An eighteen-year-old female student presented to us with complaints of pain, redness and gradual decrease in vision in the right eye of 20 days duration. She was treated with 0.3% ciprofloxacin eye drops, by a local ophthalmologist. She had discontinued using the medication prior to presentation to us. She was not treated with steroids at any point of time. She was a myope using daily wear monthly disposable hydrogel contact lenses since eight months which she discontinued wearing with the onset of the present symptoms.
On examination, her visual acuity was restricted to perception of light and accurate projection of rays in the right eye and 20/20 in the left eye. Slit lamp examination of left eye was within normal limits. The right eye showed congestion of bulbar conjunctiva. Cornea showed a paracentral solitary, large, well circumscribed, full thickness, and yellowish white stromal infiltrate measuring 4.5 mm × 5.5 mm with a central 2-mm perforation. Anterior chamber was shallow (Fig. ).
Figure 1 Clinical and virological investigations: A. Slit lamp biomicroscopy under optical section of the right eye showing a solitary paracentral, well circumscribed, large, full thickness stromal infiltrate, collapsed anterior chamber and a central area of perforation. (more ...)
Based on the history and clinical findings a clinical diagnosis of perforated corneal ulcer, probably of bacterial origin (Pseudomonas
spp.) was made. Corneal scrapings were collected for microscopic examination, bacterial, fungal and acanthamoeba cultures as described elsewhere [3
]. Contact lenses and the cleaning solution were also collected for microbiological investigations. Gram, Giemsa stained smears and the potassium hydroxide preparation of the scraping did not reveal any organisms. However, Giemsa stained smear showed the presence of multinucleated giant cells, with characteristic molding of nuclei (Fig. ), suggesting infectious keratitis, probably of a viral etiology. Scrapings obtained from the lower palpebral conjunctiva, on the following day (corneal scrapings could not be collected due to the application of tissue adhesive and a bandage contact lens), was positive for HSV-1 antigen (Fig. ) by an immunoperoxidase assay. Patient was prescribed 3% acyclovir ointment application 5 times daily. None of the cultures yielded any growth.
She returned to the clinic after a week. On examination, the tissue adhesive and bandage contact lens were dislodged. Repeat corneal scrapings were obtained for microbiological investigations. HSV-1 antigen was detected by an immunoperoxidase assay (Fig. ) in the repeat corneal scrapings while bacterial and viral cultures (shell vial and conventional tube cultures for HSV-1) were negative.
Clinical condition did not improve during the subsequent week. Hence, the patient underwent a therapeutic penetrating keratoplasty (PK). Corneal tissue was obtained at PK. She received oral acyclovir 400 mg, 5 times a day and 1% prednisolone acetate eye drops, 6 times a day. Corneal tissue was positive for HSV-1 antigen by immunohistochemistry (Fig. ) and for HSV DNA by PCR (Fig. ). Histopathological examination of the formalin fixed corneal tissue revealed polymorpho nuclear neutrophils admixed with mononuclear cells, multinucleated giant cells in H & E and PAS (Fig. ) stained sections. Stromal melting was seen in the central cornea. The visual acuity improved to 20/20. There was no recurrence and the graft was clear (14 months post PK).
Figure 2 A. Corneal tissue section showing absence of HSV-1 antigen in the epithelium (Negative control, Immunohistochemistry, X 500). B. Corneal tissue section showing presence of HSV-1 antigen in the epithelium (Immunohistochemistry, X 500). C. Corneal tissue (more ...)