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 (HbA1c), 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 HbA1c 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 HbA1c did not differ between those who did and those who did not develop complications (52 vs 50 mmol/mol, p = 0.12). After adjustment, HbA1c 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. HbA1c 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.

People with suboptimally controlled diabetes (as measured by glycated haemoglobin, HbA_1c) who have an operation are at increased risk of post-operative complications. However, whether this risk extends to cataract surgery is unknown. Our single-centre study showed that 34.6% of all cataract operations during the calendar year 2016 were performed on someone with diabetes­a number far higher than previously reported. In addition, we looked at the post-operative outcomes of the 1525 people with diabetes who had a cataract operation. We showed that, overall, more people with diabetes had complications than previously reported: 7.5%. However, in the whole cohort, HbA_1c did not differ between those who did and those who did not develop complications. The factors that were associated with differences in the risk of developing complications were whether the person was looked after in secondary care for their diabetes and whether they had any kidney disease.