Choroidal Thinning in Leber's Hereditary Optic Neuropathy (LHON) using In Vivo Optical Coherence Tomography.

Abstract

Purpose : Changes in retinal vasculature have been implicated in mitochondrial optic neuropathies. However, these vascular changes remain neglected and poorly characterized. Using swept-source optical coherence tomography (SS-OCT), we hypothesize that patients with chronically severe LHON will exhibit a significant reduction in choroidal vascular thickness.

Methods : We conducted a prospective, case-controlled study enrolling 26 patients with chronically severe LHON, 11778 mtDNA mutation (mean age: 35.1± 16.04 years), and 27 healthy age-matched control patients (mean age: 32.39± 11.14 years). Swept-source optical coherence tomography (SS-OCT) scans of the choroid in the macular and peripapillary regions. The retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) were scanned for comparison. Thickness measurements in LHON patients were compared with healthy controls and statistically analyzed using linear regression and Welch’s t-test.

Results : Choroidal thickness was significantly reduced in both macular and peripapillary regions. Mean total choroidal thickness in the macular region measured 250.514 ± 62.23μm in LHON compared to 313.89 ± 60.17μm in controls (p<0.0001). Mean total thickness in the peripapillary region measured 135.661± 51.36 μm in LHON compared to 183.01± 61.83μm in controls (p= 0.0007). In addition, the RNFL and choroid displayed a similar pattern of thinning in LHON, which was more closely shared in macular region (R² = 0.72, p<0.0001) than in the peripapillary region (R² = 0.53, p=0.003)

Conclusions : Our study demonstrated an overall 26% decrease of the choroid in longstanding cases of severe LHON, confirming vascular involvement of the disease. Choroidal thinning in LHON was also significantly correlated with thinning of the RNFL. Validation of these chronic disease stage findings with post-mortem histopathology may offer the choroid as an additional in vivo biomarker to monitor disease progression and assess the efficacy of available treatments.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.