Large Diameter Penetrating Keratoplasty For Corneal Keratolysis Of Unknown Origin

The purpose of this case report is to present the importance of management of peripheral corneal ectasia, making a good differential diagnosis and studying its etiology. If a large diameter penetrating keratoplasty is performed it is essential to know the postoperative risks and complications.

Corneal keratolysis is the progressive thinning of the cornea that can lead to ocular perforation. This process can arise from bacterial, viral or fungal infections; sterile inflammation associated or not with systemic disease (for example rheumatoid arthritis); or surgical or pharmacological damage (for example topical NSAIDs).

A 74-year-old female patient with a history of acute anterior uveitis underwent phacoemulsification and IOL implantation in the right eye. In the immediate postoperative period, the patient presented ectasia with inferior corneal thinning, painless and without epithelial defect or ocular inflammation. The patient provided optical reports prior to surgery showing progressive astigmatism from 0 to -3x85º in 2 years. Topography confirmed right corneal thinning with the appearance of pellucid marginal degeneration. Despite the topical treatment, the ectasia progressed, so it was decided to perform a large diameter penetrating keratoplasty (PK). Immunosuppressive treatment was introduced while waiting for a systemic study, which ended up ruling out connective tissue diseases and autoimmune diseases. In the postoperative period after PK, an inferior epithelial defect appeared that progressed to ulceration despite treatment with autologous serum. Amniotic membrane transplant was performed on two occasions and also a tarsorrhaphy. It stabilized, leaving a thinned leukoma, but after 9 months the graft was rejected and needed a second PK. By increasing the immunosuppressive treatment, the new graft remains stable, but presents calcium keratopathy and a best corrected visual acuity of hand movement.

In cases of corneal keratolysis it is necessary to be clear about the differential diagnosis, perform an etiological study and rule out treatable causes. In cases where keratolysis is caused by sterile inflammation, management consists of immunosuppressive treatment. Even so, in many cases such as the one included, given the rapid progression, keratoplasty is necessary. As it is a peripheral thinning, a large diameter keratoplasty may be necessary, implying a greater risk of persistent epithelial defects, risk of rejection and glaucoma.