Comparing microscope light-associated glare and comfort between heads-up 3D digital and conventional microscopes in cataract surgery: a randomised, multicentre, single-blind, controlled trial

ObjectiveTo compare subjective levels of comfort and visual experiences related to microscope light in patients undergoing their first cataract surgery with topical anaesthesia using a digital microscope (the NGENUITY three-dimensional (3D) visualisation system) or a conventional microscope.Methods and analysisA prospective, randomised, single-blinded, parallel-group, multicentre, interventional study. Patients (n=128) were randomly assigned to one of two treatment groups: the experimental group (n=63) had surgery using the digital microscope and the control group (n=65) had surgery with a conventional microscope. The primary outcome was patients’ subjective experience of glare from the microscope light during surgery on a numerical scale from 0 to 10. Key secondary outcomes were patients’ subjective levels of comfort and visual experiences related to the microscope light.ResultsThe experimental group reported significantly lower levels of glare; median levels were 1.0 (0.0–4.0) for the experimental group vs 3.0 (0.0–6.0) for the control group (p=0.027). They also reported higher levels of comfort; median ratings were 8.0 (6.5–10.0) in the experimental group and 7.0 (5.0–9.0) in controls (p=0.026). There were no group differences in ratings of subjective pain or visual disturbances. Median microscope light intensity was lower in the experimental group than controls; 3425.0 (2296.0–4300.0) Lux vs 24 279.0 (16 000.0–26 500.0) Lux (p