American Journal of Ophthalmology
Forty-three consecutive patients were included in this study. Sixteen patients underwent pterygium surgery with conjunctival autograft and MMC for recurrent pterygium and 27 patients underwent pterygium excision without MMC for primary pterygium removal (control group) at the Toronto Western Hospital. Endothelial images were acquired at the center of the cornea with a specular microscope before surgery and at one week, one month, and three months following surgery......Mean preoperative endothelial cell counts were 2330 ± 318 cells/mm2 in the pterygium excision without MMC group and 2486 ± 327 cells/mm2 in the pterygium excision with MMC group (P = .13). One month after surgery, the pterygium with MMC group showed a significant endothelial cell loss of 6% which was not present in the control group (P = .03). Three months after surgery, endothelial cell loss was reduced to 4%. (P = .08 compared with the control). In the pterygium excision with MMC group, endothelial polymeghatism was increased (at one and three months) and the percentage of hexagomal cells was reduced (at one month).ConclusionsThe use of topical MMC during recurrent pterygium surgery was found to have a deleterious effect on corneal endothelium one month following surgery. Judicious use of this drug is therefore recommended.
Friday, February 27, 2009
Sutures for pediatric cataract patients
EyeWorld
Ophthalmologists know cataract surgery can be challenging in children—especially in those without capsular support. What many may not know is that there could be some risk involved using 10-0 polypropylene sutures, according to research published in the December 2007 issue of Transactions of the American Ophthalmological Society.
“Several recent reports have indicated that over time the 10-0 polypropylene suture can degrade, resulting in spontaneous subluxation of the intraocular lens,” wrote lead study author Edward G. Buckley, M.D., professor of ophthalmology and pediatrics, Duke Eye Center, Durham, N.C. “The key point emphasized in these articles is that this happens years after implantation, typically 4 to 5 years or later.”
Much research into this issue has focused on suture breakdown in a matter of months, which typically doesn’t happen.
Hence, Dr. Buckley analyzed eyes with follow-up time of more than five years and, indeed, found a number of suture breaks. He also found other ophthalmologists revealing similar problems.
Ophthalmologists may not recognize this problem as severe at first because a suture can be reattached. But over time, sutures could break down again and again, posing unwanted risks to these patients.
Ophthalmologists know cataract surgery can be challenging in children—especially in those without capsular support. What many may not know is that there could be some risk involved using 10-0 polypropylene sutures, according to research published in the December 2007 issue of Transactions of the American Ophthalmological Society.
“Several recent reports have indicated that over time the 10-0 polypropylene suture can degrade, resulting in spontaneous subluxation of the intraocular lens,” wrote lead study author Edward G. Buckley, M.D., professor of ophthalmology and pediatrics, Duke Eye Center, Durham, N.C. “The key point emphasized in these articles is that this happens years after implantation, typically 4 to 5 years or later.”
Much research into this issue has focused on suture breakdown in a matter of months, which typically doesn’t happen.
Hence, Dr. Buckley analyzed eyes with follow-up time of more than five years and, indeed, found a number of suture breaks. He also found other ophthalmologists revealing similar problems.
Ophthalmologists may not recognize this problem as severe at first because a suture can be reattached. But over time, sutures could break down again and again, posing unwanted risks to these patients.
Inhibition of surgically induced miosis and prevention of postoperative macular edema with nepafenac
Journal of clinical ophthalmology
This was a prospective, randomized, single-masked comparative study in 60 patients undergoing phacoemulsification cataract surgery. Patients were randomized to either the nepafenac or the control group. ..... The difference in mean pupil size, at the end of surgery, between the control group (6.84 ± 0.93 mm) and the nepafenac group (7.91 ± 0.74 mm) was statistically significant (p <>Conclusion: Prophylactic use of nepafenac was effective in reducing macular edema after cataract surgery and in maintaining trans-operative mydriasis.
This was a prospective, randomized, single-masked comparative study in 60 patients undergoing phacoemulsification cataract surgery. Patients were randomized to either the nepafenac or the control group. ..... The difference in mean pupil size, at the end of surgery, between the control group (6.84 ± 0.93 mm) and the nepafenac group (7.91 ± 0.74 mm) was statistically significant (p <>Conclusion: Prophylactic use of nepafenac was effective in reducing macular edema after cataract surgery and in maintaining trans-operative mydriasis.
Effect of haemodialysis on intraocular pressure
Eye
To study the effect of haemodialysis on intraocular pressure (,,,Prospective, single centre study on patients undergoing haemodialysis with a sample size of 98 eyes (49 patients). Plasma osmolarity changes and volume of fluid removed were noted. Patients on antiglaucoma treatment or who have had earlier laser or surgical procedures for it were excluded. ....Plasma osmolarity decreased significantly (-11.610.0mOsm/l, P<0.001).>0.05) in all subgroups of non-operated/operated and diabetic/non-diabetic eyes were seen.
Conclusions
Haemodialysis does not cause significant changes in IOP in non-glaucomatous and non-occludable angle eyes
To study the effect of haemodialysis on intraocular pressure (,,,Prospective, single centre study on patients undergoing haemodialysis with a sample size of 98 eyes (49 patients). Plasma osmolarity changes and volume of fluid removed were noted. Patients on antiglaucoma treatment or who have had earlier laser or surgical procedures for it were excluded. ....Plasma osmolarity decreased significantly (-11.610.0mOsm/l, P<0.001).>0.05) in all subgroups of non-operated/operated and diabetic/non-diabetic eyes were seen.
Conclusions
Haemodialysis does not cause significant changes in IOP in non-glaucomatous and non-occludable angle eyes
Efficacy and safety of latanoprost in eyes with uveitic glaucoma
journal of glaucoma
To compare the efficacy and safety of latanoprost against a fixed combination of dorzolamide and timolol in eyes with elevated intraocular pressure (IOP) or glaucoma and anterior or intermediate uveitis.
.....Results Ten patients (34%) in the latanoprost group and sixteen patients (57%) in the dorzolamide/timolol group experienced relapses of anterior uveitis (p = 0.93). There was no statistical difference between the two groups in respect of inflammatory relapses (p = 0.21). Twenty-one patients were followed up before starting latanoprost. The number of recurrences of anterior uveitis per patient per year before treatment with latanoprost was 0.82 ± 1.2. The rate of relapses per patient per year after starting latanoprost was 0.39 ±0.7 for these patients (p = 0.038). After 1 year of treatment, intraocular pressure was dropped from 27.8 ± 8.4 mmHg to 18.6 ± 5.3 mmHg (p < 0.001) in the latanoprost group and from 28.2 ±8.1 mmHg to 22.6 ±10.1 mmHg (p < 0.001) in the dorzolamide/timolol group. Four patients during treatment with latanoprost and five patients during treatment with dorzolamide/timolol developed macular edema. Conclusion Latanoprost is safe and equally effective to a fixed combination of dorzolamide and timolol in the treatment of uveitic glaucoma.
To compare the efficacy and safety of latanoprost against a fixed combination of dorzolamide and timolol in eyes with elevated intraocular pressure (IOP) or glaucoma and anterior or intermediate uveitis.
.....Results Ten patients (34%) in the latanoprost group and sixteen patients (57%) in the dorzolamide/timolol group experienced relapses of anterior uveitis (p = 0.93). There was no statistical difference between the two groups in respect of inflammatory relapses (p = 0.21). Twenty-one patients were followed up before starting latanoprost. The number of recurrences of anterior uveitis per patient per year before treatment with latanoprost was 0.82 ± 1.2. The rate of relapses per patient per year after starting latanoprost was 0.39 ±0.7 for these patients (p = 0.038). After 1 year of treatment, intraocular pressure was dropped from 27.8 ± 8.4 mmHg to 18.6 ± 5.3 mmHg (p < 0.001) in the latanoprost group and from 28.2 ±8.1 mmHg to 22.6 ±10.1 mmHg (p < 0.001) in the dorzolamide/timolol group. Four patients during treatment with latanoprost and five patients during treatment with dorzolamide/timolol developed macular edema. Conclusion Latanoprost is safe and equally effective to a fixed combination of dorzolamide and timolol in the treatment of uveitic glaucoma.
Saturday, February 21, 2009
Topical Vitamin A vs. Cyclosporine A for Dry Eye Syndrome
American Journal of Ophthalmology
In a randomized group study, Kim et al. compared the efficacy of vitamin A (retinyl palmitate) eye drops and cyclosporine A eye drops in treating patients with dry eye disease.
A total of 150 patients with defined dry eye disease participated (50 in each treatment group). In three identical clinical trials, patients were treated either twice daily with cyclosporine A 0.05 percent, four times daily with retinyl palmitate 0.05 percent or with neither. Adjunctive treatment with preservativefree artificial tears was undertaken four times daily in all three groups. Corneal fluorescein staining results, Schirmer tear test (without anesthesia) results, tear film break-up time, dry eye symptom score and impression cytologic analysis results were obtained before treatment and at the first, second and third months of treatment.
Both vitamin A and cyclosporine A treatments led to significant improvement in blurred vision, tear film breakup time, Schirmer results and impression cytologic findings in patients with dry eye syndrome, when compared with the control group treated with preservative- free artificial tears alone
In a randomized group study, Kim et al. compared the efficacy of vitamin A (retinyl palmitate) eye drops and cyclosporine A eye drops in treating patients with dry eye disease.
A total of 150 patients with defined dry eye disease participated (50 in each treatment group). In three identical clinical trials, patients were treated either twice daily with cyclosporine A 0.05 percent, four times daily with retinyl palmitate 0.05 percent or with neither. Adjunctive treatment with preservativefree artificial tears was undertaken four times daily in all three groups. Corneal fluorescein staining results, Schirmer tear test (without anesthesia) results, tear film break-up time, dry eye symptom score and impression cytologic analysis results were obtained before treatment and at the first, second and third months of treatment.
Both vitamin A and cyclosporine A treatments led to significant improvement in blurred vision, tear film breakup time, Schirmer results and impression cytologic findings in patients with dry eye syndrome, when compared with the control group treated with preservative- free artificial tears alone
Cataract Surgery Does Not Increase Risk of AMD Progression
February’s Ophthalmology
Data from the Age-Related Eye Disease Study (AREDS) suggest there is no clinically important increased risk of progression to advanced age-related macular degeneration following cataract surgery.
This study involved 4,577 participants (8,050 eyes) from AREDS who had varying degrees of AMD and were followed every six months for up to 11 years. The researchers said this was the only prospective study in which the severity of AMD was documented prior to and following cataract surgery in a large number of cases with more than five years of regular follow-up. The Cox regression model allowed them to examine the effect of covariables on progression to late AMD. An absence of any pattern in the direction of harm indicated there was little evidence cataract surgery increased the risk of progression to late AMD.
The authors conclude that while the risk of advanced AMD does not appear to be accelerated by cataract surgery, patients should still be told of the natural course of AMD.
Data from the Age-Related Eye Disease Study (AREDS) suggest there is no clinically important increased risk of progression to advanced age-related macular degeneration following cataract surgery.
This study involved 4,577 participants (8,050 eyes) from AREDS who had varying degrees of AMD and were followed every six months for up to 11 years. The researchers said this was the only prospective study in which the severity of AMD was documented prior to and following cataract surgery in a large number of cases with more than five years of regular follow-up. The Cox regression model allowed them to examine the effect of covariables on progression to late AMD. An absence of any pattern in the direction of harm indicated there was little evidence cataract surgery increased the risk of progression to late AMD.
The authors conclude that while the risk of advanced AMD does not appear to be accelerated by cataract surgery, patients should still be told of the natural course of AMD.
Suturing microscopic wound leaks can avoid myopic shifts
OCULAR SURGERY NEWS U.S. EDITION March 10, 2009
To test the association between wound leaks and myopic shifts with the Crystalens, our center performed a controlled, retrospective study that was presented as a poster at the 2008 American Academy of Ophthalmology meeting. For several months, we had been routinely performing a Seidel test at the end of cataract surgery. Initially our surgeons were surprised to find small wound leaks, not detectable without a Seidel test, in about one-third of patients. Retrospectively, we reviewed 100 charts of Crystalens patients – 50 who had Seidel negative wounds and 50 with small leaks, detectable only with a Seidel test. Neither group had received sutures. Comparing 1-month postoperative refractions to target, we learned that leaking wounds had an average refractive “surprise,” compared with target refraction, 0.54 D more myopic than those that were Seidel negative at the time of surgery.
It is now our standard of practice to suture any Seidel positive Crystalens wounds. Newer, better methods of sealing incisions may allow us to use a technology even better than suture in the future
To test the association between wound leaks and myopic shifts with the Crystalens, our center performed a controlled, retrospective study that was presented as a poster at the 2008 American Academy of Ophthalmology meeting. For several months, we had been routinely performing a Seidel test at the end of cataract surgery. Initially our surgeons were surprised to find small wound leaks, not detectable without a Seidel test, in about one-third of patients. Retrospectively, we reviewed 100 charts of Crystalens patients – 50 who had Seidel negative wounds and 50 with small leaks, detectable only with a Seidel test. Neither group had received sutures. Comparing 1-month postoperative refractions to target, we learned that leaking wounds had an average refractive “surprise,” compared with target refraction, 0.54 D more myopic than those that were Seidel negative at the time of surgery.
It is now our standard of practice to suture any Seidel positive Crystalens wounds. Newer, better methods of sealing incisions may allow us to use a technology even better than suture in the future
Adherence to Single-Dose Glaucoma Medication
February’s Ophthalmology 2009
--------- patient adherence with once-daily prostaglandin therapy for glaucoma is not substantially better than once-daily drops of beta blockers or four-times daily pilocarpine.---------researchers used the Travatan Dosing Aid that electronically records the time and date of a travoprost dose. Of the 196 patients with evaluable data at three months, 109 (55.6 percent) took more than 75 percent of the expected doses. Those who took less than 50 percent of expected doses showed significantly increased dose taking immediately after the office visit and just prior to the return threemonth visit. In addition, neither patient self-report nor physician estimation of adherence accurately reflected the true behavior as measured by the Travatan Dosing Aid.
The investigators conclude that 44 percent of participants who knew they were being monitored and were provided free medications nevertheless took less than 75 percent of the doses, suggesting that poor patient adherence remains a challenge in providing care to glaucoma patients
--------- patient adherence with once-daily prostaglandin therapy for glaucoma is not substantially better than once-daily drops of beta blockers or four-times daily pilocarpine.---------researchers used the Travatan Dosing Aid that electronically records the time and date of a travoprost dose. Of the 196 patients with evaluable data at three months, 109 (55.6 percent) took more than 75 percent of the expected doses. Those who took less than 50 percent of expected doses showed significantly increased dose taking immediately after the office visit and just prior to the return threemonth visit. In addition, neither patient self-report nor physician estimation of adherence accurately reflected the true behavior as measured by the Travatan Dosing Aid.
The investigators conclude that 44 percent of participants who knew they were being monitored and were provided free medications nevertheless took less than 75 percent of the doses, suggesting that poor patient adherence remains a challenge in providing care to glaucoma patients
Light-scattering technique may pinpoint protein changes, early cataract risk
Arch Ophthalmol. 2008;126(12):1687-1693.
A noninvasive imaging technique detected early protein changes associated with lens opacity and potential cataract in a National Eye Institute-NASA clinical trial./////Dynamic light scattering (DLS) identified decreases in alpha-crystallin, a protein that maintains lens transparency by preventing damaged lens proteins from binding and forming cataracts, the study authors said./////"Clinical detection of pre-cataractous lens damage in clinically clear lenses and identification of patients at high risk for cataracts would be useful for many reasons," they said. Early detection may provide ample warning and allow patients to minimize factors such as smoking and alcohol consumption.----The compact fiber-optic probe was based on a DLS device used to study the growth of protein crystals in space, according to a press release from the NEI and NASA.,,,,The clinical trial included 380 eyes of 235 patients ranging in age from 7 years to 83 years with nuclear lens opacity grades of 0 (clear) to 3.8 (opaque). The primary outcome measure was the alpha-crystallin index (ACI), a measurement of unbound alpha-crystallin based on DLS testing.Data showed a significant correlation between increased lens opacity grade and decreased ACI (P < .001). Mean ACI values decreased with age, even in clear lenses. The mean ACI in subjects younger than 22 years with clear lenses was 31%; the mean ACI in eyes with opacity grades of 2 or higher was 2%. DLS detected early protein changes even in clinically clear lenses with no visible signs of opacity, the authors said.
This study confirms that cataract formation (specifically nuclear sclerosis in this case) is a process that probably starts at birth. It has been apparent that the earliest known optically important changes in nuclear sclerosis is the formation of multilamellar bodies that create light scatter and are clinically noticed as glare even with excellent visual acuity. Tom Vandenberg has shown that light scattering is directly related to aging because of this phenomenon, and the present study shows that the loss of alpha-crystallin over time represents the loss of a key lens repair mechanism to help maintain clarity.
Tom Vandenberg invented the C-Quant as a clinical means of measuring light scatter in patients, and this could become an important and more objective tool to document clinical progression. It tells us much the same information as the study set-up, which I think will be used mainly for research and in clinical studies of proposed pharmaceutical treatments of nuclear sclerosis (yes, there are some proposed treatments out there). Both clinical instruments will better quantify glare, is my best guess, probably with similar findings. Might light scatter become a standard clinical measure of nuclear sclerosis? Possibly, but this will not supplant the need for clear clinical correlation and patient subjective symptomatic response to the cataract process in any decision for surgery.
Visco-cannula assists in reinversion of phakic lens
OCULAR SURGERY NEWS U.S. EDITION March 10, 2009
Accidental upside down opening of the phakic Visian ICL (Implantable Collamer Lens, STAAR Surgical) in the anterior chamber is a rare complication of ICL implantation, and we will describe a new, simple technique of repositioning the inverted ICL on the table without explantation.
Upside down unfolding
....In the older loading technique, the ICL is kept in the cartridge and pushed into the nozzle. This can lead to the lens coming out inverted, which is what happened in this case. To solve this problem, STAAR devised a new method of loading. In this new technique, instead of pushing, the ICL is pulled using special forceps passed through the nozzle of the cartridge. This prevents the ICL from coming out of the cartridge in the upside down position. Good preoperative mydriasis and controlled release of force while injecting are the other factors that aid in easy insertion.
Visco-cannula aided repositioning
The anterior chamber was formed with the viscoelastic Viscomet (2% hydroxypropyl methylcellulose, Sun Pharmaceutical Industries). The haptic edge of the ICL was tilted with the tip of the visco-cannula and at the same time, the viscoelastic was injected behind the ICL. This step was repeated until the ICL was halfway folded. Then the visco-cannula tip was placed below the lower flap of the folded ICL, and the haptic edge was pushed up, thereby unfolding the ICL. This placed the ICL in the correct position Care was taken not to touch the optical center of the ICL. Surgical peripheral iridectomy was performed, and the entry wound in the cornea was hydrated. The patient was put on topical antibiotics and steroids in the postoperative period (
In our cases, there was no endothelial damage or lens change, even at 6 months follow-up. We believe this method of reinversion can be comfortably done in phakic eyes with a minimum anterior chamber depth of 2.8 mm. This technique can be an easy way of positioning the ICL without explantation and a second surgery.
Accidental upside down opening of the phakic Visian ICL (Implantable Collamer Lens, STAAR Surgical) in the anterior chamber is a rare complication of ICL implantation, and we will describe a new, simple technique of repositioning the inverted ICL on the table without explantation.
Upside down unfolding
....In the older loading technique, the ICL is kept in the cartridge and pushed into the nozzle. This can lead to the lens coming out inverted, which is what happened in this case. To solve this problem, STAAR devised a new method of loading. In this new technique, instead of pushing, the ICL is pulled using special forceps passed through the nozzle of the cartridge. This prevents the ICL from coming out of the cartridge in the upside down position. Good preoperative mydriasis and controlled release of force while injecting are the other factors that aid in easy insertion.
Visco-cannula aided repositioning
The anterior chamber was formed with the viscoelastic Viscomet (2% hydroxypropyl methylcellulose, Sun Pharmaceutical Industries). The haptic edge of the ICL was tilted with the tip of the visco-cannula and at the same time, the viscoelastic was injected behind the ICL. This step was repeated until the ICL was halfway folded. Then the visco-cannula tip was placed below the lower flap of the folded ICL, and the haptic edge was pushed up, thereby unfolding the ICL. This placed the ICL in the correct position Care was taken not to touch the optical center of the ICL. Surgical peripheral iridectomy was performed, and the entry wound in the cornea was hydrated. The patient was put on topical antibiotics and steroids in the postoperative period (
In our cases, there was no endothelial damage or lens change, even at 6 months follow-up. We believe this method of reinversion can be comfortably done in phakic eyes with a minimum anterior chamber depth of 2.8 mm. This technique can be an easy way of positioning the ICL without explantation and a second surgery.
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