A Retrospective Observational Study On Ga And La + Ivs To La Conversion Rates For Cataract Surgery

Cataract surgery is the most common surgical procedure performed in ophthalmology departments. Most patients undergo the surgery under local anaesthetic (LA) while select few may require further intravenous (IV) sedation or general anaesthetic (GA) for various patient, surgeon, and setting-related reasons. While there have been several studies published on anaesthetic preferences and trends for cataract surgery, there is limited information available how general anaesthesia rates were affected, and the conversion of general to local anaesthesia with or without sedation, during the pandemic when ophthalmology units were under significant burden. 

This is a retrospective observational study analysing the conversion of GA/ LA + IVS to LA for cataract surgeries performed in a tertiary-care centre from March 2020 (the first COVID-19 lockdown in England) to March 2022.

Documentation of anaesthetic choice for cataract surgery performed in a tertiary-care hospital and surgery booking details were retrieved from electronic medical records.  The primary outcome was the conversion rates of GA/ LA + IVS to LA alone, and secondary outcomes included indications for GA or sedation, and waiting times for each anaesthetic choice. Data was analysed using Microsoft Excel and SPSS Statistic Premium. Welch’s t-test was used to compare the means for waiting times for the secondary outcome.

The conversion rate from GA to LA was 34.3%, and that from LA + IVS to LA during the COVID-19 pandemic was 56.6%. The mean difference in waiting times between GA/ LA + IVS and LA alone was 12.7 weeks (p < 0.05) in the first year of the pandemic, and 9.7 weeks (p < 0.05) in the second year. Only 29.8% of listing reasons were deemed to be strong indications, while 65.2% had weak indications for GA or sedation.

This study highlights a need to stratify indications for GA or LA + IVS when a surgeon is considering listing a patient. This is to ensure that there is efficient utilisation of the lists, and also to avoid unnecessarily long waiting times for patients who have the potential for successful cataract surgery under LA instead. There is a need for ophthalmology units to re-design patient care pathways to adapt to the post-COVID era. With limited theatre and anaesthetist availability, reducing the number of general anaesthesia procedures may be necessary to manage the backlog of elective operations.