Argon Laser Peripheral Iridoplasty for Primary Angle-Closure Glaucoma
Narayanaswamy et al. recently assessed the effectiveness of argon laser peripheral iridoplasty (ALPI) against travoprost eyedrops in chronic primary angle-closure (PAC) and primary angle-closure glaucoma (PACG) patients. In this study, conducted at 2 tertiary care centers in Singapore, the authors found lower treatment success rates with ALPI than with travoprost.
This randomized controlled trial included 80 PAC or PACG patients who had undergone laser iridotomy but still had at least 180 degrees of persistent appositional angle closure and an intraocular pressure (IOP) of more than 21 mm Hg. Forty patients were randomized to receive 360-degree ALPI, and the remaining half received medical therapy (travoprost, 0.004%).
Participants received repeat ALPI if they had IOP reduction of less than 20% from baseline along with inadequate angle widening at the month 1 or month 3 visit. Medication was added for ALPI patients if IOP control was not achieved 4 weeks after retreatment; travoprost patients could be prescribed additional medications as needed at any follow-up visit.
The primary outcome measure was the success rate at 1 year. Complete treatment success was defined as IOP of 21 mm Hg or less without medication. Qualified success was defined as IOP of 21 mm Hg or less with additional medication, while failure was defined as IOP of more than 21 mm Hg despite the use of additional medications, or the need for glaucoma surgery.
Complete success was achieved in 35% of eyes in the ALPI group compared with 85% of eyes in the travoprost group, while qualified success was attained in 35% and 7.5%, respectively. A failure rate of 30% was seen in the ALPI group compared with 7.5% in the medication group. IOP decreased by 4.9 mm Hg in the ALPI group and by 6.1 mm Hg in the travoprost group. Although the mean angle width increased significantly in the ALPI group, it did not attain the desired Shaffer anatomic grade of 3.
The authors concluded that ALPI lacks the desired effectiveness to control IOP over the long term in eyes with chronic angle closure. They hypothesized that this was caused, at least in part, by dysfunction of the trabecular meshwork as a result of chronic iridotrabecular contact. They noted that because all patients in their study were Asian, further studies are needed among other ethnic groups.
Ocular Complications in Patients With Noninfectious Uveitis
Dick et al. compared the risk of ocular complications among patients with noninfectious intermediate uveitis, posterior uveitis, or panuveitis (NIIPPU) and among matched controls in a retrospective analysis of a large insurance claims database. They found that NIIPPU was associated with a higher rate of several important ophthalmic conditions.
Drawing from 16.4 million insurance claims from January 1998 through March 2012, the researchers identified 1,769 uveitis patients aged 18 to 64 years who had 2 or more claims for NIIPPU diagnoses.
Uveitis cases were matched 1:1 by gender, age, region, company, employment status, and index date with controls who did not have uveitis. The mean age of cases and controls was 47 years, and 53% were women. Participants who had an ocular complication at baseline were excluded.
The study’s main outcome measures included percentages of cases and controls that had ocular complications, as well as Kaplan-Meier survival analysis to estimate risk at 1, 5, and 10 years. Adjusted Cox regression analysis was used to determine hazard ratios (HRs) for each complication. The researchers found that NIIPPU cases had a higher risk of developing any ocular complication; the 5-year risk was 66% for uveitis patients compared with 24% for controls.
More specifically, NIIPPU cases had greater 5-year risks than controls, respectively, for developing the following conditions: glaucoma (20% vs. 9%); cataract (35% vs. 13%); visual disturbance (29% vs. 9%); blindness or low vision (5% vs. 0.5%); retinal detachment (11% vs. 0.8%), and retinal disorder (28% vs. 2%).
HRs indicated greater risks of ocular complications in NIIPPU cases during the observation period: HR, 5.2 for any ocular complication; HR, 4.8 for visual disturbance; HR, 3.2 for cataract; and HR, 2.7 for glaucoma (all p < .001). They found that HRs were even worse for the 302 persistent uveitis cases identified in the study. They concluded that treatment initiatives are needed to reduce the visual burden of NIIPPU.
Association of Statin Use With Cataract Progression and Surgery
Epidemiologic studies have investigated an association between statin use and the development of cataracts but have not established a definitive link. Al-Holou et al. examined this issue in a substudy within the Age-Related Eye Diseases Study 2 (AREDS2) population and found that the use of statins was associated with cataract surgery and progression of both cortical and posterior subcapsular (PSC) lens opacities.
AREDS2 involved 4,203 participants aged 50 through 85 between 2006 and 2008; the main study concluded in October 2012, after a median follow-up of 5 years. From that population, 2,771 individuals—who were bilaterally phakic at baseline, with less than 5% center subfield cortical or PSC opacity—were included in the present substudy. Statin use was self-reported at baseline.
Progression to more than 5% central opacity was the outcome for both cortical and PSC cataracts, and cataract surgery was used as a surrogate of moderate to severe lens opacity of unspecified type. Slit-lamp examination was conducted at annual study visits, and telephone calls were made every 6 months to inquire about cataract surgery between the study visits.
Among the 2,771 participants, 1,184 (42.7%) were statin users. Statin users tended to be older, male, and former or current smokers; they also tended to have a history of diabetes and aspirin use as well as a history of cardiovascular disease and its risk factors.
In this analysis, statin users had an increased risk of cataract surgery (hazard ratio [HR], 1.90; 95% CI, 1.17-3.10), cortical lens opacity progression (HR, 1.52; 95% CI, 1.08-2.12), and PSC lens opacity progression (HR, 1.84; 95% CI, 1.25-2.71). Female statin users had an increased risk of cataract progression and cataract surgery. Statin users under the age of 75 years also had an increased risk of PSC lens opacity progression and cataract surgery.
The authors noted that AREDS2 study participants do not necessarily represent the wider population, and thus, the findings may not be generalizable. Nevertheless, the authors concluded that this study raises important questions, and given the large number of people who take these drugs, further study is needed to elucidate potential associations. Meanwhile, they said, patients should be encouraged to take statins when medically indicated and maintain regular eye examinations.
Ophthalmology summaries are written by Marianne Doran and edited by Susan M. MacDonald, MD.
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American Journal of Ophthalmology