Abstract
Purpose: :
To assess the effects of accommodating IOLs for restoring accommodation in cataract surgery compared to monofocal IOLs.
Methods: :
Search Strategy:We searched MEDLINE (Jan 1950-Oct 2008), the Cochrane Library (2008, Issue 3), and ClinicalTrials.gov (Oct 2008) using no limits; reviewed reference lists; and contacted experts in the field.Selection Criteria: Randomized controlled studies comparing accommodative IOLs versus monofocal IOLs in cataract surgery patients.Data Collection and Analysis: Two authors independently extracted data and assessed trial quality. We contacted study investigators for missing information. Due to variations in measurement scales, we pooled the efficacy outcomes distance corrected near visual acuity (DCNVA) and pilocarpine-induced IOL shift as standardized mean differences (SMD, 95% confidence interval), using random effects models. Some of the secondary outcomes and adverse effects such as posterior capsular opacification were summarized qualitatively.
Results: :
Twelve RCTs involving 727 eyes were included in the meta-analysis. Based on ten trials involving 545 eyes, accommodating IOLs improved DCNVA more than monofocal IOLs [SMD -1.36 (-2.32, -0.41)], however the substantial heterogeneity across studies (I2=94%) could not be explained by any characteristic of the study population or methodology. Pooling the six homogeneous trials (I2 =45%) involving 216 eyes, we found no significant difference in DCNVA [SMD -0.07 (-0.45, 0.31)]. Based on four studies involving 182 eyes that evaluated pilocarpine-induced IOL shift, accommodative IOLs were associated with significantly more anterior lens shift compared to monofocal IOLs [SMD -1.44 (-1.84, -1.04)]. Four of the five studies that mentioned posterior capsular opacification reported increased rates in the accommodating IOL group several months post-operatively.
Conclusions: :
This is the first quantitative analysis comparing accommodative IOLs to monofocal IOLs using both subjective and objective measures of accommodation. While incorporating all available data suggests statistically significant improvements in both measures, the unexplained heterogeneity of the DCNVA findings and unclear clinical relevance of the anterior shift findings greatly limit interpretation. In light of the lack of subjective benefit from 6 homogeneous trials, further rigorous RCTs with standardized methodology and adequate adverse effects monitoring are needed to clarify the trade-offs.
Keywords: cataract • intraocular lens • accomodation