advertisement
Manjunath et al. (209) reported a retrospective, cross-sectional study describing Spectral Domain Optical Coherence Tomography (SD-OCT) findings in eyes with parapapillary atrophy (PPA). The authors described six morphological characteristics associated with clinically visible PPA: 1) retinal pigmented epithelium (RPE) and photoreceptor loss; 2) inner and outer retinal thinning; 3) RPE disruption; 4) retinal nerve fiber layer (RNFL) thickening with plaque-like formation; 5) intra-retinal cysts; and 6) abnormal retinal sloping. Moreover, they found that the peripapillary total retinal thickness of normal healthy controls was 15% thicker than in eyes with PPA. The study is relevant as it describes real-time, in vivo characteristics of a prominent glaucoma feature that thus far had been only described in post-mortem and enucleated eyes. The authors confirmed those histological descriptions and added new information that may help elucidate the pathogenesis of PPA.
Peripapillary atrophy could be a surrogate sign of accelerated aging of the optic nerve complex
Their findings are also consistent with the ones our group recently described showing that the area of alpha and beta-zone PPA measured with SD-OCT matches the corresponding area seen during photograph review.1 The presence and area of PPA (particularly beta-zone PPA) is associated not only with glaucoma onset2 but also with rapid visual field progression in eyes with established disease.3 Therefore, PPA detection and measurement is important for risk assessment in clinical practice. The present study is a first step towards developing objective methods to identify and measure PPA using imaging devices. Additionally, the authors described micro-structural characteristics of PPA that closely resemble the ones described in age-related macular degeneration (AMD).4 This finding supports the hypothesis that PPA could be a surrogate sign of accelerated aging of the optic nerve complex. More studies are needed to corroborate this hypothesis as well as to understand longitudinal changes associated with PPA enlargement and glaucoma progression.