IN TWO MINDS -RECURRENCE VERSUS REJECTION POST KERATOPLASTY IN A CASE OF VIRAL KERATITIS

This case report features the diagnosis and management of a challenging case with features of microbial keratitis following a penetrating keratoplasty (PKP). The purpose of this case report is to help distinguish clinically between recurrence of viral keratitis versus true rejection as well as to outline the correct protocol to proceed in such cases.

The patient presented to us at a tertiary eye care set up, on an outpatient basis, in North India. He gave a history of PKP done in the right eye,elsewhere,  approximately three months back.

A 27 year old male patient was referred to us for managment of post PKP keratitis in the right eye. Patient gave us a detailed history of a background of HSV keratitis in the same eye one year ago for which he was given medical management and the keratitis resolved. Later, he developed a corneal opacity involving visual axis which was hampering his day to day function. The patient was advised to undergo a PKP under antiviral cover with the aim of visual rehabilitation.

After an initial uneventful post operative period of three months, he complained of redness and discharge from the operated eye. At presentation, a large 3 x 4 mm central, deep stromal corneal infiltrate was noted at the inferior edge of the graft tissue with a small epithelial defect. Reduced corneal sensation was also noted in the area. A feeder vessel was also noted along the inferior graft-host junction along the margin of the infiltrate. This helped us move towards the diagnosis of an impending graft rejection. Snellen visual acuity was noted to be finger counting close to face.

Corneal scraping from the area of infiltrate was performed for microscopy, culture and sensitivity and was found to be normal. 6 inferior sutures were removed. Patient was already on Tab Famciclovir 250 mg thrice a day. Ganciclovir eye gel 0.15% was added along with antibiotic eyedrops cover and lubrication along with eyedrop Atropine 1% for mydriasis. Low dose steroid (Loteprednol Etabomate 0.5 %) was addded two hourly and tapered on subsequent follow ups based on clinical observation.

Patient improved symptomatically and the size of the infiltrate reduced on follow up.

A mixed picture is often encountered in patients who have undergone keratolplasty after viral keratitis. Features favouring a diagnosis of recurrence of HSV included presence of a neurotrophic ulcer, symptomatic presentation and a high degree of suspicion. Features that clinched the diagnosis of an impending rejection included a negative report on scraping, presence of feeder vessel along the graft margin and location of the infiltrate. Although the medical managment of both conditions overlap to a high degree, removal of the sutures prevents new corneal vascularisation, migration of inflammatory factors into the graft tissue, that lead to graft rejection. Important learning points include identifying sequelae of HSV correctly and to always check for loose sutures.