Abstract
Purpose :
To evaluate optical coherence tomography (OCT) and visual field (VF) measures (metrics) as clinical endpoints for progression of early glaucomatous damage in eyes with confirmed progression.
Methods :
OCT scans of the disc and the macula and 24-2 and 10-2 VFs were obtained from 87 eyes [33 healthy controls (HC), 54 patients with 24-2 mean deviation (MD) better than -6dB] with at least 4 tests (mean: 7.1±1.5) and at least 1 year between baseline (first) and last follow-up test (mean: 3.4yrs; range: 1.2 – 5.34yrs). 10 of the 54 patient eyes were labelled as ‘Definite Progressors’ (DP), based on qualitative assessment of structural and functional series of tests.1 Metrics of the circumpapillary RNFL (cpRNFL) and the macular ganglion cell layer (GCL) thickness were extracted from the OCT scans and the MD and visual field index (VFI) from the 24-2 and 10-2 VFs. Ordinary linear regression analyses over time were performed for all metrics and eyes. For each sector, negative slopes less than a criterion value based on the HC eyes and a 95% specificity were considered indicative of progression. A Kaplan-Meier method of survival analysis was used to identify the time to progression.
Results :
Progression in all 10 DP eyes was detected by at least one OCT or VF metric within 2.2 years of follow-up. However, the VF metrics alone detected only 7 of the 10 DP eyes, while the OCT metrics detected all 10. At 1.5 yrs, the superior MD of the 24-2 was the best VF metric detecting 30% of the DP eyes, while five OCT metrics, 3 from GCL and 2 from cpRNFL, exceeded a detection rate of 30%, ranging between 40-60% (Table 1). The cpRNFL temporal inferior (TI) was the fastest in detecting progression in 7 eyes. For the eye in Fig. 1, for example, the cpRNFL TI and temporal superior (TS), as well as GCL TI, were the fastest, while none of the VF metrics detected progression. For the remaining 3 eyes, the GCL inferior (I) metric was the fastest in 2, and the cpRNFL TS in 1. The global (G) metrics of cpRNFL and GCL were fastest in 3 eyes; however, it was always in conjunction with another sectoral metric.
Conclusions :
While it was possible to detect progression in eyes with confirmed progression within 2.2 yrs, no one metric identified all eyes within that time period. The a priori selection of a sectoral metric, based on glaucomatous damage at baseline, might enhance the ability to detect progression.
1.Hood et al., Ophthal Glau, 2022.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.