Search

Purpose. To evaluate early changes in visual function and visual quality parameters after Descemet membrane endothelial keratoplasty (DMEK) and to compare the outcomes with healthy controls. Methods. Thirteen patients who underwent DMEK and 14 controls were evaluated. All subjects underwent visual function evaluation, including visual acuity under photopic and mesopic lighting conditions and contrast sensitivity (CSV) tests CSV 1000 and Pelli-Robson. Corneal parameters were assessed with Oculus Pentacam. Corneal mean keratometry (Km), corneal densitometry values, and low and high order aberrations (LOA and HOA) were recorded. In DMEK patients, all tests were performed before surgery and 1 and 6 months after surgery. Results. In patients who underwent DMEK, photopic visual acuity improved from 0.59 to 0.31 at 1 month (p=0.013) and 0.13 at 6 months (p=0.008); mesopic visual acuity and all contrast sensitivity values (both CSV and Pelli-Robson test) improved significantly in the first month (p<0.005). A significant decrease was observed in corneal density in the 0–2 mm ring (from 43.83 to 35.60, p=0.043) and mean posterior Km (from −5.84 to −6.80, p=0.005) in the first month. Corneal HOAs and all corneal densities improved at 6 months after DMEK (p<0.05). All visual function parameters and corneal aberrations remained lower and higher, respectively, compared with healthy controls (p<0.05). Corneal densities were comparable with controls at 6 months after DMEK (p>0.05). Conclusions. Patients undergoing DMEK present visual function improvement and a decrease in corneal density at 1 month after surgery. Decrease in corneal posterior HOAs can be observed at 6 months. However, visual function outcomes and corneal aberrations remained worse compared with healthy controls. [ABSTRACT FROM AUTHOR]

Purpose. To evaluate the ability of frequency-doubling technology (FDT) perimetry in detecting visual field defects in young adults with type I diabetes prior to retinopathy or with minor retinovascular changes. Methods. This comparative cross-sectional study included 30 healthy subjects and 73 age-matched patients with type I diabetes mellitus. All subjects underwent a full ocular examination including an FDT with the threshold C-20-5 strategy. Only one eye per subject was randomly included in the statistical analysis. FDT results and time to perform the test were compared between the groups. Results. The mean age was 27.1 years in the control group and 26.6 years in the diabetic group (P=0.875). The mean period from the onset of diabetes was 12.6±6.7 years, while minimal retinovascular changes were observed in 18 eyes. Mean deviation of FDT did not differ between the groups. Although global indices of FDT were within normal limits, pattern standard deviation of FDT was higher in the diabetic group (P=0.035). The area under the receiver operating characteristic curve was 0.647 for pattern standard deviation of FDT (standard error = 0.052;P=0.0017). Conclusion. FDT can detect retinal dysfunctions in diabetic patients prior to the onset of significant vascular complications. [ABSTRACT FROM AUTHOR]

Purpose: To test intrasession, intersession, intervisit and interoperator reproducibility of retinal nerve fibre (RNFL) measurements and retinal thickness in healthy subjects using Cirrus Fourier-domain optical coherence tomography (OCT) (Carl Zeiss Meditec, Inc). Methods: Seventy-two eyes of 72 healthy subjects were included in the study. All the eyes underwent three 512 × 128 volume cube centred on the fovea and three 360° circular scans centred on the optic disc by one observer. This sequence was redone by another observer on a second visit within a 2-week period. Descriptive statistics, analysis of variance, intraclass correlation coefficients (ICCs) and coefficients of variation (COVs) were calculated for the nine areas corresponding to the Early Treatment Diabetic Retinopathy Study and for quadrants and RNFL clock hr sectors. Results: Retinal thickness and RNFL measurements were highly reproducible. Mean total retinal thickness was 285.2 ± 15.3 μm by observer 1 and 284.2 ± 12.9 lm by observer 2. Mean COV was 1.2%. Mean RNFL average thicknesses were 96.0 ± 7.7 and 95.7 ± 7.9 lm by observer 1 and 2, respectively. Mean COV was 4.4%. The ICCs ranged from 0.823 to 0.992. Mean differences between both operators were lower than 3 μm, and no significant differences were found. Conclusions: Retinal and RNFL thickness measurements obtained using Cirrus OCT show good repeatability for healthy eyes and few differences between intra- and interobserver evaluations. It can be considered a valid device for measuring retinal and optic nerve parameters in normal eyes. [ABSTRACT FROM AUTHOR]