Histopathology and treatment of corneal disease in keratitis, ichthyosis, and deafness (KID) syndrome

Sir,

A 34-year-old male with keratitis–ichthyosis–deafness (KID) syndrome and documented mutation in the GJB2 gene was examined for progressive corneal neovascularization in the left eye. He had been treated for over 10 years with intermittent topical corticosteroids; systemic doxycycline; and a penetrating keratoplasty, which had failed because of recurrent surface disease.

Examination revealed a visual acuity of 20/30 in the right eye and HM in the left eye, partial loss of eyebrows, complete loss of eyelashes, and atrophy of meibomian gland openings (Figure 1a and b). Tear production was low according to Schirmer's test. The right cornea showed abnormal peripheral epithelium with fine superficial neovascularization (Figure 1c). The left cornea had extensive superficial and deep neovascularization and scarring (Figure 1d).

Figure 1

Clinical pictures of patient with keratitis–ichthyosis–deafness (KID) syndrome. (a) Forehead skin with deep furrows, complete loss of eyelashes and partial loss of eyebrows. (b) Loss of eyelashes with atrophy and plugging of the meibomian gland orifices. (c) The right cornea showing a rim of abnormal epithelium with superficial neovascularization peripherally. (d) The left cornea showing significant stromal scarring with extensive neovascularization.

The patient underwent a keratolimbal allograft and a penetrating keratoplasty in the left eye with systemic immunosuppression consisting of prednisone, tacrolimus, and mycophenolate. Histopathology showed thickened epithelium with parakeratosis and dyskeratosis, but no goblet cells in the cornea (Figure 2). The conjunctiva had very few goblet cells with occasional keratinization.

Figure 2

Photomicrograph of the corneal button. The corneal epithelium is thickened with poorly differentiated epithelial cells towards the surface. There is loss of Bowman's layer, chronic inflammation in the sub-epithelial region, and neovascularization in the stroma.

Postoperatively, the patient developed significant inflammation and suture induced neovascularization resulting in surface failure and stromal scarring. Therefore, he required a repeat keratolimbal allograft and penetrating keratoplasty. He subsequently maintained a vision of 20/50–20/100 for 4 years before gradually developing recurrent surface disease (Figure 3). The patient is being considered for a Boston Keratoprosthesis.

Figure 3

Postoperative appearance of the left eye at 3 years after keratolimbal allograft and penetrating keratoplasty. There is mild recurrence of the surface disease with superficial neovascularization in some areas.

The right eye has been managed effectively with cyclosporine 0.05% two to three times a day, and a large scleral gas permeable contact lens which significantly reduces the patient's photophobia. His visual acuity remains 20/40.

Previous treatments of the corneal disease in KID syndrome have included superficial keratectomy and penetrating keratoplasty, both of which lead to recurrence.^{1, 2} Topical corticosteroids and cyclosporin have been shown to improve the surface disease, whereas systemic treatment with vitamin A actually worsens the surface disease.^{3, 4} Previously, amniotic membrane and limbal transplantation were not successful in a patient.⁵

This report shows that the corneal epithelium in our patient with KID syndrome had abnormal differentiation. Although we could not confirm true limbal stem cell deficiency, the improvement with limbal transplantation lends further support to this possibility.

Conflict of interest

The authors declare no conflict of interest.