Repeatability of corneal pachymetry and epithelial thickness measurements with spectral-domain optical coherence tomography (SD-OCT) and correlation to ocular surface parameters.

PURPOSE: To assess the repeatability of corneal pachymetry and epithelial thickness measurements with spectral-domain optical coherence tomography (SD-OCT) and identify correlations between epithelial thickness and ocular surface parameters. METHODS: Adults who happened to have prolonged computer use were recruited, excluding those with conditions interfering with corneal measurements or tear production. All subjects filled in the ocular surface disease index (OSDI) questionnaire. Three consecutive measurements of central and peripheral corneal and epithelial thickness were performed with SD-OCT (RTVue XR). Schirmer test I and tear film break-up time (TBUT) were performed. Repeatability was evaluated with intraclass correlation coefficient (ICC), coefficient of variation and repeatability limit. Spearman correlation was used for non-parametric variables. RESULTS: 113 eyes of 63 subjects were included in the study. ICC was ≥ 0.989 for all corneal and ≥ 0.944 for all epithelial pachymetry segments. The best repeatability was found centrally and the worst superiorly both for corneal and epithelial measurements. Central epithelial thickness was weakly correlated with Schirmer test I (rho = 0.21), TBUT (rho = 0.02), OSDI symptoms and OSDI score (rho <|0.32|). OSDI symptoms and OSDI score were weakly correlated with Schirmer test I (rho <|0.3|) and TBUT (rho <|0.34|). CONCLUSION: RTVue XR measurements of corneal and epithelial thickness are highly repeatable in all segments. The lack of correlation between epithelial thickness and ocular surface parameters could suggest the assessment of epithelial integrity with reliable methods such as SD-OCT.

Prediction of Postoperative Visual Outcome in Patients with Idiopathic Epiretinal Membrane.

PURPOSE: The aim of this study was to estimate the association between preoperative characteristics in subjects with idiopathic epiretinal membrane (ERM) and visual acuity improvement after vitrectomy and create an algorithm for predicting postoperative visual outcome. METHODS: In a retrospective, cross-sectional study, we included adults with idiopathic ERM and excluded subjects with low-quality scans, other ocular conditions, and previous surgery except cataract surgery. Baseline characteristics were extracted from medical files, spectral-domain OCT, and OCT angiography. Visual improvement was expressed as a binary variable. RESULTS: Fifty-four subjects were included in the study. Three months postoperatively, 30 subjects improved, 10 remained stable, and 14 deteriorated. Spearman correlation showed no correlation between variables and visual acuity improvement (<0.39). Reduced dimensionality showed that baseline visual acuity, lens status, foveal aspect, spherical equivalent, and 2 interactive variables including foveal aspect and lens status have the strongest effect on improvement. Five-fold logistic regression based on these variables provided a model with AUC 0.9 ± 0.06. CONCLUSION: No variable has a direct predictive role on visual acuity improvement; however, baseline visual acuity, lens status, foveal aspect and spherical equivalent, when combined, provide a predictive model that could serve as a tool for more informed decisions.

FOVEA PLANA ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY: New Perspectives.

PURPOSE: To report on the reliability of optical coherence tomography angiography (OCTA) to diagnose fovea plana. METHODS: A retrospective, cross-sectional, case-control study included patients with foveal persistence of the inner retinal layers, confirmed by spectral domain OCT, and superficial capillary plexus (SCP) and deep capillary plexus foveal vascularization confirmed by OCTA. A healthy control group was selected. The best-corrected visual acuity was obtained. Spectral-domain OCT was used for measuring the outer nuclear layer thickness, and OCTA determined the foveal avascular zone, SCP, and deep capillary plexus vascular density. RESULTS: Optical coherence tomography angiography reliability, based on all parameters, reached 97%, whereas based only on SCP vascular density 91%. The plana group (n = 57) differed significantly from the control group (n = 28) in terms of foveal avascular zone, SCP, and deep capillary plexus foveal vascular density (P < 0.005). Subjects with SCP foveal vascular density >30% or foveal avascular zone <0.1 mm2 had fovea plana. The best-corrected visual acuity of the plana group had no correlation with OCTA quantitative parameters (Pearson |r|<0.18, Spearman |r|<0.44). CONCLUSION: Optical coherence tomography angiography has a high accuracy in diagnosing fovea plana, as its characteristics differ significantly from the normal population. The lack of correlation between the best-corrected visual acuity and OCTA parameters implies that reduced the best-corrected visual acuity is likely to result from coexistent diseases rather than from the foveal structure.

The effect of hormone replacement therapy and tibolone on lipoprotein (a) concentrations in postmenopausal women: A systematic review and meta-analysis.

OBJECTIVE: Data on the effect of hormone replacement therapy (HRT) and tibolone on lipoprotein (a) [Lp(a)], an independent risk factor for cardiovascular disease, are heterogeneous and conflicting. Studies of the effect of HRT and tibolone on Lp(a) concentrations in post-menopausal women are reviewed in this meta-analysis. DESIGN AND METHODS: MEDLINE, Scopus, EMBASE and Cochrane databases were searched (up to February 10, 2017). Two researchers identified randomized controlled studies and extracted data. Potential controversies were resolved by a third reviewer. RESULTS: In 24 eligible studies, HRT caused a significant reduction in Lp(a) concentrations compared with placebo or no treatment [mean relative difference: -20.35%, 95% Confidence Interval (CI): -25.33% to -15.37%, p<0.0001], with significant heterogeneity between studies (I2=98.5%), but without evidence of publication bias. No significant effect was found for tibolone (n=7) (mean relative difference: -23.84%, 95% CI: -63.43% to 15.74%, p=0.238) (I2=98.7%, but without publication bias). Oral estrogen caused a greater reduction in Lp(a) concentrations than transdermal estrogen (n=10) (mean relative difference: 37.66%, 95% CI: 16.84% to 58.48%, p<0.0001), with significant heterogeneity between studies (I2=99%), but no evidence of publication bias. No difference was observed when continuous was compared with cyclical HRT, conventional with low-dose estrogen, and estrogen monotherapy with estrogen combined with progestogen. No difference was observed between HRT and tibolone regarding their effect on Lp(a). CONCLUSIONS: HRT significantly decreases Lp(a) concentrations, with oral being more effective than transdermal estradiol. The type of HRT, dose of estrogen and addition of progestogen do not seem to modify the Lp(a)-lowering effect of HRT.