Evaluation of the World Health Organization outcome standards at the early and late post-operative visits following cataract surgery.

Abstract

This study was conducted to determine whether the World Health Organization (WHO) visual acuity standards are correlated between the early and late early post-operative periods following phacoemulsification (phaco) and small incision extracapsular cataract surgery (SICS). Secondary aims were to compare visual outcomes and complications following SICS and phaco. Retrospective cohort study following phaco and SICS performed by one surgeon. Primary outcome measures included uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) at the early (≤72 hours) and late (≥21 days) post-operative visits. Secondary outcome measures included complications and astigmatism. 705 eyes were studied (509 phaco, 196 SICS). The correlation for UCVA between early and late follow-up examinations was higher for phaco (rs=0.58) compared to SICS (rs=0.45, p=0.04) while correlation for BCVA was similar (phaco,rs=0.52; SICS, rs=0.47; p=0.44). At the early post-operative visit, a higher proportion in the phaco group achieved ≥6/18 UCVA (81.5% phaco vs 64.8% SICS, p<0.0001) and BCVA (87.8% phaco vs 73.5% SICS, p<0.0001). At the late post-operative visit, a higher proportion following phaco also achieved ≥6/18 UCVA (93.9% phaco vs 85.2% SICS, p=0.0004) and BCVA (96.9% phaco vs 91.3% SICS, p=0.004). After exclusion of eyes with pre-existing ocular comorbidities, a similar proportion had ≥6/18 late UCVA (98.9% phaco vs 96.9% SICS, p=0.22) and BCVA (100% phaco vs 99.2% SICS, p=0.27). Early and late post-operative WHO visual acuity levels are correlated, but not equivalent, following both phaco and SICS. In eyes without comorbidities, similar final visual outcomes can be achieved after phaco and SICS.