Corneal ectasia following cataract extraction surgery in a patient with keratoconus: a case report

According to experimental and clinical published studies, patients with keratoconus have a genetic predisposition to corneal ectasia; however, ectasia might not be activated or reactivated unless an additional stressful event triggers the disease. Triggering factors are sources of reactive oxidative stress; among them, mechanical trauma (vigorous eye rubbing, poorly fit contact lenses), exposure to ultraviolet light, and atopy/allergies. The aim of this case report is to present for the first time a case of rapidly progressive corneal ectasia in a patient with keratoconus following uncomplicated phacoemulsification surgery for cataract removal.

A 38-year-old Caucasian man was referred to our out-patient's service due to bilateral cataract. He also had bilateral keratoconus and had undergone corneal cross-linking in both his eyes 5 years prior to his referral. Ever since the corneal cross-linking, keratoconus had been stable. He underwent a full ophthalmological examination including slit-lamp biomicroscopy, optical biometry, Scheimpflug tomography, corneal biomechanical assessment, and fundus examination. He presented advanced centrally located cataract with count fingers for preoperative best-corrected visual acuity. An uncomplicated cataract extraction surgery was performed. Preoperative flat keratometry reading was 40.5 diopters, steep keratometry reading was 41.8 diopters, astigmatism was 1.3 diopters, corneal hysteresis was 8.2, corneal resistance factor was 7.5, and thinnest corneal thickness was 503 μm. Within 3 months, he demonstrated rapidly progressing corneal ectasia in his operated eye, while 6 months postoperatively, flat keratometry reading was 45.5 diopters, steep keratometry reading was 48.3 diopters, astigmatism was 2.8 diopters, corneal hysteresis = 6.8, corneal resistance factor = 7.5, and thinnest corneal thickness = 318 μm.

To the best of our knowledge, this is the first report to describe corneal ectasia in a patient with keratoconus following phacoemulsification surgery. Cataract surgeons should provide extra caution to patients with keratoconus and take into consideration this rare but potentially sight-threatening complication.