Case study: ocular manifestations lead to referral and subsequent diagnosis of MPS27
Ocular manifestations in an infant lead to subsequent diagnosis of MPS I-H
Description:
- Infant referred for ocular assessment because of abnormally increasing head circumference at 12 months of age
- Corneal opacities of unknown origin detected, together with a dysmorphic face, telecanthus and atypical eyebrows
- Diagnosed with MPS I-H at 18 months of age
Patients with slowly progressing MPS can easily remain undiagnosed.
Case history
Age 12 months:
- Referred for ocular assessment to rule out papilledema because of an abnormally increasing head circumference
- Corneal opacities of unknown origin detected, together with a dysmorphic face, telecanthus and atypical eyebrows
- After ventriculoperitoneal shunting surgery, subject’s pre-existing strabismus disappeared, but hypersensitivity to light remained
Age 18 months:
- Diagnosed with MPS I
- Underwent stem cell transplantation
- Grating acuity was 3.6 cycles/degree binocularly, but reflexes from ocular fundi reported as dull
Age 3 years:
- Binocular visual acuity, 0.5; stereopsis negative; hyperopia (+5 in right and left eyes) detected
- Refractive filter glasses prescribed and well accepted
Age 4.5 years:
- Right-sided microesotropia and amblyopia detected
- Intensive occlusion therapy started
- Right eye remained amblyopic
- Corneas remained slightly cloudy
Age 6.7 years:
- Corneal thickness showed no remarkable deviation from normal
Summary
Delayed diagnosis of MPS leads to disease progression and poses a threat to patients.
However, clinical evaluation of children with MPS poses challenges for ophthalmology:
- Retinoscopy may be difficult to perform due to dull fundus reflexes
- Examination may be hampered by severe photophobia and lack of cooperation, cognitive delay or hyperactivity disorders
In this case, early diagnosis of MPS I-H enables early intervention and management, which are associated with improved clinical outcomes.
Better knowledge of the ocular and non-ocular manifestations of MPS may help in the early diagnosis of children with MPS who present with ocular problems but are not yet diagnosed with the disease.1,10
Any number of ocular manifestations, especially if coupled with other classical or non-classical signs, should prompt referral to a geneticist or metabolic centre.12