Diurnal Variation in Straylight in Patients With Fuchs Endothelial Corneal Dystrophy and Controls.

PURPOSE: The goal of this study was to investigate diurnal changes in intraocular straylight in relation to other corneal parameters and subjective complaints in patients with Fuchs endothelial dystrophy and healthy controls. METHODS: This is a prospective study conducted in 2 tertiary care hospitals in Germany and the Netherlands. Patients with Fuchs endothelial dystrophy (n = 71) and healthy controls (n = 34) were included. Patients with Fuchs dystrophy were grouped by the presence of subjective complaints and measured over multiple time points during the day. Measurements included intraocular straylight using the C-Quant and corneal thickness and backscatter using a Scheimpflug camera. A separate group of healthy controls was measured intensively with repeated straylight measurements directly after waking. An exponential decay model was used to model the diurnal change. RESULTS: Healthy controls showed an average straylight baseline of 1.17 log(s) with an increase in straylight after waking of 0.22 log(s). In the repeated measurements subgroup, the increase in morning straylight lasted for 22 minutes. Patients with Fuchs dystrophy showed a morning increase in straylight of 0.21 log(s) present up to 4 hours after waking before reaching an average baseline of 1.30 log(s). Straylight was positively correlated with anterior corneal backscatter, r = 0.21, P = 0.022, and corneal thickness, r = 0.46, P < 0.01. CONCLUSIONS: Healthy eyes experience a diurnal straylight increase similar to patients with Fuchs dystrophy in intensity. However, in Fuchs dystrophy, the resolution of increased straylight is prolonged over multiple hours compared with minutes in healthy eyes. This suggests pathological exacerbation of a physiological diurnal change. This mechanism can play a role in subjective complaints experienced by patients with Fuchs dystrophy.

Straylight in posterior polar cataract.

PURPOSE: To study straylight before and after posterior polar cataract removal. SETTING: Academic Medical Center, Amsterdam, the Netherlands. DESIGN: Prospective case series. METHODS: Patients diagnosed with posterior polar cataract who agreed to cataract surgery were included in the study. Intraocular straylight was measured before and after surgery with the compensation comparison method using a straylight meter (C-Quant). RESULTS: Measurements were performed on 8 eyes of 4 patients. The mean preoperative corrected distance visual acuity was relatively good (0.15 logarithm of the minimum angle of resolution [logMAR] ± 0.18 (SD). The mean postoperative CDVA was -0.08 ± 0.09 logMAR (P < .01). The mean preoperative straylight was extreme (2.01 ± 0.38 log[s]), 13 times that of a young normal eye; however, it improved postoperatively to 1.04 ± 0.26 log(s) (P < .01). CONCLUSIONS: Straylight in eyes with posterior polar cataract patients can be extremely bothersome, while visual acuity is relatively well preserved. Surgery was effective in lowering straylight levels. For these patients, straylight measurements can help objectively measure the quality of vision complaints, and elevated straylight levels can be an indication for surgery independent of visual acuity.

Effects of Corneal Scars and Their Treatment With Rigid Contact Lenses on Quality of Vision.

OBJECTIVES: To study the effects of corneal scars and the treatment of these scars with rigid gas-permeable (RGP) contact lenses on quality of vision including straylight. Visual effects were related to scar characteristics such as size and grade. METHODS: Straylight and best-corrected visual acuity were measured in 23 patients with corneal scars during and after RGP contact lens wear. Contralateral eyes were used as controls, and age-normal values in case of bilateral scars. Straylight measurements were performed using the compensation comparison method of the Oculus C-Quant instrument. RESULTS: Scarred eye straylight values were 1.53 log(s) without contact lens and 1.60 log(s) with contact lens (P=0.043). Healthy eyes without contact lens had a mean straylight value of 1.13 log(s), corresponding to age-normal values. Contact lens wear increased straylight in healthy eyes to 1.26 log(s) (P<0.001). Visual acuity improved from 0.66 logarithm of minimal angle of resolution (logMAR) to 0.19 logMAR with contact lens wear in eyes with a corneal scar (P<0.001). CONCLUSIONS: Corneal scars can have a strong effect on quality of vision by diminishing visual acuity and increasing straylight. The increase in straylight from corneal scars on its own can lead to a serious visual handicap. Contact lens treatment did not improve straylight, but showed a slight worsening. As the recovery of visual acuity with contact lens wear far exceeded straylight increase, contact lenses remain a clinically useful treatment option in most patients with corneal scars.