2020–2021 BCSC Basic and Clinical Science Course™
8 External Disease and Cornea
Chapter 8: Systemic Disorders With Corneal and Other Anterior Segment Manifestations
Dermatologic disorders commonly have associated ophthalmic findings, particularly involving the eyelids.
Ichthyosis represents a diverse group of hereditary skin disorders characterized by excessively dry skin and accumulation of scales. These diseases are usually diagnosed during the first year of life.
Ichthyosis vulgaris, an autosomal dominant trait, is the most common hereditary scaling disorder, affecting 1 in 250–300 people. Ocular involvement varies with this form of ichthyosis.
Eyelid scaling, cicatricial ectropion, and conjunctival thickening are common in ichthyosis. Primary corneal opacities are noted in 50% of patients with X-linked ichthyosis but are rarely seen in patients with ichthyosis vulgaris. Dotlike or filament-shaped opacities appear diffusely in pre–Descemet membrane or in deep stroma and become more apparent with age without affecting vision. Nodular corneal degeneration and band keratopathy have been described. Secondary corneal changes such as vascularization and scarring from severe ectropion-related exposure can develop.
The goal of treatment in all ichthyosis disorders is to hydrate the skin and eyelids, remove scales, and slow the turnover of epidermis, when appropriate. These disorders are not responsive to corticosteroids.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.