« February 2006 | Main | April 2006 »
March 31, 2006
Stopping systemic coumarin therapy before cataract surgery appears unnecessary
European Journal of Ophthalmology, March 2006
This nonrandomized study included 441 patients (441 eyes) undergoing standard phacoemulsification with clear cornea incision and topical anesthesia. Researchers compared the complication rate between patients who continued coumarin therapy (21 patients) with a control group that didn’t take the anticoagulant drug before surgery (420 patients). The frequency of intraoperative or postoperative hemorrhages, intraoperative complications such as posterior capsule rupture, postoperative visual acuity and intraocular pressure did not vary significantly (p>0.30) between the two groups of patients.
Posted by kjalali at 10:26 AM | Comments (0)
Long-term diabetes patients have thicker corneas
Eye, March 2006
Ultrasound pachymetry and noncontact specular microscopy were performed on 200 patients with diabetes and on 100 control subjects. Patients with diabetes not only had thicker corneas, but also less cell density and hexagonality, and more irregular cell size of the corneal endothelium than did the control group (P<0.05). After controlling for age, researchers observed that central corneal thickness and the coefficient of variation for cell size were significantly higher in patients who lived with the disease for more than 10 years compared to patients who had the disease less than 10 years (P<0.05). Endothelial cell density and percentage of hexagonal cells were lower for long-term diabetes patients compared to those who had the disease less than 10 years (P>0.05). Central corneal thickness was correlated with duration of diabetes (P<0.05), but corneal endothelial morphology was not (P<0.05).
Posted by kjalali at 10:21 AM | Comments (0)
A Prospective Study of Alternating Occlusion Before Surgical Alignment for Infantile Esotropia: One-Year Postoperative Motor Results
Journal of AAPOS,Feb,2006
Alternating occlusion before surgical alignment has been suggested by some strabismologists as a possible method to enhance the treatment of infantile esotropia. This report presents 1-year outcome results of a prospective trial of forty-four patients with infantile esotropia who were assigned randomly to alternating occlusion or control groups. Alternating occlusion was full time and symmetric for those with no amblyopia but asymmetric for those with amblyopia. The control group that did not receive alternating occlusion had occlusion for amblyopia only. Initial surgeries were performed when the patients were between the ages of 6 and 13 months. Seventy-five percent of all patients were aligned by the initial surgery. Ninety-one percent of those patients aligned within 10 PD at 6 weeks also were aligned 1 year postoperatively. The results were similar for the alternate occlusion group and the control group.
Conclusion: In our sample of patients, alternating occlusion does not detectably alter the increase in angle of deviation between the dates of entry and the date of the initial surgical alignment procedure, nor does it influence the postoperative alignment at 6 weeks or at 1 year.
Posted by afarahi at 02:05 AM | Comments (0)
Is There a Latent Period for the Surgical Treatment of Children With Dense Bilateral Congenital Cataracts?
Journal of AAPOS,Feb,2006
It generally is accepted that cataract surgery during the first 6 weeks of life is associated with the best visual outcomes for children with dense unilateral congenital cataracts. The latent period for children with dense bilateral congenital cataracts has not been clearly defined.The best-corrected visual acuity (BCVA) at 4 to 6 years of age was collected retrospectively on a series of 43 children with dense bilateral congenital cataracts from 4 institutions. All of the children underwent a lensectomy, posterior capsulotomy, and anterior vitrectomy at 36 weeks of age or younger. The visual acuities of 26 (60%) were 20/40 or better, 12 (28%) were 20/50 to 20/80, and 5 (12%) were 20/100 or worse. There was a trend for worse BCVA with increasing age at the time of surgery (r = 0.28, P = 0.07). We noted that a BCVA of 20/100 or worse occurred only among eyes undergoing surgery when infants were older than 10 weeks (≤10 weeks: 0/21 = 0% vs. >10 weeks: 5/22 = 23%, P = 0.049). Children with preoperative nystagmus had worse visual outcomes; only 38% of children with preoperative nystagmus achieved a BCVA of 20/40 or better compared with 74% of children without preoperative nystagmus (P = 0.03). Conclusion: Previous reports have proposed that cataract surgery during the first 5 to 8 weeks of life is associated with better visual outcomes in children with dense bilateral congenital cataracts. Our results would suggest that good visual outcomes can be achieved beyond this age, but the incidence of poor visual outcomes increases if cataract surgery is delayed beyond 10 weeks of age. The absence of preoperative nystagmus is a better predictor of a good visual outcome than the age at surgery.
Posted by afarahi at 01:35 AM | Comments (0)
Changes in Corneal and Conjunctival Sensitivity, Tear Film Stability, and Tear Secretion After Strabismus Surgery
Journal of Pediatric Ophthalmology and Strabismus March/April 2006
Some patients complain of a foreign body sensation, a burning sensation, or dryness after strabismus surgery. We prospectively investigated the changes in corneal and conjunctival sensitivity, tear film stability, and tear secretion after strabismus surgery.
There were no significant changes in corneal sensitivity, tear film stability, or tear secretion after strabismus surgery (P > .05). Conjunctival sensitivity decreased significantly after strabismus surgery (P < .05). CONCLUSION:Discomfort and dryness after strabismus surgery do not seem to be related to changes in corneal sensitivity, tear film stability, or tear secretion.
Posted by afarahi at 01:25 AM | Comments (0)
Comparison of Results of Medial Rectus Muscle Recession Using Augmentation, Faden Procedure, and Slanted Recession in the Treatment of High Accommodative Convergence/Accommodation Ratio Esotropia
Journal of Pediatric Ophthalmology and Strabismus ,March/April ,2006
Davoud Gharabaghi, MD; Leila Kazemi Zanjani, MD
Twenty-eight children (4 to 14 years old) with high AC/A esotropia with a near–distance disparity greater than 10 PD were included in a prospective, randomized, blinded clinical trial. Nine children underwent recession of both medial rectus muscles and posterior fixation suture (Faden procedure), 9 children underwent augmented recession of the medial rectus muscles, and 10 children underwent slanted recession of both medial rectus muscles. In the augmented recession group, the mean near –distance disparity was reduced from 16.33 ± 2.17 PD preoperatively to 7.55 ± 3.87 PD postoperatively (54.21%; P = .056). In the Faden procedure group, it was reduced from 15.22 ± 4.08 PD to 2.55 ± 4.03 PD (80.7%; P = .056). In the slanted recession group, it was reduced from 15.50 ± 4.30 PD to 4.10 ± 4.80 PD (67.55%; P = .056).
CONCLUSIONS:The Faden procedure had the best outcome, but slanted recession also was successful. Because of our good results and an easy, noninvasive approach without any additional complications, we recommend slanted recession to treat high AC/A esotropia.
Posted by afarahi at 01:12 AM | Comments (0)
March 22, 2006
Pseudophakic Retinal Detachment Following Phaco-Emulsification Cataract Surgery: a Ten Year Retrospective Review
Investigators here launched a retrospective study on 1793 consecutive patients undergoing cataract surgery with phacoemulsification. They found that there was a 1.17% rate of rhegmatogenous retinal detachment in this study group. Those under the age of 50 were at particular risk with a retinal detachment rate of 5.17%. Meanwhile, those over the age of 70 were found to be at reduced risk, with just a 0.64% rate of detachment. The detachments occurred at a median interval of 39 months. Investigators determined that the difficulty of the cataract surgery was a factor here, with those who underwent complicated procedures, at higher risk for detachments. However, having to undergo an Nd-yag capsulotomy did not play a role here. Investigators concluded that there was just a small risk of retinal detachment overall with phaco-emulsification. They also determined, however, that the risk was higher among younger patients. In light of this, they recommended reassessing the requirement for cataract surgery in this group.
Posted by mehdi khanlari at 04:39 PM | Comments (0)
Amniotic membrane can remain intact after transplanted into corneal stroma
Rabbit amniotic membrane allografts persist intact within an intracorneal space for many months post-op and are not quickly broken down or dissolved by the host tissue The investigators said that successful use of amniotic membrane is attributed to its anti-inflammatory, anti-angiogenic, and antibacterial properties as well as its resultant transparency.In the study rabbit amniotic membranes were stained with 0.5% dichlorotriazinyl amino fluorescein and implanted unilaterally into the corneal stroma of four adult rabbits. Corneas were examined clinically and by transmission electron microscopy and fluorescent microscopy at one, three, seven, and 10 months after surgery.At one month post-op the cornea remained hazy in and around the position of the implanted amniotic membrane; however, visibility gradually increased over time and finally resulted in a clear cornea by 10 months, according to the study.Fluorescent and electron microscopy, however, clearly demonstrated that the amniotic membrane remained structurally unchanged and intact within the corneal stroma up to 10 months after implantation."This study indicates that amniotic membrane, once transplanted into the corneal stroma, can remain intact within the cornea for many months postoperatively without being broken down or dissolved by the host tissue," the investigators concluded.
Posted by mehdi khanlari at 04:29 PM | Comments (0)
Water drinking test may effectively detect IOP variations
Eyeworld March 2006
In a recent study, Remo Susanna Jr., M.D., concluded that the water drinking test is a low-cost and feasible test that highlights the peak and variations of IOP that should be considered when analyzing glaucoma progression risk factors.The study, by Dr. Susanna, University of São Paulo, Brazil, which was published in the October issue of British Journal of Ophthalmology, reviews the relation between IOP peak measured with the water test and visual field progression in glaucoma“Mean IOP peak and percentage of IOP variation during the water drinking test were significantly higher in patients with visual field progression compared with patients who did not progress,” Dr. Susanna said.
Posted by mehdi khanlari at 08:05 AM | Comments (0)
Determining when glaucoma patients should stop driving
....Those individuals who had moderate field defects, in the six to 11 AGIS range, were about four times more likely to have been crash involved,” . “Individuals with severe visual field defects, with AGIS scores between 12 and 20 were about six times more likely to have a crash.”Because the AGIS score is an index that can be computed on a Humphrey visual field test (Carl Zeiss Meditec, Dublin, Calif.), Dr. Owsley told attendees that she sees this as a practical tool that practitioners could use.“Many ophthalmologists aren’t sure how much visual impairment needs to be present before they start cautioning their patients against driving,” Dr. Owsley said. “This at least provides the beginning of some guidance to the ophthalmologist.“Clearly our data show that just because your patient is diagnosed with glaucoma, that is not in and of itself a cause for concern or a threat to road safety,” Dr. Owsley said. “What appears to be a threat is if the patient has a moderate to severe visual field loss in an eye.”
Posted by mehdi khanlari at 07:57 AM | Comments (0)
The connection between headaches and subacute angle-closure glaucoma
A simple test can be used on a patient with headaches to determine if that patient suffers from subacute angle-closure glaucoma, according to a recent study.Patients with subacute angle closure have intermittent episodes of elevated IOP lasting minutes to hours with symptoms that include blurred vision, pain, or mild redness, according to the study, which appeared in the September 2005 issue of Neurology.“Recurrent episodes can lead to permanent angle scarring, glaucomatous optic nerve damage, and loss of peripheral vision,” the authors stated.However, if physicians are able to identify narrow angles at risk for angle closure by viewing the anterior chamber angle by gonioscopy, then the patient can be treated through laser peripheral iridotomy (LPI) to prevent further episodes.
“So we thought it would be useful to try and quantify this and see some of the characteristics of these patients so that maybe we could draw attention and prevent delay in their diagnosis,”Using gonioscopy, the investigators revealed narrow, occludable angles in the 11 patients, and six patients had peripheral anterior synechiae (PAS). The PAS varied from scattering to large areas of synechial scarring angle closure.Ten of the 11 patients underwent sequential, bilateral LPIs (one patient did not return).“All 10 patients had improvement of their headaches, with six patients reporting complete resolution and four patients reporting a significant decrease in frequency and severity,” Dr. Shindler said one of characteristics patients with acute angle-closure glaucoma in this study shared was that they were older at the onset of headaches. Usually people began having headaches as a teenager or in their 20s and 30s.The patients in the study also had shorter headaches lasting only minutes or occasionally as long as an hour, Dr. Shindler said. In addition to these two characteristics, physicians also should take into consideration the traditional factors that are associated with angle closure such as hyperopia.But while the test is quick and easy, there are apparently not many affected patients to find.“While gonioscopy is a quick and easy way to find these patients, you have to perform a lot of unnecessary gonioscopies to find the few at risk,”
Posted by mehdi khanlari at 07:46 AM | Comments (0)
Retinitis pigmentosa treatment shows promise in early trial
INDUSTRY NEWS
Neurotech reports that Phase I results show NT-501 can be safely implanted into the eye and was found to be well tolerated by patients. While the study was not designed to assess clinical efficacy, the company reports that three of seven patients with evaluable visual acuity experienced an improvement in visual acuity. NT-501 is an intraocular, polymer implant containing human retinal pigment epithelial cells genetically modified to secrete Ciliary Neurotrophic Factor (CNTF). The implant is designed to continuously release CNTF directly in the eye to retinal tissue for sustained periods of time
Posted by kjalali at 01:52 AM | Comments (0)
TA treatment prevents panretinal photocoagulation-induced visual dysfunction in patients with severe diabetic retinopathy
Ophthalmology, March 2006
This prospective study included 10 patients (20 eyes) with severe nonproliferative diabetic retinopathy or non–high-risk proliferative diabetic retinopathy and good vision (20/40) before panretinal photocoagulation treatment (PRP). Before PRP treatment, one eye of each patient was randomly chosen to receive a single, posterior sub–Tenon’s capsule injection of 20 mg of triamcinolone acetonide (TA). The un-injected eye served as a control. After TA injection, parafoveal thickness decreased significantly. During and after PRP, foveal thickening was suppressed, which prevented PRP-induced visual dysfunction. In control eyes, foveal thickness increased dramatically and reached 312.0±68.2 µm at 24 weeks, which compares to 235.3±38.6 µm at 24 weeks in TA-injected eyes. Best-corrected visual acuity in the control eye decreased with time to 0.24±0.13, compared to 0.085±0.11 in injected eyes.
Posted by kjalali at 01:47 AM | Comments (0)
March 21, 2006
The latest data on Epilasik
Eyeworld March 2006
One-year results from a cohort of 44 eyes (31 patients) that had Epi-LASIK are encouraging, said Dr. Pallikaris. All procedures were performed with the Centurion Epi-Edge epikeratome (Norwood Eyecare, Duluth, Ga.), The Allegretto excimer laser (Wavelight Laser Technologie AG, Erlangen, Germany) was used for all treatments.
At one year, 97% of patients had an uncorrected visual acuity (UCVA) of 20/25 or better, compared with 92% at that level at three months, said Dr. Pallikaris. The UCVA was 20/20 or better in 86% of patients. After a year, the patients also had an improvement in high- and low-contrast sensitivity.“Eighty-six percent of patients had an absolutely clear cornea, with no haze, and 14% had trace haze seen only in the slit lamp,” said Dr. Pallikaris. At three months, 56% of patients had clear corneas and 41% had only haze.The mean epithelial healing time in these patients was 4.86 days, with a range of three to five days.The mean logMAR UCVA on the day of reepithelialization was 0.19, with a range of 0.40 to 0.10. At three months, the mean spherical equivalent was –0.10 D, compared with 3.71 D pre-op.Patients in the study also recorded their pain level. In the first two hours post-op, 16% of patients had burning pain that required medication. Sixty-five percent of patients reported no pain and 19% said they had mild discomfort. By post-op day one, 26% of patients had mild discomfort. By post-op day three, all reports of pain were gone. One next step for Epi-LASIK is further follow-up with these study patients. In fact, Dr. Pallikaris has two-and-half-year results for some of them. “All signs show continued improvement,” he said.
Dr..
Posted by mehdi khanlari at 09:27 AM | Comments (0)
March 20, 2006
Happy New Year ( Nowruz Mobarak )
Posted by mmiraftab at 10:24 AM | Comments (0)
March 19, 2006
Suturing a tear of the anterior capsulorhexis
British Journal of Ophthalmology 2006;90:423-426
Continuous curvilinear capsulorhexis (CCC) with lens removal was done in five fresh cadaver eyes. The diameter of the CCC was measured with a calliper. Using the same calliper a tear of the CCC was created while opening the calliper’s arms. The distance between the calliper’s arms needed to tear the CCC was documented. Using 9-0 Ethilon 9011, CS 160-6 sutures in two eyes, 9-0 Prolene, D-8229, CTC-6L sutures in two eyes, and 10-0 Prolene, 9090, CTC-6 suture in one eye, the tears were sutured. A tear in the CCC was created again in the same way as the first tear. The distance between the calliper’s arms needed to tear the CCC was documented again.
Results: Suturing of the tear restored some of the strength/elasticity of the CCC. Better results were found while using the 9-0 Prolene, D-8229, CTC-6L sutures than with the two others sutures.
Conclusions: Suturing of a broken CCC can restore at least some of the strength/elasticity of the CCC. This can be important before intraocular lens (IOL) implantation for the safety of the implantation or after the implantation to ensure proper fixation of the IOL.
Posted by mmiraftab at 05:56 PM | Comments (0)
March 17, 2006
Recruitment halted on ESCRS study on antibiotic prophylaxis of endophthalmitis following clear beneficial result
Dublin, Ireland - March 13, 2006
The European Society of Cataract and Refractive Surgeons has terminated recruitment for their two year study of antibiotic prophylaxis of endophthalmitis following cataract surgery. Quarterly analysis of the figures to date by the study’s statisticians at the University of Strathclyde clearly indicates a beneficial treatment effect. In January 2006 the Data Monitoring Committee recommended that the study be unmasked and found the result to be so clear that they recommended to the Study Chairman that recruitment be halted.
The study has found that the risk of contracting endophthalmitis following phacoemulsification cataract surgery is significantly reduced by an intracameral injection of cefuroxime at the end of surgery. By the end of 2005 approximately 16,000 patients had been recruited to the study, 13,698 of which had completed follow-up. Of the 13,698 patients the incidence of endophthalmitis in those treatment groups not receiving cefuroxime prophylaxis (23 cases in 6862 patients) is almost five times as high as that observed in the group receiving treatment (5 cases in 6836 patients). As not all follow-up procedures have been completed it is possible that further cases of endophthalmitis may be reported, however it is not expected that this will alter the main conclusion.
Posted by mmiraftab at 07:13 PM | Comments (0)
March 15, 2006
Human Recombinant Erythropoietin and the Incidence of Retinopathy of Prematurity
Journal of American Association for Pediatric Ophthalmology and Strabismus February 2006,
Recombinant human erythropoietin (rhEPO) has been used for the treatment of anemia of prematurity, effectively decreasing blood transfusion requirements. However, it has also been found to have properties similar to vascular endothelial growth factor (VEGF), the major angiogenic factor implicated in the pathogenesis of retinopathy of prematurity (ROP). Conclusion: These findings represent the first use of multiple logistic regression to demonstrate rhEPO as an independent risk factor for ROP.
Posted by mehdi khanlari at 02:26 PM | Comments (0)
IMAGING THE RETINA BY EN FACE OPTICAL COHERENCE TOMOGRAPHY.
Retina. 26(2):129-136, February 2006.
To present the possibilities of a new system that combines optical coherence tomography (OCT) and confocal ophthalmoscopy, producing en face OCT images in patients with retinal diseases. A prototype OCT Ophthalmoscope (OTI, Toronto, Canada) was used to scan patients with retinal conditions. The system uses a super luminescent diode ([lambda] = 820 nm; [DELTA][lambda] = 20 nm) and currently scans at a rate of 2 frames per second. In each frame, the OCT Ophthalmoscope simultaneously produces a transversal OCT scan and a confocal image in the X/Y plane. Both images correspond pixel to pixel.Between January 2002 and August 2003, >800 patients with various retinal diseases were scanned with the OCT Ophthalmoscope. Illustrative cases with regularly seen macular diseases are presented, such as macular hole and central serous retinopathy.Conclusion: Current difficulties as well as future possibilities of this new en face OCT ophthalmoscope are discussed. By presenting normal and pathologic transversal OCT images made by a prototype OCT Ophthalmoscope, we show that it can provide information not available using conventional OCT imaging
Posted by mehdi khanlari at 02:06 PM | Comments (0)
March 11, 2006
Vision restoration therapy shows promise in stroke and brain trauma patients
INDUSTRY NEWS
During the annual meeting of the North American Neuro-Ophthalmology Society, NovaVision, Inc. announced that visual field enlargements gained from its Vision Restoration Therapy (VRT)have remained stable for at least three and a half years. The company says VRT is the first and only FDA-cleared therapy to improve visual field deficits caused by stroke and traumatic brain injury. The average therapy regimen takes six months, involving brief daily therapy sessions with a clinically configured field of visual stimuli on a VRT medical device patients use at home. VRT is based on the principle of neuroplasticity – the ability of partially damaged neurons in the brain to compensate for injury and adjust their activity in response to stimulation from the environment.
Posted by kjalali at 10:43 PM | Comments (0)
Two genes responsible for nearly 75 percent of AMD cases
Nature Genetics, March 5 2006
The same team of researchers that last year announced the identification of a single gene variant (Factor H) that increases the risk of developing AMD by at least threefold has now identified the role of a second gene, Factor B. Factor H encodes a protein that helps shut down an immune response against bacterial or viral infection, once the infection is eliminated. People with these inherited risk-increasing variations of Factor H are less able to control inflammation caused by infectious triggers, which may spark AMD later in life. As investigators looked for additional culprits they focused on genes in the same immune response pathway that contains Factor H. Their genetic analysis of 1,300 people quickly identified Factor B as the major modifier of the disease. These two genes explained nearly three out of four AMD cases: 74 percent of the subjects with AMD had either the Factor H or Factor B risk variant (or both), but no protective variants of either gene.
Posted by kjalali at 10:35 PM | Comments (0)
March 10, 2006
Ocular NSAIDs : A new option
Bromfenac was approved in Japan in May 2000 under
the trade name Bronuck for the treatment of blepharitis,
conjunctivitis, scleritis, and postoperative inflammation.
To date, more than 6 million patients have been treated with bromfenac in that country. The FDA approved the same formulation that was approved and used in Japan in March 2005 as the first nonsteroidal anti-inflammatory drug (NSAID) dosed b.i.d. for the treatment of ocular inflammation following cataract surgery. In January 2006, the FDA granted an expanded indication for bromfenac for the treatment of pain following cataract surgery.Since bromfenac’s initial marketing in Japan beginning in July 2000 to date, the drug has been used in more than 6 million patients, and there has been no reported case of serious systemic adverse events and only 14 cases of serious ocular adverse events (including three corneal erosions, three corneal perforations, four corneal ulcers, three conjunctival disorders, and one epithelial defect), an event rate of 0.00023%.
According to available data, it took 3.7 times less bromfenac than diclofenac, and 6.5 times less bromfenac than amfenac to inhibit the COX-2 enzyme.
In summary, bromfenac is a more powerful inhibitor of COX-2 than either diclofenac or nepafenac, and therefore more potent than either diclofenac or nepafenac.
Posted by mmiraftab at 01:06 PM | Comments (0)
NSAIDs and Delayed Healing
As these cases demonstrate, Nevanac applied directly to the stromal bed can impede epithelial healing and cause corneal haze. Interestingly, although Dr. Trattler prescribed Nevanac after surgery, Dr. Abad did not have patients use any type of NSAID drop during the postoperative period. Other surgeons, including Jeff Gold, MD,have described similar experiences with Nevanac when using it on the stromal bed.
Daniel Durrie, MD, and others have reported that they have not observed delayed epithelial healing after surface ablation. They used Nevanac after the placement of a contact lens for a short period of time (typically for 48 hours), and delays in epithelial healing had not occurred. The difference in epithelial healing with this switch in routine is interesting.
The following recommendations are based on our experience:
1. Avoid applying Nevanac to the stromal surface prior to placing a contact lens after surface ablation.
2. Limit the use of Nevanac to the first 48 hours after laser ablation when using the drug for the prevention of postoperative pain.
3. If a delay in epithelial healing occurs, make every effort to encourage its rapid resolution. Steps include stopping the topical NSAID and placing punctal plugs. Once the epithelium has healed, care must be taken to identify haze, which should receive aggressive treatment with topical steroids.
Continuing studies will provide ophthalmologists with a better understanding of the off-label use of Nevanac and its optimal application with laser vision correction procedures. In the mean time, surgeons should be aware of the delayed epithelial closure and postoperative haze associated with Nevanac when it is applied directly to the stromal bed.
Posted by mmiraftab at 12:58 PM | Comments (0)
Peer-Reviewed Literature:Is Cataract Surgery Associated With AMD?
Unfortunately, the literature on the association between cataract surgery and AMD is inconsistent. As both AMD and cataracts occur in the aged and potentially share risk factors, it is difficult to comment on a definitive relationship without well-designed, randomized, controlled trials. Only with such studies can ophthalmologists confidently conclude whether an association truly exists. In the meantime, physicians should advise patients that progressive AMD is a potential risk of cataract surgery and follow patients postoperatively for the development or progression of the disease.
Posted by mmiraftab at 12:54 PM | Comments (0)
Corneal Ulceration and Perforation With Ketorolac Tromethamine (Acular(R)) Use After PRK
Cornea. 25(2):232-234, February 2006
Purpose: To report a case of corneal ulceration and perforation after PRK connected with high doses of ketorolac tromethamine (Acular(R)).
Methods: A 31-year-old man presented 5 days after PRK in the left eye with corneal ulceration and perforation requiring penetrating keratoplasty. The patient admitted to using Acular(R) every hour, ciprofloxocin every hour, and prednisolone acetate 1% QID postoperatively.
Results: Laboratory tests, including corneal cultures, were normal. A diagnosis of corneal ulceration secondary to incorrect use of high-dose ketorolac tromethamine was made.
Conclusion: Judicious patient counseling is recommended when using topical NSAIDs in the setting of PRK.
Posted by mmiraftab at 12:51 PM | Comments (0)
Three Cases of Corneal Melting After Instillation of a New Nonsteroidal Anti-Inflammatory Drug
Cornea. 25(2):224-227, February 2006
Purpose: Three cases of corneal melting caused by a new nonsteroidal anti-inflammatory drug (NSAID), bromfenac sodium, are reported.
Case Reports: Case 1: A 58-year-old man with a history of bullous keratopathy caused by Fuchs' corneal dystrophy was treated for episcleritis with topical bromfenac sodium. After 15 days of treatment, melting (80% depth) was observed inferiorly in the paracentral cornea. Case 2: A 71-year-old man underwent uncomplicated pterygium surgery, followed by treatment with topical bromfenac sodium. After 40 days of treatment, a 60%-depth corneal melt occurred in the nasal limbus. Case 3: A 76-year-old woman had a suspected bacterial corneal ulcer that resolved with topical ofloxacin; however, after 5 days of treatment with topical bromfenac sodium, a perforation occurred in the inferonasal cornea.
Results: In all three cases, severe corneal melting was characterized by mild hyperemia, very faint infiltration, and mild pain. Conservative treatment, including the use of a bandage soft contact lens and/or antibiotics and lubrication, led to resolution in all cases.
Conclusions: A new NSAID, bromfenac sodium, can lead to severe corneal melting. These findings, together with similar previous reports concerning diclofenac sodium and ketorolac, suggest that careful observation is required when using topical NSAIDs in the treatment of corneal disease.
Posted by mmiraftab at 12:49 PM | Comments (0)
Mitomycin C Inhibits Recurrent Avellino Dystrophy After Phototherapeutic Keratectomy
Cornea. 25(2):220-223, February 2006
Purpose: To report 4 patients with Avellino corneal dystrophy (ACD) who were treated with 0.02% mitomycin C (MMC) during phototherapeutic keratectomy (PTK).
Methods: ACD was confirmed by polymorphism of the exon region in the BIGH3 gene using polymerase chain reaction followed by DNA sequencing analysis. Three patients with recurrent ACD and 1 patient with primary ACD underwent PTK. Intraoperative 0.02% MMC was applied topically with a soaked microsponge.
Results: There was no recurrence of ACD in the heterozygotes, but there were recurrences with best-corrected visual acuity of 20/30 in the 2 homozygotes.
Conclusion: Intraoperative use of topical 0.02% MMC in conjunction with PTK may prevent or delay the recurrence of ACD for at least for 1 year.
Posted by mmiraftab at 12:48 PM | Comments (0)
Efficacy of Commercially Available Topical Cyclosporine A 0.05% in the Treatment of Meibomian Gland Dysfunction
Cornea. 25(2):171-175, February 2006
Twenty-six patients completed the study. All patients were tested for ocular symptoms, lid margin vascularity, tarsal telangiectasis, meibomian gland inclusions, tear breakup time, and fluorescein staining. At the 3-month visit, the tCsA group showed a greater improvement in ocular symptoms than the placebo group, but this difference was not statistically significant. At the 3-month visit, several objective examination findings were statistically significantly (P < 0.05) improved in the tCsA group compared with the placebo group. These differences included lid margin vascular injection, tarsal telangiectasis, and fluorescein staining. The most significant finding (P = 0.001) was the greater decrease in the number of meibomian gland inclusions in the tCsA group compared with the placebo group.
Conclusions: Topical CsA may be helpful in the treatment of meibomian gland dysfunction (posterior blepharitis). Topical CsA did not induce an improvement in the symptoms, but it did decrease the number of meibomian gland inclusions in patients with meibomian gland dysfunction.
Posted by mmiraftab at 12:46 PM | Comments (0)
March 07, 2006
Blue-light-absorbing lenses and their effect on scotopic vision
Journal of Cataract & Refractive Surgery Volume 32, Issue 1 , January 2006, Pages 141-144
The transmission characteristics of conventional and AcrySof Natural IOL materials immersed in a balanced salt solution were examined to determine the differences in scotopic vision. The removal of the crystalline lens during cataract surgery and its effect on scotopic vision were also analyzed.
Results
When only considering the IOL properties, the AcrySof Natural lens decreased light entering the eye under scotopic by 14.6%, much lower than previously reported. Furthermore, when removal of the crystalline lens was taken into consideration, the AcrySof Natural material actually increased the amount of light entering the eye by 52% under these same conditions.
Conclusions
Previous discrepancies in the transmission characteristics of IOL materials have led to an underestimation of the performance of the AcrySof Natural material under scotopic conditions. Accounting for both transmission and the crystalline lens demonstrates an increase in light levels entering the eye with the AcrySof Natural material when compared to young phakic subjects.
Posted by mmiraftab at 06:22 PM | Comments (0)
Aberrations induced in wavefront-guided laser refractive surgery due to shifts between natural and dilated pupil center locations
Journal of Cataract & Refractive Surgery Volume 32, Issue 1 , January 2006, Pages 21-32
Shifts in pupil center were measured between dilated phenylephrine hydrochloride (Neo-Synephrine [2.5%]) and nonpharmacological mesopic conditions in 65 myopic eyes treated with wavefront-guided laser in situ keratomileusis (Technolas 217z, Bausch & Lomb). Each patient's preoperative and 6-month postoperative wave aberrations were measured over the dilated pupil. Aberrations theoretically induced by decentration of a wavefront-guided ablation were calculated and compared with those measured 6 months postoperatively (6.0 mm pupil).
Results
The mean magnitude of pupil center shift was 0.29 mm ± 0.141 (SD) and usually occurred in the inferonasal direction as the pupil dilated. Depending on the magnitude of shift, the fraction of the higher-order postoperative root-mean-square wavefront error that could be due theoretically to pupil center decentrations was highly variable (mean 0.26 ± 0.20 mm). There was little correlation between the calculated and 6-month postoperative wavefronts, most likely because pupil center decentrations are only 1 of several potential sources of postoperative aberrations.
Conclusions
Measuring aberrations over a Neo-Synephrine-dilated pupil and treating them over an undilated pupil typically resulted in a shift of the wavefront-guided ablation in the superotemporal direction and an induction of higher-order aberrations. Methods referencing the aberration measurement and treatment with respect to a fixed feature on the eye will reduce the potential for inducing aberrations due to shifts in pupil center.
Posted by mmiraftab at 06:19 PM | Comments (0)
March 04, 2006
TESTING INTRAVITREAL TOXICITY OF BEVACIZUMAB (AVASTIN)
RETINA
To evaluate the retinal toxicity of varying doses of bevacizumab when injected intravitreally in rabbits. Twelve New Zealand albino rabbits were used for this study and divided into four groups. Four concentrations of bevacizumab were prepared: 500 [mu]g/0.1 mL, 1.0 mg/0.1 mL, 2.5 mg/0.1 mL, and 5.0 mg/0.2 mL. Each concentration was injected intravitreally in one eye of each of three rabbits; 0.1 mL volume of sterile balanced saline solution was injected into the contralateral eyes. Slit-lamp and funduscopic examinations were performed and the animals were observed for 2 weeks for signs of infection, inflammation, or toxicity. A baseline electroretinogram (ERG) was performed before the drug treatment and at day 14 before the animals were killed. The enucleated eyes were prepared for histologic evaluation of retinal toxicity. Histologic and ERG results in all groups showed no retinal toxicity. However, some inflammatory cells were found in the vitreous at the 5-mg dose. So, intravitreal bevacizumab did not appear toxic to the retina in albino rabbits at a concentration of 2.5 mg.
Posted by kjalali at 11:57 PM | Comments (0)
ELECTROPHYSIOLOGIC FINDINGS AFTER INTRAVITREAL BEVACIZUMAB (AVASTIN) TREATMENT
RETINA
To evaluate the short-term electrophysiologic effects of intravitreal bevacizumab in the treatment of exudative age-related macular degeneration (AMD), nine subjects with AMD who received treatment with intravitreal bevacizumab for exudative AMD underwent pre-treatment and post-treatment testing with multifocal electroretinography (mf-ERG) or Ganzfeld electroretinography (G-ERG). In this study, the intravitreal use of bevacizumab resulted in improvement of mf-ERG macular function responses and relatively stable G-ERG responses. The macular electrophysiologic response suggests that macular function improves with treatment. G-ERG suggests that there is no significant measurable photoreceptor toxicity with the use of intravitreal bevacizumab over the short term.
Posted by kjalali at 11:51 PM | Comments (0)
INTRAVITREAL BEVACIZUMAB (AVASTIN) TREATMENT OF PROLIFERATIVE DIABETIC RETINOPATHY COMPLICATED BY VITREOUS HEMORRHAGE
RETINA
To report the short-term anatomic and visual acuity response after intravitreal injection of bevacizumab (Avastin, Genentech) in patients with proliferative diabetic retinopathy complicated by vitreous hemorrhage, two patients with vitreous hemorrhage due to proliferative diabetic retinopathy were treated with at least one intravitreal injection of bevacizumab 1.25 mg in 0.05 mL. The patients underwent Snellen visual acuity testing, ophthalmoscopic examination, and fluorescein angiography at baseline and follow-up visits. Initial treatment results of patients with vitreous hemorrhage and proliferative diabetic retinopathy did not reveal any short-term safety concerns. Intravitreal bevacizumab resulted in marked regression of neovascularization and rapid resolution of vitreous hemorrhage. The favorable short-term results suggest further study is needed in a larger group of patients.
Posted by kjalali at 11:47 PM | Comments (0)
INTRAVITREAL BEVACIZUMAB (AVASTIN) TREATMENT OF MACULAR EDEMA IN CENTRAL RETINAL VEIN OCCLUSION
RETINA
To report the short term anatomic and visual acuity response after intravitreal injection of bevacizumab (Avastin, Genentech) in patients with macular edema due to central retinal vein occlusion (CRVO), a retrospective study of patients with macular edema due to CRVO who were treated with at least one intravitreal injection of bevacizumab 1.25 mg in 0.05 mL. Patients underwent Snellen visual acuity testing, optical coherence tomography (OCT) imaging, and ophthalmoscopic examination at baseline and follow-up visits.The results suggest that initial treatment results of patients with macular edema secondary to CRVO did not reveal any short-term safety concerns. Intravitreal bevacizumab resulted in a significant decrease in macular edema and improvement in visual acuity. The number of patients in this pilot study was limited and the follow-up is too short to make any specific treatment recommendations, but the favorable short-term results suggest further study is needed.
Posted by kjalali at 11:42 PM | Comments (0)
RADIAL OPTIC NEUROTOMY WITH ADJUNCTIVE INTRAOCULAR TRIAMCINOLONE FOR CENTRAL RETINAL VEIN OCCLUSION
RETINA
Pars plana vitrectomy and RON were performed on a case-by-case basis on 63 consecutive patients with CRVO and visual acuity of 20/200 or worse. At the end of the case, 4 mg of triamcinolone was injected into the vitreous cavity (RON/IOK). Patients were observed with serial fundus photographs, fluorescein angiography (FA), Snellen visual acuity (VA), intraocular pressures (IOP), and biomicroscopy for anterior segment neovascularization (ANV). Anatomic and visual outcomes were compared to a previous series of 117 patients with severe CRVO undergoing RON alone. Clinical improvement as determined by fundus examination, photography, and FA was noted in 93% of patients following RON/IOK. Snellen VA improved by an average of three lines (range one to seven) in 68% of all patients. Two or more lines were gained in 44% of patients and four or more lines were gained in 20% of patients. ANV developed in 7% of patients following RON/IOK. Persistent CME and MP were noted in 17% and 28% of patients, respectively. These outcomes were similar to patients undergoing RON alone without IOK. Elevated IOP was noted in 25% of patients and one patient developed endophthalmitis following RON/IOK. So, surgical decompression of CRVO via RON/IOK is a technically feasible procedure. Clinical resolution of the CRVO and improved visual function noted in RON/IOK paralleled outcomes following RON alone. RON/IOK was associated with a higher incidence of elevated IOP and endophthalmitis.
Posted by kjalali at 11:39 PM | Comments (0)
ONE-YEAR RESULTS OF A PILOT STUDY USING ORAL 13-CIS RETINOIC ACID AS A TREATMENT FOR SUBFOVEAL PREDOMINANTLY OCCULT CHOROIDAL NEOVASCULARIZATION IN PATIENTS WITH AGE-RELATED MACULAR DEGENERATION
RETINA
To evaluate the safety and evidence of efficacy for oral 13-cis retinoic acid as a treatment for patients with subfoveal occult choroidal neovascularization (CNV) due to age-related macular degeneration (ARMD), patients with active, subfoveal occult CNV with no prior treatment of the subfoveal component were eligible for inclusion. Patients received 40 mg of 13-cis retinoic acid twice daily for 5 months, stopped treatment for 2 months, and then resumed treatment for 5 months. Eleven patients, aged 64 to 88 years, were enrolled and followed for 1 year. Based on the results, oral 13-cis retinoic acid is too toxic to be useful in patients with ARMD. Oral 13-cis retinoic acid did not improve vision although it may have slowed visual acuity loss in patients with ARMD with occult subfoveal CNV.
Posted by kjalali at 11:34 PM | Comments (0)
RETINAL DAMAGE CAUSED BY AIR-FLUID EXCHANGE DURING PARS PLANA VITRECTOMY
RETINA
To report two cases of retinal damage associated with air infusion during pars plana vitrectomy, the course of two patients who had retinal damage during par plana vitrectomy and air-fluid exchange for the treatment of macular hole and optic pit-related macular detachment had reviewed. As a result of high air infusion flow during air-fluid exchange, retinal damage was created in the area contralateral to the infusion port. In Case 1, an oval area of whitening was noted on the first postoperative day. This area subsequently developed into a large retinal break associated with retinal detachment. In the second case, retinal whitening was noted intraoperatively. This region of pallor resolved quickly during the early postoperative period but resulted in a corresponding inferotemporal visual field defect. High infusion flow during air-fluid exchange in eyes undergoing vitrectomy surgery may result in significant retinal damage. This pressure-induced trauma initially causes retinal whitening that may be seen intraoperatively or during the early postoperative period. The region of damaged retina may develop a retinal break and detachment or a corresponding visual field defect.
Posted by kjalali at 11:28 PM | Comments (0)
INTRAVITREAL TOXICITY OF THE KENALOG VEHICLE (BENZYL ALCOHOL) IN RABBITS
RETINA
To test the toxicity of intravitreal injections of benzyl alcohol, nine New Zealand rabbits were injected with either a control or a test article at elevating concentrations. Eyes injected with benzyl alcohol concentrations of 0.073%, 0.222%, and 0.733% displayed changes in the outer retina including loss of, and shortening of, outer segments and photoreceptors, so, benzyl alcohol at concentrations modestly higher than what is present in commercial Kenalog is toxic to the rabbit eye. This has been shown in other organ systems. If commercial preserved Kenalog is to be used clinically, decanting the supernatant or using other means to remove the benzyl alcohol may be considered, especially if a volume of >0.1 mL of solution is used and the noninfectious inflammation seen clinically after Kenalog injection is due to the presence of a toxic preservative at unsafe concentrations.
Posted by kjalali at 11:20 PM | Comments (0)
Short interfering RNA drug shows early promise in retinal disease studies
OSN
A new type of drug technology has shown promising early results for the treatment of both age-related macular degeneration and diabetic macular edema. If we can inhibit messenger RNA inside the cell from releasing the VEGF into the vitreous, we can then perhaps decrease this vascular permeability molecule and vascular endothelial growth factor and decrease neovascularization and leakage. An important finding of the phase 1 safety trial of the drug for AMD was that no evidence of short interfering RNA circulating in the circulating blood was found.
Posted by kjalali at 11:10 PM | Comments (0)
Contact Lens Suturing for Prevention of Flap Displacement During Retinal Detachment in LASIK Patients
Specialty News and Views: Refractive Management/Intervention - February 2006
A team of Spanish researchers at Hospital Príncipe de Asturias in Madrid recently devised a surgical maneuver that successfully preserved optimal fundus visualization and ocular motility in laser in situ keratomileusis (LASIK) patients during retinal detachment (RD) surgery. The technique involves the intraoperative use of a contact lens during a vitreoretinal procedure.
After dissecting the conjunctiva, Lopez and colleagues placed a 14.5 mm diameter plano soft contact lens in its normal position and secured it with sutures in such a way as to prevent wrinkling in the contact lens. A drop of viscoelastic was added to the interface to avoid air bubble collection. The researchers then continued the normal vitreoretinal procedure, removing the contact lens at the end.
Posted by mriazi at 09:29 AM | Comments (0)
Posterior Sub–Tenon’s Capsule Injection of Triamcinolone Acetonide Prevents Panretinal Photocoagulation-Induced Visual Dysfunction in Patients with Severe Diabetic Retinopathy and Good Vision
Ophthalmology
Volume 113, Issue 3 , March 2006
Methods
In all patients, PRP was performed every other week for 4 sessions on both eyes, and 1 week before PRP; 1 eye received the TA injection, and the other eye served as a control. The clinical course of BCVA and FT was monitored for up to 24 weeks after beginning PRP.
Results
Before TA injection, BCVA and FT were 0.055±0.072 and 235.5±37.5 μm in the TA-injected eye and 0.065±0.071 and 233.7±39.8 μm in the control eye, respectively; there was no significant difference between eyes. After the TA injection, FT in the TA-injected eyes was significantly decreased. During and after the PRP, FT in the control eye increased dramatically and reached 312.0±68.2 μm at 24 weeks, which was significantly different from that in the TA-injected eyes (235.3±38.6 μm at 24 weeks). Best-corrected visual acuity in the control eye decreased with time to 0.24±0.13; in contrast, and BCVA in the TA-injected eye was good (to 0.085±0.11) .
Conclusions
As a pretreatment for PRP, a single sub–Tenon’s capsule injection of TA has beneficial effects for preventing PRP-induced foveal thickening and visual dysfunction in patients with severe diabetic retinopathy and good vision.
Posted by mriazi at 09:18 AM | Comments (0)
Intravitreal Bevacizumab (Avastin) for Neovascular Age-Related Macular Degeneration
Ophthalmology
Volume 113, Issue 3 , March 2006
Methods
Patients received intravitreal bevacizumab (1.25 mg) on a monthly basis until macular edema, subretinal fluid (SRF), and/or pigment epithelial detachment (PED) resolved. Ophthalmic evaluations included nonstandardized Snellen visual acuity (VA), complete ophthalmic examination, fluorescein angiography, and optical coherence tomography (OCT).
Main Outcome Measures
Assessments of safety, changes in Snellen VA, OCT retinal thickness, and angiographic lesion characteristics were performed.
Results
No significant ocular or systemic side effects were observed. Most patients (55%) had a reduction of >10% of baseline retinal thickness at 1 week after the injection. At 4 weeks after injection, 30 of 81 eyes demonstrated complete resolution of retinal edema, SRF, and PEDs. Of the 51 eyes with 8 weeks’ follow-up, 25 had complete resolution of retinal thickening, SRF, and PEDs. At 1, 4, 8,and 12 weeks, the mean retinal thickness of the central 1 mm was decreased by 61, 92, 89, and 67 μm, respectively (P<0.0001 for 1, 4, and 8 weeks and P<0.01 for 12 weeks). At 4 and 8 weeks, mean VA improved from 20/200 to 20/125 (P<0.0001). Median vision improved from 20/200 to 20/80− at 4 weeks and from 20/200 to 20/80 at 8 weeks.
Conclusions
Short-term results suggest that intravitreal bevacizumab (1.25 mg) is well tolerated and associated with improvement in VA, decreased retinal thickness by OCT, and reduction in angiographic leakage in most patients, the majority of whom had previous treatment with photodynamic therapy and/or pegaptanib. Further evaluation of intravitreal bevacizumab for the treatment of choroidal neovascularization is warranted.
Posted by mriazi at 09:06 AM | Comments (0)
Early Optical Coherence Tomography Changes After Photodynamic Therapy in Patients With Age-Related Macular Degeneration
American Journal of Ophthalmology
Volume 141, Issue 3
To evaluate early changes after photodynamic therapy (PDT) in patients with age-related macular degeneration (AMD) by optical coherence tomography (OCT).
Design
Prospective interventional case series.
Methods
PDT was performed on 20 eyes of 20 patients who presented with subfoveal choroidal neovascularization (CNV) attributable to AMD. OCT was used to evaluate changes at 2, 12, and 24 hours and at 3, 7, 15, and 30 days after therapy.
Results
In the first 24 hours, OCT showed an increase in the subretinal fluid (SF) in all eyes and an increase in intraretinal fluid (IF) in 13 eyes. On the 15th day and the 30th day after therapy, reduction of SF and IF was observed in almost all eyes.
Conclusions
Serial OCT evaluation of patients with subfoveal CNV attributable to AMD suggests that the initial response after PDT is an increase in SF and IF.
Posted by mriazi at 09:03 AM | Comments (0)
March 02, 2006
Contact lens overrefraction variability in corneal power estimation after refractive surgery
JCRS Pages 2287-2292 (December 2005)
USA.To evaluate the accuracy and precision of the contact lens overrefraction (CLO) method in determining corneal refractive power in post-refractive-surgery eyes.
14 of 7 subjects who had a single M LASIK.CLO was compared with the historical method of predicting the corneal power using 4 different lens fitting strategies and 3 refractive pupil scan sizes (3 mm, 5 mm, and total pupil). Rigid lenses included 3- 9.0 mm CL fit (flat, medium,steep fit). Cycloplegic CLO was performed using the autorefractor function of the Nidek OPD-Scan ARK-10000. Results with each strategy were compared with the corneal power estimated with the historical method. The bias (mean of the difference), 95% limits of agreement, and difference versus mean plots for each strategy are presented.
Results
In each subject, the CLO-estimated corneal power varied based on lens fit. On average, the bias between CLO and historical methods ranged from −0.38 to +2.42 diopters (D) and was significantly different from 0 in all but 3 strategies. Substantial variability in precision existed between fitting strategies, with the range of the 95% limits of agreement approximating 0.50 D in 2 strategies and 2.59 D in the worst-case scenario. The least precise fitting strategy was use of flat-fitting 9.0 mm diameter lenses.
Conclusions
The accuracy and precision of the CLO method of estimating corneal power in post-refractive-surgery eyes was highly variable on the basis of how rigid lense were fit. One of the most commonly used fitting strategies in clinical practice—flat-fitting a 9.0 diameter lens—resulted in the poorest accuracy and precision. Results also suggest use of large-diameter lenses may improve outcomes.
Posted by alireza habibollahi at 09:28 PM | Comments (0)
LASIK in patients with corneal guttata and family history of Fuchs' endothelial dystrophy
JCRS Pages 2281-2286 (December 2005)
USA,To report 1-year results of LASIK in 7 eyes with corneal endothelial guttata and a family history of Fuchs' endothelial dystrophy.7 eyes who had trace to 1+endothelial guttata and a family history of Fuchs dystrophy and then had uneventful LASIK for the correction of myopia and myopic astigmatism. Preop and postop UCVA,BSCVA, corneal pachymetry, endothelial cell density (ECD), MRSE, and SE. The changes in ECD, pachymetry, and SE after LASIK were subjected to statistical analysis using a paired Student t test to determine significance.
Results
Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost ≥2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% was observed at 1 year compared with baseline ,An increase in corneal thickness and a statistically significant myopic shift in spherical equivalent was also noted at 1 year compared with 3 months.Conclusions
Patients with mild corneal guttata and a family history of Fuchs' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism.
Posted by alireza habibollahi at 09:18 PM | Comments (0)
Influence of pupil and optical zone diameter on higher-order aberrations after wavefront-guided myopic LASIK
JCRS Pages 2272-2280 (December 2005)
To investigate the influence of pupil and optical zone (OZ) diameter on higher-order aberrations (HOAs) after myopic wavefront-guided LASIK.
Methods
27 eyes of 19 patients.The mean preop SE −6.86 D;mean OZ diameter was 6.26 mm .patients had wavefront-guided LASIK (Zyoptix version 3.1) and F/U 12 months. Wavefront measurements were performed with a Hartmann-Shack sensor in maximum mydriasis preoperatively and 12 months after LASIK. Wavefront errors were computed for pupil diameters (PDs) of 3.0, 3.5, 4.0, 5.0, 6.0, and 7.0 mm for the individual OZ diameter and for the individual mydriatic PD (7.93 mm). The impact of the relationship between pupil diameter and OZ diameter (fractional clearance [FC]) on HOA was described and quantified using curvilinear regression with a 4th-order polynomial fit.
Results
There was a reproducible relationship between FC and the amount of induced HOA. The change in HOA root mean square and primary spherical aberration (Z40) was significantly correlated with FC. If the OZ was 16.5% larger than the pupil (FC = 1.17), only half the amount of HOA was expected to be induced than if the OZ equaled the pupil. In contrast, an OZ that was 9% smaller than the pupil (FC = 0.91) resulted in an HOA induction 50% higher than at FC = 1.
Conclusion
The OZ zone to pupil ratio (fractional clearance) had a significant impact on HOA induction after wavefront-guided LASIK.
Posted by alireza habibollahi at 08:48 PM | Comments (0)
Secondary Artisan–Verysise aphakic lens implantation
JCRS Pages 2266-2271 (December 2005)
Spain,To evaluate efficacy, predictability and safety of Artisan–Verysise intraocular lens (IOL) secondary implantation for aphakia correction.
UCVA,BCVA.MRSE,endothelial cell count, and clinical complications were evaluated. Sixteen consecutive eyes of 14 patients with aphakia were submitted to surgery. Postoperative examinations were done at 6 weeks, 6 months, 1 year, and every year for at least 3 years. An iris-supported Artisan–Verysise IOL was implanted for aphakia correction.
Results
Thirty-six months after Artisan–Verysise lens implantation, BSCVA was 20/40 or better in 6 eyes (37.5%). Preoperatively, 5 eyes had the same BSCVA (31.25%). Mean postoperative SE was 0.46 diopter D. Mean endothelial cell loss was 10.9% 36 months postoperatively. The cell loss occurred predominantly during the first year (7.78%). Cystoid macular edema was observed in 2 cases, 1 of them associated with chronic unresponsive low intraocular pressure. No other serious complications were observed.
Conclusion ;
Artisan–Verysise IOL implantation seems a safe, predictable, and effective option for aphakic eyes without capsule support.
Posted by alireza habibollahi at 08:39 PM | Comments (0)
Limbal relaxing incisions versus on-axis incisions to reduce corneal astigmatism at the time of cataract surgery
JCRS 2261-2265 (December 2005)
Australia , To compare LRIs with placement of the corneal cataract incision on the steepest keratometric axis for the reduction of preexisting corneal astigmatism at the time of cataract surgery.
patients having 1.5 D or more of keratometric astigmatism were randomly assigned to 2 surgical techniques: on-axis incisions (OAIs) consisting of a single clear corneal cataract incision centered on the steepest corneal meridian or LRIs consisting of 2 arcuate incisions straddling the steepest corneal meridian and a temporal clear corneal incision. Vector analysis of the target axis flattening effect was used to assess the efficacy of treatment.G
Results
Seventy-one eyes of 71 patients were evaluated, 33 in the OAI group and 38 in the LRI group. Six weeks postoperatively, the flattening effect was 0.41 D (median and interquartile range 0.15 to 0.78 D) in the OAI group and 1.21 D (range 0.43 to 2.25 D) in the LRI group (P = .002). After 6 months, the flattening effect was 0.35 D (range 0.00 to 0.96 D) and 1.10 D (range 0.25 to 1.79 D), respectively (P = .004).
Conclusion
The amount of astigmatism reduction achieved at the intended meridian was significantly more favorable with the LRI technique, which remained consistent throughout the follow-up period.
.
Methods
Posted by alireza habibollahi at 08:15 PM | Comments (0)