Inter-ocular Difference of Axial Lengths in Children with Unilateral Congenital and Developmental Cataracts

Abstract

Purpose: Preoperative axial length is a critical parameter for estimating eye growth and selecting intraocular lens power for surgery in children with unilateral cataracts. However, without classifying diagnosed subtypes of cataract, previous studies have failed to reach a consensus on the inter-ocular difference (IOD) of axial length between cataract eye (CE) and the fellow eye (FE). In the current study in children with unilateral congenital and developmental cataracts, IOD is compared according to previously diagnosed subtypes.

Methods: Charts of otherwise healthy patients born in 1979 through 2011 with primary unilateral cataract surgery were reviewed. All axial lengths (AL) were measured with either contact or immersion A-scan prior to ocular surgery. IOD was calculated. Surgeons classified cataracts during surgery into one of four subtypes - posterior lenticonus (PL, N=36), persistent fetal vasculature (PFV, N=22), posterior subcapsular (PSC, N=7) and nuclear (NUC, N=3).

Results: Among subtypes of diagnosis, axial lengths are significantly different for both CE (p<0.001) and FE (p<0.001); however, there is no significantly different IOD (p=0.71). NUC and PFV patients have shorter CE (IOD= -0.85 ± 0.51 (100% shorter); -0.40±1.46mm (59% shorter)); PL on average has similar CE and FE (IOD=-0.26±1.03 (71% shorter CE)); PSC patients has longer CE on average (IOD=0.11±0.53mm (43% shorter CE).

Conclusions: IOD between eyes is variable even for subtypes of diagnosis. Subtypes of cataract may explain the variety of IOD in unilateral cataract.

Keywords: 445 cataract • 461 clinical (human) or epidemiologic studies: natural history • 556 infant vision