Central Corneal Haze Increased by Radial Keratotomy Following Photorefractive Keratectomy

PURPOSE

To report a case of central corneal haze induced by minimally invasive radial keratotomy (mini-RK) after photorefractive keratectomy (PRK) and subsequent deep lamellar keratoplasty.

METHODS

We report a case (one eye of one patient) of central corneal haze that worsened after mini-RK was performed 2 years following PRK. Four years later, a second PRK was done, myopic regression was subsequently observed, and corneal haze persisted. Deep lamellar keratoplasty was performed and a corneal graft was taken, which was examined by light and electron microscopy.

RESULTS

In the ablated area, irregularity of the basal membrane and hypertrophy of the corneal epithelium were observed. In the stromal layer, collagen fibers showed disorder in their disposition. Aggregated activated keratocytes were observed. An epithelial plug filling the gap of the RK incision persisted for 6 years after the mini-RK. The RK incision was easily divided when deep lamellar keratoplasty was performed and the patient obtained a stable visual outcome.

CONCLUSIONS

It is possible that mini-RK enhancement after PRK induces central corneal haze and reduces corneal integrity. Deep lamellar keratoplasty for refractory corneal haze after refractive surgery was useful in this eye.

Corneal haze among blue eyes and brown eyes after photorefractive keratectomy

BACKGROUND

To compare the incidence and severity of corneal haze after photorefractive keratectomy (PRK) among white patients with blue eyes and Saudi patients with brown eyes.

DESIGN

Retrospective, nonrandomized, comparative trial.

PARTICIPANTS

A total of 150 patients (71 females and 79 males) were included in this study. Two hundred sixty-six eyes of 150 patients were subjected to PRK. One hundred blue eyes of 50 white patients and 166 brown eyes of 100 Saudi patients were included in this study.

METHODS

Two hundred sixty-six eyes of 150 patients were subjected to PRK with the Chiron Technolas Keracor 117C for the correction of myopia and astigmatism.

MAIN OUTCOME MEASURES

All patients had complete ophthalmologic examinations, visual acuity testing, intraocular pressure, pachymetry, corneal haze assessment (0-4+), and computerized corneal topography.

RESULTS

There were 266 eyes of 150 patients with 100 blue irides and 166 brown irides. The spherical equivalent was -0.50 diopter (D) to -8.75 D. The mean postoperative spherical equivalent at 6 months was -0.063 D (standard deviation [SD], +/-0.595) in blue eyes compared to -0.28 D (SD, +/-0.683) in brown eyes (P = 0.006). Ninety-five (95%) of 100 of the blue eyes achieved +/- 1 D of attempted correction compared to 148 (89.2%) of the 166 brown eyes. All patients with blue eyes had a visual acuity of 20/30 or better compared to 153 (92.2%) of the 166 brown eyes (P = 0.009). Forty-eight (18.04%) eyes had minimal to mild haze, 3 (1.12%) eyes had moderate haze, and 2 (0.75%) eyes had severe haze. The incidence of corneal haze among brown eyes was 48 (28.9%) of 166 eyes compared to 5 (5%) of 100 in blue eyes (P < 0.001). The difference remained significant after adjustment for age and gender with a P value of 0.0283. The relative risk for developing haze in brown eyes was found to be 7.72.

CONCLUSION

The incidence of corneal haze after PRK was significantly higher among Saudi patients with brown irides than among white patients with blue irides. This suggests that racial factors may play a role in the development of corneal haze.