African Descent and Evaluation Study (ADAGES): The relationship between the presence and enlargement of beta-zone parapapillary atrophy (bPPA), African (AD) or European descent (ED), and rates of visual field (VF) progression in patients with glaucoma

Abstract

Purpose : We have recently shown that bPPA is more common in AD than ED patients with glaucoma.[1] Nonetheless, it remains unclear whether this feature has the same clinical significance between ancestry groups when assessing progression. We tested the hypotheses that (i) bPPA enlargement during follow-up is also more frequent in AD eyes and (ii) the presence of bPPA at baseline and its enlargement are associated with faster VF progression in both groups.

Methods : From the ADAGES, 814 eyes of AD (395) and ED (421) patients with glaucoma diagnosis and who had at least one follow-up disc photo were included. Two graders masked to clinical and race data reviewed the baseline and last disc photos and graded them for the presence of bPPA at baseline and ‘bPPA progression’ (development or enlargement). We investigated the relationships between (i) the presence of bPPA at baseline and ancestry group, (ii) presence of bPPA at baseline and rates of VF progression; and (iii) bPPA progression and VF progression. Mixed-effects linear models were tested with VF mean deviation as dependent variable and ‘Time’ (alone and with interaction terms) as independent variables. Interaction terms (‘Race*Baseline bPPA’ and ‘Race*bPPA Progression’) were included to test the hypothesis that the relationship between baseline bPPA and bPPA progression vs. rates of VF progression differ between ancestry groups.

Results : AD eyes were more likely to have bPPA at baseline than ED eyes (OR=1.34, 95% CI=1.07 to 1.69, P=0.011), even though bPPA progression was less common in AD eyes (OR=0.43, 95% CI=0.24 to 0.75, P= 0.003). bPPA at baseline was associated with faster VF progression in ED but not AD eyes (β=-0.07, 95% CI= -0.13 to -0.01, P=0.014). Similarly, bPPA progression was associated with faster VF progression in ED eyes only (β= -0.13, 95% CI=-0.25 to -0.008, P=0.036).

Conclusions : Despite greater frequency of bPPA in AD patients with glaucoma, its presence at baseline and enlargement during follow-up were associated with faster VF progression in ED but not AD eyes. These findings suggest different clinical implications of bPPA and bPPA progression in ED and AD patients.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.