Is the peripapillary area completely healthy in Stargardt disease?

Aims: To evaluate the peripapillary retinal nerve fiber layer (pRNFL) thickness measured using spectral domain optical coherence tomography (SD-OCT) in patients with Stargardt disease (STGD). Methods: This was a single-center cross-sectional case-control study. Twenty eyes with STGD were staged according to Fishman STGD classification. Peripapillary RNFL thickness was measured using Heidelberg Spectralis SD-OCT. The mean pRNFL thickness of the four quadrants (temporal, superior, nasal, and inferior) and all quadrants were compared with the mean pRNFL thickness from 20 eyes of age-matched healthy subjects. Results: The mean age of Stargardt patients was 40.9 years (range, 18–59 years) and that of the control group was 40.6 years (range, 19–59 years). Twenty eyes (70%) had thinner pRNFL thickness in the temporal quadrant (mean: -7.55 µm, 95%CI -3 to -12 µm, 10% thinner than the control group), whereas in the nasal quadrant, 13 of 20 eyes (65%) had thicker pRNFL (mean: 6.85 µm, 95%CI, 1–13 µm; 9% thicker compared to the control group). There was no statistically significant difference in the thickness of the superior and inferior quadrants and the global pRNFL compared to the control group. Conclusion: STGD is considered pathognomonic for the preservation of the peripapillary retina and retinal pigment epithelium (RPE), and is mainly characterized by RPE and photoreceptor cell loss in the macula. STGD was associated with thinning of the temporal quadrant, corresponding to the macular area in the pRNFL analysis. It is not yet known whether the RNFL loss is due to transneuronal degeneration or direct damage to ganglion cells resulting from degeneration of the outer retinal layers.