Adjustment of IOL power for the second eye based on refractive error of the first-operated eye

An update on immediate sequential bilateral cataract surgery

PURPOSE OF REVIEW

The aim of this study was to present an overview of recent publications and opinions in the field of same-day bilateral cataract surgery.

RECENT FINDINGS

A Cochrane review was published comparing immediate sequential bilateral cataract surgery (ISBCS) and delayed sequential bilateral cataract surgery (DSBCS) with regard to safety outcomes, costs and cost-effectiveness. In addition, several large database studies provided more information on incidences of rare complications such as unilateral and bilateral endophthalmitis rates.

SUMMARY

Recently available evidence showed that ISBCS is an effective and cost-effective alternative to DSBCS. Nonetheless, additional (randomized) registry studies, randomized controlled trials and cost-effectiveness studies are needed to evaluate bilateral endophthalmitis rates, refractive outcomes and cost-effectiveness of ISBCS compared with DSBCS.

Refractive Outcome of Phacoemulsification Cataract Surgery in Rural Sabah Using Immersion Biometry

Background

A good refractive outcome after cataract surgery indicates adequate clinical service provision. Precise immersion biometry is critical to achieve the desired refractive outcome. While the immersion biometry results are good in the tertiary settings, it is of interest to explore the refractive outcome of cataract surgeries in a rural facility using the same technique.

Methods

A retrospective cross-sectional review was conducted on medical records of all cataract surgeries carried out in Hospital Keningau, Sabah. This study used all patients' medical records who had been assessed using immersion biometry pre-operatively, underwent phacoemulsification cataract surgery besides attending a post-operative refraction session within 90 days from the operation date. Clinical details were recorded in the form of standard proformas and analysed. The refractive outcome was evaluated using spherical equivalence (SE) and best-corrected visual acuity (BCVA). The percentage of cases with post-operative SE within ±1.00 diopter (D) and BCVA of '6/12 or better' were determined. The association between demographic factors and surgical-related factors with post-operative SE was evaluated using Fisher's exact test.

Results

Of 140 cataract surgeries, 113 fulfilled the inclusion criteria. The average patient age was 66.3 (SD = 10.9) years old. The technique was proven to replicate a good outcome of 84.1% of cases with post-operative SE within ±1.00 D while 90.3% of the cases achieved BCVA of '6/12 or better'. Age and ethnicity were found to be associated with post-operative SE.

Conclusion

The study proves the reproducibility of good refractive outcome in a rural facility using immersion biometry. The findings provide a benchmark for performance surveillance in rural facilities.

A new polynomial regression formula to improve second eye refractive outcomes in sequential bilateral cataract surgery

PURPOSE

To assess a new polynomial regression formula integrating the refractive prediction error of the first operated eye in order to improve the intraocular lens (IOL) power calculation of the second eye in cataract surgery.

SETTING

Centre Hospitalier Universitaire, Toulouse, France.

DESIGN

Retrospective multicentric dataset study.

METHODS

A polynomial regression formula called WeOptimeye2nd (WO2nd) was developed using a machine-learning algorithm trained on a dataset of 534 patients who underwent sequential bilateral cataract surgery. A separate multicentric dataset was used to retrospectively calculate predicted refraction with WO2nd, SRK/T, Barrett Universal II, and 3 other methods of constant factors (CF) second eye refinement (CF0.38, CF0.35 and CF0.5). Mean absolute errors (MAE) and percentage of eyes within ±0.25, 0.5, and 1.0 diopters (D) from predicted spherical equivalent were compared between formulas.

RESULTS

The study comprised data on 722 patients. In the overall population, WO2nd had the lowest MAE: 0.339 versus 0.347 (p=0.137), 0.340 (p=0.956), 0.350 (p=0.066), 0.399 (p<0.001), 0.410 (p<0.001) with CF0.38, CF0.5, and CF0.35 Barrett II and SRK/T respectively. WO2nd had the highest percentage of eyes within ±0.5 D of the predicted refraction and the difference was significant versus SRK/T and Barrett II, but not versus CF0.38, CF0.5, and CF0.35. WO2nd performed the best in AL<22 mm with the lowest MAE and a significant difference versus any other formula.

CONCLUSION

WO2nd can improve the refractive outcome of the second operated eye and performs well in extreme AL and Km subgroups.