Abstract
Purpose: :
To evaluate axial length and corneal curvature of microphthalmic eyes with congenital cataract, in order to provide reference data for IOL power calculation.
Methods: :
Retrospective analysis of mean keratometric power (autokeratometer,Nidek KM500) and axial length (Ocuscan biometer,Alcon) measured under general anaesthesia before congenital cataract surgery. All cases having received cataract surgery for congenital cataract with primary diagnosis of microphthalmos, microcornea, and/or primitive vitreous persistence in 1994-2006 at our Institution were reviewed. For each patient enrolled, the eye with unilateral cataract or one eye randomly selected between the two with bilateral cataract were considered for statistical analysis.
Results: :
68 children (42 female) met inclusion criteria: 44 patients had unilateral cataract (44eyes), 24 bilateral (48eyes). Mean age at surgery was 362.6±583.9 days for unilateral cataract (range:23-3427), 345.6±510.4 days (range 10-1863) for bilateral. Mean keratometry: 47.6±3.6 D (range:39.0-56.3). Mean axial length:18.4±2.0 mm (range14.6-23.6). For unilateral cataractous eyes, Km values were significantly greater than for the fellow eye with clear lens (unpaired t test, p=0.03). Age matched comparison to a group of patients with congenital cataract alone (without microcornea or persistent vitreal vasculature: mean keratometry: 45.1±3.0 D, mean axial length:20.0±2.3 mm), showed significant differences in axial length and keratometry (unpaired t test. For keratometry p=0.02, for axial length p=0.03).
Conclusions: :
In our series, eyes with cataract associated to microcornea or persistent primitive vitreous presented steeper corneas and shorter axial length as compared to age-matched eyes with congenital cataract without other ocular anomalies. This data has to be taken into account for the elaboration of pediatric-specific formulas for IOL implant.
Keywords: refractive error development • cataract • intraocular lens