Sinthiya Sivarajah
Ichthyosis is a group of inherited skin disorders characterised by skin thickness and dry scale formation (1). There are many forms of Ichthyosis which range in appearance, severity and mode of inheritance. Ichthyosis can also present with ocular manifestations which are primarily due to abnormalities in the eyelid and tear film. This can lead to development of exposure keratopathy. In more severe forms of Ichthyosis, such as harlequin ichthyosis, the skin around the eyelids can become tight and inflexible leading to cicatricial ectropion (2).
Epidemiology and Prevalence
As mentioned previously, many types of ichthyosis exist (1). Ichthyosis caused by mutations in the same gene can vary significantly from person to person in terms of severity and symptoms. Ichthyosis has been found to be more common in Asian, Mongolian and Native American groups (4). The condition affects both men and women equally (5).
Clinical presentation
The most common ocular manifestation of ichthyosis is an ectropion which can lead to exposure keratopathy if left untreated. The exposure of the cornea to the environment can also increase the risk of corneal ulceration (6).
Another ocular manifestation is meibomian gland dysfunction. The reduced lipid layer of the tear film can lead to subsequent dry eye symptoms, predisposing the eye to complications such as keratitis (7). Other ocular manifestations include chronic blepharitis, trichiasis and conjunctival inflammation (5).
Diagnosis
Diagnosis can be made by clinical examination of the skin for characteristic thickened, dry scale (1). This can be confirmed through genetic testing to identify specific mutations associated with the disorder. For example KAL1 gene in X-linked ichthyosis associated with Kallman’s syndrome (3). Early diagnosis is essential to prevent complications such as vision loss or corneal scarring (6).
Management
In patients with ichthyosis, regular eye examination is crucial to detect complications early (6). The use of topical therapy such as lubricating eye drops and ointments may be beneficial in treating ocular symptoms such as chronic dryness and irritation (1). In severe cases of ectropion, where conservative measures have failed, surgical management may be considered (7).
References
1. Limmer AL, Nwannunu CE, Patel RR, Mui UN, Tyring SK. Management of ichthyosis:
a brief review. Skin Therapy Letter. 2020 Jan 1;25(1):5-7.
2. Fischer J, Bourrat E. Genetics of inherited ichthyoses and related diseases. Acta dermato-venereologica. 2020;100(7).
3. Oji V, Preil ML, Kleinow B, Wehr G, Fischer J, Hennies HC, Hausser I, Breitkreutz D, Aufenvenne K, Stieler K, Tantcheva‐Poór I. S1 guidelines for the diagnosis and treatment of ichthyoses–update. JDDG: Journal der Deutschen Dermatologischen Gesellschaft. 2017 Oct;15(10):1053-65.
4. Esperón-Moldes US, Pardo-Seco J, Montalván-Suárez M, Fachal L, Ginarte M, Rodríguez-Pazos L, Gomez-Carballa A, Moscoso F, Ugalde-Noritz N, Ordonez-Ugalde A, Tettamanti-Miranda D. Biogeographical origin and timing of the founder ichthyosis TGM1 c. 1187G> A mutation in an isolated Ecuadorian population. Scientific Reports. 2019 May 9;9(1):7175.
5. Al-Amry MA. Ocular manifestation of Ichthyosis. Saudi J Ophthalmol.
2016;30(1):39-43.
6. Bhedasgaonkar SS, Nadkarni SU. Corneal ulcer secondary to ectropion in lamellar Ichthyosis: a rare congenital disorder. Saudi Journal of Ophthalmology. 2020 Jan 1;34(1):59-61.
7. Kim WJ, Ahn YJ, Kim MH, Kim HS, Kim MS, Kim EC. Lipid layer thickness decrease due to meibomian gland dysfunction leads to tear film instability and reflex tear secretion. Annals of Medicine. 2022 Dec 31;54(1):893-9.