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Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher
Published on: February 23, 2018
The nexus between pupillary constriction characteristics and accommodative facility: A quantitative and correlational
Pritam Dutta1, Zerin M Mollah, Mrinmoy Goswami
1Ridley College of Optometry, A Unit of Chandraprabha Eye Hospital, Jorhat, Assam, India.
Purpose:
To analyze the interplay between pupillary constriction dynamics and variations in accommodative facility.
Methods:
This study included 400 eyes from 200 subjects, divided into high and low-accommodative facility groups based on performance measured in cycles per minute (CPM) using accommodative flippers (±2.00D). Pupillary constriction dynamics were assessed using an iPhone-based pupillometer application, focusing on constriction speed and amplitude.
Results:
The high accommodative facility group (mean ± SD: 14.2 ± 1.1 CPM) significantly outperformed the low facility group (mean ± SD: 9.4 ± 1.2 CPM, P < 0.001). Pupillary constriction speed was faster in the high facility group (mean ± SD: 3.8 ± 0.5 mm/s) compared to the low facility group (mean ± SD: 3.2 ± 0.6 mm/s, P = 0.002). Amplitude of constriction was greater in the high facility group (mean ± SD: 2.3 ± 0.3 mm) versus the low facility group (mean ± SD: 1.9 ± 0.4 mm, P = 0.005). Significant positive correlations were found between constriction speed and accommodative facility ( r = 0.58, P = 0.001) and between constriction amplitude and accommodative facility ( r = 0.52, P = 0.003). Multiple regression analysis indicated that constriction speed and amplitude collectively predicted accommodative facility, with an R² of 0.47 ( P < 0.001), explaining 47% of the variance.
Conclusion:
Increased pupillary constriction speed and amplitude are significantly associated with higher accommodative facility. These findings highlight the role of pupillary dynamics as predictors of accommodative performance and provide insights into the mechanisms underlying accommodative dysfunction.
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