gms | German Medical Science

Introduction: Neurosarcoidosis (NS) is described in 10-15% of patients with systemic sarcoidosis and inflammation of the posterior segment may occur in up to 30-50%. Spectralis SD-OCT (Heidelberg Engineering) is a noninvasive and reproducible imaging technique, which permits the assessment of the retinal and peri-papillary nerve fiber layer (RNFL) thickness, as well as the assessment of choroidal morphology and thickness. All of these structures are often affected by posterior granulomatous uveitis.

This study analyzes SD-OCT data on variations in peripapilary retinal nerve fiber layer RNFL thickness, macular thickness, choroidal thickness and the morphology of choroid, in patients with neurosarcoidosis in acute and quiescent phases of the disease.

Methods: Ten eyes of six consecutive patients diagnosed with neurosarcoidosis and ocular involvement were retrospectively studied. All six patients were evaluated with the SD-OCT. The RNFL thickness measurements included the global average value as well as the analysis of quadrants (superior, temporal, inferior and nasal). The macular thickness study calculated average thickness values of the central macula in millimeters. A retinal thickness map was made using a rasterscan of a 20º x 15º rectangle composed of a 90 B-scan, average 54 times each. Enhanced Depth Imaging (EDI) was used to assess the morphology of the choroid layer.

Results: All Patients were female, Caucasians, with a mean age of 48.3 years. The mean follow-up period was 4.6 years, ranging from 4 months to 9.3 years. The acute phase and the quiescent phase could each be studied in four patients, in a total of seven eyes.

The RNFL had an average thickness of 169 µm in the acute phase and 126 µm in the quiescent phase. The macular thickness ranged from 334 µm in the acute phase to 298 µm in the quiescent phase. Regarding the qualitative SD-OCT findings a patient in acute phase showed multiple, small, round and hiporreflective lesions in the choroid with topographic correlation with the choroidal granulomas found in the Indocyanine Green (ICG) angiography.

Conclusion: According to our study neurosarcoidosis seems to condition an increase in macular and RNFL thickness that persists in the chronic phase. The highest increase of the RNFL was found in the superior and inferior quadrants. Choroid thickness seems to be diminished in the quiescent phase.

SD-OCT imaging using the EDI technique allowed visualization of choroidal granulomas. To our knowledge, this is the first report of this kind of findings with SD-OCT. The evaluation of a larger sample of patients with longer follow-up period could help to further establish the role of these findings and their clinical use.