Late-onset haze associated with chikungunya infection
A 42-year-old woman had photorefractive keratectomy without mitomycin-C for correction of 1.50 diopters (D) of myopia in both eyes with good visual outcomes. The postoperative central corneal thickness measured by 50 MHz ultrasonic pachymetry was 533.0 mm and 534.0 mm in the right and left eyes, respectively. In the interim, she presented with no complaints about her visual acuity, and although she had visited another clinic, the medical records were not available.

Later she was diagnosed with chikungunya fever through a positive immunoglobulin M antibody captured in enzyme-linked immunosorbent assay, and along with other systemic symptoms, she reported mild redness and photophobia of the left eye with no discharge. However, she was not seen by an ophthalmologist at that time.

Two weeks after the infection, she noticed acute impairment of visual acuity in the left eye, hence returned to our facility. On initial examination, her visual acuity was 20/20 in the right eye and 20/200 in the left eye. There was no improvement noted on correction or with rigid contact lenses. The right eye was normal; however, the left eye had a dense superficial stromal scar over the pupil, measuring 6.0 mm at its greatest diameter. The surface of the scar was grossly irregular, and the central corneal thickness on the high-resolution rotating Scheimpflug device (Pentacam HR—Oculus) and on anterior segment optical coherence tomography (OCT) (Cirrus HD-OCT 5000/500) was 661 µm and 690 µm in the left eye and 539 µm and 544 µm in the right eye, respectively. No conjunctival injection was observed, and the remaining anterior segment structures were normal. The dilated fundus examination performed was unremarkable. The patient was prescribed topical prednisolone acetate 1.0% 4 times a day for a month. However, no improvement in vision or corneal appearance was observed.

Three months after the diagnosis, because of the patient's complaints, the severity of a visual disability, and the intensity of corneal opacity, manual debridement combined with phototherapeutic keratectomy of the left eye was performed. mitomycin-C 0.02% was applied for 1 minute after the ablation, and the total amount of the ablated cornea was approximately 100 µm. One week after the surgery, the patient reported mild improvement in her vision. At 1 month, her corrected distance visual acuity was 20/80, and the haze seemed to have comparatively diminished. Nine months after the surgery, her visual acuity remained stable, and rigid gas-permeable contact lens fitting was tried again. This time, smoother surface and more transparency was noted than before, and thus, she achieved a visual acuity of 20/25 on the left eye with mild apical clearance, centration, and good movement; she refused additional surgeries.