Abstract
Purpose :
While the thickness of the peripapillary nerve fiber layer (RNFLT) has been used for the detection of early glaucoma through optical coherence tomography (OCT), recently, the measurement of the minimum distance of the opening of the Bruch membrane (BMO) to internal limiting membrane (BMO-MRW) has been proposed as a valid option for structural measurement. When micro/macrodiscs are present, the diagnosis of glaucoma presents a greater challenge for clinicians.
Methods :
Retrospective, observational, quantitative, descriptive and cross-sectional study in patients with glaucoma and controls by OCT. Two groups were obtained: glaucoma patients and controls; each group was divided into subgroups, depending on the BMO: <3 – macrodiscs, 2-3 – normodiscs and <2 – microdiscs. Each sector of each parameter was compared between groups to find out if there is a significant difference, to deduce if one is more reliable to observe glaucomatous changes depending on the size of the disc.
Results :
The total sample was 376 patients. The normodisc was the most frequent, followed by microdisc and finally macrodisc. Normality tests (Kolmogorov-Smirnof) (p<0.05) were performed, and all groups were out of normality. The Kruskal Wallis test (KW) (nonparametric one-way ANOVA test) was used for each OCT parameter (RNFLT, BMO-MRW; CCG) by disc size, comparing patients vs controls in the temporal, superior temporal, inferior temporal, nasal, superior nasal, inferior nasal, global. p>0.05 was used. In the normodiscs, significant differences were found in most of the sectors, in the 3 parameters. The microdisks presented a greater number of sectors with significant differences in the BMO-MRW parameter. No significant differences were found in the macrodiscs.
Conclusions :
In normodiscs we can evaluate RNFLT, MRW and CCG and finding alterations in them, will help us to notice glaucomatous changes. In microdiscs, the parameter with the greatest number of significant sectors is BMO-MRW, so it could be inferred, that it is the parameter would be the most useful for observing changes due to glaucoma. Patients with macrodisc showed no significant difference with controls, so it could be expected that the OCT would be normal, even though it presented glaucomatous changes.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.