|Year : 2023 | Volume
| Issue : 1 | Page : 154-156
Atypical corneal clouding in mucopolysaccharidoses
Mary Stephen1, M Loganathan2, S Swathi3, B Priyavadhana2
1 Department of Ophthalmology, JIPMER, Puducherry, India
2 MS Ophthalmology, Department of Ophthalmology, SVMCH&RC, Puducherry, India
3 Department of Ophthalmology, Sri Venkateshwara Medical College Hospital and Research Centre, Puducherry, India
|Date of Submission||11-Jan-2022|
|Date of Decision||05-Jul-2022|
|Date of Acceptance||14-Nov-2022|
|Date of Web Publication||21-Feb-2023|
JIPMER, No. 6, Vallalar Street, Kadhirkamam, Puducherry
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The etiology for corneal clouding from the birth is varied and includes conditions such as sclerocornea, birth trauma, corneal ulcer, Peters anomaly, and rare causes like mucopolysaccharidoses (MPS). The lysosomal storage disorders are associated with a varied ocular manifestation including bilateral corneal clouding which is often mild and stippled except in few cases like Hunter syndrome where cornea is often clear. We report a case of MPS Type I S (MPS 1) with near-normal visual acuity and bilateral dense corneal clouding with sparing of central 3 mm of cornea. The patient also had typical facial and skeletal abnormalities of lysosomal storage disorder. To our best knowledge, MPS 1 with marked corneal clouding with sparing of central cornea is very rare and has not been reported. This case report emphasizes on the atypical ocular presentation of MPS and the need for ophthalmological screening in the storage disorders.
Keywords: Corneal clouding, mucopolysaccharidoses Type 1, mucopolysaccharidoses, skeletal deformities, storage disorders
|How to cite this article:|
Stephen M, Loganathan M, Swathi S, Priyavadhana B. Atypical corneal clouding in mucopolysaccharidoses. Oman J Ophthalmol 2023;16:154-6
| Introduction|| |
Mucopolysaccharidoses (MPS) are rare storage disorders characterized by the accumulation of glycosaminoglycans (GAG) in different tissues resulting in multisystem dysfunction. It is a cluster of conditions with overlapping clinical features that often require enzyme assay for the diagnosis. Ocular features in MPS syndromes include prominent corneal clouding, refractive error, pigmentary retinopathy, cherry red spot, and cataract. However, ocular involvement is typically absent in Hunter and Sanfilippo syndrome. Typical facial features in MPS include low-set ears, broad nasal bridge, short neck, sparse hair, and skeletal abnormality., We report a young girl with MPS Type I S (MPS 1) who presented with bilateral corneal clouding and clear central zone with a good visual acuity with skeletal and facial features. This reports the atypical nature of corneal involvement and the need for careful ophthalmological evaluation for diagnosis of the specific condition.
| Case Report|| |
A 21-year-old female patient was presented with the complaints of gradual onset painless diminution of vision in both eyes since early childhood. She was using spectacles, but was not comfortable. She was born out of second-degree consanguineous marriage, full-term normal vaginal delivery. No clinical abnormalities were found in her parents and siblings.
The child had characteristic features such as frontal bossing, hypertelorism, short stature, low-set ears, macroglossia, bowed legs, short stubby fingers, and hoarseness of voice [Figure 1]. Snellen visual acuity in both eyes of 6/60, with correction of +4.50 DS OD and +4.00 DS OS, was improved to 6/9 OU. Intraocular pressure was normal in both eyes. Gonioscopy was attempted, but details could not be made out clearly due to hazy cornea. Slit-lamp biomicroscopic examination showed a significant corneal clouding in both eyes with central corneal clear zone of 3 mm; no vascularization or degenerative changes were observed. Lens appeared clear and fundus appeared normal as far as seen.
|Figure 1: (a) Clinical photograph of the patient showing facial dysmorphism like frontal bossing, hypertelorism, corneal opacity, and broad nose, (b) X-ray of the patient knee joint showing the presence of bowed legs|
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Multidisciplinary approach has been sought, and the patient was extensively worked up with the department of medicine and orthopedics. Baseline investigations were normal, and urine toluidine blue test turned positive; X-ray showed short bones with thickened metaphysis, and abdominal scans revealed mild hepatosplenomegaly. Enzyme activity assays for various MPS have been carried out, and iduronidase activity was on the lower side indicating the possibility of MPS I. The patient was treated with spectacle correction and advised close follow-up. Enzyme replacement therapy could not be commenced due to financial issue and nonavailability in the institute.
| Discussion|| |
MPS are a group of lysosomal storage disorders which occurs due to enzyme deficiencies resulting in disturbed metabolism of GAG which are complex carbohydrates. This condition is characterized by the accumulation of GAG in various tissues including tendons, cornea, liver, spleen, and heart. Corneal stroma has chondroitin sulfate and keratan sulfate. The ocular manifestations apart from cloudy cornea include pigmentary retinopathy, cherry red spot, and optic atrophy. MPS syndromes include Hurler, Hunter, Scheie, Sanfilippo, Morquio, and Maroteaux–Lamy, and the clinical features are often overlapping. Corneal involvement is often microscopic in most syndromes, but characteristically cloudy cornea is seen in Hurler and MPS 1. Systemic features typically include abnormal facial characteristics and skeletal deformities. Urine analysis for the GAG metabolites with reduced leukocyte enzyme activity helps in diagnosis, but corneal involvement gives a reliable clinical clue toward the condition.
We report a case of a young girl with bilateral cloudy cornea and clear central zone with near-normal visual acuity and typical systemic features of MPS, who on further evaluation found to be a case of Scheie syndrome. The previous case reports of MPS I reported stippled corneal clouding of entire cornea without any sparing [Figure 2]. Those patients with severe corneal involvement and retinal changes often have a very poor visual acuity, and visual prognosis is not favorable. Most cases reported with MPS I also had associated pigmentary retinopathy and optic atrophy. Atypical presentation of dense corneal clouding with central sparing and normal fundus with a good visual acuity as in our case is very rare to the best of our knowledge. The patient requires enzyme replacement therapy as treatment, but most cases could not receive due to its cost and nonavailability.
|Figure 2: Photograph of the patient showing dense corneal clouding with central clear zone of cornea in both eyes|
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| Conclusion|| |
Storage disorders are multisystem disease often diagnosed clinically, and corneal clouding gives a clue toward it. However, MPS presenting with dense corneal clouding and clear central zone is very rare, and enzyme analysis helps in making the diagnosis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that the name and initials will not be published, and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]