Evaluation of Visual System in Microphthalmic Eyes

Background: Microphthalmia is defined as a globe with a total length that is at least two standard deviations below the mean for age. It can be isolated or occur with other anomalies or as part of a syndrome. Objective: The aim of our work was to evaluate any functional or structural abnormality along the whole visual system in microphthalmic eyes. Patient and Methods: The study included 70 eyes of 42 individuals having microphthalmos. The mean age was 12.47 years (ranged from 9 months to 15 years). All cases were subjected to full ophthalmological history, and examination. Some investigative tools were used as A scan ultrasound, ultrasound biomicroscopy (USB), optical coherence tomography (OCT), visually evoked potential (VEP), and impression cytology. All data were recorded and analysed. Results: Positive family history was present in 29 cases (69%) while positive consanguinity was present in 24 cases (58%). Axial length ranged from 12.8 to 19.9mm (mean 16.1 ± 2.3). Simple microphthalmos (without any ocular dysgenesis) was recorded in 9 cases (21.4%). Nystagmus was present in 19 cases (45.2%), convergent squint in 9 cases (21.4%), Congenital contract was present in all eyes included in this study. Other ocular dysgenesis found were microcornea 28 eyes (40%), iris coloboma in 3 cases (7.2%), sclerocornea in 1 patient bilaterally (2.4%), posterior synechiae with pinpointed pupil in 11 eyes (15.7%), patches of iris atrophy in 3 cases (7.2%). Increased intraocular pressure with pallor optic nerve was present in 32 eyes (45.7%). Retinal examination showed picture like retinitis pigmentosa in 3 cases bilaterally (7.2%). Venous congestion and arterial attenuation with decrease vascular reflex were evident in 12 eyes (17.2%). VEP showed marked decreased in signals in all the cases which denotes functional defect of optic nerve. UBM confirmed the presence of congenital cataract in all the cases (100%). Persistent hyperplastic primary vitreous (PHPV) was encountered in 3 cases (7.2%), corneal hyperreflectivety with wrinkling at Descement's membrane in 1 case (2.4%), and peripheral anterior synichea was present in 2 eyes (2.9%), while abnormal shaped angle was found in 3 eyes (4.3%). Impression cytology showed marked squamous metaplasia (Grade IV) in almost all cases with completely absent goblet cells. Correspondence to: Dr. Ahmed A. Radwan, The Department of Ophthalmology, Faculty of Medicine, Ain Shams University. OCT showed no abnormalities except in 9 cases (21.4%) with alternating retinal nerve fiber reflectivity being thin in one area and thick in another. Conclusion: Microphthalmic eyes comprise large entity ranging between simple microphthalmos to complex type. Thus ophthalmological evaluations using examinations and different investigative tools help in suitable management together with control of the necessity of any surgical intervention and perform an accurate follow-up.