Pre-perimetric OCT Indicators of Progression in Early Glaucoma

Nova Southeastern University, Davie, Florida, USA

Objective. To document two cases exhibiting optical coherence tomography (OCT) progressive retinal nerve fiber layer (RNFL) loss without Humphrey’s visual field (HVF) loss or progression. To highlight estimates of RNFL loss (rate of SD-OCT RNFL loss, estimation to conversion to glaucoma). Background (case 1). A 61 year-old female glaucoma suspect demonstrated isolated HVF defects without progression. OCT showed RNFL OU progressive trend, (case 2) a 67 year old female using Lumigan for diagnosed glaucoma. HVF was normal OD with stable inferior arcuate defects OS. SDOCT showed a RNFL and GCC OU progressive trend from baseline. Results (case 1). The calculated rate of AVG RNFL loss were 1.63 and 1.4 um/year (rate of change in average RNFLT -0.41 ± 0.47 um/yr in non-progressors1, mean global change -0.82 um/yr in non-converters to glaucoma2, mean RNFL loss 0.90 um/yr in non-progresors3. The estimated years to glaucoma conversion was 5 and 6 years OD and OS respectively. Treatment was initiated, (case 2) the calculated rate of AVG RNFL loss was similar following treatment as documented for non-progressors3, 0.80 and 0.54 um/year OD and OS respectively. No additional medications were indicated. Conclusion. Although current evidence suggests no preference for structural or functional loss in early glaucoma, cases exhibiting significant rate loss or decrease RNFL should be prudently considered to represent structural progression even if no progression is evident on visual field assessment. Estimation of the rate of progression of RNFL loss associated in progressors vs. non-progressors and the time of conversion to glaucoma may contribute to justify management. Grants. N/A.