Optic Nerve and Macular OCT in Hurler Syndrome (MPS I)
Title: Optic Nerve and Macular OCT in Hurler Syndrome (MPS I)
Author (s): Marshall J. Huang, BS
Photographer: Glen Jenkins
Keywords/Main Subjects: Hurler syndrome, Mucopolysaccharidosis, MPS, Optic disc edema
Diagnosis: Mucopolysaccharidosis Type I – Hurler Syndrome
Description of Image:
The images above include a photos of the optic nerve and SD-OCT of the macula in an 18-month male with a severe form of Mucopolysaccharidosis Type I (MPS I), also known as Hurler Syndrome. MPS I is an autosomal recessive, progressive, multisystem disorder caused by an absence or deficiency of the lysosomal enzyme α-L-iduronidase. This leads to a buildup of glycosaminoglycans within the lysosomes, resulting in a cascade of intracellular events that causes tissue damage and multi-organ dysfunction. This disease comprises of a spectrum of phenotypes, generally classified as Hurler (severe), Hurler-Scheie (intermediate), and Scheie (mild) syndromes.
Common systemic manifestations of Hurler syndrome include gargoyle facies, hepatospenomegaly, impaired cognitive development, dysostosis multiplex, and cardiorespiratory problems. Ocular manifestations include corneal opacification, pigmented retinopathy, central foveal ELM thickening, parafoveal IS/OS thinning, open angle glaucoma, and optic disc edema and atrophy. These symptoms can be delayed or even temporarily reversed using enzyme replacement therapy and hematopoietic stem cell transplant (HSCT).
This patient already received a HSCT but still had significant corneal clouding, as well as craniomegaly and hepatosplenomegaly. In order to evaluate the patient’s degree of retinal involvement, an exam under anesthesia was performed. Indirect ophthalmoscopy and photos of the optic nerve revealed significant disc edema in the left eye, a common finding in Hurler syndrome. In addition, SD-OCT of the macula showed early central foveal ELM thickening, greater in the left eye compared to the right. We also performed an electroretinogram (ERG) and visual evoked potentials (VEP). Those studies revealed significantly decreased flash ERG, 30Hz ERG, and flash VEP signals, with the left eye more attenuated than the right eye.
- Parini R, Deodato F, Di Rocco M, et al. Open issues in Mucopolysaccharidosis type I-Hurler. June 2017:1-9. doi:10.1186/s13023-017-0662-9.
- Ana Maria Martins MD P, Ana Paula Dualibi MD P, Denise Norato MD P, et al. Guidelines for the Management of Mucopolysaccharidosis Type I. The Journal of Pediatrics. 2009;155(S):S32-S46. doi:10.1016/j.jpeds.2009.07.005.
Faculty Approval by: David C. Dries, MD; Griffin Jardine MD
Disclosure (Financial or other): None