Factors Predictive of Refractive Error After Toric Lens Implantation

Area of Science:

• Ophthalmology
• Refractive Surgery
• Biomedical Engineering

Background:

• Toric intraocular lenses (IOLs) are widely used to correct astigmatism during cataract surgery.
• Achieving optimal refractive outcomes with toric IOLs depends on accurate pre-operative assessment and surgical technique.
• Suboptimal outcomes can lead to patient dissatisfaction and necessitate further interventions.

Purpose of the Study:

• To identify pre-operative and intra-operative factors associated with suboptimal refractive results after toric IOL implantation.
• To analyze the impact of prior ocular surgeries and specific corneal conditions on toric IOL outcomes.

Main Methods:

• A retrospective case-control study involving 446 eyes undergoing toric IOL implantation by a single surgeon.
• Data collected included pre-operative findings, biometry, and post-operative visual acuity and refraction at one and three months.
• Cases were defined by uncorrected distance visual acuity (UDVA) worse than 20/40, spherical equivalent (SE) >1 diopter (D) off target, or cylinder >1 D off target.

Main Results:

• The majority of eyes achieved good visual acuity (93.7%) and refractive targets (92.7% for SE, 90.9% for cylinder).
• Factors significantly associated with suboptimal UDVA included prior LASIK and keratoconus.
• Suboptimal SE outcomes were linked to prior radial keratotomy (RK) and keratoconus.
• Suboptimal cylinder outcomes correlated with prior LASIK and higher pre-operative astigmatism. Higher toric IOL power was also associated with suboptimal outcomes across all analyses.

Conclusions:

• Prior LASIK, RK, keratoconus, and higher pre-operative astigmatism are significant risk factors for suboptimal refractive outcomes after toric IOL implantation.
• These findings highlight the importance of careful patient selection and pre-operative evaluation in optimizing toric IOL outcomes.
• Further research may explore refined surgical techniques or lens selection criteria for patients with these risk factors.