This Issue at a Glance

Abstract

Watanabe et al (p. 2103) investigated the effect of corneal guttae severity on the quality of vision in patients with mild Fuchs’ corneal dystrophy. They found that corneal guttae—even without edema seen on slit-lamp examination—have a negative impact on patients’ quality of vision, and that intraocular forward light scatter caused by the guttae may result in visual disturbances. This cross-sectional study included 23 eyes of 14 patients who had Fuchs’ dystrophy but no evident edema. The researchers evaluated the area ratio of the guttae and correlated that with corrected distance visual acuity (CDVA), letter contrast sensitivity (LCS), and intraocular straylight. The severity of the guttae was negatively associated with all 3 visual parameters. In addition, patients with higher straylight had worse CDVA and LCS. Brøndsted et al (p. 2115) set out to investigate 2 questions: (1) Does cataract surgery have an effect on circadian photoentrainment, and (2) do blue-blocking or neutral intraocular lenses (IOLs) differ with regard to their impact on sleep quality? Although they found negative answers to both questions, they also observed some subtle changes and noted that longer follow-up and fellow eye surgery might reveal a connection with sleep disturbances. This single-center trial involved the first eye in 76 patients with bilateral cataracts; the patients were randomized to receive either a blue-blocking or a neutral IOL. The primary outcome was activation of intrinsic photosensitive ganglion cells using post-illumination pupil response to blue light; secondary outcomes were circadian rhythm analysis and salivary melatonin measurements, as well as sleep quality measurements. While some circadian parameters were affected by surgery, others were not. Overall, sleep quality remained unchanged during the 3-week follow-up period, and no differences were noted between blue-blocking and neutral IOLs. How much lead time can optical coherence tomography (OCT) provide when it comes to detecting glaucoma in patients before visual field (VF) defects are evident on standard automated perimetry? Kuang et al (p. 2002) investigated this question and found that OCT could detect damage in approximately one-third of glaucoma patients up to 5 years before the earliest VF defects were evident—and could provide a lead time of up to 8 years in 19% of patients. For this observational cohort study, the researchers evaluated 75 glaucoma suspects (75 eyes) who were part of a larger longitudinal study and matched them with a control group of 75 healthy patients (75 eyes). At the time of development of the earliest VF defect, mean average retinal nerve fiber layer (RNFL) thickness obtained by OCT was 75 μm in glaucomatous eyes, versus 90 μm in healthy eyes. The authors emphasize that OCT should be used as an ancillary diagnostic tool for glaucoma rather than as a replacement for the visual field. In the first study to do so, Siah et al (p. 2029) evaluated the relationship between macular pigment (MP) optical density, and structural parameters of the macula and optic nerve head in glaucomatous eyes. They found that MP density is lower in more severe cases of glaucoma exhibiting foveal involvement. Data for this cross-sectional analysis were collected during the Macular Pigment and Glaucoma Trial, which involved 88 patients with open-angle glaucoma. Structural parameters were captured via Fourier-domain optical coherence tomography (FD-OCT), and MP density was measured using a customized flicker photometry technique. Patients with ganglion cell complex (GCC) loss involving the foveal zone had lower MP at several measurement points. They also had more severe disease, as measured by GCC and retinal nerve fiber layer thickness, greater cup-to-disc area ratio, and lower optic disc rim area. Further study is needed to better define factors that influence MP levels in glaucoma, the researchers said, as well as to evaluate whether oral dietary MP supplementation in glaucoma patients might have a beneficial effect. Brown et al (p. 2044) compared the efficacy and safety of 2 dosing regimens of intravitreal aflibercept with that of macular laser photocoagulation for diabetic macular edema (DME). They found that the results of treatment with aflibercept were visually and anatomically superior to those achieved with laser through week 100, with similar efficacy in the 2 aflibercept groups. Moreover, both dosing regimens of aflibercept were superior to laser with regard to diabetic retinopathy progression using the ETDRS scale, and the incidence of adverse events was low. This study reports the second-year results of 2 prospective, randomized phase 3 trials (VISTA and VIVID) that involved 872 patients (872 eyes) with type 1 or 2 diabetes and DME with central involvement. Patients received either 2 mg of aflibercept every 4 weeks, 2 mg of aflibercept every 8 weeks following 5 monthly doses, or laser control.