Authors: Joseph Kam, Jasmine Cheng, Samuel Wong, Hermina Strungaru, Allan Slomovic, Lawrence Weisbrod, Edsel Ing

Author Disclosure Block: J. Kam: None. J. Cheng: None. S. Wong: None. H. Strungaru: None. A. Slomovic: None. L. Weisbrod: None. E. Ing: None.

Abstract Body:

Purpose: To investigate the incidence and characteristics of post-cataract surgery non-arteritic ischemic optic neuropathy (PCNAION) after topical clear corneal cataract extraction (CCCE) in Canada. 

Study Design: Canada-wide internet survey followed by meta-analysis of the data. Methods: Identical surveys were distributed to five regions in Canada in August 2018, and repeated one month later. CCCE surgeons were asked to provide an anonymous estimate the number of CCCE they had performed in their career, and the number of PCNAION events that occurred within one year following CCCE. The results were analyzed using a random effects meta-analysis of proportions for rare events. 

Results: The 133 survey respondents estimated they performed a total of 1,094,455 CCCE with 84 events of PCNAION. Twenty-nine percent of surgeons had at least one patient with PCNAION. Meta-analysis revealed a pooled estimate incidence of 3.1 PCNAION events (95% CI, 1.7 - 5.5) per 100,000 cataract procedures. Seventy-five percent (63/84) of the PCNAION cases occurred within 3 weeks of surgery, and five patients had bilateral PCNAION.The estimated survey response rate was 15.4% (range 10.6% to 58.0%) and was likely a representative sample of Canadian surgeons as the survey responses per region were proportionate to the distribution of ophthalmologists in Canada, and the proportionate number of PCNAION events per region were comparable. 

Conclusions: PCNAION is a rare complication following topical CCCE. Its incidence is important to estimate for patient care and epidemiologic reasons.