Measurements were based on the Bruch's membrane opening (BMO) and the anterior lamina cribrosa insertion (ALI) as fixed reference points in each eye. Variables included the distance between the BMO reference plane and the ALI, the anterior lamina cribrosa insertion depth (ALID), and lamina cribrosa depth (LCD), the maximum inward curvature in the lamina cribrosa. The mean LCCI was computed using an average of 12 radial measurements around the periphery of the lamina cribrosa.
All of the measurements based on scans from a DRI OCT-1 Atlantis 3D SS-OCT (Topcon ) OCT radial scan. All of the images were enhanced with an adaptive compensation technique, Dr. Ha said. Poor quality scans that did not provide accurate measurements were excluded.
Patients in the study had early-stage POAG with a mean visual field deviation of more than -5.0 dB and well-controlled IOP. Eyes with a history of intraocular surgery except uncomplicated cataract were excluded. Any eyes with poster pole lesions that affected the visual field were also excluded.
The mean age of patients was just over 64 years and slightly more than half (53%) were male. Pre-treatment IOP was 16.2 mm Hg and the mean post-treatment IO was 12.4 mm Hg, a mean IOP reduction of 23.4%.
Visual field testing showed a baseline mean deviation of -3.8 dB and a baseline pattern standard deviation of 5.1. Patients had a mean of 7.2 visual field exams over a mean follow up period of 3.6 years, or a visual field exam roughly every six months.
Ahnul Ha, MD
e. [email protected]
This article was adapted from Dr. Ha's presentation at the 2017 meeting of the American Academy of Ophthalmology. Dr. Ha did not indicate a proprietary interest in the subject matter.