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Effective lens position and pseudophakic refraction prediction error at 10½ years of age in the Infant Aphakia
Deborah K VanderVeen1, Thaddeus S McClatchey2, Scott K McClatchey3
1Department of Ophthalmology, Harvard Medical School, Boston, Massachsuetts.
Insights
Refraction prediction error after infant intraocular lens (IOL) implantation is large. Effective lens position (ELP) variations did not significantly correlate with prediction error in children at age 10½ years.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Biomedical Engineering
Background:
- Infant intraocular lens (IOL) implantation can result in significant refractive prediction error (PE).
- This error may be linked to differences in effective lens position (ELP) compared to adult eyes.
- Persistent PE could arise if non-adult ELPs continue into childhood.
Purpose of the Study:
- To investigate the correlation between effective lens position (ELP) or biometric parameters and refraction prediction error (PE) at age 10½ years.
- To assess the impact of ELP on refractive outcomes in children who underwent IOL implantation in infancy.
- To analyze factors influencing PE in the Infant Aphakia Treatment Study (IATS) cohort.
Main Methods:
- Compared measured refraction with predicted refraction using the Holladay 1 formula at age 10½ years.
- Excluded eyes with incomplete data or IOL exchange.
- Performed multiple regression analysis on absolute PE against axial length, corneal power, refractive growth rate, refractive error, and visual acuity, using measured anterior chamber depth (ACD) to assess ELP's effect.
Main Results:
- Forty-three eyes were analyzed, with a mean PE of 0.63 ± 1.68 D.
- Median absolute PE was 0.85 D (IQR, 1.83 D).
- Using measured ACD for predicted refraction calculation resulted in significantly higher median absolute PE compared to the standard A-constant (1.88 D vs. 0.85 D, P = 0.03). No significant correlation was found between absolute PE and other parameters.
Conclusions:
- Effective lens position (ELP) variations do not significantly contribute to prediction error (PE) a decade after infant cataract surgery.
- The findings suggest that factors other than ELP are primarily responsible for refractive prediction errors in this cohort.
- Further research is needed to identify the key drivers of PE in pediatric IOL implantation.
Background:
The refraction prediction error (PE) for infants with intraocular lens (IOL) implantation is large, possibly related to an effective lens position (ELP) that is different than in adult eyes. If these eyes still have nonadult ELPs as they age, this could result in persistently large PE. We aimed to determine whether ELP or biometry at age 10½ years correlated with PE in children enrolled in the Infant Aphakia Treatment Study (IATS).
Methods:
We compared the measured refraction of eyes randomized to primary IOL implantation to the "predicted refraction" calculated by the Holladay 1 formula, based on biometry at age 10½ years. Eyes with incomplete data or IOL exchange were excluded. The PE (predicted - measured refraction) and absolute PE were calculated. Measured anterior chamber depth (ACD) was used to assess the effect of ELP on PE. Multiple regression analysis was performed on absolute PE versus axial length, corneal power, rate of refractive growth, refractive error, and best-corrected visual acuity.
Results:
Forty-three eyes were included. The PE was 0.63 ± 1.68 D; median absolute PE, 0.85 D (IQR, 1.83 D). The median absolute PE was greater when the measured ACD was used to calculate predicted refraction instead of the standard A-constant (1.88 D [IQR, 1.72] D vs 0.85 D [IQR, 1.83], resp. [P = 0.03]). Absolute PE was not significantly correlated with any other parameter.
Conclusions:
Variations in ELP did not contribute significantly to PE 10 years after infant cataract surgery.
