Cytomegalovirus Induced Infectious Crystalline Keratopathy After Penetrating Keratoplasty

to report a rare case of post PKP infectious crystalline keratopathy caused by Cytomegalovirus 

Infectious Crystalline Keratopathy is a rare infection of the cornea that results in grey-white, branching stromal opacities with little surrounding inflammation. Predisposing factors include immunocompromised corneal state, contact lens wear, topical anesthetic abusing ,et. The most common causative organisms is streptococcus viridans however Staphylococcus epidermidis, Streptococcus pneumoniae, Haemophilus, Enterococcus, and Candida have been reported.

a 55 year old diabetic man presented to our hospital with complaint of pain, redness and decreased vision in his left eye since 2 weeks ago. The patient’s right eye had been eviscerated due to penetrating injury 25 years ago. In the left eye, there was a history of post photorefractive keratectomy keratitis 6 years ago. After that there was a history of therapeutic penetrating keratoplasty and then optical penetrating keratoplasty within 6 month. He was prescribed eye drops  tacrolimus 0.01% three times a day, betamethasone four times a day.

At his first visit the vision in the left eye was counting finger. There was scar of perivous PKP in the peripheral cornea and some of the sutures of PK were in place and none of them were loose. A branching whitish opacity was visible in the supratemporal quadrant of cornea. 

An initial diagnosis of infectious crystalline keratopathy was made for the patient. Firstly, corneal sampling for smear and culture was done 2 times but both of them were negative for bacterial or fungal species. Then, corneal confocal microscopy was done which was negative for acanthamoba. As the last step was looking for a causative organism, corneal sampling was done which turned out positive for CMV. Therefore, we prescribed discontinuing predisposing topical medications such as drop tacrolimus and betamethasone. Also, we added tab valgancyclovir 900mg 2 times a day and eye drop levofloxacin to address the viral issue.

The viruses may be the causative organism of an infectious crystalline keratopathy. So, PCR of Aqueous humor is advised if primary investigations such as corneal smears/cultures and confocal microscopy are negative. Management strategies for infectious crystalline keratopathy include both reducing the dose of topical medications which compromise ocular immunity and antimicrobial treatments.