Retinal Artery Contraction After Phenylephrine as a Cardiovascular Risk Biomarker.

BACKGROUND AND AIM: We investigated the in vivo changes of artery diameter (AD) and vein diameter (VD) after topical phenylephrine 2.5% instillation, and its relationship with the Systematic Coronary Risk Evaluation (SCORE). METHODS: This is a cross-sectional study. Healthy control patients were included. All of the participants underwent enhanced depth imaging by spectral-domain optical coherence tomography before and 30 minutes after phenylephrine instillation, using eye-tracking and follow-up software. Changes in AD and VD were assessed. RESULTS: The study included 45 eyes of 45 patients (14 males and 31 females). The mean age was 58.6 ± 15.1 years (26-88 years). Mean SCORE risk estimation value was 2.0 (0-14). No significant correlation was found between pre-phenylephrine AD or VD with age (p=0.237 and p=0.821, respectively), SCORE (p=0.545 and p=0.723, respectively). AD significant thinned after phenylephrine (p<0.001), whereas no significant changes could be depicted in VD (p=0.474). Changes in AD after phenylephrine were significantly related with SCORE risk estimation (p=0.035). Discordantly, changes in VD after phenylephrine were not significantly related with SCORE (p=0.505). CONCLUSION: As a significant thinning of AD occurred following phenylephrine instillation, and as the magnitude of this thinning is related with SCORE, it is useful to test the retinal artery contraction to infer the cardiovascular health status.

Outer Nuclear Layer Damage for Detection of Early Retinal Toxicity of Hydroxychloroquine.

In hydroxychloroquine (HCQ) retinopathy, early detection of asymptomatic retinal changes and the interruption of the drug are essential to prevent permanent vision loss. Our purpose was to investigate the roles of ganglion cell layer (GCL) and outer nuclear layer (ONL) thicknesses measured by optical coherence tomography (OCT) in the early diagnosis of retinopathy. One hundred and fourteen eyes of 76 individuals with HCQ treatment were enrolled in the study (42 eyes with impaired visual field (VF) and 72 eyes with nondamaged VF). We found that ONL was significantly decreased in the HCQ retinopathy group compared with the control group in the nasal macula (p = 0.032) as well as in four sectors (p < 0.044), whereas no significant differences were found comparing GCL in both groups. If VF were altered superiorly or temporarily, ONL was significantly thinned inferiorly (p = 0.029) and nasally (p = 0.008), respectively. Duration of HCQ treatment was significantly related with ONL in seven sectors of ONL (p < 0.047). We suggest that ONL measured with OCT might be used to assess early HCQ retinal toxicity.

Topographic correlation and asymmetry analysis of ganglion cell layer thinning and the retinal nerve fiber layer with localized visual field defects.

PURPOSE: To evaluate the accuracy of the measurement of the ganglion cell layer (GCL) of the posterior pole analysis (PPA) software of the Spectralis spectral-domain (SD) optical coherence tomography (OCT) device (Heidelberg Engineering, Inc., Heidelberg, Germany), the asymmetry of paired GCL sectors, the total retinal thickness asymmetry (RTA), and the peripapillary retinal nerve fiber layer (pRNFL) test to discriminate between healthy, early and advanced glaucoma eyes. METHODS: Three hundred eighteen eyes of 161 individuals with reliable visual fields (VF) were enrolled in this study. All participants were examined using the standard posterior pole and the pRNFL protocols of the Spectralis OCT device. VF impairment was graded in hemifields, and the GCL sectors were correlated with this damage. Thicknesses of each GCL, the GCL map deviation asymmetry and the pRNFL were compared between control and glaucomatous eyes. The area under the receiver operating characteristic curve (AUC) of these analyses was assessed. RESULTS: Fourteen of the 16 sectors of the GCL and pRNFL were significantly thinner in eyes with glaucoma than in control eyes (p<0.006). Similarly, the GCL map deviation showed a significant difference between these eyes and both the control eyes as well as the eyes with early glaucoma (p = 0.001 and p = 0.039, respectively). The highest values of AUC to diagnose both early and advanced glaucoma corresponded to the average pRNFL analysis and the GCL map deviation (AUC>0.823, p<0.040 and AUC>0.708, p<0.188, respectively). CONCLUSIONS: Although 16 central sectors of the GCL observed with PPA showed good correlation with VF damage, the pRNFL and the GCL map deviation were more effective for discrimination of glaucomatous damage.

Peripapillary and macular choroidal thickness before and after phenylephrine instillation.

OBJECTIVES: We investigated the effects of topical phenylephrine 2.5% instillation on choroidal thickness (CT), peripapillary choroidal thickness (pCT) and retinal nerve fibre layer (RNFL). METHODS: Healthy control patients underwent enhanced depth imaging (EDI) by spectral-domain optical coherence tomography (OCT) before and 30 min after phenylephrine instillation, using eye-tracking and follow-up software. Changes in 14 different locations of CT, 2 locations of pCT and RNFL were assessed. RESULTS: The study included 119 eyes of 62 patients (19 males and 43 females), with a mean age of 59.8 ± 15.3 years (range: 26-88 years). Within 30 min after instillation, the mean subfoveal CT both in vertical and horizontal scan were significantly thinned (p = 0.005 and p = 0.018, respectively). In total, 1500, 1000 and 500 µm temporal CT measurements showed also a significant thinning (p = 0.021, p = 0.037 and p = 0.020, respectively), as well as 500 µm both superior (p = 0.045) and inferior (p = 0.009). 1500, 1000 and 500 µm nasal CT, and 1500 and 1000 µm CT superior and inferior measurements showed no significant thinning after phenylephrine instillation. pCT was significantly thinned after phenylephrine in both superior (p = 0.016) and inferior (p = 0.050) measurements. RNFL analysis did not significantly change after phenylephrine instillation (p = 0.209). CONCLUSIONS: A significant thinning of CT and pCT occurred following phenylephrine instillation. Future studies analysing CT and pCT should detail if this mydriatic agent was used or not.

Contact lens-induced corneal peripheral swelling: Orbscan repeatability.

PURPOSE: To compare the repeatability and agreement of corneal thickness measurements using central and peripheral ultrasound and Orbscan pachymetry to detect contact lens (CL)-induced corneal swelling after extended wear (EW). METHODS: Corneal thickness was measured in five corneal locations (central, superior, inferior, nasal, and temporal) with ultrasound and Orbscan pachymetry 1 week before CL wear commenced and after 1 week of EW. High oxygen permeability (lotrafilcon A) and low oxygen permeability (etafilcon A) CL were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health to induce different amount of corneal swelling. RESULTS: Poor repeatability and poor agreement in peripheral ultrasound and Orbscan pachymetry was found between corneas with and without corneal swelling. Ultrasound coefficients of repeatability (central, superior, inferior, nasal, and temporal) in corneas without (0.95, 2.1, 3.2, 3.9, and 3.8%) and with (0.91, 1.89, 2.45, 2.66, and 2.26%) corneal swelling were higher than Orbscan coefficients of repeatability without (0.74, 1.67, 1.29, 1.11, and 1.11%) and with (0.74, 1.47, 1.28, 1.78, and 1.23%) corneal swelling. Lotrafilcon A induced significantly less corneal swelling in all five corneal locations compared with etafilcon A. Peripheral corneal swelling differences between lens types were significant only with Orbscan measurements (p < 0.05, Paired t-test and re-analysis of variance). CONCLUSIONS: The assessment of corneal thickness shows higher repeatability using Orbscan pachymetry than using ultrasound to measure corneas with and without corneal swelling and could be useful to study central and peripheral corneal swelling variations in CL EW.

Contact lens-induced corneal peripheral swelling differences with extended wear.

PURPOSE: To compare central and peripheral corneal swelling with high-Dk (lotrafilcon A) and low-Dk (etafilcon A) contact lenses (CLs) during extended wear (EW). METHODS: Corneal thickness was measured in 5 corneal locations (central, superior, inferior, nasal, and temporal) with Orbscan II pachymetry 1 week before the wearing of CLs and after 1 week of EW. High-Dk (lotrafilcon A) and low-Dk (etafilcon A) soft CLs were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health. Orbscan was also performed before CL removal after 3 and 7 days of EW. RESULTS: Lotrafilcon A induced a lower percentage of corneal swelling in all 5 corneal locations than etafilcon A (P < 0.05, paired t test). Lotrafilcon A swelling percentages were as follows: central (1.67% +/- 2.22%), superior (2.04% +/- 3.25%), inferior (1.38% +/- 1.74%), nasal (1.50% +/- 2.00%), and temporal (1.27% +/- 1.47%). Etafilcon A swelling percentages were as follows: central (4.98% +/- 3.07%), superior (6.62% +/- 8.39%), inferior (5.24% +/- 5.54%), nasal (3.41% +/- 3.14%), and temporal (4.46% +/- 3.32%). Differences between the central and peripheral corneal swelling during EW of both types of lenses were not significant (P > 0.05, repeated-measures analysis of variance). CONCLUSIONS: Central and peripheral corneal thicknesses increase more with etafilcon A than with lotrafilcon A during EW, as measured by Orbscan pachymetry.

Initial comfort of lotrafilcon A silicone hydrogel contact lenses versus etafilcon A contact lenses for extended wear.

PURPOSE: To compare the initial comfort afforded by silicone hydrogel lenses (lotrafilcon A) versus the comfort afforded by conventional hydrogel lenses (etafilcon A) in extended wear (EW). DESIGN: Prospective, double-masked and randomized controlled trial. METHODS: Lotrafilcon A and etafilcon A contact lenses were eye randomly fitted on an EW basis for 7 days and nights in 20 subjects. A forced-choice subject preference questionnaire was made. Subjects were comfort, dryness, red eye and visual quality after night wear and at the end of the day. Subjective scored satisfaction (scale: 1-5) and lens preference were assessed. RESULTS: Lotrafilcon A proved more comfortable after night wear (60%, CI95% 38-82%) and at the end of the day (70%, CI95% 49-90%) than etafilcon A after night wear (10%, CI95% 0-23%, P<0.05) and at the end of the day (20%, CI95% 2-38%, P<0.05). The feeling of dryness was more marked with etafilcon A after night wear (50%, CI95% 27-72%) and at the end of the day (50%, CI95% 27-72%) than it was with lotrafilcon A (15%, CI95% 0%-31%) after night wear (P>0.05) and at the end of the day (25%, CI95% 5%-44%, P<0.05). General satisfaction with the lotrafilcon A lens was 3.65 points (CI95% 3-4.2) and with etafilcon A 2.95 points (CI95% 2.5-3.3, P<0.05). Eighty percent (CI95% 62%-98%) of subjects preferred lotrafilcon A (P<0.05) for EW. CONCLUSIONS: In EW, lotrafilcon A contact lenses were more comfortable and led to less dryness after night wear and at the end of the day than etafilcon A contact lenses.