Abstract
Purpose :
Determine critical limits for differentiation of clinically suspect glaucoma from clinically not suspect glaucoma.
Methods :
A total of 88 individuals with suspicion of glaucoma were examined for intraocular pressure (IOP), visual field depression (MD), cup-to-disc ratio (HRT- CD), cross-sectional area of the optic nerve head (ONH) nerve fiber layer (HRT-NRA), and nerve fiber layer thickness in the ONH (OCT-RnflT and GDx-Tsnit). The dataset was obtained from the Uppsala Glaucoma Evaluation Study (UGES) of Swedish patients during the years 2006-2019. Variable dependence on age and sex from the first iteration of the first visit was assessed with regression analysis. Variables were fitted to the normal distribution, then, the critical limit value was defined as the upper 0.95 confidence interval of the upper 0.95 tolerance limit.
Results :
A total of 41 non-suspect eyes were analyzed. There was no dependence of any of the measured quantities on age or sex. The critical limits to distinguish pathological from non-pathological parameters were estimated as 22 mmHg,-3.2 dB, 0.84, 0.6 mm2, 56 µm and 33 µm for IOP, MD, HRT- CD, HRT-NRA, OCT-RnflT and GDx-Tsnit respectively.
Conclusions :
The capacity to distinguish pathological from non-pathological is, for all critical limits, limited by substantial variability among subjects. Our finding that the MD measurements are independent of age nor sex is consistent with the fact that MD by definition is age and sex adjusted. For the other quantities measured it is possible that the substantial variability among subjects obscure a slight age and or sex dependence. Comparisons of indicators of glaucoma progress are always limited to the population examined and the unique definition of the phenotype of glaucoma used in the specific study.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.