Refractive Outcomes Of Immediate Sequential Bilateral Cataract Surgery (Isbcs) In West Of Scotland Rural And Urban Populations.

One factor affecting confidence in performing ISBCS is concern over refractive surprise or anisometropia; as clinicians are unable to make an IOL selection based on 1st eye outcomes. Therefore we aim to analyse the visual outcomes and risk of anisometropia in our practice.

This sample was divided into geographical subgroups; an urban population from Glasgow City (G) and a rural population from the Scottish Argyll peninsula, (A). The G subgroup were younger (average age 72, range 30-92) but had greater ocular co-morbidities and operative risk factors, (76% eyes). The A subgroup were older (average age 75, range 55-86) but co-morbidities were present in only 3 (3.8% eyes) and operative risk factors in only 18 (23% eyes).

Retrospective electronic data was recorded from all patients who received ISBCS in NHS Greater Glasgow & Clyde (Glasgow South) between April 2019 and October 2022. Perioperative IOL choice and refractive aim was compared to post-operative data returned by community optometrists. A total of 105 patients were identified. Data was not available for 16 patients.

Refractive information was returned for 50 patients (100 eyes) from Glasgow postcodes (G) and 39 patients (78 eyes) from Argyll (A). The absolute difference in positive cylinder, post-operative spherical equivalent was used to calculate bilateral anisometropia. In the G subgroup 48 patients had an outcome within 1.5D (96%), 46 within 1D (92%) and 41 within 0.5D, (82%). In the A subgroup all 39 patients had a bilateral outcome within <1D (100%) and 35 patients within 0.5D (92%). Combined the results suggest only 2/89 patients had post operative anisometropia >1.5D. Those cases were 1.62D and 2D. Both patients shared factors that can cause inaccuracy; herpetic corneal scar, axial length (< 21) and a trainee operator.

RCOphth published professional guidance on how to balance NICE principles with ISCBS. International guidelines also exist for best practice. There remains local debate in the West of Scotland and the UK on the use of ISCBS. Refractive analysis has previously been avoided as the challenging factors present in our G subgroup were felt to be unrepresentative of the general population. Our data provides evidence of the reliability of biometry formula and nurse led pre-assessment skill. The results are superior to international studies that analyse anisometropic outcomes. Additional benefits included reduced hospital encounters, increased theatre efficiency and a more environmentally sustainable service.