Comparison of clinical and biometric characteristics between nanophthalmic children and age-matched controls.

Purpose: To compare the clinical and biometric characteristics of children presenting with nanophthalmos (NO group) with that of age-matched controls (CO group). Methods: Electronic medical records of 40 children (<18 years of age) with diagnosis of nanophthalmos (NO), presented to a tertiary center in Tamil Nadu between January 2010 and December 2019, were reviewed and compared with 30 age-matched controls (CO) presenting for routine eye examination between October 2019 and December 2019. Clinical parameters compared were best-corrected visual acuity (BCVA), axial length (AxL), keratometry (K), anterior chamber depth (ACD), lens thickness (LT), retinochoroidal scleral thickness (RCS), corneal diameter, central corneal thickness (CCT), intraocular pressure (IOP), lens axial length factor (LAF), and lens thickness/anterior chamber depth ratio (LT/ACD). Results: Mean age of the NO group was 8.95 ± 4.0 years. Mean spherical equivalent (SE) in NO group was 10.87 ± 3.1 D and was inversely correlated to AxL (r = -0.46, P value = 0.003). All biometric parameters (AxL, ACD, LT, RCS, LAF, and LT/ACD), except CCT were significantly different between NO and CO groups. NO group children had 52.5% visual impairment with BCVA ≤ 6/24 and 17.5% had esotropia. Common ocular associations in NO group were amblyopia (64.3%), primary angle-closure glaucoma (PACG) (17.8%), pigmentary retinopathy (14.3%), and retinal detachment (3.6%). Angle-closure disease was seen in 50% of NO group and 30% underwent laser peripheral iridotomy (LPI). There was a significant difference in SE, ACD, and LAF among NO children with AxL <17 mm or >17 mm. Multivariable regression analysis revealed a significant correlation of SE and ACD with AxL. Conclusion: Nanophthalmos in children often present as amblyopia with visual impairment and strabismus. NO group with AxL <17 mm, had angle-closure disease as a common association with significantly lower ACD, higher SE, and LAF. All morphometric characteristics, except CCT, were significantly different between NO and CO groups. Close monitoring with serial biometry in NO group is needed for the timely diagnosis and prompt intervention to avoid visual impairment, due to glaucoma.