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July 31, 2004
Surgeons Share Their Preferences in ASCRS Survey
Review Of Ophthalmology
At this year’s meeting of the American Society of Cataract and Refractive Surgery in San Diego the survey was mailed to 6,350 physicians, and about 16 percent (985 surgeons) responded.The survey also showed that surgeons may be less likely to use LASIK for higher levels of correction, possibly because they’re waiting for final approval of phakic lenses. For a -12 D patient, 13 percent (down from 22 percent in 2002) say they would use LASIK, and 33 percent (up from 15 percent the previous year) would choose a phakic lens. Thirty-nine percent would wait, 8 percent would perform clear lens extraction, three percent like LASEK and only 2 percent would choose PRK. In a large, catch-all question, the survey asked surgeons which refractive procedures they were either doing or planned to do,. The procedures that seem to be fading and the percentage of respondents who are doing them or plan to start are radial keratotomy (12 percent), laser thermokeratoplasty (7 percent), Intacs (19 percent, though this is an increase from last year’s 13 percent) and scleral expansion for presbyopia (14 percent).The hottest procedures are clear-lens extraction/intraocular lens implantation (85 percent are doing it or plan to, which is up from 73 percent in 2002), LASIK (84 percent, up from 69 percent last year), phakic IOLs (79 percent, compared to 64 percent in 2002) and PRK (77 percent, up from just 58 percent in 2002).On the cataract surgery side, some findings included: • For anesthesia, 61 percent use topical, 11 percent use retrobulbar without facial block and 17 percent use peribulbar anesthesia. Around 2 percent use blunt subtenon’s injection. Seventy-three percent use intracameral lidocaine when they administer topical anesthesi• The IOLMaster is gradually gaining surgeons’ interest, with 27 percent saying they use it for preop biometry, compared to 21 percent the previous year. Sixty-one percent of the surgeons say they use applanation tonometry (down from 70 percent last year) and 12 percent use immersion A-scan.
Posted by mehdi khanlari at 11:57 PM
Treating Flap Complications with MMC
Review of Ophthalmology
Based on the successful use of MMC to treat haze after PRK, my(Dr. Majmudar) colleagues and I decided to test the theory that PRK with adjunctive use of MMC to prevent corneal haze might be a better option than a second attempt at LASIK in these cases.The technique can also be in combination with PTK for buttonholed flaps that develop fibrosis or scarring. In a recent study (in press), we evaluated transepithelial phototherapeutic keratectomy/photorefractive keratectomy (PTK/PRK) with prophylactic MMC following flap complications in LASIK.The study looked at 10 eyes of 10 patients who sustained LASIK flap complications and underwent transepithelial PTK/PRK for correction of ametropia. The mean preoperative UCVA was 20/400 (range 20/40-counting fingers), mean preoperative BSCVA was 20/28.5, and spherical equivalent of refractive errors ranged from +4 to -10.75 D. Following laser ablation, we applied MMC 0.02% to the stroma for two minutes. After the procedure, the mean UCVA was 20/28, the mean BSCVA was 20/21 and spherical equivalent refractive errors ranged from +0.375 to -1 D. The mean follow up time ranged from eight to 28 months. No patients experienced delayed re-epithelialization, haze or other signs of toxicity.Another group recently reported successful use of PRK with MMC to manage a LASIK flap complication after penetrating keratoplasty. The patient developed a buttonhole secondary to an attempted LASIK in an eye that had undergone prior PKP for keratoconus. Three months after the PRK/MMC procedure, the patient demonstrated a clear cornea and a BCVA of 20/20.
The keys to success with MMC include proper patient selection, a thorough informed consent discussion, and meticulous attention to the established protocol.
Posted by mehdi khanlari at 11:29 PM
A New Femtosecond Laser Arrives
Review of Ophthalmology
The Intralase Pulsion’s stint as the only femtosecond laser available for making LASIK flaps may be over, at least in Europe and Asia. Another company, 20/10 Perfect Vision (Heidelberg, Germany), maker of Visx’s WaveScan aberrometer, is throwing its hat in the flapmaking ring with the Femtec laser. Though some of the principles behind the Femtec’s operation are the same as the Pulsion’s, there are some differences as well. Here’s an early look at the new device.The salient feature of the Femtec is where the machine meets the eye. Rather than attaching to the eye with high vacuum, the laser has a curved interface that’s fixed on the cornea at low vacuum levels, so the intraocular pressure remains below 26 mmHg, sparing the patient from blacking out in the operative eye or feeling pain. With a microkeratome, you may get a flap that’s thin in the middle and thicker in the periphery, but a curved interface gives an even thickness throughout the flap.”The Femtec lays down its energy in a circular pattern from the outside of the flap to the inside, and the surgeon can set parameters for depth, angle, and hinge position and width. The minimum flap thickness possible is90 µm.
Posted by mehdi khanlari at 10:44 PM
Bimanual pearls
Eyeworld July 2004
Those interested in learning bimanual microincision phacoemulsification should heed these suggestions, said Eric D. Donnenfeld, M.D.
- Raise your irrigation bottle to get more flow
- Use a large bore irrigation cannula and a vacuum of 300 mm Hg, which is low so you don’t get chamber shallowing;
- Place incisions at 10 o’clock and 2 o’clock
- Use a 1.2-mm MVR blade
- Use a perpendicular incision to prevent oral locking
- Create a new incision for the IOL
- Perform capsulorhexis through a 1.2-mm incision in a normal way
- Perform hydrodissection in a normal way; and
Posted by mehdi khanlari at 12:45 PM
Epithelial abrasions can be serious complications
Eyeworld July 2004
Central epithelial abrasions can be serious complications, as they are associated with heightened risk of DLK, epithelial ingrowth, and delayed visual recovery. During LASIK, if an abrasion occurs in one eye, there is an increased risk that it also will occur in the second eye. And performing surgery on the second eye without discussing the increased risks to the second eye — and LASIK alternatives — could be considered deviation from the standard of care if the patient suffers bilateral complications and the case goes to court. So if an abrasion occurs in the first eye, defer LASIK on the second eye and allow the first eye to heal. Then practitioners should re-evaluate the second eye, discuss the situation with the patient, and together decide on the best procedure — either LASIK or PRK. This is the best option for both the patient and the surgeon.
Posted by mehdi khanlari at 12:33 PM
July 27, 2004
A Portable Microkeratome for Harvesting the Human Anterior Corneal Surface.
Cornea,July 2004
A portable, gas-driven turbine microkeratome device capable of harvesting the entire anterior corneal surface for lamellar transplantation on human donor globes was evaluated. The device consisted of a modified LASIK microkeratome with an enlarged suction ring, head, and blade. Vacuum was achieved by a simple hand pump. Lamellar keratectomy was performed on 5 fresh human donor globes. Lenticule dimensions were measured on days 0, 3, 6, and 9 after storage in preservation media at 4[degrees]C. On day 0, the obtained lenticules were 13.9 +/- 0.9 mm and 13.5 +/- 0.4 mm, vertical and horizontal diameters, respectively. The average central lenticule thickness was 152.2 +/- 52 [mu]m. Each lenticule was uniform in thickness over 5 measurement points (P = 0.74). Repeat measurements of corneal thickness over the 9 days showed no statistically significant difference (P = 0.51). This device proves to be an economical alternative to electric-powered systems for the harvest of transplantable corneal sections.
Posted by shebadollahi at 08:10 PM
Corneal and Conjunctival Changes Caused by Commonly Used Glaucoma Medications.
Cornea,July 2004
Thirty eyes of 15 New Zealand white rabbits were randomized to 1 of 6 treatment groups: artificial tears BID, brimonidine Purite(R) 0.15% BID, bimatoprost 0.03% QD, dorzolamide 2% BID, timolol maleate 0.5% BID, or latanoprost 0.005% QD for 30 days. Corneal damage was evaluated by scanning electron microscopy and graded on a standard scale by a masked observer. Conjunctival inflammation was evaluated with light microscopy, and inflammatory cells were counted in the epithelium and superficial and deep stroma by a masked observer according to a standard protocol.
In the cornea, artificial tears produced significantly less damage than dorzolamide or latanoprost and brimonidine Purite(R) produced significantly less damage than dorzolamide, timolol, or latanoprost. In the conjunctiva, the number of inflammatory cells in the epithelium was significantly lower in eyes treated with artificial tears or brimonidine Purite(R) than in eyes treated with timolol or latanoprost .
Conclusions: Although the adverse effects of glaucoma medications on the ocular surface are likely multifactorial, 1-month treatment with glaucoma medications containing higher levels of benzalkonium chloride (BAK) resulted in greater corneal damage and conjunctival cell infiltration than medications preserved with Purite(R) or with lower levels of BAK.
Posted by shebadollahi at 07:37 PM
Relationship between anterior capsule contraction and posterior capsule opacification after cataract surgery in patients with diabetes mellitus
JCRS JULY 2004
JAPAN.In all eyes, the anterior capsule opening area and degree of PCO were determined by diaphanoscopy using an anterior eye segment analysis system (EAS-100, Nidek, Inc.) 1 day and 1 year postoperatively.Contraction of the anterior capsule opening and PCO after cataract surgery cannot be explained by a common mechanism.
Posted by alireza habibollahi at 04:31 PM
Relationship between anterior capsule contraction and posterior capsule opacification after cataract surgery in patients with diabetes mellitus
JCRS JULY 2004
JAPAN.In all eyes, the anterior capsule opening area and degree of PCO were determined by diaphanoscopy using an anterior eye segment analysis system (EAS-100, Nidek, Inc.) 1 day and 1 year postoperatively.Contraction of the anterior capsule opening and PCO after cataract surgery cannot be explained by a common mechanism.
Posted by alireza habibollahi at 04:31 PM
Milling trabeculoplasty for nonpenetrating glaucoma surgery
JCRS JULY 2004
Spain,To describe the use of a motorized milling drill to perform nonpenetrating glaucoma surgery and to assess its safety. This prospective noncomparative study included 16 eyes (13 patients) diagnosed with primary open-angle glaucoma. The eyes were divided into 2 groups. Group 1 (8 eyes) had a milling procedure, and Group 2 (8 eyes) had combined phacoemulsification and milling. A fornix-based conjunctival flap was created, and then the milling procedure was performed using a notched hemispherical metallic tip. Evolution of intraocular pressure (IOP), visual outcomes, and the development of intraoperative and postoperative complications were evaluated. Conclusion: The motorized milling drill can be safely used to mill and refine the remaining scleral thickness, eliminating the rupture of trabeculo-Descemet's membrane.
Posted by alireza habibollahi at 04:26 PM
Retinal thickness measurement after phaco
JCRS JULY 2004
USA,To measure macular thickness using the Retinal Thickness Analyzer (RTA) (Talia Technologies, Ltd.) before and after routine phaco Conclusions:Measurements by the RTA indicate that the decrease in macular thickness indices in surgical eyes from before surgery to 6 weeks after routine phacoemulsification is an artifact of imaging the retina through hazy media. Therefore, the results must be interpreted in the context of the clinical situation.
Posted by alireza habibollahi at 04:17 PM
Neodymium:YAG laser posterior capsulotomy after implantation of AcrySof
JCRS JULY 2004
USA,incidence of Nd:YAG laser posterior capsulotomy after phaco and implantation of AcrySof IOLs,An Nd:YAG laser posterior capsulotomy was performed in 6.1% of the 12419 cases. The incidence of posterior capsulotomy was approximately 1% at 1 year, increasing in linear fashion by approximately 1% to 2% per year. Conclusions: The Nd:YAG laser posterior capsulotomy rate after implantation of AcrySof IOLs was relatively low; the cumulative rate was approximately 1% to 2% new cases per year over a 7-year period, with a plateau suggested at year 6.
Posted by alireza habibollahi at 04:11 PM
July 24, 2004
Stereopsis in bilaterally pseudophakic patients
JCRS JULY 2004
Japan,To investigate the stereoacuity in patients who have had implantation of a monofocal(IOL) in each eye and to identify the principal risk factors for impaired stereoacuity.
Near stereoacuity was measured approximately 2 weeks after surgery using the Titmus test. Various parameters that may be associated with stereoacuity in pseudophakic patients were measured using the New Aniseikonia Test (Handaya Corp.). Parameters included age, visual acuity, spherical equivalent, astigmatism, axial length, pupil diameters, IOL decentration and tilt, and aniseikonia. Stepwise multiple regression analysis was performed to identify independent predictors of impaired stereoacuity. Conclusions:90% of patients with bilateral pseudophakia had useful stereoacuity. The main risk factor for poor stereoacuity was a greater difference in the spherical equivalent between the eyes, followed by older age and a larger pupil diameter. These results indicate the need for an accurate preoperative IOL power calculation.
Posted by alireza habibollahi at 10:59 PM
Where is Lid Weight Better Placed?
Review of Ophthalmology,July,2004
Oculoplastic surgeons in Oregon suggest reanimating the paretic eyelid by insertion of a gold weight in the orbit rather than in a pretarsal pocket. A review of 59 patient charts over a 10-year period reveals this method to be an excellent means of prevention of the unfortunate sequelae of exposure keratopathy, they say.A single surgeon used a 2.2-g gold weight implant in each case, with no wrapping materials. The ages of the 59 patients ranged from 15 to 92 years. No patients in the study group were Asian. .In this series of patients, the surgeons found that the septum, orbicularis muscle and skin combined provided an adequate barrier to extrusion of the gold weight. They note their technique of a standard weight placed intraorbitally makes preop weight selection and intraoperative implant-wrapping unnecessary. The intraorbital location reduces the potentially unsightly bulk effect over the tarsus.None of their patients had inflammation or infection from the implant. Only two patients suffered complications (both with confounding factors including previous surgeries). One had shifting of the gold weight, which was repositioned; the other had extrusion of the gold weight that required removal.The surgeons believe that their technique of placing the implant in an intraorbital space attached to the levator aponeurosis provides excellent results without complication in standard lagophthalmos cases.
Posted by afarahi at 01:21 PM
July 23, 2004
Smoking: The universal risk factor
OCULAR SURGERY NEWS 7/15/2004
Smoking is not only a cause of diseases of the heart and lungs, it is also a trigger for the development of age-related macular degeneration and cataract and is associated with increased risk for other major ocular diseases.
Although the exact mechanisms of damage are unknown, it is thought that smoking may increase the number of free radicals in the blood, molecules that are capable of corroding tissue in the macula and elsewhere throughout the body, said Lylas Mogk, MD, chairwoman of the Visual Rehabilitation Committee for the American Academy of Ophthalmology. It may also induce an immune system response, causing ocular irritation, inflammation and nuclear opacification, and it may affect ocular circulation.
Posted by mmiraftab at 06:54 PM
July 22, 2004
A number of measures should be implemented to perform high-flow (up to 100 cc per minute), high-vacuum (greater than 700 mm Hg) phacoemulsification,.
- Raise the bottle height as much as possible;
- lower the bed completely;
- keep both main and paracentesis incisions water tight; and
- ensure via the product manufacturers that you have high-resistance tubing and phacoemulsification hardware designed to achieve high pressure, he said.
Posted by mehdi khanlari at 08:41 PM
A good cataract surgeon now has to be a refractive cataract surgeon, which means not only calculating the IOL power correctly but managing astigmatism as well, said Louis D. Nichamin, M.D To that effect, there should be three different ways to approach astigmatism correction, based on the degree of cylinder. For low to moderate cylinder (up to 3 D), suggested the use of limbal relaxing incisions (LRIs). For high cylinder (3 D to 6 D), recommended an LRI in addition to a toric IOL or an LRI plus LASIK. Finally, for very high cylinder (6 D to 9 D), try an LRI plus a toric IOL and LASIK.Dr. Nichamin’s decision to use a toric IOL is based on whether he believes the patient is a good candidate for the STAAR Toric IOL (STAAR Surgical, Monrovia, Calif.).One thing to keep in mind about the LRI is that surgeons don’t truly incise the limbus, Dr. Nichamin said. Rather, the incision is just inside the limbus at the peripheral most extent of the clear corneal tissue.The advantage of the LRI is that the incision will not likely result in a frustrating axis shift,. The incision also is less likely to induce irregular flattening, and therefore, irregular astigmatism, .
Posted by mehdi khanlari at 08:30 PM
Posted by mehdi khanlari at 08:24 PM
Eyeworld July 2004
Intracameral gatifloxacin appears safe in human eyes at a dose of 100 micrograms,. The study examined the impact of 100 micrograms of the drug injected into the anterior chamber through the paracentesis site at the conclusion of cataract surgery on 40 eyes, which received clear corneal incisions. He found no significant change in ultrasound pachymetry at one week, all eyes quiet at one week post-op, no endophthalmitis and no visible retinal pathology. He also found supplementation of intracameral gatifloxacin with topical Zymar may significantly prolong therapeutic anterior chamber levels of gatifloxacin. He cautioned that the practices require further study, and they are not yet ready for general use.
Posted by mehdi khanlari at 08:18 PM
Drops in intraocular pressure after clear cornea incisions might result in poor wound apposition
Eyeworld July 2004
Posted by mehdi khanlari at 08:00 PM
July 21, 2004
Iquix
Eyeworld July 2004
Posted by mehdi khanlari at 08:59 PM
The Glarometer
Eyeworld July 2004
The Glarometer is a portable device that is easily administered. It includes a card and diode. “This device can help ophthalmologists help their patients to understand that glare already exists before laser vision correction. If it changes after the correction, the change is not dramatic,” Dr. Siepser said.The Glarometer used on patients before and after surgery so that they can see whether the amount of glare has changed. Before performing the test,asked patients whether they have glare
;read more
Posted by mehdi khanlari at 07:03 PM
Zeroing in on target pressure guidelines
Eyeworld July 2004
Posted by mehdi khanlari at 05:47 AM
July 20, 2004
Computer-simulated phacoemulsification
Ophthalmology Volume 111, Issue 4 , April 2004, Pages 693-698
The system consists of a personal computer, a 3-dimensional visual interface, a phacoemulsification handpiece, and a nucleus manipulator and foot pedals for control of the phacoemulsification procedure and microscope adjustments. The simulation is based on generalized simulation software that can be also used for the development of other medical simulations.
Main outcome measures
Qualitative statements given in a questionnaire. Medical students and ophthalmic surgeons with varying experience of phacoemulsification were tested.
Results
A simulator for training in phacoemulsification has been developed. The surgical procedures can be practiced any number of times, and there is no risk to patients. The efforts of the surgeon can be evaluated objectively.
Conclusions
Studies have shown that the number of complications for an ophthalmic surgeon learning phacoemulsification decreases exponentially, reaching close to the asymptote only after several hundred procedures. Simulator training might shorten the learning period, reduce expensive supervision by an experienced surgeon, and maintain and improve the skills of experienced surgeons.
Posted by mmiraftab at 10:54 PM
July 19, 2004
Eyeworld July 2004
Namely, the EVS study found that vitrectomy was only advantageous in cases of extremely poor visual acuity and that expensive intravenous antibiotics were no better than intravitreal antibiotic therapy alone. .
However, do the EVS findings continue to hold true today? Thomas A. Hanscom, M.D recently took a look back at this important study in an article published in a recent issue of Clinical Infectious Diseases. “The EVS was a trial to settle a few questions,” said Dr. Hanscom. To determine whether IV antibiotics could better eradicate the serious infection, patients in the EVS study were randomized to receive conventional IV antibiotics or intravitreal therapy. “One of the findings of the study was there was basically no difference between the two groups in terms of final outcome,Today’s medications are more potent than ever before with new fourth-generation fluoroquinolones such as Vigamox (Alcon, Fort Worth, Texas) and Zymar (Allergan, Irvine, Calif.). Also, Iquix (Santen, Napa, Calif.) is now in the mix. “Some of the fluoroquinolones can achieve therapeutic levels in the vitreous even with oral administration,” Dr. Hanscom said. He points to an article in the Archives of Ophthalmology in 2003, which showed therapeutic levels in the vitreous and aqueous after patients took orally administered gatifloxacin These new drugs might prove even more beneficial against endophthalmitis if taken systemically.
Posted by mehdi khanlari at 11:04 PM
July 17, 2004
Correction of presbyopia with refractive multifocal phakic intraocular lenses
JCRS JULY 2004
France. Patients had implantation of a foldable anterior chamber multifocal phakic IOL. The initial refraction was between ?5.00 diopters (D) and +5.00 D. The IOL had an addition of +2.50 D. An uncorrected distance acuity of 0.6 or better (decimal scale) and an uncorrected near acuity (Parinaud scale) of 3 or better (Parinaud 2 ? Jaeger 1) was considered a successful postoperative result. Conclusions:Implantation of an anterior chamber multifocal phakic IOL to correct presbyopia was effective and gave good predictability. The procedure is reversible in cases of patient intolerance to the IOL, unwanted optical phenomena, or complications. Strict inclusion criteria should be used for patient selection.
Edited by M.khanlari
Posted by alireza habibollahi at 11:13 PM
Evaluation of a satisfied bilateral scleral expansion band patientLisa
JCRS JULY 2004
One bilateral scleral expansion patient (age 50 years), 9 age-matched normal presbyopic control subjects (age range 48 to 52 years), and 1 normal control subject (age 27 years) participated. The scleral expansion patient had a complete eye examination, corneal topography, and wavefront measurements 19 months postoperatively. Accommodation was measured subjectively with the push-up technique, minus to blur, and dioptric range of clear vision. Accommodation was determined objectively by measuring the accommodative responses to negative lenses and pilocarpine 6% with a Hartinger coincidence refractometer and to real targets with a dynamic infrared optometer .Conclusions:No increase in accommodative amplitude above normal age-matched controls was found. Patient satisfaction may have come from the high expectations this patient had for a positive surgery outcome
Edited by M.Khanlari
Posted by alireza habibollahi at 10:55 PM
JCRS JULY 2004
Accommodation was measured monocularly using 3 subjective approaches—the push-up test, minus lenses to blur, and a focometer—and 2 approaches measured with a Hartinger coincidence refractometer, in which accommodation was stimulated with minus lenses to blur and topical pilocarpine 6%.Conclusion:Hartinger-measured accommodation provides more realistic measurement of accommodative amplitude than the subjective methods tested, especially in the presbyopic population. In presbyopic subjects, the subjective tests resulted in accommodative amplitudes up to 4.0 diopters greater than those measured with objective tests. Measurements of accommodative amplitude are best achieved with objective methods to stimulate and measure accommodation
Edited by M.Khanlari
Posted by alireza habibollahi at 10:46 PM
JCRS JULY 2004
USA:20 eyes that had cataract extraction with IOL implantation or refractive lens exchange after radial keratotomy, hexagonal keratotomy, or LTK. The effective refractive power (EffRP) of the Holladay Diagnostic Summary on the EyeSys Corneal Analysis System was used to determine the central corneal refractive power, which was input into the Holladay 2 IOL calculation formula. Results: 80% of eyes achieved a postoperative SE REF within ±0.50 diopter of emmetropia. Conclusion: The use of the EffRP increases the likelihood of an acceptable refractive outcome after cataract or refractive lens exchange surgery in eyes with a history of keratorefractive surgery.
Posted by alireza habibollahi at 10:37 PM
JCRS JULY 2004
Japan, A prospective study was conducted of 64 eyes of 39 patients having overnight orthokeratology for myopia. Inclusion criteria were an uncorrected visual acuity (UCVA) of 20/20 or better after treatment and a minimum follow-up of 3 months. Using Fourier series harmonic analysis, videokeratography data were decomposed into spherical component, regular astigmatism, asymmetry (tilt or decentration), and higher-order irregularity. Conclusions: Irregular corneal astigmatism significantly increased, even in clinically successful orthokeratology cases. The effect of the changes on visual function should be studied further.
Edited by M.Khanlari
Posted by alireza habibollahi at 10:26 PM
July 16, 2004
The Ocular Hypertension Treatment Study
Intraocular Pressure Lowering Prevents the Development of Glaucoma, but Does That Mean We Should Treat Before the Onset of Disease?
ARCH OPHTHALMOL/VOL 122, MAR 2004
The following articles suggest that there will be fewer patients receiving ocular antihypertensive medications based, in part, on applying the results of the Ocular Hypertension Treatment Study to clinical practice. Readers are invited to review these articles to see if they concur with the authors.
Posted by mmiraftab at 01:50 PM
NEW INSTRUMENTS:Plotting Visual Fields Using Contralateral Fixation A Novel Honeycomb Device
Arch Ophthalmol. 2004;122:1052-1056
A device that maintains steady fixation while plotting the visual field of an eye with a large central defect is presented. The device is composed of multiple adjacent pinhole tubes mounted on an eye shield and placed in front of the seeing fellow eye. The device constricts the visual field of the fixating nontested eye to preserve only the central 3°, thus not interfering with the visual field of the tested eye. We tested 3 healthy volunteers with simulated visual field defects and more than 100 patients with unilateral loss of central vision. The use of this device allowed us to plot visual field defects with clear-cut borders while no meaningful results could be obtained without it. We found this device to be efficient, simple to use, and suitable for all varieties of perimetry.
Posted by mmiraftab at 01:42 PM
Multifocal Electroretinographic Evaluation of Long-term Hydroxychloroquine Users
Arch Ophthalmol. 2004;122:973-981.
Methods Multifocal ERG with 103-hexagon stimulation was performed on 19 patients (36 eyes) treated with hydroxychloroquine for systemic lupus erythematosus, rheumatoid arthritis, or localized atypical scleroderma. Visual acuity testing, Amsler grid testing, and Ishihara color vision testing were also performed. In 2 of the patients, hydroxychloroquine was discontinued due to concerns about toxicity. Both of these patients had additional mfERG performed after discontinuation of medication.
Results Twelve patients (19 eyes) had a normal response density in one or both eyes, including 6 patients (12 eyes) with a low lifetime dose (438 g) of hydroxychloroquine who had normal response densities in both eyes. Eleven patients (17 eyes) had abnormal response densities in one or both eyes, and 2 of these patients (4 eyes) had significant attenuation of response densities in almost the whole tested field; 4 patients had a normal mfERG result for one eye but had a slight decrease of response densities for the other eye. There were 4 patterns of abnormal mfERG amplitude change observed: (1) paracentral loss, (2) foveal loss, (3) peripheral loss, and (4) generalized loss. Implicit times were abnormal for pericentral responses in 3 patients. The results of color vision and Amsler grid testing were normal, except for one patient with a generalized loss pattern. In 2 subjects in whom hydroxychloroquine toxicity was suspected, response densities improved after termination of hydroxychloroquine.
Conclusions Long-term hydroxychloroquine use may be associated with mfERG abnormalities. The mfERG appears to detect retinal physiological change earlier than visual acuity testing, color vision testing, or Amsler grid testing can. The greatest value of the mfERG is in differentiating a retinal cause and, hence, providing important evidence for hydroxychloroquine toxicity, for whatever visual field loss is apparent on perimetry.
Posted by mmiraftab at 01:30 PM
July 13, 2004
An ideal ocular nutritional supplement?
Ophthalmic and Physiological Optics Volume 24 Issue 4 Page 339 - July
The role of nutritional supplementation in prevention of onset or progression of ocular disease is of interest to health care professionals and patients. The aim of this review is to identify those antioxidants most appropriate for inclusion in an ideal ocular nutritional supplement, suitable for those with a family history of glaucoma, cataract, or age-related macular disease, or lifestyle factors predisposing onset of these conditions, such as smoking, poor nutritional status, or high levels of sunlight exposure. It would also be suitable for those with early stages of age-related ocular disease. Literature searches were carried out on Web of Science and PubMed for articles relating to the use of nutrients in ocular disease. Those highlighted for possible inclusion were vitamins A, B, C and E, carotenoids beta-carotene, lutein, and zeaxanthin, minerals selenium and zinc, and the herb, Ginkgo biloba. Conflicting evidence is presented for vitamins A and E in prevention of ocular disease; these vitamins have roles in the production of rhodopsin and prevention of lipid peroxidation respectively. B vitamins have been linked with a reduced risk of cataract and studies have provided evidence supporting a protective role of vitamin C in cataract prevention. Beta-carotene is active in the prevention of free radical formation, but has been linked with an increased risk of lung cancer in smokers. Improvements in visual function in patients with age-related macular disease have been noted with lutein and zeaxanthin supplementation. Selenium has been linked with a reduced risk of cataract and activates the antioxidant enzyme glutathione peroxidase, protecting cell membranes from oxidative damage while zinc, although an essential component of antioxidant enzymes, has been highlighted for risk of adverse effects. As well as reducing platelet aggregation and increasing vasodilation, Gingko biloba has been linked with improvements in pre-existing field damage in some patients with normal tension glaucoma. We advocate that vitamins C and E, and lutein/zeaxanthin should be included in our theoretically ideal ocular nutritional supplement.
Posted by mmiraftab at 07:35 PM
Enterovirus uveitis
Reviews in Medical Virology Volume 14, Issue 4 , Pages 241 - 254
Enterovirus uveitis (EU) is a new infant eye disease that was first observed in 1980. Three distinct subtypes of human echoviruses, EV19/K, EV11/A and EV11/B, caused five hospital outbreaks of EU in different Siberian cities in 1980-1989, affecting approximately 750 children, predominantly below 1 year of age. Sporadic EU cases were also retrospectively diagnosed in other regions of Russia and in different countries of the Former Soviet Union. The illness was characterised by rapid iris destruction and severe complications, including cataract and glaucoma. The disease has been a subject of intensive studies and was reproduced in lower primates after intraocular inoculation of isolated enterovirus strains. Importantly, prototype EV11 and EV19 strains did not induce notable disease in experimental monkeys. Some of the EU-causing strains were shown to be similar phylogenetically and in their pathogenetic properties to the enterovirus strains associated with multisystem hemorrhagic disease of newborns. In this review we present a summary of the vast epidemiological, virological, clinical and experimental data on this new form of ophthalmic infection.
Posted by mmiraftab at 07:29 PM
A Complication of Cosmetic Surgery
The New England Journal Of Medicine July 2004
fat injection.bmp
45-year-old woman who had received local anesthesia un-derwent injection of abdominal subcutaneous fat into the vertical glabellar frown lines to remove wrinkles. Within a minute after the procedure, she had a severe frontal headache and right periorbital pain, which were followed by swelling of the right eyelid and diplopia. Examination the next day showed right-eye proptosis,chemosis, and ptosis with retraction of the frontalis muscle. Facial sensation was spared, and there was no ocular bruit. Cranial computed tomography showed a focal,linear hypodensity, consistent with the presence of fat, in the right cavernous sinus. Magnetic resonance imaging showed an enlarged right superior ophthalmic vein and a linear, fat-density signal in the right cavernous sinus. Images obtained with fat suppression confirmed the presence of fat in the right superior ophthalmic vein and right cavernous sinus. A pocket of retained fat in the left glabellar area was also seen (Panel C, arrow). It appears that the fat was injected into the frontal vein and that it then reached the cavernous sinus by way of the superior ophthalmic vein. The patient’s condition improved rapidly over the next several days.
Posted by mmiraftab at 10:58 AM
Charles Kelman
Thelancet Vol 364 July 10, 2004
Ophthalmologist who developed technique of
phacoemulsi?cation. Born May 23, 1930, in
Brooklyn, New York, USA; died of lung cancer
on June 1, 2004, in Boca Raton, Florida, USA;
aged 74 years.Read More...
Posted by mmiraftab at 10:30 AM
Genes not responsible for myopia
OSN July 2004
East Asians are no more genetically prone to myopia than other ethnicities, according to a group of researchers in Australia who analyzed past studies.Ian Morgan and Kathryn Rose of the University of Sydney say the higher rates of myopia in countries such as Singapore and Japan are directly related to lifestyle and not genetic makeup. In Singapore, for example, 80% of 18-year-old army recruits are myopic, up from 25% 30 years ago. According to the researchers, the true cause of myopia is the increased amount of near work children now do, such as playing video games or computer work.The researchers found 70% of 18-year-old men of Indian descent living in Singapore have myopia, compared with 10% of Indian men living in India. Similarly, the rate of myopia for male adolescents age 14 to 18 in Israel is 80% in schools that emphasize reading religious texts, compared with 30% in state schools.The simplest explanation is that you have a massive environmental effect that is swamping out the genetic influence,” Mr. Morgan said in an article in New Scientist.The researchers note lifestyle is affecting myopia rates outside of Asia as well. In Sweden, 50% of 12-year-old children are myopic; the researchers expect that figure to be more than 70% when those children turn 18.
Posted by mmiraftab at 12:30 AM
July 11, 2004
Quantitative evaluation of regular and irregular corneal astigmatism in patients having overnight orthokeratology
JCRS JULY 2004
Japan,patients having overnight orthokeratology for myopia. Inclusion criteria were an UCVA 20/20 or better after treatment and F/U of 3 months.Conclusions: Irregular corneal astigmatism significantly increased,in clinically successful orthokeratology cases. The effect of the changes on visual function should be studied further.
Posted by alireza habibollahi at 04:32 PM
Corneal aberrations after astigmatic keratotomy (AK)combined with LASIK
JCRS JULY 2004
Spain. AK increased HOCA, both coma-like and spherical-like, whereas LASIK performed after AK increased the spherical-like aberration and reduced the coma-like aberration.
J Cataract Refract Surg 2004; 30:1418–1424 © 2004 ASCRS and ESCRS
Posted by alireza habibollahi at 04:12 PM
lasik vs lasek for the correction of high myopia
JCRS JULY 2004
South Korea 470 eyes of 240 patients with refraction greater than –6.00 diopters (D) were assigned to 2 groups: 324 eyes treated with LASIK and 146 eyes with LASEK. UCVA, BSCVA, remaining refractive error, corneal haze, and complications 12 M f/u.
Results: At 12 months SE was within ±0.50 D of emmetropia 63.3% LASIK group and 55.5% t LASEK group.The UCVA was 20/25 or better in LASIK eyes (83.0%) and LASEK eyes (76.0%). There was more than a 1-line loss of BSCVA in LASIK eyes (1.2%) and LASEK eyes (14.3%). The between-group differences in SE, magnitude of cylinder, UCVA, and haze were statistically significantConclusions: Both LASIK and LASEK were safe and effectively treated eyes with high myopia. Laser in situ keratomileusis provided superior results in visual predictability and corneal opacity.
J Cataract Refract Surg 2004; 30:1405–1411 © 2004 ASCRS and ESCRS
Posted by alireza habibollahi at 04:02 PM
Phaco after retinal detachment surgery
JCRS JULY 2004.
Japan,patients who had phacoemulsification after previous RD surgery were included. . Recurrence of RD, visual acuity, complications, and the neodymium:YAG (Nd:YAG) laser capsulotomy rate were examined.Results:Conclusions:The rate of recurrent RD after phacoemulsification in eyes that had previous RD surgery was similar to that of new occurrence of RD in fellow eyes without RD before phacoemulsification. Because the Nd:YAG capsulotomy rate was lower in eyes with acrylic IOLs than in eyes with PMMA IOLs, acrylic IOLs are recommended for eyes at high risk for RD.
Posted by alireza habibollahi at 03:45 PM
July 10, 2004
Eyeglasses overprescribed for children, study asserts
OSN,July,2004
Children with “satisfactory vision” are often prescribed unnecessary eyeglasses following vision screenings, according to a large retrospective study of school-aged children in Tennessee. Sean P. Donahue, MD, reviewed eye examination results of more than 100,000 children screened in Tennessee from 1997 to 2003. Of the 3,640 children referred for follow-up exams, 890 were found to have satisfactory vision and thus were considered false-positives, he reported in the June issue of the Journal of the American Association of Pediatric Ophthalmology and Strabismus.
Of the false-positives, he said, almost 20% were prescribed eyeglasses. Extrapolating the data from Tennessee to the whole United States, Dr. Donahue said that at a rate of $150 per pair of glasses, the annual cost of prescribing unnecessary glasses could exceed $200 million. Dr. Donahue also found that the rate of unnecessary glasses prescriptions was 35.1% when the child was evaluated by an optometrist, 11.7% when evaluated by a comprehensive ophthalmologist and 1.8% when examined by a pediatric ophthalmologist.
Posted by afarahi at 01:11 PM
Progressive addition lenses helpful in slowing myopic progression in kids
OSN,July,2004
For children with large lags of accommodation, progressive addition lenses may not only improve visual performance, but may delay the progression of myopia as well, according to a study. Jane Gwiazda and colleagues collected data from children enrolled in the Correction of Myopia Evaluation Trial, which included 469 ethnically diverse children between 6 and 11 years old. Their myopia ranged from –1.25 D to –4.5 D. Of those identified for the study, 235 were assigned to progressive addition lenses with a +2 addition, and 234 were assigned to receive single vision lenses. All children were observed for 3 years.
Children with a larger accommodative lag — defined in this study as more than 0.43 D for a 33 cm target — wearing single vision lenses showed the most myopic progression at 3 years. Once moved to progressive addition lenses, myopia progression slowed in these children. There was statistically significant 3-year treatment effects for those with larger lags in accommodation in combination with near esophoria, shorter reading distances or lower baseline myopia. The 3-year treatment effect for children with larger lags and more near work was not significant.
Posted by afarahi at 12:34 PM
Ophthalmoplegic Migraine
Current Pain and Headache Reports 2004, 8:306-309
Ophthalmoplegic migraine is a rare condition, previously thought to represent a variant of migraine. Recent observations regarding its usual clinical presentation and common magnetic resonance imaging findings have given rise to speculation that this illness is more likely to represent an inflammatory cranial neuropathy. The recent revision of the International Headache Classification has reclassified ophthalmoplegic migraine from a subtype of migraine to the category of neuralgia. In this article, potential pathophysiological mechanisms are discussed. The typical clinical presentation of ophthalmoplegic migraine generally involves transient migraine-like headache accompanied by often long-lasting oculomotor, abducens or, rarely, trochlear neuropathy with diplopia and (if oculomotor nerve is involved) pupillary abnormalities and ptosis. Ophthalmoplegic migraine generally occurs in children, but a number of adult cases have been reported. Prognosis is good because symptoms almost always resolve, but, after several episodes, some deficits may persist. Differential diagnosis is rather large, although most other possible causes of ophthalmoplegia and headache have distinctive presentations or can be excluded with fairly straightforward diagnostic testing. Optimal prophylactic and acute treatment is still unclear, but migraine prophylactic medications such as b blockers and calcium channel blockers have been proposed. Steroids have been used with mixed results.
Posted by afarahi at 12:29 PM
July 09, 2004
The Renaissance of Keratophakia(Results from the clinical studies of the Anamed stromal implants)
CRS Today June 2004
The Anamed implant is composed of the company’s proprietary,microporous, HEMA-based silicone hydrogel called Nutrapore that mimics the human stroma. The material is 78% water and is highly permeable to water, oxygen, and glucose. The lens is approximately 5.5 mm in diameter, has a refractive index of 1.376 ±0.005, and provides wonderful optical clarity (99% transmission).In the phase II US clinical trial, five sites are open,and 22 eyes have received the lens thus far. Three of these eyes have reached 24-month follow-up. To date,we have had no instances of corneal haze and only one adverse event—the unrelated development of a cataract.
Posted by mmiraftab at 07:46 PM
Ophthalmic Drug Delivery through Contact Lenses
Investigative Ophthalmology and Visual Science. July 2004;45:2342-2347
PURPOSE. Currently available ophthalmic drug delivery systems are inefficient and may lead to side effects. To increase efficiency and reduce side effects, the authors propose disposable particle-laden soft contact lenses for ophthalmic drug delivery.
METHODS. The essential idea is to encapsulate the ophthalmic drug formulations in nanoparticles and to disperse these drug-laden particles in the lens material, such as poly-2-hydroxyethyl methacrylate (p-HEMA) hydrogels. The drug-laden p-HEMA hydrogels were synthesized by free radical solution polymerization of the monomers in presence of nanoparticles. The particle-laden hydrogels were characterized by light-transmission and electron microscopy studies. Release profiles of lidocaine, a model hydrophobic drug, were measured by UV-Vis spectrophotometry.
RESULTS. Microemulsions of hexadecane in water stabilized with a silica shell around the particles produced transparent hydrogels. Contact lenses made with particle-laden hydrogels released therapeutic levels of drug for a few days.
CONCLUSIONS. Particle-laden hydrogels are promising candidates for ophthalmic drug delivery. They are transparent and can release drugs for extended periods. The drug delivery rates can be controlled by varying the loading of nanoparticles in the gel.
Posted by mmiraftab at 07:39 PM
July 05, 2004
Fuchs heterochromic cyclitis: rubella virus antibodies and genome in aqueous humor
American Journal of Ophthalmology Volume 138, Issue 1 , July 2004, Pages 46-54
Intraocular antibody synthesis is detected in aqueous humor with the Antibody Index [AI] (improved Goldmann-Witmer Index) and quantified as specific antibody fraction, Fs (intraocular specific antibody concentration in percent of intraocular total immunoglobulin G in aqueous humor). Virus detection is by nested polymerase chain reaction.
Results
Fifty-two eyes of 52 patients with clinically defined FHC (aged 16–73 years) had an intraocular synthesis of rubella antibodies (AI ?1.5). The rubella genome was detected in 5 (18%) of 28 aqueous humor samples investigated, or in 5 (56%) of 9 patients aged <40 years. Oligoclonal IgG was synthesized in 34 (87%) of 39 eyes. Unaffected fellow eyes (n = 3) or cerebrospinal fluid (n = 2) were normal. In FHC the median rubella AI = 20.6 (total range 1.5–309) was seven times higher than in multiple sclerosis (MS) patients (n = 15) with uveitis intermedia or periphlebitis retinae. In MS the intraocular rubella antibody synthesis (frequency 73%) is part of a polyspecific immune response (increased measles AI in 80%, varicella zoster virus AI in 47%, herpes simplex virus AI in 23%). The median rubella-Fs = 2.6% in FHC (range = 0.14%–45.9%) was approximately 40 times higher than in MS, consistent with a virus-driven antibody response in FHC. Noninflammatory controls (50 senile cataracts) had neither an intraocular rubella antibody synthesis (normal AI ?1.4) nor rubella antigen in aqueous humor. The rubella AI was normal in all patients with an intraocular toxoplasmosis (n = 24), anterior uveitis (n = 27), herpes simplex virus iritis (n = 25), and varicella zoster virus iritis (n = 14).
Conclusions
Fuchs heterochromic cyclitis is a rubella virus-driven disease with persistence of the virus preferentially detected in the younger patients. The proposed laboratory supported diagnosis of FHC is based on the increased rubella Antibody Index. The virus etiology gives a rationale for omitting the ineffective corticosteroid therapy of FHC.
Posted by mmiraftab at 08:49 PM