Association Between Pseudoaccommodation Measured With the Salzburg Reading Desk Versus the Reading Chart in Pseudophakic Patients.

Purpose

To assess the incidence and contributing factors of pseudoaccommodation in pseudophakic eyes implanted with aspherically neutral monofocal intraocular lenses (IOLs), comparing printed chart reading under standardized ambient illumination with assessment using the backlit Salzburg Reading Desk (SRD) (SRD Vision, LLC).

Methods

This was a prospective, non-randomized, single-eye cohort study of patients undergoing monofocal IOL implantation for cataract surgery. Uncorrected near visual acuity (UNVA) was measured at 1 and 3 to 9 months postoperatively using both the Precision Vision Chart (chart-based, 40 cm) and the SRD (screen-based, 40 cm). Chart-based assessment was performed first, followed by SRD-based assessment, in a consistent order. Both assessments were conducted in the same room under standardized ambient illumination (∼500 lux). Pseudoaccommodation was defined as simultaneous uncorrected distance visual acuity (UDVA) better than 20/40 (0.3 logarithm of the minimum angle of resolution [logMAR]) and UNVA 0.3 logMAR (J4). Binary logistic regression (backward and forward stepwise, with Firth-penalized regression as a sensitivity analysis) identified independent predictors. A worst-case attrition sensitivity analysis and a sensitivity analysis restricted to eyes within ±0.50 diopters (D) of emmetropia were performed.

Results

Of 412 patients recruited, 301 (73.1%) had complete data (27.0% were lost to follow-up due to the coronavirus disease 2019 pandemic). Pseudoaccommodation occurred in 21 patients (6.9%) with printed charts versus 29 patients (9.6%) with SRD; only 9 patients (3.0%) met criteria by both methods. In a worst-case attrition analysis, rates were 5.1% (chart) and 7.0% (SRD), preserving the directional difference. Multivariable analysis revealed total spherical aberration as the sole independent predictor of chart-based pseudoaccommodation (odds ratio [OR]: 3.3 × 10-6, 95% CI: 0.00 to 0.08, P = .02). For SRD-based pseudoaccommodation, independent predictors were lower (more myopic) spherical equivalent (OR: 0.49, 95% CI: 0.31 to 0.78, P = .01), smaller mesopic pupil diameter (OR: 0.41, 95% CI: 0.24 to 0.72, P < .01), lower total spherical aberration (OR: 9.6 × 10-6, 95% CI: 0.00 to 0.02, P = .01), and shorter preoperative axial length (OR: 0.40, 95% CI: 0.22 to 0.73, P < .01). In a sensitivity analysis restricted to eyes within ±0.50 D of emmetropia (n = 218), spherical aberration and mesopic pupil size remained significant predictors, indicating their contribution is independent of residual refractive error.

Conclusions

Pseudoaccommodation is multifactorial, with the assessment method and nature of the visual stimulus (self-luminous backlit screen versus reflective printed chart) significantly influencing its incidence and predictive factors. Spherical aberration was the sole independent predictor for chart-based pseudoaccommodation, whereas spherical equivalent, mesopic pupil size, spherical aberration, and axial length were independent predictors for SRD-based pseudoaccommodation.