Abstract
Purpose :
To measure Bruch’s membrane opening-minimum rim width (BMO-MRW) and cup depth using optical coherence tomography (OCT) in eyes with compressive chiasmal lesions and band atrophy (BA) of the optic nerve. To compare the ability of BMO-MRW and retinal nerve fiber layer (RNFL) thickness measurements to detect structural abnormalities in such eyes.
Methods :
We performed a cross-sectional, prospective study, with 49 eyes with BA and bitemporal hemianopia caused by optic chiasm compression and 39 eyes of normal age-matched controls. BMO-MRW and RNFL measurements with OCT and visual field (VF) testing were acquired and analyzed between both groups. BMO-MRW was measured with disc centered radial OCT scans as the shortest distance between the Bruch’s membrane terminations to the internal limiting membrane. Cup depth was measured from the line connecting Bruch’s membrane termination to the bottom of the cup. BMO-MRW and RNFL parameters in BA eyes and controls were compared. The area under the receiver operating characteristic (AUC) curves was calculated and compared for global and sectoral optic disc parameters. Correlation between VF and BMO-MRW parameters were assessed.
Results :
BMO-MRW measurements were generally reduced in eyes with BA compared to controls. The highest reduction rates were found in the nasal, temporal and horizontal values, with strong correlation with VF parameters. AUCs were significantly greater for RNFL thickness parameters than BMO-MRW in the global, temporal, nasal, inferonasal and horizontal measurements. No significant difference was found in cup depth measurements between BA and healthy eyes.
Conclusions :
BMO-MRW reduction occurs in all optic disc sectors but is greater in the nasal and temporal quadrants and correlates with peripapillary RNFL and VF loss in eyes with BA of the optic nerve while depth does not differ from controls. BMO-MRW and RNFL are useful parameters in evaluating BA of the optic nerve and addressing the cup depth may be useful to differentiate from glaucomatous cupping.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.