Ocular Manifestations of Leprosy 

In patients with leprosy (Hansen disease), the eyes frequently are affected with lagophthalmos, loss of eyebrows, corneal exposure, keratitis, uveitis, scleritis, leproma of the conjunctiva and sclera, retinal pearls, and loss of sensation with corneal ulceration with scarring.^{[1, 2, 3]} At the United States Public Health Service (USPHS) Hospital in San Francisco, the incidence of leprotic uveal infections in patients with Hansen disease is 6-7%.

Ocular therapy depends on the manifestations and may involve medical or surgical measures.

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Ocular manifestations of Hansen disease include the following:

• Insidious chronic anterior uveitis (chronic plasmoid iridocyclitis; see the image below)
• Posterior synechia, keratic precipitates, iris pearls, complicated cataract, vitreous opacities, retinal detachment, secondary glaucoma, and phthisis bulbi
• Diffuse plastic reactions (acute diffuse plasmoid iridocyclitis)
• Isolated leproma
• Posterior uveal involvement (rare) - Retinal pearls, uveal effusionHansen disease plasmoid (plastic) iridocyclitis.

Beading of corneal nerves (abnormally wide edematous nerves) is probably the earliest detectable ocular finding (see the image below). These abnormal nerves are sometimes difficult to detect and are seen best by means of slit-lamp broad beam, retroillumination, or sclerotic scatter. The opacification and beading are due to the localization and multiplication of bacilli in or adjacent to nerves, with or without infiltration of plasma cells, lymphocytes, and epithelioid cells.

The corneal stroma then reacts, and the cornea becomes covered with milky chalky deposits, causing a keratitis pathognomonic of Hansen disease. These avascular punctate subepithelial opacities usually require a slit-lamp examination for their detection. The lesions are seen between the epithelium and the Bowman membrane, and they later spread and become confluent. They are lepromas containing acid-fast organisms, lymphocytes, and macrophages, and some become calcified and can destroy the Bowman membrane.

With progression of the disease, superficial and deep vascularization develops with reduced vision. In Carville Public Health Service (PHS) Hospital, 16% of the first ocular lesions noticed were episcleritis, scleritis, or uveitis. This type of episcleritis usually has early pain, tenderness and circumcorneal injection, and lack of exudates or bacteria. Late lepromas may develop in the episcleral area because this is a low-temperature area. Bacilli are present in the ciliary body and pass through the sclera, episclera, conjunctiva, cornea, and also into the anterior chamber and iris.

Iris pearls with uveitis represent miliary lepromas and are diagnostic lesions (see the image below). They are creamy round spheres, usually less than 0.5 mm in diameter, that are typically located near the papillary border or the chamber angle; they may also migrate and fuse with other pearls. Iris pearls contain acid-fast material, remains of lepromatous cellular debris, and calcium salts. They form deep in the iris stroma and are extruded to the surface, where they may persist for months or years.

Leprous pannus usually develops in the superior limbus and later extends around the entire corneal circumference.

The uveitis in Hansen disease may follow a severe and prolonged course and may be associated with extensive anterior or posterior synechia. After repeated attacks, extensive iris atrophy and intractable glaucoma develop.

Uveal effusion in association with conjunctival and episcleral hyperemia (see the first image below), as well as retinal pearls (see the second image below), may occur in rare cases.

Typical systemic disease is confirmed by histopathology of corneal conjunctival or subcutaneous skin scrapings (see the first image below), anterior chamber^[4] or vitreous taps (see the second image below), or skin tissue biopsy (see the third image below). Findings show multiple acid-fast bacilli with acid-fast stains or Fite-Faraco stain, along with iris pearls.

Lagophthalmos (see the image below) or unexplained seventh nerve weakness, associated with skin or neurologic disorders, should be considered in the differential diagnosis of Hansen disease. Exposure keratitis and corneal ulceration also may occur, especially in association with decreased corneal sensation, thickened eyelids and incomplete blinking, decreased mucin and meibomian secretions, and denervation of the lacrimal gland.

Medical therapy

Ocular therapy depends on the manifestations. Aggressive treatment of iridocyclitis is probably one of the more important considerations, as well as protection of anesthetic corneas from exposure, erosion, and ulceration in the face of lagophthalmos.

If corneal staining is demonstrated by fluorescein solution, frequent use of artificial tears (1% methylcellulose drops) or lubricating ointment is indicated. Commercially available moisture shields, plastic wrap (eg, Saran Wrap), or swimming goggles may be used to occlude the eyes. Taping the eyelids closed at night is also useful. Secondary glaucoma may be treated with acetazolamide (Diamox) to reduce intraocular fluid production and reduce intraocular tension.

Plasmoid (plastic) iridocyclitis with anterior uveitis should be treated aggressively to avoid synechia, iris bombé, and other complications.

Surgical therapy

Cataracts may be treated with reduction of vision or surgical extraction. (The authors generally elect to be conservative and not to insert intraocular lenses, because of the problems of repeat uveitis and synechia.)

Iris bombé due to posterior synechia and glaucoma may be treated with sector iridectomies to help reduce intraocular pressure and improve vision in some patients with complicated cataracts or corneal opacities.

Eyebrow loss may be treated with makeup, tattooing, or free grafts from the scalp. Lagophthalmos due to seventh nerve palsy may be treated by a partial tarsorrhaphy or lateral canthoplasty or other lid-shortening procedures. Temporalis transfers are also useful in some patients.^{[5, 6]}

Entropion or ectropion should be treated by appropriate surgical procedures. Trichiasis may be treated with repeated epilation or with electrolysis. In patients who have a painful blind eye as a result of glaucoma, enucleation may be the treatment of choice.

Consultations

With the present treatment available, the sequelae can be minimized, but the deformities can be stigmatizing for the patient and their families. If the disease goes untreated, the disability aspect is tremendous.

It is strongly recommended that a trained leprologist, if available, be included in the treatment of Hansen disease patients with ocular manifestations.