Vitreopapillary Findings in Nonarteritic Ischemic Optic Neuropathy versus Healthy Eyes: A Clinical and OCT Comparison.

Purpose: To study the vitreopapillary interface in nonarteritic ischemic optic neuropathy (NAION) for features that may predispose to optic nerve perfusion defects.

Design: Case-control study.

Participants and controls: Patients with NAION (study group) were compared with healthy non-NAION patients with crowded discs (control group I) and noncrowded optic discs (control group II).

Methods: The vitreopapillary interface was studied in 32 eyes with NAION using high-resolution OCT scans. Results were compared with 2 control groups consisting of age, sex, and refraction-matched non-NAION individuals with crowded optic discs (control group I: 31 eyes) and noncrowded optic discs (control group II: 32 eyes).

Main outcome measures: The incidence of total posterior vitreous detachment (PVD), vitreopapillary and vitreovascular attachments, and epipapillary membranes.

Results: The rate of PVD over the macula was similar between groups (NAION: 62.5%, control I: 61.3%, and control II: 65.6%, P = 0.93), whereas the posterior hyaloid remained attached to the crowded discs at a significantly higher rate (NAION: 81.2%, control I: 83.9% and control II: 43.7%, P = 0.0005). A higher rate of focal vitreopapillary attachments on crowded discs than on noncrowded discs was noted (NAION: 72.2%, crowded control I: 58.7%, and noncrowded control II: 19.1%, P = 0.007). Vitreovascular attachments (NAION: 68.8%, crowded control I: 3.2% vs. noncrowded control II: 6.3%, P = 0.00001) and dense epipapillary membranes were observed in NAION eyes.

Conclusions: Crowded discs may have stronger vitreopapillary attachments. A close relationship of these attachments with optic nerve vessels may lead to the transmission of strong tractional forces by a syneretic vitreous gel, especially after macular PVD. This transduced mechanical force may contort the vessel wall and disrupt the blood flow in NAION.

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