Characteristics of Patients with a Localized Retinal Nerve Fiber Layer (RNFL) Defect and Normal Optic Disc Appearance

1. Jeongmin Lee, MD, PhD
2. Kunho Bae, MD
3. Junglim Kim, MD
4. Changwon Kee, MD, PhD

Sungkyunkwan University School of Medicine, Samsung medical center, Seoul, Korea

Purpose: To investigate characteristics for patients with a localized retinal nerve fiber layer (RNFL) defect and normal optic disc appearance

Methods: Forty four eyes of 39 patients who had a localized RNFL defect but in whom the optic disc appearance was normal, regardless of visual field defect (Group A) were enrolled. We recruited forty eyes of 40 age-matched patients with normal tension glaucoma who had a localized RNFL defect (Group B). On RNFL photograph, we evaluated angle of RNFL defect. Angle α and angle β were the angle made by a line from the center of the fovea to the disc center and a line from the disc center to the disc margin, where the proximal border and the distal border of the defect met respectively. Angle θ was width of the defect. We compared systemic diseases, baseline IOP, location and angle of the RNFL defect between two groups.

Results: Systemic diseases such as DM and hypertension were significantly different between two groups (66.7% vs 25%). The IOP in group B was greater than in group A. The percentage of superotemporal RNFL defect in group A was greater than in group B (75% vs 28.6%). Angle α was significantly greater in group A (61.4° vs 44.3°), but angle β and angle θ were significantly smaller in group A (69.9° vs 87.8°, 8.8° vs 43.5°). There were no significant differences in other factors.

Conclusions: The percentage of systemic diseases and superotemporal defect were greater in group A, and angle β in group A was smaller than in group B. These findings suggest that if the patients with a superotemporal RNFL defect and normal disc appearance had systemic diseases and the distal border of defect is closer to macula, then it is unlikely that they would progress to glaucoma.