This issue at a glance

Abstract

Krupin et al's Low-Pressure Glaucoma Treatment Study (LoGTS) (p. 376) is the first large (13 centers) double-masked clinical trial comparing the courses of low-pressure glaucoma (LPG) patients randomized to intraocular pressure (IOP) reduction with topical twice-daily brimonidine tartrate 0.2% versus twice-daily timolol maleate 0.5%. Recruitment efforts between 1998 and 2000 identified 190 LPG patients 30 years or older. Those with an untreated pressure of >21 mmHg with advanced visual field loss were excluded from the study. Baseline patient characteristics of note included a preponderance of females (59.5%), unilateral field loss in 27.9% of the participants, and frequent optic disc hemorrhage. The central corneal thickness had a normal distribution and did not account for false low pressure measurements. The authors expressed optimism that results from this study will help them formulate better treatment alternatives for open-angle glaucoma patients with IOPs at the lower end of the disease spectrum. Asian patients have eyes with a shallow anterior chamber, and the prevalence of angle-closure glaucoma (ACG) is higher than in non-Asian patients. It is important to identify patients—before peripheral anterior synechia (PAS) develops—at risk for ACG. Kunimatsu et al (p. 407) conducted a cross-sectional study using ultrasonic biomicroscopy to determine the prevalence of appositional angle closure in Japanese patients with a shallow peripheral anterior chamber but no PAS. The researchers found appositional angle closure in at least 1 quadrant in 57.5% of 80 eyes with a narrow angle with no PAS under normal room light and in 85% in the dark. The angle width, evaluated with conventional gonioscopic grading, and the quadrant of the angle were significantly related to the presence of appositional angle closure. The authors conclude that, though appositional angle closure is probably not a rare finding among Japanese patients, more knowledge about appositional angle closure and a shallow iridotrabecular angle should provide a better understanding of the development of PAS and ACG. Findings from a study by Seitzman et al (p. 441) indicate that cataract surgery recommendations in selected patients with Fuchs' corneal dystrophy may be safely and effectively expanded to exclude simultaneous keratoplasty. Current practice for these patients includes an initial triple procedure that combines penetrating keratoplasty (PK), cataract extraction, and intraocular lens placement. However, a 12-year retrospective experience of 136 patients with Fuchs' dystrophy showed that a majority with preoperative pachymetry measurements of >600 μm maintained excellent visual rehabilitation with cataract surgery alone and did not require PK within the first year after surgery. The authors attribute these findings to the fact that instruments and cataract surgical techniques are continuously improving, with safer small-incision phacoemulsification techniques that are less damaging to the corneal endothelium. Although a prospective study is necessary to validate these findings, they conclude that changing current guidelines may help avoid the unnecessary cost and delay in visual rehabilitation associated with the initial triple procedure. Results from a case–control study by McGwin et al (p. 488) add to the growing body of evidence that cholesterol-lowering medications may reduce the risk of developing age-related macular degeneration (AMD). The objective of this research was to evaluate the association between the use of cholesterol-lowering medications and the risk of AMD in the Atherosclerosis Risk in Communities study. This large, prospective, population-based cohort study conducted in 4 communities across the United States involved 15 792 individuals aged 45 to 65 years enrolled between 1987 and 1989. The researchers identified 871 AMD cases and 11 717 controls. Of the AMD cases, 11% used cholesterol-lowering medications, as compared with 12.3% of controls. Individuals with AMD seemed to have a lower frequency of cholesterol-lowering medication use—a relationship that was statistically significant. In light of these findings and the detrimental impact of AMD on quality of life, the authors assert that a clinical trial on the impact of statins on AMD “should be pursued without delay.” A case report by Sallo et al (p. 502) highlights the role of animal filariae in causing human eye infections. A 65-year-old male from western Hungary complained of rapidly progressive peripheral visual field loss and the sensation of an actively moving object in his central vision field. Slit-lamp biomicroscopy revealed a thin filariform object surrounded by an opaque transparent coat in the anterior vitreous cavity just behind the posterior lens capsule. They observed irregular spontaneous coiling and thrashing movements, which intensified in the direct light of the slit lamp. The live nematode—identified as an immature filarial, most likely a member of the genus Onchocerca—was removed by pars plana vitrectomy. The authors note that a worm entering the eye is quite unusual because members of the genus usually inhabit dense connective tissue of their definitive hosts. The findings suggest that, with Onchocerca infections apparently on the increase, small worms recovered from the eye cannot arbitrarily be classified as Dirofilaria.