Investigating the Impact of Sun/UV Protection and Ease of Skin Tanning on the Risk of Pseudoexfoliation Glaucoma: A Mendelian Randomization Study.

Purpose: To investigate the potential causal associations between the use of sun/ultraviolet (UV) protection and ease of skin tanning and the risk of pseudoexfoliation glaucoma (PXG) in European populations. Methods: Single nucleotide polymorphisms (SNPs) associated with the use of sun/UV protection and ease of skin tanning were selected from the UK Biobank genome-wide association study database consisting of 498,751 European participants. SNPs of PXG were obtained from the FinnGen study including 3424 PXG cases and 326,434 controls. Two-sample Mendelian randomization (MR) analyses were performed to assess the association between the use of sun/UV protection and ease of skin tanning and risk of PXG. Results: Inverse variance weighted regression of genetic susceptibility predicted that both use of sun/UV protection and ease of skin tanning were potentially positively associated with the decreased risk of PXG in the European ancestry (use of sun/UV protection: odds ratio [OR] = 0.47; 95% confidence interval [CI], 0.24-0.92; P = 0.028; ease of skin tanning: OR = 0.81; 95% CI, 0.67-0.97; P = 0.025). Conclusions: We found genetic evidence supporting a potential causal association between UV protection and a decreased risk of PXG in European population. Further research will help elucidate the underlying mechanisms and promote UV protection for eyes, especially in people with a high risk of PXG.

YAG laser peripheral iridotomy for the prevention of pigment dispersion glaucoma a prospective, randomized, controlled trial.

PURPOSE: To test the hypothesis that neodymium:yttrium-aluminum-garnet (Nd:YAG) laser peripheral iridotomy (LPI) significantly reduces the incidence of conversion from pigment dispersion syndrome (PDS) with ocular hypertension (OHT) to pigmentary glaucoma (PG). DESIGN: Prospective, randomized, controlled 3-year trial. PARTICIPANTS: One hundred sixteen eyes of 116 patients with PDS and OHT. INTERVENTION: Patients were assigned randomly either to Nd:YAG LPI or to a control group (no laser). MAIN OUTCOME MEASURES: The primary outcome measure was conversion to PG within 3 years, based on full-threshold visual field (VF) analysis using the Ocular Hypertension Treatment Study criteria. Secondary outcome measures were whether eyes required topical antiglaucoma medications during the study period and the time to conversion or medication. RESULTS: Fifty-seven patients were randomized to undergo laser treatment and 59 were randomized to no laser (controls). Age, gender, spherical equivalent refraction, and intraocular pressure at baseline were similar between groups. Outcome data were available for 105 (90%) of recruited subjects, 52 in the laser treatment group and 53 in the no laser treatment group. Patients were followed up for a median of 35.9 months (range, 10-36 months) in the laser arm and 35.9 months (range, 1-36 months) in the control arm. Eight eyes (15%) in the laser group and 3 eyes (6%) in the control group converted to glaucoma in the study period. The proportion of eyes started on medical treatment was similar in the 2 groups: 8 eyes (15%) in the laser group and 9 eyes (17%) in the control group. Survival analyses showed no evidence of any difference in time to VF progression or commencement of topical therapy between the 2 groups. Cataract extraction was performed on 1 patient in the laser group and in 1 patient in the control group during the study period (laser eye at 18 months; control eye at 34 months). CONCLUSIONS: This study suggests that there was no benefit of Nd:YAG LPI in preventing progression from PDS with OHT to PG within 3 years of follow-up.

Iris and trabecular meshwork pigment changes after posterior chamber phakic intraocular lens implantation.

PURPOSE: To evaluate the changes in laser iridotomies, intraocular pressure (IOP), angle structures, and pupil diameter after implantable contact lens (ICL) (Version 4 Staar Surgical) implantation in myopic Asian eyes. SETTING: Department of Ophthalmology, Chung-Ang University Yongsan Hospital, Seoul, Korea. METHODS: The ICL was implanted in 81 eyes of 43 patients with spherical equivalent greater than -6.00 diopters. Gonioscopy examination was performed 1 day after laser iridotomy and 6 and 12 months after ICL implantation. The changes in laser iridotomy sites, IOP, and pupil diameter were also evaluated. RESULTS: Ten eyes (12.3%) had occlusion or narrowing of the laser iridotomy sites. The angle width was more than 30 degrees in all cases preoperatively but narrowed to less than 20 degrees in 16 eyes (19.8%) 6 months postoperatively. The mean pigment, measured by the semiquantitative method (grade 0 to 4), was 2.03 in the inferior angle, 0.18 in the nasal angle, 0.12 in the temporal angle, and 0.00 in the superior angle 12 months postoperatively. The pigment in all quadrants increased temporally as a result of the laser iridotomy or iris rubbing by the ICL; however, the pigments absorbed gradually and decreased to values before laser iridotomy 12 months postoperatively. There was a temporary increase in IOP from the instillation of steroid eyedrops 1 week and 1 month postoperatively; IOP returned to the preoperative level and remained there 12 months postoperatively. There was a significant decrease in pupil diameter 1 and 3 months postoperatively; the diameter returned to the preoperative size at 6 and 12 months. Pigment dispersion syndrome and pigmentary glaucoma were not seen. CONCLUSION: Implantation of the ICL narrowed the angle width but did not increase trabecular pigmentation compared with values after laser iridotomy, indicating ICL implantation is safe regardless of the pigmentary changes in the trabecular meshwork.

Factors associated with long-term progression or stability in exfoliation glaucoma.

OBJECTIVE: To evaluate the effect of intraocular pressure (IOP) reduction on long-term progression or stability in patients with exfoliation glaucoma. DESIGN: Multicenter (Greece, Spain, Russia, and Hungary), retrospective analysis. METHODS: Medical record analysis of 167 patients with at least 5 years of follow-up, who were stable (n = 85) or whose condition had progressed (n = 82) after the beginning of the follow-up period. RESULTS: The mean +/- SD IOP was 18.1 +/- 2.6 mm Hg in the stable group and 20.1 +/- 4.3 mm Hg in the progressed group (P<.001). The mean +/- SD follow-up time was 6.1 +/- 2.3 years for the stable group and 3.4 +/- 1.7 years for the progressed group. The mean SD for each patient's average IOP was 2.9 mm Hg for the stable group and 4.6 mm Hg for the progressed group (P<.001). Twenty-eight percent of patients who had a mean IOP of 17 mm Hg or lower, 43% of those with an IOP of 18 to 19 mm Hg, and 70% of those with an IOP of 20 mm Hg or higher progressed. Progressed patients had statistically greater optic disc damage at baseline and more medication changes and trabeculectomies during follow-up than stable patients (P<.05). CONCLUSION: This study suggests that IOP reduction helps to prevent glaucoma progression in patients with exfoliation glaucoma, although it does not guarantee the prevention or worsening of the disease.

Implantable contact lens for moderate to high myopia: short-term follow-up of 2 models.

PURPOSE: To confirm the safety, efficacy, and predictability of the surgical correction of moderate to high myopia by the ICM V3 and ICM V4 implantable contact lenses (ICLs), with emphasis on vaulting, intraocular pressure (IOP), and pigment dispersion. SETTING: University Eye Hospital, Lausanne, Switzerland. METHODS: Thirty-two eyes had implantation of an ICL. In 22 eyes with a mean spherical equivalent (SE) of -11.5 diopters (D), the target was emmetropia; in 10 eyes with a mean SE of -22.3 D, the goal was a reduction in the myopia. Nineteen eyes received the ICM V3 ICL and 13, the ICM V4 ICL. The mean follow-up was 7.4 months. RESULTS: The mean postoperative SE in the 32 eyes was -2.16 D. Best spectacle-corrected visual acuity was maintained or improved in all eyes. In the 22 eyes targeted to achieve emmetropia, 10 (45%) were within +/-1.00 D; 15 (68%) had an uncorrected visual acuity of 20/40 or better and 4 (18%), of 20/20 or better. Vaulting of the ICL over the crystalline lens was more pronounced with the V4 than with the V3, and the difference was statistically significant. Subtle, localized anterior subcapsular opacification was encountered in 4 eyes. In 3 of them, the ICL (model V3) vaulting was minimal and 1 ICL (model V4) did not show any vaulting. Eighteen eyes had an IOP higher than the preoperative level, and the difference was statistically significant. No correlation was seen between final IOP and vaulting. Pigment dispersion on the ICL did not appear to be related to vaulting or ICL thickness. CONCLUSION: Implantation of an ICL was effective in correcting moderate to high myopia of up to -17.50 D. Although the procedure appears to be safe, the predictability of the refractive outcome must be improved. The new generation of ICLs for myopia (ICM V4) offers a better vault over the crystalline lens than the older models (ICM V3), which should decrease the risk of cataract. No explanation was found for the IOP increase in several eyes 3 months or more after surgery.

The effectiveness of dapiprazole in preventing exercise-induced IOP increase in patients with pigmentary dispersion syndrome.

PURPOSE: The authors investigated the use of dapiprazole, an alpha-adrenergic blocking agent, in preventing pigment release and IOP increase after exercise in patients affected with PDS. METHODS: Three young myopic males (31, 34 and 35 years old) affected with pigmentary dispersion syndrome performed 30 minutes of jogging on a computerized treadmill. Telemetric heartbeat measurement was performed to obtain constant pulse rate training. Computerized tonography and IOP measurement were performed 10 minutes after the exercise. After one month the patients repeated the same exercise after pre-treatment with dapiprazole 0.5% eyedrops (one drop 30, 20 and 10 minutes before the exercise). Ten minutes after the exercise IOP measurements and computerized tonography were repeated. RESULTS: After 30 minutes of exercise IOP measurements showed values ranging from 19 to 45 mmHg (mean 30.33; SD 8.73). Computerized tonography C values after exercise ranged from 0.04 to 0.16 (mean 0.09; SD 0.04). After pre-treatment with dapiprazole 0.5% eyedrops, IOP values ranged from 18 to 28 mmHg (mean 23.33; SD 3.44) and tonography C values ranged from 0.10 to 0.20 (mean 0.14; SD 0.03). CONCLUSIONS: The study supports the concept that exercise-induced pigment release temporarily obstructs the acqueous outflow channels, causing IOP increase in some patients with PDS. Pre-treatment with dapiprazole was useful in reducing IOP spikes and in increasing tonographic total outflow facility after exercise. The absence of induced myopia and the lack of dangerous vitreoretinal tractions on retinal periphery make dapiprazole a safe method to reduce exercise-induced pigment dispersion.

Iris chafing in pseudophakia.

Iris defects occur in pseudophakic patients with posterior chamber intraocular lens in sulcus. Prevalence of pigmentary dispersion syndrome and pigmentary glaucoma has been evaluated in 920 pseudophakic patients (920 eyes). 16.08% of patients showed pigment dispersion syndrome, while 1.96% developed pigmentary glaucoma. Diabetic patients had a statistically significant greater prevalence of these complications than non-diabetic ones (p < 0.05). The authors suggest the preventive use of alpha-blockers in presence of pigment dispersion syndrome or diabetes mellitus, even in absence of ocular hypertension.