Abstract
Purpose :
Primary open angle glaucoma (POAG) suspects may be risk-stratified based on a provider’s likelihood of referral to a glaucoma specialist, though criteria for referral can vary widely between institutions. This study evaluated Humphrey visual field (HVF) indices in high-risk (referred) compared to low-risk (non-referred) glaucoma suspects, with the hypothesis that these indices may be predictors of referral.
Methods :
Retrospective analysis of 78 eyes of 50 POAG suspects at a single academic tertiary care facility. Patients were classified as either high-risk or low-risk suspects. High-risk suspects were defined as those referred to a single subspecialty glaucoma clinic at the same institution based on fulfilling all of the following criteria: 1) disc changes as outlined by ISGEO disc classification for suspects in prevalence studies (BJO 2002;86(2):238-242), and 2) decision of referring providers to initiate prophylactic intraocular pressure-lowering topical therapy, or to follow the patient at intervals shorter than one year. Low-risk suspects were defined as those who did not meet all of these referral criteria. HVF indices were analyzed, and comparison of means between groups was achieved using independent samples t tests.
Results :
49 eyes of 31 patients met high-risk criteria, and 28 eyes of 19 patients met low-risk criteria. There was a statistically significant difference in mean deviation (MD) between high-risk (-2.19 ± 0.34 dB) versus low-risk eyes (-0.43 ± 0.24 dB; P < 0.01). Similarly, pattern standard deviation (PSD) was significantly higher in high-risk compared to low-risk eyes (2.48 ± 0.32 dB versus 1.69 ± 0.23 dB; P < 0.01). Foveal threshold (FT), conversely, was not significantly different (P = 0.19) between the two groups (33.87 ± 4.25 dB versus 35.88 ± 4.20 dB for high-risk and low-risk eyes, respectively.) Similarly, visual field index (VFI) did not vary with statistical significance between high-risk (96.74 ± 0.39%) and low-risk eyes (98.93 ± 0.18%; P = 0.31).
Conclusions :
In this group of glaucoma suspects from a single academic center, high-risk (referred) patients demonstrated significantly worse MD and PSD than low-risk suspects, despite these not being specified referral criteria. FT and VFI, however, did not differ between the two groups. MD and PSD may therefore be able to be used as specific predictors of glaucoma subspecialty referral.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.