant of spectacle and contact lens correction due to astigmatic anisometropia after keratoplasty (15 penetrating and 1 lamellar) had topography-assisted customized excimer laser treatments. Corneal topographic data using a Keratron Scout, Placido disk system allowed for preoperative analysis of wavefront anomalies of the anterior corneal surface from which a customized excimer laser correction of both lower-order aberrations (LOAs) and higher-order aberrations (HOAs) was prepared (ORK software) for treatment with a Schwind Esiris flying-spot laser. All eyes had laser-assisted subepithelial keratectomy (LASEK) using 15% alcohol with a 20-second to 30-second application. Four eyes received an application of mitomycin-C (MMC) 0.2 mg/mL for 1 minute after stromal ablation.
Results
The mean preoperative spherical equivalent (SE) was −3.50 diopters (D) ± 3.97 (SD) (range +1.625 to −9.25 D). The preoperative cylindrical error was −7.2 D (range −2.75 to −13.5 D). The programmed laser correction was −3.14 D (range +1.62 to −9 D) with a maximum attempted cylindrical correction of −7 D. Adherent LASEK epithelial flaps along suture lines and the graft–host junction were noted in 9 eyes (56%), although it was possible to obtain and replace a partial flap. A follow-up of 18 months was achieved in all eyes. At the final follow-up visit, the mean postoperative SE was −1.08 ± 1.85 D (range +3 to −4.78 D) (P<.01, F<.01). Ten eyes (62.5%) were within ±1 D of the intended correction. The mean postoperative cylindrical error was −2.72 D (range −0.5 to −6.5 D) (P<.001), with vector analysis demonstrating a mean 6.23 D correction. Analysis of HOAs using a 6.0 mm pupil size demonstrated a significant reduction of higher-order root mean square (RMS) (P<.002), trefoil (P<.005), and 4th-order spherical aberration (P<.02) at 18 months compared with preoperative values. Uncorrected visual acuity improved in all eyes (P<.0001). Best spectacle-corrected visual acuity was unchanged or improved in 13 eyes (81%) and worse in 2 eyes by 1 line; 1 eye lost 3 lines due to an increase in preexisting cataract. In eyes that did not receive MMC, corneal haze (grade II to IV) was encountered in 3 eyes (27%). One eye required phototherapeutic keratectomy with MMC application at 12 months. Of the 4 eyes treated with MMC, 1 had trace haze and 3 had no detectable haze. There were no reported cases of epithelial instability, ectasia, or graft rejection.
Conclusions
Topography-assisted customized LASEK was effective in the correction of postkeratoplasty astigmatism. A significant improvement of both LOAs and HOAs was obtained with good refractive stability for over 18 months. Iatrogenic haze typically occurred but appeared to be minimized with adjunctive use of intraoperative MMC.

Posted by mmiraftab at 11:46 AM | Comments (0)

Opacification of the Hydroview H60M intraocular lens: Total patient recall

Journal of Cataract & Refractive Surgery Volume 32, Issue 6 , June 2006, Pages 944-948

A total of 1330 eyes of 1265 patients who had cataract surgery with Hydroview IOL implantation between September 2000 and April 2001 were reviewed between April and October 2004. The visual acuity, visual symptoms, IOL status, and associated ocular comorbidity were recorded.
Results
One hundred ninety-three (14.5%) of 1330 eyes had evidence of IOL opacification. A total of 56 (4.2%) had visually significant opacification and had IOL exchange. The prevalence of IOL opacification ranged from 1.1% in patients who had surgery in September 2000 to 36.3% in the December 2000 group. In eyes with IOL opacification, the visual symptoms were decreased vision (57%), glare (32%), and mistiness of vision (27%). One hundred forty-four eyes (75%) with IOL opacification had visual acuity of 6/12 or better; 21.5% of diabetic eyes had IOL opacification compared with 14.3% of nondiabetic eyes (P =.06); 20.5% of glaucomatous eyes had IOL opacification compared with 14.0% of nonglaucomatous eyes (P = .033).

Conclusions
This is the first large sample recall of patients implanted with the Hydroview H60M IOL. The overall prevalence of IOL opacification was 14.5%, with peak prevalence in patients who had surgery in December 2000.

Posted by mmiraftab at 11:44 AM | Comments (0)

Short term oral minocycline treatment of meibomianitis

British Journal of Ophthalmology 2006;90:856-860
Methods: 16 patients were prospectively enrolled, 11 male and five female (mean age 69 years old). Each patient received routine clinical evaluations before, after 3 months therapy, and at 6 month study follow up visit. The clinical appearance, tear volume, flow and turnover, evaporation, Schirmer I test, meibomian gland dropout, lissamine green staining, and bacteriology wer evaluated.
Results: Improvement was observed in clinical signs of meibomianitis at the second and third visits. Microbial culture findings improved. Decreased aqueous tear volume and flow, and increased evaporation rate range at 35–45% relative humidity (RH) (p<0.05) were also detected. Other related tear parameters did not change. Meibomian gland dropout showed no improvement.
Conclusions: 3 months of oral minocycline resulted in clinical improvements in all meibomianitis signs that persisted for at least 3 months after discontinuation despite decreased aqueous tear volume and flow with increased evaporation (35–45% RH). However, there was improvement in the turbidity of secretions. Short term minocycline therapy probably has efficacy in the management of meibomianitis that extends beyond eradication of bacteria.

Posted by mmiraftab at 11:40 AM | Comments (0)

Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia

British Journal of Ophthalmology 2006;90:819-822

Results: One to three 7 day cycles of topical MMC 0.04% four times a day were given to 59 eyes with localised corneal-conjunctival intraepithelial neoplasia (CIN), 19 eyes with diffuse CIN, six eyes with recurrent CIN, one eye with ocular surface squamous cell carcinoma, three eyes with primary acquired melanosis (PAM) with atypia, nine eyes with conjunctival malignant melanoma (MM), two eyes with sebaceous carcinoma with pagetoid spread, and one eye with recurrent atypical fibroxanthoma. Nine patients had bilateral CIN. 31 (34%) cases developed an allergic reaction to MMC and 14 (14%) eyes had epiphora secondary to punctal stenosis at a mean follow up period of 26.5 months.
Conclusion: In the largest study looking at complications of topical MMC in the treatment of ocular surface neoplasia, allergic reaction and punctal stenosis are relatively common. Serious complications were not observed suggesting the safe use of MMC in mid-term follow up.

Posted by mmiraftab at 11:36 AM | Comments (0)

June 29, 2006

Age-Related Distance Esotropia

Journal of AAPOS,June,2006
A retrospective consecutive case series of 26 patients with this condition was reviewed. The patients ranged in age from 62 to 91 years old with a median age of 77 years. The distance deviation varied from 4 prism diopters (PD) ET (esotropia) to 20 PD ET, with a median angle of 9 PD ET. At near fixation, the measurements ranged from 9 PD ET′ to 10 PD X′ (exophoria), with a median deviation of 3 PD ET′. Ductions and versions were full, with no evidence of lateral rectus paresis. None of these patients had an obvious underlying neurologic disorder, such as tumor or stroke. Treatment consisted of prescribing the minimum prismatic correction that eliminated distance diplopia, which was then incorporated into the patients’ current spectacles. This treatment successfully eliminated the symptoms in all patients. No patient in this study required surgery.
Conclusion: A distinctive form of strabismus occurs in older adults that is characterized by esotropia greater at distance than near fixation. The etiology of this disorder is unknown, but it is likely secondary to anatomical changes in the orbit and/or muscles associated with aging. Most patients are readily corrected by prisms but, surgical correction might be required in some cases.

Posted by afarahi at 07:06 PM | Comments (0)

June 26, 2006

Incidence and Prevalence of Glaucoma in Severe Ocular Surface Disease.

CORNEA June 2006
A retrospective case series was compiled from all charts of patients in the Cincinnati Eye Institute/University of Cincinnati and University of Minnesota population with a diagnosis of severe OSD from 1991 to 2003.
Results: Of the 108 eyes evaluated in this study, 71 were diagnosed with glaucoma. The overall prevalence of glaucoma in patients with severe OSD is 65.7%, with a range from 42.9% to 88.4%. Analysis by subgroup shows the highest percentage of patients with concurrent glaucoma fall into the categories of aniridia and chemical injury, and the lowest was noted in those patients with autoimmune or iatrogenic OSD. Overall, the incidence of glaucoma was 20.4%, with a range of 13.6% to 60%.
Conclusions: Compared with previous studies, our results show a significantly higher prevalence of glaucoma in patients with severe OSD. This information warrants increased attention to treatment and management of OSD and concurrent glaucoma.

Posted by aman at 12:32 AM | Comments (0)

Wound Dehiscence After Penetrating Keratoplasty: Clinical Characteristics of 51 Cases Treated at Bascom Palmer Eye Institute.

Cornea June 2006
A retrospective chart review was completed, evaluating patients seen at Bascom Palmer Eye Institute between 1989 and 2001.
Results: All dehiscence occurred at the graft-host junction with an average of 5 hours of dehiscence, but no site preference was identified. Dehiscence occurred because of trauma (53%), suture-related complications (27%), infectious keratitis (8%), and spontaneous wound separation (12%). Twelve patients had either intraocular lens dislocation or expulsion; 42 patients underwent primary repair; 7 patients underwent primary PK; and 1 patient underwent primary evisceration. Surgical details were unavailable for 1 patient. Final visual acuity ranged from 20/20 to no light perception. Acuity was unavailable for 2 patients. Visual acuity was 20/200 or better in 23 patients (47%) and less than 20/200 in 26 patients (53%). Two patients (4%) had no light perception. The visual acuity of 13 patients (27%) was 20/40 or better at their last clinic visit. Comparison of predehiscence and postdehiscence visual acuity showed that 23 eyes (54%) had comparable vision after dehiscence, 11 eyes (25%) had improved vision, and 9 eyes (21%) had worsening of vision.

Posted by aman at 12:19 AM | Comments (0)

June 25, 2006

LASIK, LASEK have similar HOA rates in scotopic conditions

OSN BREAKING NEWS
Kyoung Yul Seo, MD, PhD, and colleagues compared the higher-order aberrations in 70 eyes of 38 Korean patients who had undergone wavefront-guided LASIK for the treatment of myopia with 70 eyes of 40 Korean patients who had undergone wavefront-guided LASEK for the treatment of myopia. The patient made the choice about which procedure the eye underwent. Follow-up was 6 months. The main outcome measures included best corrected visual acuity, uncorrected visual acuity, manifest refraction and wavefront aberrations. Outcomes were measured at baseline and at 1, 3 and 6 months postoperatively, according to the study.
No significant differences were found in postop BCVA, UCVA or manifest refraction between the LASIK and LASEK groups. The wavefront error of higher-order aberrations for a scotopic pupil in the LASIK group was significantly smaller than in the LASEK group at the 1-month follow-up, the report said. Spherical aberration and second coma were significantly smaller in the LASIK group than in the LASEK group at 1 month. The differences disappeared, however, by 6 months.

Posted by aman at 11:51 PM | Comments (0)

FDA grants approval of CL plasma treatment to B&L

OSN BREAKING NEWS
Bausch & Lomb has received Food and Drug Administration approval to add a cold oxygen plasma treatment to its manufacturing process of gas permeable contact lenses, according to a company press release.

Plasma treatment is a process “that bombards the lens surface with ions in a vacuum,” the release said. The treatment “may reduce the lens hydration time by reducing the wetting angle,” which may improve patient comfort, the company said.

Posted by aman at 11:48 PM | Comments (0)

June 24, 2006

Several factors involved in TASS, preliminary report states

OSN TOP STORY for June 23,2006
More than 100 centers have now reported cases of toxic anterior segment syndrome from February through May 2006, according to the American Society of Cataract and Refractive Surgery.
Preoperative use of nonsteroidal anti-inflammatory drugs may be a potential factor in several of the cases, according to the report. Intracameral anesthetics are also a potential factor, “especially given the short ultrasound time in the majority of cases,” ASCRS said.
ASCRS said a “potential problem” may be the addition of epinephrine to balanced salt solution, as the epinephrine “must be truly preservative free.” Stabilizing agents, such as bisulphites, are not considered preservative free, the report stated.
Reusable cannulas may allow a residue of ophthalmic viscosurgical devices, cortex or other materials that can be toxic when injected into the anterior chamber, ASCRS added.
According to the report, Alcon had manufactured “a majority” of the IOLs reported. However, the statement indicated that the company’s large market share of IOLs may explain the “larger than expected” relationship of one IOL to the reported cases of toxic anterior segment syndrome (TASS). Additionally, the report states that “there may be an issue involved regarding the cleaning of the reusable inserter which is used with a disposable cartridge to place the lens.”
According to the report, Alcon had manufactured “a majority” of the IOLs reported. However, the statement indicated that the company’s large market share of IOLs may explain the “larger than expected” relationship of one IOL to the reported cases of toxic anterior segment syndrome (TASS). Additionally, the report states that “there may be an issue involved regarding the cleaning of the reusable inserter which is used with a disposable cartridge to place the lens.”
Other issues that ASCRS identified: short surgical turnaround time may affect the sterility of surgical instruments, reusable I&A handpieces could be a potential source of TASS and instrument cleaning could be related if the cleaning materials are not thoroughly flushed from the instruments.

Posted by aman at 12:44 AM | Comments (0)

June 23, 2006

Re-recession of the Lateral Rectus Muscles In Patients With Recurrent Exotropia

Journal of AAPOS,April,2006
Ziaeddin Yazdian, MD, Guita Ghiassi, MD
We describe 16 consecutive patients (age 6 to 35 years; median, 10 years; 13 children and 3 adults). In most cases, bilateral LR muscles were rerecessed to a distance of 15 mm from the limbus, but in 5 cases with larger amount of deviation, these muscles were rerecessed to 17 mm from the limbus. A relation was found between the amount of rerecession and change in far alignment in prism diopters (r = 0.46, P = 0.07), but not for near deviation. The success rate (esotropia ≤ 10 PD or exotropia ≤ 8 PD) 1 to 7 days after surgery and in long-term follow-up (6-96 months; median, 25.5 months) was 100%. No significant underaction of the LR muscles was noted.
Conclusions: The results support the notion that bilateral LR rerecession to 17 mm from the limbus successfully corrects recurrent exotropia up to 33 PD and that it is particularly effective in children and adults without producing significant limitation of abduction.

Posted by afarahi at 07:48 PM | Comments (0)

Bilateral Medial Rectus Muscle Recession: Results in Children With Developmental Delay Compared With Normally Developed Children

Journal of AAPOS
A higher rate of surgical failure was found in developmentally delayed children who received a smaller recession amount of the medial rectus muscles when compared with the developmentally normal children who received a standard amount of recession. The main reason for surgical failure in the developmentally delayed group, in a follow-up period of 2 years, was undercorrection of the angle of esotropia. It seems that decreasing the surgical table by a certain amount in children with developmental delay may lead to undercorrection. Therefore, we need to delineate the ideal amount of surgery in this unique group of individuals.

Posted by afarahi at 07:43 PM | Comments (0)

The Role of Botulinum Toxin A in Augmentation of the Effect of Recession and/or Resection Surgery

Journal of AAPOS,April,2006
Ten patients were included in the study. Mean age of the patients was 27 ± 20 years. Of these 10 patients, 7 were esotropic and 3 exotropic. The average preoperative esodeviation was 73.6 ± 16.5 prism diopters and exodeviation was 76.7 ± 5.8 PD. Five units of BTA were injected intraoperatively into one of the recessed horizontal rectus muscles in all of the patients.The average follow-up was 14 ± 10 months (range, 8 to 40 months). The average final deviation in the esotropia group was 13 ± 9.6 PD of esotropia. The average final deviation in the exotropia group was 4.7 ± 5 PD of exotropia. The final deviation of the 70% patients was within 10 PD of esotropia or exotropia. Conclusion: The results of this study suggest that the combination of BTA injection with recession may increase the expected correction of a conventional horizontal rectus muscle surgery.

Posted by afarahi at 07:37 PM | Comments (0)

Incidence and Risk Factors for Glaucoma After Pediatric Cataract Surgery With and Without Intraocular Lens Implantation

Journal of AAPOS,April,2006
After pediatric cataract surgery, 10 (3.8%) of 266 eyes with primary intraocular lens implantation were diagnosed with glaucoma, whereas 8 (17.0%) of 47 aphakic eyes were diagnosed with glaucoma. During the initial analyses, we noted that all of the patients who developed glaucoma underwent cataract surgery when they were 4.5 months or younger. For all patients who underwent surgery during the first 4.5 months of their life, the glaucoma incidence was 24.4% (10/41) in children with pseudophakic eyes and 19.0% (8/42) in age-matched children with aphakic eyes.In patients who underwent surgery during the first 4.5 months of their life, the average age of the patients who developed glaucoma was not significantly different than those who did not develop glaucoma in pseudophakic eyes or aphakic eyes .Glaucoma was diagnosed in patients at an average of 8.6 months and 117.9 months after cataract surgery in those with pseudophakic eyes and aphakic eyes, respectively.
Conclusions: Patients undergoing cataract surgery at an early age are at high risk for the development of glaucoma with or without an intraocular lens implant.

Posted by afarahi at 07:29 PM | Comments (0)

Long-Term Results of Hang-Back Lateral Rectus Recession

Journal of Pediatric Ophthalmology and Strabismus May/June 2006

The medical records of 79 consecutive patients who underwent unilateral or bilateral hang-back lateral rectus recession were reviewed. The amount of surgery performed was based on the distance exotropic deviation.Forty-two patients met the inclusion criteria. Four of the patients were not orthophoric: three had recurrent exotropia and one had a consecutive esotropia.
CONCLUSION:The hang-back technique is a safe and effective alternative to conventional lateral rectus recession.

Posted by afarahi at 07:19 PM | Comments (0)

Myopia in Preterm Children at 12 to 24 Months of Age

Journal of Pediatric Ophthalmology and Strabismus May/June 2006
Fifty eyes of 25 patients with myopia and 70 eyes of 35 patients with emmetropia at 12 to 24 months of age were selected from a group of preterm children who had been screened for retinopathy of prematurity and returned for follow-up examinations. Forty eyes of 20 full-term children of the same age were also included in the study as a control group. The myopic group had a significantly greater axial length than did the other groups. However, the three groups did not differ in lens thickness or anterior chamber depth. The degree of myopia increased with the increase in axial length and the decrease in anterior chamber depth.
CONCLUSIONS:The development of myopia in preterm children 12 to 24 months of age appears to be influenced mainly by axial length, whereas the degree of myopia seems to be related to axial length and anterior chamber depth. Among refractive components, axial length plays a major role in myopia occurring at this age in preterm patients.

Posted by afarahi at 07:12 PM | Comments (0)

Increased diabetic maculopathy following cataract surgery linked to changes in angiogenic and antiangiogenic growth factors

BJO, June 2006
This retrospective analysis of baseline and postoperative aqueous growth factors in six patients finds an increase in VEGF-165 and HGF concentration, as well as a decrease in the protective function of PEDF. These changes may induce subclinical and clinical worsening of diabetic maculopathy.

Posted by kjalali at 08:36 AM | Comments (0)

ROP screening in infants with a higher birth weight appears cost-effective

JAAPOS, April 2006
ROP incidence among infants weighing between 1250 g and 1800 g (259 patients) was 4.2 percent. Risk factors for ROP in infants weighing between 1501 g to 1800 g were sepsis, ventilation >96 hours, antibiotic use >14 days, RBC transfusions greater than seven units and central line placement. All higher birth rate infants who developed ROP had two or more of these risk factors.

Posted by kjalali at 08:34 AM | Comments (0)

Smoking may damage lipid layer of the ocular surface

AJO, June 2006
DR-1 interferometry kinetic analysis shows higher grades of lipid layer changes among the 60 smokers in this comparative case series. Mean Schirmer 1 test value was 10.8 mm in smokers, mean breakup time was 5.3 seconds, the average conjunctival sensitivity was 26.2 mm and the average central corneal sensitivity was 37.6 mm.

Posted by kjalali at 08:32 AM | Comments (0)

Peribulbar anaesthesia may reduce pain and blood pressure increase after PRP

Eye, June 2006
Compared to three other types of oral pain relief and intramuscular injection of ketorolac tromethamine, peribulbar anaesthesia had a significantly lower pain score than the control group (P<0.0001). This randomized trial (220 patients) also finds these patients had a significantly smaller PRP-associated rise in blood pressure.

Posted by kjalali at 08:31 AM | Comments (0)

Increased open-angle glaucoma risk after vitrectomy

AJO, June 2006
Mean IOP in glaucoma suspects was significantly higher in the operated eye compared with the fellow eye in this retrospective case series (453 eyes). The time between vitrectomy and development of glaucoma was significantly longer in phakic eyes. Patients with glaucoma before surgery may require more anti-glaucoma medication after surgery.

Posted by kjalali at 08:28 AM | Comments (0)

Medical implants help four blind patients see light and simple patterns

INDUSTRY NEWS
Intelligent Medical Implants announced in a press release results of a limited clinical study that shows the Learning Retinal Implant System enabled blind patients to see light and simple patterns through a wireless transmission of data and energy.

Posted by kjalali at 08:09 AM | Comments (0)

June 20, 2006

Combined phacoemulsification, foldable intraocular lens implantation, and 25-gauge transconjunctival sutureless vitrectomy

JCRS Pages 727-731 (May 2006)

We describe a technique for combined cataract and vitreoretinal surgery using a 25-gauge transconjunctival sutureless vitrectomy system. This technique was successfully performed in 20 consecutive cases. Outcomes were assessed in terms of visual acuity, intraocular pressure, postoperative refractive error, and incidence of complications. The technical feasibility, rationale, and advantages and disadvantages of this technique are discussed.

Posted by alireza habibollahi at 10:09 PM | Comments (0)

Two-string technique to manage dislocated posterior chamber plate-haptic intraocular lens

JCRS Pages 722-726 (May 2006)
We describe a technique for repositioning and transscleral fixation of a dislocated plate-haptic foldable collamer PC IOL. The displaced IOL was positioned in the anterior chamber, and a double-armed suture on a curved needle was fixed to the sclera at 10:30 o'clock. The needle then entered the globe and passed through the superior haptic eyelet of the IOL. Both were withdrawn through the scleral wound on the opposite side. The inferior haptic was fixed at 4:30 and 7:30 o'clock and provided the mirror reflection of the suture path of the upper fixed haptic. This technique may be a useful alternative to lens removal or exchange.

Posted by alireza habibollahi at 10:04 PM | Comments (0)

Customized ablation algorithm for the treatment of steep central islands after refractive laser surgery

JCRS Pages 717-721 (May 2006)
Farhad Hafezi, MD, Mirko Jankov, MD, Michael Mrochen, PhD, Christian Wüllner, PhD, Theo Seiler, MD, PhD
Steep central island (SCI) formation after PRK and LASIK represents a major drawback in the visual rehabilitation of patients after refractive laser surgery. Because of the small size of SCIs, current ablation algorithms are unable to properly calculate an ablation pattern for customized retreatment. We present the use of a new ablation algorithm for the treatment of SCIs that occurred after PRK or LASIK surgery. This algorithm uses a smaller zone of approximation and takes into account the spherical shift induced by removal of the SCI. In all 3 eyes treated, best spectacle-corrected visual acuity increased to 20/16 and remained stable at the 1- and 3-month follow-up, with disappearance of the SCI in corneal topography. This new treatment algorithm may be of benefit to patients experiencing visual side effects due to SCI formation after PRK or LASIK surgery.

Posted by alireza habibollahi at 10:00 PM | Comments (0)

Modified flexible iris retractor to retract superior iris and support inferior capsule in eyes with iris coloboma and inferior zonular deficiency

JCRS Pages 715-716 (May 2006)

Flexible nylon iris retractors are a useful adjunct to cataract surgery in cases of small pupil and subluxated lenses. A modification is presented of the standard application of iris hooks to retract the superior iris and support the inferior capsule during phacoemulsification in cases of iris coloboma with inferior zonular deficiency. Three iris hooks are applied to retract the iris, and 2 iris hooks are applied to the inferior capsule margin to support the crystalline lens in that quadrant. Clear corneal temporal phacoemulsification is then performed with adequate pupillary diameter and capsular support.

Posted by alireza habibollahi at 09:56 PM | Comments (0)

Wavefront-supported Photorefractive Keratectomy With the Bausch & Lomb Zyoptix in Patients With Myopic Astigmatism and Suspected Keratoconus

JRS June 2006
Forty eyes of 20 patients with myopia -4.0 to -8.0 diopters (D) (mean: -6.25±1.04 D), cylinder -1.0 to -2.50 D (mean: -1.61±0.71 D), and corneal thickness 440 to 488 µm were treated with wavefront-supported PRK. Corneal topography evaluation revealed a significantly irregular cylinder (inferior-superior difference >1.5 D) with possible mild or forme fruste keratoconus. Aberrometry was performed with the Hartmann-Shack aberrometer, and corneal data were evaluated with the Orbscan system. Eyes were treated with the Technolas 217z Bausch & Lomb excimer laser and followed for a minimum of 40 months.
RESULTS
Following surgery, mean spherical equivalent refraction was +0.33±0.8 D. It was within ±0.5 D of the intended refraction in 95% of eyes and within ±1.0 D in 100% of eyes. Mean uncorrected visual acuity improved from 20/400 preoperatively to 20/25 postoperatively. Mean best spectacle-corrected visual acuity (BSCVA) remained unchanged (20/20) or improved to 20/20 in 92.5% of eyes and to 20/25 in 7.5% of eyes. Individually, BSCVA did not change in 28 (70%) eyes and increased by >2 Snellen lines in 9 (22.5%) eyes; 3 (7.5%) eyes lost 1 Snellen line because of corneal haze. Laser treatment induced a significant flattening of the preoperative inferior corneal steepness in all eyes. Wavefront analysis demonstrated a significant decrease in high order aberrations (total root-mean-square and coma).

Posted by aman at 12:44 AM | Comments (0)

Dental prosthesis may restore sight to those with end-stage corneal disease

OSN TOP STORY for June 19, 2006
A novel osteo-odonto keratoprosthesis procedure is offering hope to patients with end-stage corneal disease, such as Stevens-Johnson syndrome or severe chemical burns, a surgeon here said.
Prof. Tan said the patients being considered for the surgery must have bilateral blindness but still have a functioning retina and optic nerve.
Since February 2004, the procedure has been performed on 15 patients at the Singapore National Eye Centre in collaboration with the Singapore National Dental Centre. In results on 13 patients with the longest follow up of 24 months, Prof. Tan reported 7 of 13 patients achieved 6/6 vision; 9 out of 13 are 6/12 or better; and the others have stable vision between 6/30 and 6/120. He attributed the poorer visual acuity in the last group to pre-existing glaucoma or retinal detachment.
In the first stage of the procedure, a canine tooth of the patient is removed and shaved down to receive an optical PMMA cylinder. This is then implanted under the cheek muscle of the patient.
In the procedure, Prof. Tan said, “We no longer use the ocular surface anymore. We provide a new surface from the mouth. We use a canine tooth because it’s the largest tooth with a single root. So this tooth-cylinder [implant] is then implanted into the cheek under the muscle and the tooth is still living, so it’s a combined living, biological implant. Over the next 3 months it will grow a fibrous capsule. There’s a blood supply, and the tooth will recover within this living tissue in the cheek.”
At the end of this first procedure, a large piece of buccal mucosal tissue is removed from the cheek, the surface of the eye is denuded, and the buccal mucosal tissue is used to create the front part of the eye.
“We let the buccal mucosa recover, and we let the tooth recover, and about 2 to 3 months later we perform the second stage of the operation,”
During the second part of the surgery, the tooth is removed from the cheek, with the surgeon checking for viability and good blood flow .
We flap the buccal mucosa to expose the cornea, which is still there. We drill a hole in the cornea, and we remove the iris, the lens and the vitreous,” Prof. Tan said. “We just core out the whole front part of the eye to make space for the tooth, and then we put the tooth implant into the cornea.” Concurrent glaucoma and vitreoretinal procedures are also performed as necessary,
The tooth-cylinder complex is then sutured in place and the buccal mucosal flap is stitched back in place. Then a hole is cut in the mucosa, through which the PMMA optic can protrude.

Posted by aman at 12:32 AM | Comments (0)

June 18, 2006

Promising results for PASCAL (Pattern Scan Laser) method of photocoagulation

INDUSTRY NEWS
OptiMedica Corp. announced in a press release that the clinical experience of the first 550 eyes treated with this method resulted in an improvement in patient tolerance and reduced treatment time. The company also states that the PASCAL method represents an advancement in the treatment of diabetic retinopathy and other retinal disorders.

Posted by kjalali at 08:27 PM | Comments (0)

Carbohydrate intake and glycemic index may be linked to development of AMD and cataract

American Journal of Clinical Nutrition, April and May 2006
Two studies indicate trends in the relationship between AMD and lenticular opacities in women who consume high-dietary glycemic index diets (a classification of foods based on their blood glucose-raising potential) and high carbohydrate intake.

Posted by kjalali at 08:17 PM | Comments (0)

Treating patients with an IOP of 24 mm Hg or greater may be cost effective

Archives of Ophthalmology, June 2006
Researchers applied a cost-utility analysis to the treatment recommendations of the Ocular Hypertension Treatment Study. They conclude that while treatment decisions depend largely on the patient’s attitude toward the risk of disease progression and blindness, treating patients with an IOP of ≥24 mm Hg and a ≥2 percent annual risk of the development of glaucoma may be cost-effective.

Posted by kjalali at 08:15 PM | Comments (0)

June 17, 2006

Diagnosis and treatment of cytomegalovirus iridocyclitis without retinal necrosis

BJO Jult 2006
Patients referred between 2001 and 2003 for management of unilateral, chronic, recurrent uveitis associated with secondary glaucoma underwent extensive investigation including laboratory tests for herpes virus infections. Specific antiviral treatment was initiated in all cases and the level of ocular inflammation was evaluated during the follow up.
Results: Five patients, three men and two women, were included. Median age was 50 years old (range 30–80 years). Anterior unilateral uveitis without iris atrophy was observed in all cases. Uveitis was chronic in three cases and recurrent in two cases. Glaucoma was observed in all patients with a median intraocular pressure of 30 mm Hg (range 22–43 mm Hg). Five patients responded initially to specific anti-CMV therapy. Even though glaucoma surgery was necessary in two cases, both ocular inflammation and glaucoma were controlled in all cases. Relapses occurred in three cases after cessation of therapy, requiring prolonged maintenance therapy with valganciclovir.
Conclusions: CMV infection and specific antiviral therapy should be considered in all cases of relapsing or chronic iridocyclitis and secondary glaucoma. Maintenance regimens of valganciclovir may be necessary to prevent further relapses.

Posted by aman at 11:26 PM | Comments (0)

The effects of gabapentin and memantine in acquired and congenital nystagmus: a retrospective study

BJO July 2006
Pharmacological treatment has been successful in some forms of acquired neurological nystagmus. However, drugs are not known to be effective in idiopathic infantile nystagmus or nystagmus associated with ocular diseases.
The authors retrospectively analysed Snellen visual acuity (VA), subjective visual function, and eye movement recordings of 23 patients with nystagmus (13 secondary to multiple sclerosis, three associated with other neurological diseases, two idiopathic infantile, and five with associated ocular diseases) treated with gabapentin or memantine.
Conclusion: Gabapentin and memantine may be effective in acquired nystagmus secondary to MS. To the authors’ knowledge this is the first series of patients showing that gabapentin is effective in improving nystagmus in congenital nystagmus/nystagmus associated with ocular pathology. Memantine may be useful as an alternative drug in treating patients with nystagmus.

Posted by aman at 11:16 PM | Comments (0)

Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia

BJO July 2006
A retrospective and consecutive study of 100 eyes in 91 patients with ocular surface neoplasia treated with MMC in a single centre between November 1998 and January 2005. Outcome measures included complications of MMC and the treatment required for these complications.
Results: One to three 7 day cycles of topical MMC 0.04% four times a day were given to 59 eyes with localised corneal-conjunctival intraepithelial neoplasia (CIN), 19 eyes with diffuse CIN, six eyes with recurrent CIN, one eye with ocular surface squamous cell carcinoma, three eyes with primary acquired melanosis (PAM) with atypia, nine eyes with conjunctival malignant melanoma (MM), two eyes with sebaceous carcinoma with pagetoid spread, and one eye with recurrent atypical fibroxanthoma. Nine patients had bilateral CIN. 31 (34%) cases developed an allergic reaction to MMC and 14 (14%) eyes had epiphora secondary to punctal stenosis at a mean follow up period of 26.5 months.
Conclusion: In the largest study looking at complications of topical MMC in the treatment of ocular surface neoplasia, allergic reaction and punctal stenosis are relatively common. Serious complications were not observed suggesting the safe use of MMC in mid-term follow up.

Posted by aman at 11:12 PM | Comments (0)

June 16, 2006

Clinical Utility of Intraocular Pressure Monitoring Outside of Normal Office Hours in Patients With Glaucoma

ARCHIVES June 2006
We reviewed the records of all patients with glaucoma who were admitted for 24-hour IOP monitoring during 3 years. Applanation IOP was recorded in the sitting position from 7 AM until midnight and in the supine position at 6 AM.
Results Thirty-two patients (22 women and 10 men) were enrolled (mean ± SD age, 67.3 ± 12.1 years). Mean ± SD 24-hour IOP was 13.0 ± 2.2 mm Hg. Mean ± SD peak 24-hour IOP (16.8 ± 3.2 mm Hg) was significantly higher than peak office IOP (14.7 ± 3.2 mm Hg) (P<.001). Peak IOP was recorded outside of office hours in at least 1 eye in 22 patients (69%). Mean IOP fluctuation during 24-hour monitoring (6.9 ± 2.9 mm Hg) was significantly greater than that during office hours (3.8 ± 2.3 mm Hg) (P<.001). Peak 24-hour IOP was higher than the peak IOP noted during previous office visits in 40 eyes (62%). Results of 24-hour IOP monitoring led to immediate treatment change in 23 eyes (36%).
Conclusions In glaucoma patients with advanced disease or progression that are disproportionate to known IOP measurements, 24-hour monitoring of IOP may reveal a greater role for pressure-related risk for glaucoma progression than previously suspected and may alter treatment strategies.

Posted by aman at 09:36 PM | Comments (0)

Effect of Trabeculectomy on Lens Opacities in an East Asian Population

ARCHIVES June 2006
This was an observational case series of 243 people aged 36 to 82 years. Trabeculectomy was performed on 1 eye of each subject. Lens opacity was measured yearly using the Lens Opacification Classification System III. The main outcome measure was worsening of lens opacity defined as an increase of 2 or more Lens Opacification Classification System III units in any of the 3 lens regions, nuclear, cortical, and posterior subcapsular. Risk of progression was evaluated using logistic regression models.
Results Data for 177 people were analyzed. One hundred seventeen (66%) of 177 subjects showed progression in opacity in any lens region at 3 years. Seventy-seven (66%) of 117 of those who progressed did so during the first year. Of these, 63 (82%) of 77 had lens opacity in the posterior subcapsular region. Factors associated with progression of posterior-subcapsular lens opacity at 1 year were diabetes , use of antiglaucoma medication, dosage of topical steroid postoperatively, and being operated on by a trainee surgeon .
Conclusions Trabeculectomy is associated with progression of lens opacity predominantly in the posterior subcapsular region. Modification of risk factors such as postoperative steroid use may delay progression.

Posted by aman at 09:26 PM | Comments (0)

Clinical Study of Fuchs Corneal Endothelial Dystrophy Leading to Penetrating Keratoplasty

ARCHIVES June 2006
To review 30 years' clinical experience with Fuchs corneal endothelial dystrophy leading to penetrating keratoplasty (PK).
We reviewed the clinical records of patients diagnosed histopathologically as having Fuchs corneal endothelial dystrophy who underwent PK at Duke University Medical Center between January 1, 1972, and December 31, 2001. This observational case series included 424 patients (546 eyes).
Results Women represented 77.6% of patients. Mean age at the time of PK for all patients was 69.2 years. Bilateral PK was required in 28.8% of patients, and the mean interval between the 2 PKs was 3.2 years. There was no difference with regard to sex in the likelihood of requiring bilateral PK (P = .59). Among 376 documented family histories, 13.6% were known to be positive for Fuchs dystrophy. Patients with a positive family history underwent PK a mean of 5 years earlier (P<.002) and were more likely to require bilateral PK (P<.003). Patients who underwent bilateral PK were twice as likely to have a positive family history compared with those undergoing unilateral PK (P<.001). Mean visual acuities at corneal thicknesses of 539 to 650 µm, 651 to 750 µm, and greater than 750 µm were 20/60, 20/60, and 20/80, respectively. Patients who underwent bilateral PK and had a preceding cataract extraction on 1 eye required PK of the pseudophakic eye on average 3.2 years earlier than the fellow eye. The mean time from cataract extraction to PK was 2.2 years.
Conclusions This large study affirms that Fuchs dystrophy is a disorder of aging that predominantly affects women (3.5:1) and is often familial. Pachymetry-determined corneal thickness was a poor predictor of visual acuity until extreme levels of corneal edema were reached. Cataract extraction in an eye with Fuchs dystrophy leads to earlier PK.

Posted by aman at 08:59 PM | Comments (0)

Hyperopic LASIK Retreatments With the Technolas Laser

JRS June 2006
Jorge L. Alió, MD, PhD; Ahmed Galal, MD,
85 eyes underwent hyperopic LASIK retreatment with 1-year follow-up.
Patients were divided into two groups according to the preoperative spherical equivalent refraction: group 1, <+3.9 diopters (D) and group 2> +4.0 D.
RESULTS
The UCVA improved from 0.31±0.2 to 0.7±0.2 in group 1 and from 0.2±0.2 to 0.6±0.2 in group 2 following retreatment. Mean spherical equivalent refraction improved from +2.8±0.85 to +0.2±0.9 in group 1 and from +5.3±0.9 to +0.3±1.3 in group 2 after retreatment. In group 1, 32 (72.7%) of 44 eyes had BSCVA >20/25, and in group 2, 24 (58.5%) of 41 eyes had BSCVA >20/25. After primary hyperopic LASIK, 25 (56.8%) of 44 eyes in group 1 and 19 (46.3%) of 41 eyes in group 2 maintained BSCVA or gained >1 lines postoperatively in contrast to 21 (47.7%) of 44 eyes in group 1 and 22 (53.9%) of 41 eyes in group 2 after retreatment. In group 1, 11 (25%) of 44 eyes lost >2 lines of BSCVA after initial hyperopic LASIK compared to 14 (31.8%) of 44 eyes after retreatment. In group 2, 10 (24.4%) of 41 eyes lost >2 lines of BSCVA after initial hyperopic LASIK compared to 12 (29.2%) of 41 eyes after retreatment. After hyperopic LASIK retreatment, 31 (70.5%) of 44 eyes in group 1 and 19 (46.4%) of 41 eyes in group 2 were within ±0.5 D of emmetropia. Safety was 0.9 in both groups and efficacy was 0.8 and 0.7 in groups 1 and 2, respectively. Complications included epithelial ingrowth of 1 to 3 mm (30%) and flap edge melting (2%).
CONCLUSIONS
Hyperopic LASIK retreatment improved the refractive results of initial hyperopic LASIK surgery with 20% to 30% of eyes gaining >1 lines of BSCVA. The loss of BSCVA was greater after primary hyperopic LASIK than after retreatment.

Posted by aman at 08:47 PM | Comments (0)

The Effect of Topical Apraclonidine on Subconjunctival Hemorrhage and Flap Adherence in LASIK Patients

JRS June 2006

Topical apraclonidine 0.125% was randomly applied to 1 eye of 66 myopic patients who underwent primary bilateral LASIK. Apraclonidine was instilled 1 hour prior to and 30 seconds before placing the vacuum ring of the microkeratome, whereas the other eye served as control. Thirty minutes after the operation, all patients were examined by the surgeon to evaluate hyperemia and identify flap-related complications (eg, slippage, dislocation, or flap folds). The size of subconjunctival hemorrhage was also evaluated on postoperative days 1 and 7. All 132 eyes in the study were examined after surgery to identify flap folds and/or their dislocation.
RESULTS
In the apraclonidine group, 48 (72.8%) eyes had no hyperemia, 16 (24.2%) eyes had mild hyperemia, 2 (3%) eyes had moderate hyperemia, and no (0%) eyes had severe hyperemia. In the control group, 37 (56.1%) eyes had mild hyperemia, 21 (31.8%) eyes had moderate hyperemia, 1 (1.5%) eye had severe hyperemia, and 7 (10.6%) eyes had no hyperemia. In the apraclonidine group, 44 (66.7%) eyes had no subconjunctival hemorrhage (grade 0); grade 1 was present in 19 (28.8%) eyes whereas grades 2 and 3 were present in 2 (3%) eyes and 1 (1.5%) eye, respectively. In the control group, 19 (28.8%) eyes showed grade 0, 13 (19.7%) eyes had grade 1, and grades 2 and 3 were present in 20 (30.3%) eyes and 14 (21.2%) eyes, respectively. Chi-square test showed a highly significant difference between the two groups (P<.001). No flap-related problems were reported in either group.
CONCLUSIONS
Topical apraclonidine applied before LASIK surgery may prevent immediate postoperative hyperemia and prolonged subconjunctival hemorrhage by its alpha-mimetic vasoconstrictor effect without inducing flap adherence complication.

Posted by aman at 08:37 PM | Comments (0)

Effect of Prophylactic and Therapeutic Mitomycin C on Corneal Apoptosis, Cellular Proliferation, Haze, and Long-term Keratocyte Density in Rabbits

JRS June 2006
In 224 New Zealand rabbits, -9.0 diopter PRK with mitomycin C or balanced salt solution was performed. Haze level was graded at the slit-lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks, or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67, and -SMA.
RESULTS
TUNEL-positive apoptotic cells marginally increased in all mitomycin C groups whereas Ki67-positive mitotic cells decreased significantly following mitomycin C application. A greater decrease in myofibroblasts was noted with prophylactic mitomycin C treatment than therapeutic mitomycin C treatment. There was, however, an anterior stromal acellular zone (approximately 20% of the total stroma) in eyes treated with mitomycin C, which persisted to the maximum follow-up of 6 months.
CONCLUSIONS
Mitomycin C treatment induces apoptosis of keratocytes and myofibroblasts, but the predominate effect in inhibiting or treating haze appears to be at the level of blocked replication of keratocytes or other progenitor cells of myofibroblasts. Treatment with 0.002% mitomycin C for 12 seconds to 1 minute appears to be just as effective as higher concentrations for longer duration in the rabbit model. However, a persistent decrease in keratocyte density in the anterior stroma could be a warning sign for future complications and treatment should be reserved for patients with significant risk of developing haze after PRK.

Posted by aman at 08:27 PM | Comments (0)

Corneal Higher Order Aberrations: A Method to Grade Keratoconus

JRS June 2006
Jorge L. Alió, MD, PhD; Mohamed H. Shabayek, MD, MSc
A prospective observational comparative study of 80 eyes was performed. The eyes were divided into two groups. Group A comprised 40 eyes of 20 asymptomatic individuals with no ocular pathology. Mean sphere was -0.03 diopters (D) (range: +0.75 to -0.75 D), mean cylinder was -0.27 D, mean average K was 43.28 D, and mean uncorrected visual acuity (UCVA) was 1.01. Group B comprised 40 eyes of 25 patients with keratoconus. Mean sphere was -3.70 D (range: +2.00 to -10.00 D), mean cylinder was -3.82 D, mean average K was 49.29, and mean best spectacle-corrected visual acuity (BSCVA) was 0.61.
RESULTS
In group A, mean root-mean-square (RMS) of spherical (Z4 and Z6), coma-like (Z3, Z5, and Z7), and higher order aberrations (Z3-7) were 0.38 µm, 0.35 µm, and 0.52 µm, respectively. In group B, mean RMS of spherical, coma-like, and higher order aberrations were 1.06 µm, 2.90 µm, and 3.14 µm, respectively, for a 6.0-mm simulated pupil diameter. Mean RMS differences between the two groups were 0.68 µm (P<.0002), 2.55 µm (P<.0001), and 2.61 µm (P<.0001) for spherical, coma-like, and total higher order aberrations, respectively. In group B, according to Amsler-Krumeich classification, the mean RMS of coma-like aberration was 1.87 µm in grade I (14 eyes), 2.97 µm in grade II (11 eyes), 3.46 µm in grade III (12 eyes), and 5.20 µm in grade IV (3 eyes).
CONCLUSIONS
Corneal higher order aberrations, especially coma-like aberrations, are significantly higher in eyes with keratoconus than normal eyes. Coma-like aberrations, with the aid of a corneal aberrometry map, are good indicators for early detection and grading of keratoconus.

Posted by aman at 08:20 PM | Comments (0)

LASEK found successful for dry eye associated with soft contact lenses

OSN,June,2006
Laser epithelial keratoplasty was found to be a safe and effective treatment for myopic patients with preoperative dry eye associated with extended soft contact lens use in a pilot study. Although the study included only nine patients, “the results in this small population highlight the safety and efficacy of LASEK in treating myopia/myopic astigmatism in severe dry eyes associated with complicated soft contact lens wear,” said first author Ko-Hua Chen, MD, and colleagues

Posted by afarahi at 12:38 PM | Comments (0)

Anterior ischaemic optic neuropathy after coronary artery bypass graft: the role of anaemia in diabetics

Eye (2006)
A retrospective chart review of consecutive coronary artery bypass graft (CABG) performed over a 5-year period (1995–1999) in one medical centre. A comparison of clinical characteristics was carried out between anterior ischaemic optic neuropathy (AION) cases and subjects free from AION. A total of 1594 persons were included. Three subjects experienced acute visual loss from AION following CABG, all had diabetes mellitus, and two suffered from severe postoperative anaemia. Among diabetics (n=484), the risk of AION was significantly higher in subjects with postoperative haematocrit falling below 22 (28.6%) than the rest (0.21%) (P=0.001). Blood transfusion was given in two subjects with prompt visual recovery.
Conclusions: Severe anaemia in patients undergoing CABG appears to be a risk factor for AION, especially in diabetics, and needs prompt correction to prevent or reverse the ischaemic ocular events.

Posted by afarahi at 12:27 PM | Comments (0)

Correction of Late Post-Traumatic Enophthalmos Using a Tissue Expander

Annals of Plastic Surgery. June 2006.
We described a new technique to correct late post-traumatic enophthalmos using volume augmentation with a tissue expander. A 47-year-old male requiring enucleation with an implant replacement following orbital fracture with the globe injury had been complaining of persistent enophthalmos and cosmetic defect. Computed tomography scan demonstrated significant enophthalmos resulting from a volume discrepancy between an orbita and the orbital contents. To prevent worsening of the prosthesis motility with correction of enophthalmos, projection of the prosthetic globe was postoperatively adjusted by gradual inflation of an expander placed behind the enucleation implant. As a result enophthalmos was appropriately corrected without any change of the prosthesis motility.

Posted by afarahi at 12:14 PM | Comments (0)

June 13, 2006

Myobloc(R) for the Treatment of Benign Essential Blepharospasm in Patients Refractory to Botox(R).

Ophthalmic Plastic & Reconstructive Surgery. May/June 2006.
A small percentage of cases with essential blepharospasm or hemifacial spasm will become resistant to botulinum toxin A (Botox). We present our experience treating these patients with botulinum toxin B (Myobloc).
Data were collected on 16 patients and a total of 93 treatment visits. Average total dosage was 3,633 U per treatment session. Mean duration of beneficial effect was 7.3 weeks and was most commonly rated as fair to excellent. Side effects for botulinum toxin B occurred at a higher rate than is typical for botulinum toxin A. Most common side effects were pain on injection (100%), ptosis (32.3%), facial or mouth droop (22.6%), dry mouth (17.2%), dry eye (9.7%), exposure keratitis (7.5%), and blurred vision (5.4%). The rate of occurrence of side effects appears to be dose-dependent.
Conclusions: Botulinum toxin B is a useful treatment for cases that have become refractory to botulinum toxin A. The duration of beneficial effect is shorter than for type A. The side effect profile is similar to that for toxin type A except for pain on injection and the occurrence of dry mouth. Side effects occurred at a higher frequency than with botulinum toxin A, and the pattern suggests that botulinum toxin B spreads more diffusely. Side effects appear to be dosage-related.

Posted by afarahi at 09:10 PM | Comments (0)

Prevalence and Course of Strabismus in the First Year of Life for Infants With Prethreshold Retinopathy of Prematurity

Archive of ophthalmology,June 2006

The prevalence of strabismus was tabulated for all of the infants with high-risk prethreshold disease who participated in the randomized trial of the Early Treatment for Retinopathy of Prematurity study and were examined at 6 and/or 9 months' corrected age as well as for all of the infants with low-risk prethreshold disease who were examined at 6 months' corrected age.
The prevalence of strabismus at 6 months was higher for infants with high-risk prethreshold ROP than for those with low-risk prethreshold ROP (20.3% vs 9.6%, respectively; P<.001). Risk factors associated with the development of strabismus at 9 months include abnormal fixation behavior, presence of amblyopia, and outborn birth status (ie, born outside of a study-affiliated hospital). At 9 months, 30% of infants with high-risk prethreshold ROP had strabismus, although only 42% showed strabismus at 6 months. Thirty percent of infants with strabismus at 6 months showed normal alignment at 9 months.
Conclusions : Infants with high-risk prethreshold ROP show significant variability in the presence vs absence of strabismus in the first year of life; thus, conservative management is recommended.

Posted by afarahi at 09:01 PM | Comments (0)

NSAIDs May Reduce the Efficacy of IOP-Lowering Agent

Glaucoma Today
In a study published in the March issue of the British Journal of Ophthalmology, Chiba et al1 randomly assigned to two study groups 16 patients who used latanoprost in both eyes for at least 6 weeks. All patients continued latanoprost therapy for the duration of the study, but they instilled either an NSAID (bromfenac) or a sodium hyaluronic acid control solution in one eye.
Twelve weeks later, the eyes treated with NSAIDs had slightly but consistently higher IOPs than those that received the control solution. The maximum difference in IOP between the groups was 1.08 mm Hg.
The investigators suggested that NSAIDs might nullify the effects of latanoprost by inhibiting prostaglandin biosynthesis, which is the mechanism by which this agent lowers IOP.

Posted by aman at 12:43 AM | Comments (0)

Treatment of Anisometropic Amblyopia in Children with Refractive Correction

OPHTHALMOLOGY June 2006
To evaluate the effectiveness of refractive correction alone for the treatment of untreated anisometropic amblyopia in children 3 to <7 years old.
Eighty-four children 3 to <7 years old with untreated anisometropic amblyopia ranging from 20/40 to 20/250.
Optimal refractive correction was provided, and visual acuity (VA) was measured with the new spectacle correction at baseline and at 5-week intervals until VA stabilized or amblyopia resolved.
Results
Amblyopia improved with optical correction by ≥2 lines in 77% of the patients and resolved in 27%. Improvement took up to 30 weeks for stabilization criteria to be met. After stabilization, additional improvement occurred with spectacles alone in 21 of 34 patients observed in a control group of a subsequent randomized trial, with amblyopia resolving in 6. Treatment outcome was not related to age, but was related to better baseline VA and lesser amounts of anisometropia.
Conclusion
Refractive correction alone improves VA in many cases and results in resolution of amblyopia in at least one third of 3- to <7-year-old children with untreated anisometropic amblyopia. Although most cases of resolution occur with moderate (20/40–20/100) amblyopia, the average 3-line improvement in VA resulting from treatment with spectacles may lessen the burden of subsequent amblyopia therapy for those with denser levels of amblyopia.

Posted by aman at 12:29 AM | Comments (0)

Histopathology of Blepharoptosis Induced by Prolonged Hard Contact Lens Wear

AJO June 2006
Biopsy specimens from identical sites at the levator aponeurosis and Mueller muscle from 15 long-term hard contact lens wearers were examined histopathologically (group 1). They comprised two men and 13 women with bilateral blepharoptosis ranging in age from 26 to 59 years (mean ± SD, 44.4 ± 10.70 years). The average length of hard contact lens wear was 25.4 years (range 12 to 40 years), and the average spherical equivalent refractive error was −9.100 diopters (range −2.825 to −20.375 diopters). We also examined specimens from 15 patients with involutional blepharoptosis who underwent levator resection; they comprised three men and 12 women ranging in age from 64 to 79 years (mean ± SD, 72.3 ± 4.38 years).
Results
All patients in group 1 manifested fibrosis and negligible fatty degeneration in Mueller muscle. In group 2, we detected mild fibrosis in Mueller muscle and fatty degeneration of the aponeurosis and Mueller muscle.
Conclusions
Prolonged hard contact lens wear induces fibrosis in Mueller muscle and may result in contact lens–induced blepharoptosis.

Posted by aman at 12:14 AM | Comments (0)

Ruboxistaurin shows promise for patients with diabetic retinopathy

OSN BREAKING NEWS
In two phase 3 trials, ruboxistaurin reduced the risk of sustained moderate vision loss by 41% when compared with placebo in patients with diabetic retinopathy, the drug’s developer said in a news release.
The phase 3, 3-year trials of Eli Lilly and Company’s Arxxant (ruboxistaurin) involved 813 patients treated with 32 mg per day of Arxxant (412 patients) or placebo. Patients had moderate to severe nonproliferative diabetic retinopathy at baseline.
Vision loss occurred in 6.1% of the Arxxant group, compared with 10.2% of those in the placebo arm, the release said. Over a 3-year period, that equates to a 41% relative risk reduction, the company said.
According to the release, ruboxistaurin limits protein kinase C beta overactivation. It is the first of a new class of compounds being investigated for the treatment of diabetic retinopathy.
Arxxant was submitted for U.S. regulatory approval in February, and has received priority review status, the company said. The release noted the drug did not prevent disease progression to proliferative diabetic retinopathy.

Posted by aman at 12:10 AM | Comments (0)

June 12, 2006

Statin treatment may cause unilateral blepharoptosis

Ophthalmic Plastic and Reconstructive Surgery, May/June 2006
This case report describes a 43-year-old man who was on statin monotherapy (10 mg atorvastatin) for hypercholesterolemia and developed unilateral blepharoptosis. The authors conclude that statin-induced myositis in the levator muscle should be considered as a differential diagnosis of acquired unilateral blepharoptosis of unknown cause.

Posted by kjalali at 09:36 PM | Comments (0)

June 11, 2006

Image relocation with prisms in patients with AMD

CJO June 2006
This was a retrospective comparative interventional case series of 100 patients with AMD and 5 years of available follow-up records. Participants underwent complete low vision (LV) assessments, including identification of preferred retinal locus (PRL). Prisms were added to prescription glasses to produce IR(image relocation) to the presumed PRL. Main outcome measures were best-corrected visual acuity (BCVA), location of the PRL preferred by the patient for rehabilitation, use of glasses prescribed, and number of prism diopters prescribed.
Results: Patients wearing prescribed glasses for distance with prisms for IR showed improved BCVA (t63 = 9.5, p = 0.001) as did those patients wearing prescribed glasses for distance without prisms for IR (t14 = 2.25, p = 0.04). Patients wearing prescribed glasses for distance with prisms for IR achieved better BCVA than those patients wearing prescribed glasses for distance without prisms for IR (t77 = 2.0, p = 0.05). Patients reported using distance glasses with prisms for 3 to 48 months (mean [SD], 8.4 [11.7] mo). Number of prism diopters used (mean [SD], 5.8 [1.9] D) was well tolerated by all patients. PRL preferred by patients was on the upper retina in 98.5% of cases.
Interpretation: IR with prisms to PRL in patients with AMD results in a significant and sizable improvement in BCVA. This effect is probably created by facilitation of oculomotor functions resulting from direct reduction of fixation instability.

Posted by aman at 12:20 AM | Comments (0)

Accommodative Spasm After Laser-Assisted In Situ Keratomileusis (LASIK)

AJO June 2006
Two months following LASIK surgery, a 41-year-old healthy woman complained of intolerable headaches that had interfered with her daily activities. The patient sought medical consultation, and an MRI of the brain was normal. Best-corrected visual acuity (BCVA) was 20/20 and 20/25 with manifest refraction of −2.25 −0.50 × 170 and plano in the right and the left eye, respectively. Cycloplegic refraction was plano in the right and +0.75 sphere in the left eye, and she was corrected to 20/20 bilaterally. After being treated with cyclopentolate 1% one drop at bedtime to each eye for approximately six weeks, the headache completely resolved.
Conclusions
Accommodative spasm should be considered in patients undergoing LASIK surgery complicated with fluctuating refraction of uncertain causes.

Posted by aman at 12:12 AM | Comments (0)

June 10, 2006

Face-to-Face Seated Positioning for Phacoemulsification in Patients Unable to Lie Flat for Cataract Surgery

AJO June 2006
Two patients unable to lie flat during phacoemulsification underwent this technique in a University Ophthalmology Department in the United Kingdom. Each patient was positioned erect or semirecumbent in a standard reclining cataract surgical chair. The ceiling-mounted microscope was rotated 60 degrees from the vertical to point toward the patient. The surgeon sat beside the patient, and while facing him or her, operated at nearly arm’s length.
Results
The intraoperative and postoperative periods were uneventful in both patients, with good visual outcomes after surgery.

Posted by aman at 11:57 PM | Comments (0)

Study finds that cavitation plays no role in cutting cataract tissue

OSN 6/1/2006
Jaime Zacharias, MD
The “jackhammer effect” is the mechanism of action responsible for phacoemulsification’s cataract lens cutting power, according to a study that demonstrates that equivalent phacoemulsification occurs even when cavitation is not present.
Practical implications
The ongoing debate regarding whether the jackhammer effect or cavitation is responsible for phacoemulsification inspired our study, but our desire to provide answers sprung from an impetus far greater than simple intellectual curiosity. There are practical implications involved in determining the true mechanism underlying phaco. For example, if cavitational energy is irrelevant to lens cutting, it makes sense to design and use phaco tips that enhance the jackhammer effect and to avoid those that rely on cavitation, mainly to prevent the known harmful effects of cavitation, such as free radical formation and increased turbulence.
Study methods
In our effort to determine the mechanism responsible for the actual destruction of cataractous lens tissue, we first had to document the occurrence of cavitation (Figure 1). We did this by using a combination of complex light sources, recording methods and custom-made, state-of-the-art electronics. Our efforts revealed that cavitation mainly occurs in close proximity to the tip of the phaco needle and only appears at high ultrasonic powers of 50% or more. We also found that cavitation not only occurred at the tip of the phaco needle, but also along the shaft and in proximity to the hub in the proximal portion of the phaco needle.
The final answer
For this purpose, we performed a series of experiments with real cataract fragments (Figure 3). We developed a technique to feed lens fragments to the phaco probe at ambient and hyperbaric conditions in a controlled manner. Interestingly, we observed that phacoemulsification was performed with equal efficiency under normal conditions and under suppressed cavitation conditions. Essentially, we documented that when cavitation is completely inhibited, the phacoemulsification process is unaltered.

Posted by aman at 11:49 PM | Comments (0)

June 09, 2006

Microscope-induced cervical spine disease ends surgical career

EYEWorld JUNE 2006
It has been stated that an epidemic of cervical spine disease is looming over the nation’s eye care professionals . The cause has been identified as bad ergonomics: recurrent cervical spine abuse while using the slitlamp, and operating biomicroscopes over the course of a career .
First and foremost, doctor, “mind your neck!” Listen to what your body is telling you. Take action at the first sign of cervical discomfort.
Would yoga have helped? Would fine-tuned attention to posture and equipment use have prevented my fall from grace? I can’t say. In retrospect, however, any preventative measure(s) would have been preferred to where I am today.
Next, what is the status of your practice? If you’re a senior surgeon, are you solo (bad) or do you have a partner(s) in place (good) to take over the reigns in a situation like I have faced?
Do you have, or have you thought about, a succession plan for retirement or dealing with an unexpected disability or life change? Do you have disability insurance, and if so, have you upgraded it regularly or recently?
Finally, the ultimate challenge: Who among us has seriously studied the root cause (pun intended) of this cervical spine disease “epidemic?” Why do we accept equipment designed by optical engineers and physicists, that fosters cervical spine problems rather than prevents them? Future studies into this important area are critical and desperately needed.
In the meantime, doctor: Mind your neck!

Posted by aman at 11:58 PM | Comments (0)

Age-related behavior of posterior chamber lenses in myopic phakic eyes during accommodation measured by anterior segment partial coherence interferometry

EYEWorld June 2006
The purpose of this study, involving 53 eyes of 29 consecutive myopic patients, was to determine how age affects positional shifts of the crystalline lens and the implantable contact lens (ICL, STAAR Surgical, Monrovia, Calif.). Patients ranged in age from 21 to 59 with a mean age of 33. Using partial coherence interferometry investigators measured accommodation with a stimulus of 3 D, before and after ICL implantation. In nine cases a 5 D stimulus also was used. Investigators determined that older patients were more likely to have smaller vaults between the ICL and crystalline lens during desaccommodation than their younger counterparts. In older patients there was a decrease in the vault on accommodation compared with younger patients. Also, with increased accommodation stimulus at 5 D the vault was significantly larger. Investigators concluded that while the lens does stiffen and accommodation does deteriorate with age, the ciliary muscle likely still has a role in the movement of the ICL during accommodation.

Posted by aman at 11:46 PM | Comments (0)

Acupuncture, electrotherapy may help alleviate dry eye

EYEWorld JUNE 2006
In a study led by Jaung-Geng Lin, M.D., Graduate Institute of Chinese Medical Science, China Medical University, Taichung, Taiwan, acupuncture and Silver Spike Point (SSP) electrotherapy were found to be effective in increasing tear secretion in patients with dry-eye syndrome. In addition to alleviating dry-eye syndrome, the SSP electrotherapy also reduced the number of applications of artificial tears necessary to keep the eye lubricated.
A total of 43 dry-eye syndrome patients participated in the study and were divided into control, acupuncture, and SSP electrotherapy groups. The three groups then were given artificial tears treatment. Patients in the treatment groups were given two 20-minute treatments of either acupuncture or SSP. The assessment was carried out using the Basal Schirmer test, tear breakup time (BUT), visual analog scale (VAS), and an overall score of eye condition.
The acupuncture and SSP groups showed significant improvement compared with the control group. Compared with the SSP group, the acupuncture group showed a greater eight-week improvement in Schirmer tests scores; however, the patients in the SSP group used fewer applications of artificial tears.

Posted by aman at 11:41 PM | Comments (0)

Adding ECP (endocyclophotocoagulation) to phaco

EYEWorld June 2006
Dr. Berke and his co-investigators randomized 707 patients with cataract and medically controlled glaucoma to undergo either phacoemulsification (81 patients) or phacoemulsification with ECP (626 patients). Most patients were assigned to the ECP group because “the goal of the study was to follow a large number of phacoemulsification and ECP patients over a long period of time,” In the study patients were followed for a mean of 3.2 years (range 10.5 months to 5.8 years) after surgery.
The ECP procedure was performed after completing the cataract extraction and placement of a three-piece silicone IOL. The sulcus was inflated with viscoelastic, and the ECP probe entered the eye through the phaco incision. The probe consists of a light source, the laser, and a fiber optic endoscope that permits visualization of the ciliary processes on a monitor.
In Dr. Berke’s study, 200 to 270 degrees of the ciliary body was treated. “Each process in the treatment zone was treated completely from base to tip,” he said, “and the tissue treatment endpoint was both whitening and shrinkage of the process.”
Their results were impressive.
ECP-treated eyes experienced an IOP drop from 19.08 mm Hg pre-op to 15.73 mm Hg at last follow-up. In contrast, the phacoemulsification-only eyes had a slight increase in IOP from 18.16 mm Hg pre-op to 18.93 mm Hg (figure 1).
“The phaco-only eyes had a significant drop in IOP for the first six to 12 months, but by three years IOP had increased to above pre-op levels,” explained Dr. Berke. “But in the ECP eyes IOP dropped about 3 mm Hg within the first six months and maintained this reduction throughout the study.”
“Patients who received ECP went from a mean of 1.53 medications pre-operatively to 0.65 medications post-operatively. Phaco-only eyes remained on a mean of 1.2 medications both pre- and post-operatively,” said Dr. Berke.

Posted by aman at 11:04 PM | Comments (0)

Risk calculators help identify potential glaucoma patients, clinician says

OSN BREAKING NEWS
Ophthalmologists should consider risk calculators to be “invaluable tools” for incorporating complex results into clinical practice, according to one physician.

“Glaucoma risk calculators help us find those who are at high risk for glaucoma,” said Steven L. Mansberger, MD, MPH, speaking here at the OSN Las Vegas meeting.

Dr. Mansberger said that not only do risk calculators help determine the probability of glaucoma, they can also help the physician make important treatment decisions. In a survey conducted to help establish the need for risk calculators, he said respondents “estimated a wide range of probabilities in the same ocular hypertensive patients. So we may be under- or over-treating ocular hypertensive patients. Risk calculators provide a tool to help us to incorporate complex results into clinical practice.”

Dr. Mansberger said one risk calculator he uses is www.discoveriesinsight.org.

Posted by aman at 11:01 PM | Comments (0)

June 06, 2006

Early post-phacoemulsification hypotony as a risk factor for intraocular contamination: In vivo model

JCRS April 2006
To observe cataract wound dynamics and determine the risk for intraocular contamination under induced conditions of early postoperative hypotony after anterior chamber decompression for high intraocular pressure (IOP) spikes after uneventful phacoemulsification surgery.

In a prospective case series, 30 patients were treated with anterior chamber decompression for elevated IOP (>35 mm Hg) 1 to 2 hours after uneventful phacoemulsification through clear corneal temporal incisions. A drop of 2% fluorescein was instilled in the conjunctival sac before aqueous release to study the ocular fluid movements during and after the decompression procedure. The patterns of fluorescein movement were observed and photographed under cobalt blue light.

Results
Fluorescein staining of the entire corneal tunnel was observed in all 30 eyes after decompression. An immediate fluorescein flare was observed in the anterior chamber after aqueous release in 24 eyes (80%) ,Observations over several seconds after decompression found a frank influx of fluorescein-stained fluid into the anterior chamber in 12 eyes (40%) (P<.001), giving rise to an “inverse Seidel's test.” An intermittent ingress of fluorescein-stained fluid continued for several minutes after the procedure in 6 eyes (20%) (P<.05).

Conclusions
An incompetence of clear corneal cataract wound with intraocular contamination was observed during the period of induced hypotony after anterior chamber decompression in the early post-phacoemulsification period.

Posted by alireza habibollahi at 11:31 PM | Comments (0)

Subjective difficulty of each stage of phacoemulsification cataract surgery performed by basic surgical trainees

JCRS April 2006
This prospective study comprised 100 consecutive cases of phacoemulsification performed by 8 trainee surgeons over an 11-month period. The trainees completed a questionnaire at the end of surgery, rating the degree of difficulty of 8 individual stages of phacoemulsification on a 5-point scale from 1 (very easy) to 5 (very difficult).

Results
At the start of the study, trainees had spent a mean of 9.4 months training. The mean preoperative best corrected decimal visual acuity was 20/70. The most difficult stages were phacoemulsification and capsulorhexis with the highest mean scores of 3.32 and 3.30 respectively and the lowest completion rates of 66.7% and 74.4%, respectively. The first 3 stages of peribulbar blockade (1.72 ± 0.75), draping the surgical field (1.35 ± 0.70) and corneal incision (1.97 ± 0.72) were easiest and had close to a 100% completion rate. Hydrodissection, irrigation/aspiration, and intraocular lens insertion had difficulty rates of 2.42 ± 0.92, 2.80 ± 1.10, and 2.58 ± 1.08, respectively, and completion rates of 92.3%, 78.4%, and 83.1%, respectively. Posterior capsule tear occurred in 9%, including 4% with vitreous loss; there was 1 case of zonular dehiscence.

Conclusions
Trainee surgeons found phacoemulsification and capsulorhexis the most difficult stages of cataract surgery early in the learning curve. More time can be dedicated to mastering these steps in the wet lab.

Posted by alireza habibollahi at 11:24 PM | Comments (0)

Outcome of simultaneous phakic implantable contact lens removal with cataract extraction and pseudophakic intraocular lens implantation

JCRS Pages

To assess the outcome of simultaneous implantable contact lens (ICL) removal and cataract extraction with pseudophakic intraocular lens (IOL) implantation.

This retrospective noncomparative interventional case series evaluated 14 eyes of 12 patients with ICL implantations who developed a cataract and simultaneously had ICL removal and cataract extraction with IOL implantation. The follow-up time was at least 6 months (range 6 to 24 months). Visual acuity (logMAR), manifest refraction, intraocular pressure, and adverse events were recorded.

Results
Of the 12 patients (14 eyes), 10 patients (12 eyes) had ICL surgery to correct high myopia and 2 patients (2 eyes), to correct hyperopia. The mean uncorrected visual acuity after ICL implantation (before cataract development), before cataract surgery, and after cataract surgery were 0.48 , and 0.40 , respectively. The mean BCVA before ICL implantation, after ICL implantation, and after cataract surgery were 0.31 , 0.28 , and 0.27 , respectively. The mean final manifest spherical equivalent was 0.30 diopters (D) . Ten eyes (71.4%) were within ±1.0 D of the calculated target. One eye had a tear in the posterior capsule with vitreous loss during cataract surgery. No other intraoperative, perioperative, or postoperative complications were observed. No loss of BCVA was recorded at the last postoperative visit.

Conclusions
Lens opacities and cataract formation are a potential complication of ICL surgery. The removal of the ICL and the cataract with IOL implantation was found to be safe, with predictable refractive results.

Posted by alireza habibollahi at 11:15 PM | Comments (0)

June 05, 2006

Thicker IOLs and retinal image quality

EYEWORLD May 2006
Jorge L. Alio, M.D., Ph.D.,
MTF( modulation-transfer function) is the ratio of image wave contrast to object wave contrast.
An ideal lens would perfectly transmit 100% of the light that passes though it,” according to the site’s explanation of modular transfer function. “But, no lens is perfect, and therefore there are losses. When these losses are measured in terms of contrast this is called the modulation of contrast. In other words, how much contrast is lost.”
Result
Thirty eyes were implanted with one of the three lenses studied.
The AcrySof MA60BM lens studied by the researchers had a central thickness of 820 to 880 microns depending on diopter power. Meanwhile, the ThinOptX lens measured 350 to 450 microns. And the Acri.Smart 48S measured 700 microns.
The 0.5 MTF and 0.1 MTF were calculated after surgery using the Optical Quality Analysis System (OQAS) for a 5 mm pupil.
The value of 0.5 MTF for the AcrySof IOL was 2.647 cycles per degree +/- 0.833. For the ThinOptX lens it was 2.601 cycles per degree +/- 0.986. The Acri.Smart logged a value of 3.453 cycles per degree +/- 0.778.
IOL 0.1 MTF values also were similar.
The average 0.1 MTF value for the AcrySof was 8.720 +/- 3.074 cycles per degree. It was 8.814 cycles per degree +/- 4.380 for the ThinOptX. And it was 11.418 cycles per degree +/- 2.574 for the Acri.Smart.
“Statistical analysis did not show significant differences in 0.5 MTF and 0.1 MTF between the conventional IOL and MICS IOLs,” Dr. Alio concluded.

Posted by aman at 11:34 PM | Comments (0)

How to use limbus size to predict capsular bag dimensions

EYE WORLD May 2006
Determining capsular bag dimensions is pretty important because of the endocapsular devices that are put in the bag—such as intraocular lenses and capsular tension rings (CTRs),
In the study, the investigators obtained 78 consecutive human eye bank globes. These were sectioned at the equator, with the globe flipped around so that the cornea was facing downward. To ensure that the eyes were oriented correctly, investigators looked at muscle attachments.
“We measured the capsular bag size in these sectioned eyes,” Dr. Khng said. “We then compared them [with] the white-to-white measurements that we had taken before we had sectioned the eyes.”
Results showed that the lens tended to be round. Investigators determined that the mean vertical dimension was 9.3 mm, and the mean horizontal dimension was 9.28 mm. Meanwhile, the horizontal and vertical limbus sizes did not reflect this.
“The mean vertical limbus size was 10.63, which was less than the horizontal limbus dimension, which was 11.46,” Dr. Khng. “This is roughly about 0.8 mm more.”
In fact, investigators found very little correlation between the horizontal limbus measurement and capsular bag size. However, a weak correlation was found between capsular bag size and vertical limbus measurements.
“If we look at the linear regression of lens dimension, either in the horizontal or in the vertical meridian, and correlated these with limbus size, we then obtain the linear regression value r2,” Dr. Khng said.
This r2 value gives an idea of how much variation in lens size there is as a result of limbus size. The r2 value for the vertical dimension was 0.13 (p=0.0012), a number that Dr. Khng sees as offering a weak yet statistically significant correlation. Meanwhile, the r2 value for the horizontal dimension was 0.031 (p=0.1220). Investigators determined that there was no significant correlation.

Posted by aman at 11:12 PM | Comments (0)

Corneal calcification following intensified treatment with sodium hyaluronate artificial tears

BJO TOPTEN Article
Five cases of deep calcium deposition in the cornea associated with ocular surface disease and frequent use of hyaluronic acid artificial tears are described. All patients used one formulation of phosphate buffered hyaluronate eye drops when rapid calcification developed. All eyes required corneal graft surgery for visual rehabilitation. Specimens at keratoplasty were available for light microscopy and investigation by dispersive x ray analysis. The phosphate concentration in the medication used for topical treatment was measured and compared to alternative hyaluronate preparations.
Conclusions: The hyaluronate artificial tear formulation "Hylo-Comod" favours the formation of insoluble crystalline calcium phosphate deposits in presence of epithelial keratopathy. This is because of its high phosphate concentration and typically frequent instillation. Manufacturers and prescribers should be aware that topical preparations may contain considerable amounts of phosphate which may lead to sight threatening corneal complications.

Posted by aman at 11:06 PM | Comments (0)

Diagnosis of Fusarium keratitis in an animal model using the polymerase chain reaction

BJO TOPTEN Article
Fusarium solani keratitis was induced in three eyes of three rabbits by injection of a suspension of the fungus into the anterior corneal stroma. In one rabbit the contralateral eye served as a control. From four to 28 days after inoculation, the corneas were scraped for culture, then scraped and swabbed for PCR analysis. The PCR was performed with primers directed against a portion of the Fusarium cutinase gene, and the presence or absence of this amplified target sequence was determined by agarose gel.
RESULTSThe amplified DNA sequence was detected in 25 of 28 samples from the corneas infected with Fusarium, for a sensitivity of 89%. Only three of the 14 samples from these eyes with Fusarium keratitis were positive by culture, for a sensitivity of 21%. Seven of eight control samples were negative by the PCR based test, for a specificity of 88%.

Posted by aman at 11:01 PM | Comments (0)

Keep Your Cataract Surgeries on Target

Revoph June 2006

SURGERY IS ALMOST SYNONYMOUS with precision: cutting or removing just the right amount of tissue to achieve success. Along these lines, to help surgeons make the right size capsulorhexis, Michel Perez, MD, of Dijon, France, is working with Carl Zeiss to develop a capsulorhexis guidance system for the surgical microscope. Here’s how it works.
The system is a small addition to a microscope that allows the surgeon to overlay aiming reticules onto the image of the eye. By using these reticules as guides, Dr. Perez says, the surgeon can ensure the correct diameter of the capsulorhexis as he creates it.“If you’re operating on a high myope, for example, the eye is large, so 6 mm doesn’t look very big,” he says. “But if you’re operating on a hyperopic eye, which is smaller, a 6-mm diameter would look different. You can’t adjust based solely on your intuition.”The sizes of the circles automatically scale up or down if the surgeon zooms the micro­scope, and can also be turned on or off. The device can also put axis marks on the image, to help in centering a toric IOL.Dr. Perez believes such capsulorhexis precision is required more and more with the advent of multifocal IOLs.

Posted by mehdi khanlari at 08:35 PM | Comments (0)

June 04, 2006

Three-Year Follow-up Analysis of Artisan Toric Lens Implantation for Correction of Postkeratoplasty Ametropia in Phakic and Pseudophakic Eyes

OPHTHALMOLOGY June 2006
Thirty-six eyes of 35 consecutive patients received Artisan toric lens implantation for postkeratoplasty astigmatism and/or anisometropia.
Results
The mean ± standard deviation of preoperative refractive cylinder was −7.06±2.01 diopters (D) (range, −3.0 to −11.0), which was reduced to −1.73±1.25 D, −1.69±1.15 D, −1.94±1.68 D, −2.02±1.93 D, and −2.00±1.53 D at 6 months (n = 36), 1 year (n = 36), 2 years (n = 29), 3 years (n = 15), and the last follow-up examination (28.5±12.5 months, n = 36), respectively (P<0.001 for all time points, paired t test). The spherical equivalent was reduced from −3.19±4.31 D (range, +5.5 to −14.25 D) preoperatively to −1.03±1.20 D (range, +1.0 to −5.25 D) at the last follow-up. The UCVA and BSCVA were ≥20/40 in 31.6% and 80.6%, respectively. There was a loss of BSCVA of >2 lines in 8.3% of eyes and a gain of at least 2 lines in 8.3% of eyes. Percent reductions in refractive astigmatism and anisometropia of defocus were 88.8%±29.5% and 77.8%±19.3%, respectively. The astigmatism correction index was 96.0%±24.2%. Satisfaction increased from 3.6 to 8.0 (scale, 0–10) after implantation. The endothelial cell loss as compared with preoperatively was 13.8%±18.7% (n = 34), 21.2%±21.8% (n = 33), 29.6%±27.3% (n = 26), 30.4%±32.0% (n = 18), and 34.8%±26.3% (n = 6) at 6 months (P = 0.001), 1 year (P<0.001), 2 years (P<0.001), 3 years (P = 0.001), and 4 years postoperatively (P = 0.1), respectively. In 2 patients, irreversible graft rejections occurred, and in 1 patient, gradual endothelial decompensation occurred.

Posted by aman at 07:56 PM | Comments (0)

Changes in the Optic Disc after Acute Primary Angle Closure

OPHTHALMOLOGY June 2006
To evaluate the changes in optic disc morphology in the first 4 months after an episode of acute primary angle closure (APAC) using stereoscopic optic disc photography and computer-assisted planimetry.
Forty-seven Asian subjects with unilateral APAC who were successfully treated with laser peripheral iridotomy (LPI).
Results
The majority of the subjects were female (66%) and Chinese (90%), and the mean age was 67.6±11.2 years (range, 40–94). In APAC eyes from week 2 to week 16, the mean CDR increased from 0.56±0.05 to 0.59±0.03 (P<0.001), and the mean neuroretinal rim area decreased from 1.74±0.31 mm2 to 1.59±0.27 mm2 (P<0.001). Quadrantic and sector analysis showed preferential loss of neuroretinal rim area at the superotemporal and inferotemporal areas. There was no significant change in optic disc parameters in the fellow eyes over the study period.

Posted by aman at 07:50 PM | Comments (0)

A Randomized Trial to Evaluate 2 Hours of Daily Patching for Strabismic and Anisometropic Amblyopia in Children

OPHTHALMOLOGY June 2006
To compare 2 hours of daily patching (combined with 1 hour of concurrent near visual activities) with a control group of spectacle wear alone (if needed) for treatment of moderate to severe amblyopia in children 3 to 7 years old.
Prospective randomized multicenter clinical trial (46 sites).
One hundred eighty children 3 to 7 years old with best-corrected amblyopic-eye visual acuity (VA) of 20/40 to 20/400 associated with strabismus, anisometropia, or both who had worn optimal refractive correction (if needed) for at least 16 weeks or for 2 consecutive visits without improvement.
Results
Improvement in VA of the amblyopic eye from baseline to 5 weeks averaged 1.1 lines in the patching group and 0.5 lines in the control group (P = 0.006), and improvement from baseline to best measured VA at any visit averaged 2.2 lines in the patching group and 1.3 lines in the control group (P<0.001).
Conclusion
After a period of treatment with spectacles, 2 hours of daily patching combined with 1 hour of near visual activities modestly improves moderate to severe amblyopia in children 3 to 7 years old.

Posted by aman at 07:22 PM | Comments (0)

Combined cataract-glaucoma procedures needed less frequently

OSN TOP STORIES 5/23/2006
In the past I used to perform a lot of combined procedures. Now I have reduced them to only one or two a year,” said Richard L. Lindstrom, MD,
Most patients with glaucoma who are seen by a comprehensive ophthalmologist because of visual impairment from cataract can be treated with cataract surgery and lens implantation alone, Dr. Lindstrom said. Phacoemulsification with posterior chamber IOL implant lowers the IOP of a patient by an average of 2 mm Hg to 4 mm Hg, and “every millimeter of mercury reduction lowers the risk of visual field loss by 10%,” he said.
Combined phaco-trabeculectomy procedures “have only marginally better results” with IOP lowering, Dr. Lindstrom said.
Intraocular tension might be lowered 3 to 6 mm Hg, but the risk of complications, short and long term, is much higher and visual recovery is significantly slower than after cataract surgery alone,” he said.
Cataract surgeons who operate on glaucoma patients must consider the negative effects the eye may have experienced from the disease itself, from chronic use of medications and, more important, from the preservatives contained in those medications.
Clear corneal cataract surgery spares the conjunctiva in case glaucoma surgery is required later, Dr. Lindstrom said. He recommended creating a small incision in clear cornea, “never invading the conjunctiva.” Endothelial abnormalities are likely to be present, and the endothelial reserve reduced, so specular microscopy and pachymetry should be performed preoperatively to assess the condition of the cornea.
Extra care must be taken intraoperatively with the use of viscoelastics, which can block outflow channels if left in the eye.
I normally implant the lens in the bag, but if the capsule is very loose, I place the lens in the sulcus, with the optic captured in the bag,” he said.
To reduce the inflammation that can be seen due to drug preservatives, Dr. Lindstrom asks patients to discontinue use of any potentially inflammatory drug a few days before surgery. In some cases he prescribes nonsteroidal anti-inflammatory drugs and steroids preoperatively.
Watch out for cystoid macular edema, which is also quite commonly caused by drug preservatives,” he said. Prophylactic treatment for postop pressure spikes is also advisable, he added.
A higher rate of Nd:YAG laser capsulotomy is to be expected in these patients, in whom capsular fibrosis and capsular phimosis are more frequent.

Posted by aman at 07:02 PM | Comments (0)

Torsional ultrasound could be ‘new standard’

OSN TOP STORIES 6/1/2006
Torsional ultrasound is produced by a lateral movement of the phaco tip. Traditional longitudinal ultrasound moves back and forth within the eye, whereas torsional ultrasound oscillates back and forth. Torsional ultrasound also has a smaller incision and decreased risk of wound burn, according to Dr. Akahoski.
He described several adjustments he made to the phaco sleeve and tip to further increase aspiration times and enhance wound protection. He said he added a third hole to the side of the sleeve and was able to increase irrigation time to 120 mL per second, compared with the standard 88 mL per second in traditional ultrasound.
Alcon’s OZil handpiece has “the advantage of a torsional movement combined with the traditional longitudinal movement,” he told attendees at the German Ophthalmic Surgeons meeting here. Dr. Akahoshi said he recommends using the torsional setting for soft nucleus removal and using a combination of torsional and longitudinal movements for dense cataract removal.

Posted by aman at 06:58 PM | Comments (0)