The Association Between Glycaemic Control, Renal Function and Post-operative Ophthalmic Complications in People With Diabetes Undergoing Cataract Surgery—A Single-Centre Retrospective Analysis

INTRODUCTION: In general surgery, it has been shown that poor peri-operative diabetes control, as measured by glycated haemoglobin (HbA(1c)), is associated with adverse post-operative outcomes. National data for the UK suggest that the post-operative complication rate for cataract surgery is 2.8%. It is unknown whether people with diabetes who undergo cataract surgery are also at increased risk. METHODS: This single-centre retrospective study looked at the association of peri-operative HbA(1c) and estimated glomerular filtration rate (eGFR) with the risk of post-operative complications in people undergoing phacoemulsification and intraocular lens implantation under local anaesthesia during 2016. RESULTS: 4401 individuals had cataract surgery. Of these, 34.6% (1525) had diabetes. Of those with diabetes, 114 (7.5%) developed a post-operative ophthalmological complication (as defined by the Royal College of Ophthalmologists) necessitating at least one eye clinic appointment. Mean HbA(1c) did not differ between those who did and those who did not develop complications (52 vs 50 mmol/mol, p = 0.12). After adjustment, HbA(1c) was not a significant risk (OR 1.00; 95% CI: 0.99–1.05; p = 0.85). However, eGFR had a small but statistically significant effect on outcome (OR 0.99; 95% CI: 0.98–1.00; p = 0.02). CONCLUSIONS: This study has shown that more people who undergo cataract surgery have diabetes than previously reported. Also, people with diabetes are at higher risk of developing complications than previously reported. HbA(1c) concentration was not a factor in these adverse post-operative outcomes. However, eGFR was a predictor of risk. More focus should be placed on pre-operatively optimising co-morbidities than diabetes control in those undergoing cataract surgery.