This Issue At A Glance

Abstract

Lee et al (p. 971) have demonstrated that spectral-domain optical coherence tomography (SD-OCT) can differentiate optic disc edema (ODE) from optic nerve head drusen (ONHD), as well as reveal differential points. In this case series, SD-OCT was performed with scans on the optic nerve head and measurements of retinal nerve fiber layer (RNLF) thickness on 45 patients with OHND, 15 with ODE, and 32 normal controls. The researchers found that ONHD could be differentiated from ODE using SD-OCT. The points of differentiation included (1) the presence of a hyperreflective mass under the peripapillary retina, especially in the nasal area, and (2) the profile of RNFL thickness. The authors pointed out that while direct visualization of ONHD on SD-OCT represents a simple method of detecting the condition, completely excluding ODE requires a RNFL thickness profile on SD-OCT. They conclude that compared with conventional methods for diagnosing ODE such as magnetic resonance imaging and cerebrospinal fluid tapping, SD-OCT may be a preferable noninvasive alternative to initially differentiate ONHD and ODE. In a study of diabetic macular edema (DME) treatment, Gillies et al (p. 866) have found that at 24 months, intravitreal triamcinolone acetonide (IVTA) plus laser results in a doubling of vision improvement by ≥10 letters compared with laser alone. However, IVTA eyes are more likely to experience cataract and elevated intraocular pressure (IOP). In this study, 84 eyes of 54 participants were randomly assigned to receive IVTA plus laser (42 eyes) or laser treatment alone (42 eyes). At 24 months, improvement of ≥10 logMAR letters occurred in 36% of eyes treated with IVTA plus laser, compared with 17% of eyes treated with laser alone. Cataracts were removed from 61% of phakic IVTA plus laser-treated eyes compared with 0% of laser-only eyes. Treatment for elevated IOP was required in 64% of the IVTA plus laser eyes compared with 24% of laser-only eyes. Given these possible side effects, the authors conclude IVTA may be a useful adjunctive to laser treatment in certain patients with DME. Given the challenges associated with monthly injections of ranibizumab to treat subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), would a quarterly treatment regimen be just as effective? According to findings from the EXCITE study, the first prospective trial designed to directly compare monthly and quarterly ranibizumab dosing regimens, the answer is apparently not. Schmidt-Erfurth et al (p. 831) conducted the 12-month EXCITE study, in which 353 patients with primary or recurrent subfoveal CNV secondary to AMD were randomized 1:1:1: to 0.3 mg quarterly, 0.5 mg quarterly, or 0.3 mg monthly doses of ranibizumab. Treatment involved a loading phase of 3 consecutive monthly injections followed by a 9-month maintenance phase of either monthly or quarterly injections. The gain in BCVA observed in the monthly regimen was higher than that of the quarterly regimens at 12 months. The authors conclude the results of this study are consistent with clinical guidelines recommending rigorous monthly monitoring with timely retreatment to achieve the best outcomes in these patients. Rahi et al (p. 797) report results from a life-course epidemiological investigation of myopia, studying 2487 randomly selected 44-year-old members of the 1958 British birth cohort. At age 44, cohort members underwent autorefraction, along with an epidemiological component looking at 4 “life-stage” models–preconceptional; prenatal, perinatal and postnatal; childhood; and adult–to examine the influence of early life biological, social and lifestyle factors, growth patterns, and eye-specific factors related to myopia. Results suggested that at least 1 in 3 working adults in the UK have clinically significant myopia. Myopia was associated with low birth weight for gestational age, as well as sex, greater maternal age, higher paternal occupational social class, and maternal smoking in early pregnancy. In adults, myopia was associated with higher educational attainment and socioeconomic status, and greater height. The authors conclude these results demonstrate the need for an integrated approach to myopia research that includes application of genetic and life-course epidemiological and statistical data studied across a lifetime in large, unselected populations.