Fabry Disease and Chemosis

Ophthalmic Manifestations in Fabry Disease: Updated Review

Fabry disease (FD) is an X-linked lysosomal storage disorder, causing Gb-3 (globotriaosylceramide) buildup in cellular lysosomes throughout the body, in particular in blood vessel walls, neuronal cells, and smooth muscle. The gradual accumulation of this glycosphingolipid in numerous eye tissues causes conjunctival vascular abnormalities, corneal epithelial opacities (cornea verticillata), lens opacities, and retinal vascular abnormalities. Although a severe vision impairment is rare, these abnormalities are diagnostic indicators and prognostics for severity. Cornea verticillata is the most common ophthalmic feature in both hemizygous men and heterozygous females. Vessel tortuosity has been linked to a faster disease progression and may be useful in predicting systemic involvement. New technologies such as optical coherence tomography angiography (OCTA) are useful for monitoring retinal microvasculature alterations in FD patients. Along with OCTA, corneal topographic analysis, confocal microscopy, and electro-functional examinations, contributed to the recognition of ocular abnormalities and have been correlated with systemic involvement. We offer an update regarding FD ocular manifestations, focusing on findings derived from the most recent imaging modalities, to optimize the management of this pathology.

Visual outcome, ocular findings, and visual quality of life in patients with Fabry disease

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal disease, in which diagnosis is often established several years after onset of symptoms. Ocular manifestations can occur in childhood and be a clue to earlier diagnosis. The aim was to report ocular outcome and visual quality of life (QoL) in patients with FD.

MATERIAL AND METHODS

FD-patients recruited from Karolinska University Hospital underwent ophthalmological examinations including best corrected visual acuity (BCVA), refraction, biomicroscopy, optical coherence tomography, keratometry, review of medical records and QoL Inventories. A total severity score (TSS), as estimated via Fabry Stabilization Index, was calculated.

RESULTS

Twenty-six FD-patients (16 men) mean age 36.4 years (range 5.0-63.5 years) were included. BCVA was median 1.0 (range 0.5-1.6). Conjunctival blood vessel tortuosity occurred in 15/26 patients, chemosis in 2/26 patients, cornea verticillata in 23/26 patients, lens opacities in 19/26 patients, and tortuous or dilated retinal vessels in 20/25 patients. Group-wise comparisons of adult patients showed no differences regarding age, TSS, or ocular parameters. Overall, TSS was correlated to age (r = 0.53, p = 0.02). A linear regression model showed that age and sex explained 38% of the variance in TSS. Keratometry did not reveal corneal ectasia in any of the 12 patients examined. VFQ 25 in 15 patients showed a high median composite score, 93.6 (range: 78.1-100).

CONCLUSIONS

BCVA in FD-patients was good despite corneal and lens pathology. Ocular variables did not show an association with TSS in adult patients. Corneal or lens opacities should also lead to a suspicion of FD in children.

Conjunctival lymphangiectasia associated with classic Fabry disease

Background

Fabry disease (FD) is a treatable multisystem disease caused by a defect in the alpha-galactosidase gene. Ocular signs of FD, including corneal verticillata, are among the earliest diagnostic findings. Conjunctival lymphangiectasia (CL) has not previously been associated with FD.

Methods

We examined the eyes of a cohort of 13 adult patients, eight men and five women, with documented classic FD, all treated with enzyme replacement therapy (ERT) at the University of Alabama at Birmingham between February 2014 and April 2015. The average age was 48 years with a range of 35–55 years for men and 21–71 years for women. The mean duration of ERT was 8.4 years (men 8.9 years, women 7.6 years) with a range of 4–14 years. Classical Fabry mutations included Q283X, R227X, W236X and W277X. A high resolution Haag-Streit BQ-900 slit lamp with EyeCap imaging system was used to record conjunctival images.

Results

CL was observed in 11 of the 13 patients (85%) despite long-term ERT. Clinical presentations included single cysts, beaded dilatations and areas of conjunctival oedema. Lesions were located within 6 mm of the corneal limbus. Ten of the 13 subjects (77%) had Fabry-related cataracts and all 13 demonstrated bilateral corneal verticillata. Twelve of the 13 patients had evidence of dry eye, 9 of whom were symptomatic, and 10 had peripheral lymphoedema.

Conclusion

CL represents a common but under-recognised ocular manifestation of FD, which persists despite ERT, and is often accompanied by peripheral lymphoedema and dry eye syndrome.