Multimodal ophthalmic findings in patients with mucopolysaccharidosis: A prospective observational study

Abstract

Purpose To characterize ocular involvement in pediatric patients with mucopolysaccharidosis (MPS) using multimodal assessment, with emphasis on corneal densitometry and visual electrophysiology. Methods This prospective observational study included 22 patients with molecularly confirmed MPS. Ophthalmic assessment comprised best-corrected visual acuity, cycloplegic refraction, intraocular pressure, ultrasound pachymetry, slit-lamp grading of corneal opacity, Scheimpflug densitometry, in vivo corneal confocal microscopy, optical coherence tomography (OCT), and B-scan ultrasonography. Full-field electroretinography (FF-ERG) and flash visual evoked potentials (Flash VEP) were performed in cooperative patients. Results Mean age was 9.05 +/- 3.46 years, and 11 patients (50.0%) had MPS VI. Corneal opacity was present in 20 patients: mild in nine, moderate in eight, and severe in three. Mean corneal densitometry was 30.1 +/- 10.9 grayscale units in the right eye and 28.5 +/- 9.1 in the left eye. Densitometry values correlated strongly with corneal opacity grade (right: rs = 0.858, p < 0.001; left: rs = 0.696, p = 0.006). Corneal opacity precluded fundus examination in 11 patients; B-scan ultrasonography showed no posterior segment abnormality. OCT was evaluable in 15 patients and showed preserved macular morphology. Elevated intraocular pressure requiring treatment occurred in four patients with MPS VI; one also had bilateral optic atrophy. FF-ERG abnormalities were identified in nine of 14 tested patients, and bilateral flash VEP P2 latency prolongation was reported in four. Conclusion Corneal opacity was the predominant ocular manifestation and frequently limited posterior segment assessment. Multimodal structural and functional testing provided complementary information on corneal, glaucoma-related, optic nerve, and retinal involvement in MPS.