Assessment of corneal epithelial thickness mapping in epithelial basement membrane dystrophy.

PURPOSE: To investigate the corneal epithelial thickness topography with optical coherence tomography (OCT) and its relationship with vision quality in epithelial basement membrane dystrophy (EBMD). METHODS: 45 eyes of EBMD patients, 26 eyes of dry eye (DED) patients and 22 eyes of normal subjects were enrolled. All participants were subjected to 9-mm corneal epithelial mapping with OCT and vision quality was assessed with the optical quality analysis system using the objective scatter index (OSI). Central, superior, inferior, minimum, maximum, and standard deviation of epithelium thickness (Irregularity), were analysed and correlations with the OSI were calculated. RESULTS: The mean (±SD) central, inferior and maximum epithelial thicknesses of the EBMD patients (respectively, 56.4 (±8.1) µm, 58.9 (±6.4) µm, and 67.1 (±8.3) µm) were thicker compared to DED patients (P<0.05) and normal subjects (P<0.05). We found greater irregularity of epithelial thickness in EBMD (5.1±2.5 µm) compared to DED patients (2.6±1.0 µm) (P = 4.4.10-6) and normal subjects (2.1±0.7 µm) (P = 7.6.10-7). The mean OSI was worse in EBMD patients than in DED patients (P = 0.01) and compared to normal subjects (P = 0.02). The OSI correlated with the epithelial thickness irregularity (Spearman coefficient = 0.54; P = 2.65.10-5). CONCLUSIONS: The OCT pachymetry map demonstrated that EBMD patients had thicker corneal epithelium in the central and inferior region. These changes were correlated with objective measurements of vision quality. This OCT characterisation of the EMBD provides a better understanding of the epithelial behaviour in this dystrophy and its role in vision quality.

Early recovery of quality of vision and optical performance after refractive surgery: Small-incision lenticule extraction versus laser in situ keratomileusis.

PURPOSE: To assess the early time course of the visual function after small-incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK). SETTING: Quinze-Vingts National Ophthalmology Hospital, Paris, France. DESIGN: Prospective case series. METHODS: Patients scheduled for bilateral small-incision lenticule extraction or LASIK were consecutively enrolled. In addition to standard refraction and visual acuity, contrast sensitivity, aberrometry, and patient-reported quality of vision and overall satisfaction were measured 1 day, 7 days, and 1 month postoperatively. RESULTS: Each group comprised 23 patients (46 eyes). The postoperative contrast sensitivity was better in the LASIK group at 1 day (P = .014) and 7 days (P = .001) but not at 1 month. No significant differences in visual acuity, efficacy, or safety were found between the 2 groups throughout the follow-up. The objective scatter index assessed by double-pass aberrometry was better after LASIK 1 day postoperatively (P = .036) but was not statistically different thereafter. The patient-reported quality of vision was significantly worse in the small-incision lenticule extraction group than in the LASIK group at 7 days (P = .010). Global satisfaction did not differ between groups throughout the study. Significant correlations were found between contrast sensitivity and aberrometry in both groups at all examinations. CONCLUSIONS: Targeted analysis of early quality of vision through objective and subjective methods suggested that compared with LASIK, a slight delay in corneal optical recovery after small-incision lenticule extraction might lead to reduced contrast sensitivity and specific patient-reported visual disturbance during the first postoperative week with no effect on overall patient satisfaction.