NEAR WORK–INDUCED ACCOMMODATIVE BIAS IN YOUNG MYOPES: MAGNITUDE, RECOVERY TIME, AND DISCREPANCY BETWEEN NON-CYCLOPLEGIC AND CYCLOPLEGIC REFRACTION

Abstract

BACKGROUND

Myopia is increasing rapidly worldwide, especially among students who engage in near work demands for longer periods of time. Accommodation plays an important role in determining the accurate status of the human eye, and its active state after prolonged near work may overestimate myopia in a young myopic population under non-cycloplegic conditions. Near-induced transient myopia and accommodative lag may further complicate the accuracy. Despite this, cycloplegic refraction after a sustained amount of near work is often underutilized in these students. There is limited data available on refractive variability among Pakistani students, highlighting the need for this study.

OBJECTIVE To evaluate the refractive variability after near work by comparing non-cycloplegic and cycloplegic methods among the young myopic population.

METHODOLOGY This is a quasi-experimental study design. Initial screening was done using the pen torch and slit lamp bio microscope to ensure the eligibility of the patients. The standard visual acuity chart was used to measure visual acuity. Participants were instructed to perform near work for 10 minutes under standardized conditions and at a working distance to induce a high cognitive response. Non-cycloplegic refraction was assessed using an autorefractometer for objective estimation, and the trial box was then used for subjective refraction to establish the optimal corrected visual acuity. Cycloplegia was induced using cyclopentolate 1%. After adequate cycloplegia, cycloplegic refraction was performed using a retinoscope. All findings and data were filled in on the questionnaire/Performa by the optometrist.

RESULTS The right eye's mean non-cycloplegic spherical equivalent after near work was -2.59 ± 1.46 D, with a median of -2.25 D, and the cycloplegic spherical equivalent after complete paralysis of accommodation was -1.91 ± 1.37 D, with a median of -1.50 D. The left eye's mean non-cycloplegic spherical equivalent after near work was -2.50 ± 1.42 D, with a median of -2.00 D, and the cycloplegic spherical equivalent after complete paralysis of accommodation was -1.87 ± 1.22 D, with a median of -1.50 D. The median difference between non cycloplegic and cycloplegic methods was -0.50 D for both right and left eye. These results indicate that the overestimation of myopia is caused by non-cycloplegic refraction, most likely due to active accommodation.

CONCLUSION Non-cycloplegic refraction showed a statistically significant change in spherical equivalent in both eyes, with a minimal clinically insignificant intraocular variation likely due to physiological and accommodative factors.