No significant difference in operative time between LEP and EP cataract surgery (21.7 vs 20.5 min)

Description #

Operative (surgical) time did not differ significantly between LEP and EP cataract surgeries (mean 21.7 [SD = 19.1] vs 20.5 [SD = 16.4] minutes, P = .117) (Table 2). This is a null result.

"There were no statistically significant differences in operative time, intraoperative complications such as posterior capsular rupture, vitreous loss, retained lens material, zonular dialysis, or choroidal hemorrhage." (Zafar, 2023, p. 598)

"Surgical time ... Mean (SD) 21.7 (19.1) 20.5 (16.4) .117" (Zafar, 2023, p. 597, Table 2)

Methods Context #

What? #ⓘ

The observable: surgical (operative) time, a continuous measure in minutes.

"whether a resident or attending physician was the primary surgeon, surgical time, postoperative CDVA" (Zafar, 2023, p. 596)

How? #ⓘ

Retrospective analysis of a cataract-surgery outcomes database; surgical time compared by LEP status as a continuous variable.

"We performed a retrospective analysis using the Cataract Surgery Outcomes Database developed by the Department of Ophthalmology at the University of Colorado School of Medicine." (Zafar, 2023, p. 596)

Who? #ⓘ

Surgical time was available for 865 LEP eyes and 12,680 EP eyes of the 13,590-eye cohort at a single academic eye center (2014–2020).

"A total of 13 590 eyes were included in the analytic database. Of these, 868 (6.4%) were identified from LEP patients." (Zafar, 2023, p. 596)

Caveats #

• Small LEP sample underpowered to detect differences, especially rare complications (Zafar cataract) The LEP group (n = 868 eyes) was far smaller than the EP group (n = 12,722), and the authors state the small LEP sample limited their ability to detect further significant differences. They specifically note that serious complications such as endophthalmitis and IOL dislocation were too infrequent for the study to be adequately powered to detect between-group differences. The non-significant (null) findings for intraoperative complications, operative time, and postoperative complications should therefore be read as inconclusive rather than as demonstrated equivalence.