Analysis of patients with good uncorrected distance and near vision after monofocal intraocular lens implantation
Accepted 28 December 2005.
Purpose
To analyze factors contributing to uncorrected visual acuity of at least 6/12 for distance and at least J4 for near (pseudoaccommodation) after monofocal intraocular lens (IOL) implantation.
Setting
Iladevi Cataract and IOL Research Center, Ahmedabad, India.
Methods
In a case-controlled study of 30 eyes (30 patients) that had phacoemulsification, those with pseudoaccommodation were assigned to cases and 30 eyes (30 patients) without pseudoaccommodation were designated as controls. Controls were matched by identical best corrected visual acuity, age, and postoperative duration. Subjective refraction was done with retinoscopy. Factors analyzed included corneal astigmatism, pupil size, axial IOL movement, amplitude of accommodation, axial length (AL), and age. Corneal astigmatism was noted on topography and interpreted as against the rule (ATR) (180 ± 15 degrees), with the rule (WTR) (90 ± 15 degrees), and oblique (OB) (45/135 ± 30 degrees). Pupil size was noted on topographic display and AL and anterior chamber depth (ACD) on immersion A-scan. The axial IOL movement was calculated as the difference in ACD after instillation of cyclopentolate 1% (Cyclopent) and subsequently pilocarpine nitrate 2% (Carpinol) at separate visits, and amplitude of accommodation was measured with static and dynamic retinoscopy. Multivariate logistic regression and odds ratio with 95% confidence intervals were determined.
Results
Mean spherical equivalent was −0.45 ± 0.63 diopter (D) in cases and −0.35 ± 0.83 D (P = .61) in controls. Multivariate logistic regression in cases versus controls: corneal astigmatism (ATR versus WTR and OB collectively): 10.19 [1.8,57.44], P = .009; pupil size: 0.45 [0.07,2.71], P = .38; axial IOL movement: 1.39 [0.51,0.77], P = .514; amplitude of accommodation: 2.95 [0.93,9.3], P = .065; AL: 0.55 [0.29,1.02], P = .058; and age: 0.98 [0.5,1.95], P = .963.
Conclusion
The study suggests a significant role of ATR corneal astigmatism in good uncorrected distance and near vision after monofocal IOL implantation.
From the Iladevi Cataract and IOL Research Centre (Nanavaty, Vasavada, Raj), Raghudeep Eye Clinic, Memnagar, Ahmedabad, India, Alcon Research Limited (Patel), Seattle, Washington, USA, and the Nageri Eye Hospital (Desai), Mithakali, Ahmedabad, India
Reprint requests to Abhay R. Vasavada, MS, FRCS, Iladevi Cataract and IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad 380 052, India.
Presented in part at the ASCRS Symposium on Cataract, IOL and Refractive Surgery, Washington, D.C., USA, April 2005.
No author has a financial or proprietary interest in any material or method mentioned.
ABSTRACT