Steroid-Related IOP Elevation After Photorefractive Keratectomy
Narrative Responses:
Purpose
Postoperative steroid eye drops are used routinely following photorefractive keratectomy (PRK). Elevation of intraocular pressure (IOP) is a common side effect. Different steroids and dosing regimens have been used in an effort to minimize this problem. This study compares IOP elevation following PRK with two different ophthalmic steroid regimens.
Methods
This was a retrospective analysis of IOP measurements taken before and after PRK. 19,213 eyes were evaluated from a single site over an 8 year period. Eyes were grouped by treatment: PRK with less than 50 μm ablation, fluoromethalone QID tapered over 2 months (short taper); and PRK with a 50 μm or greater ablation, fluoromethalone QID tapered over 4 months (long taper). Steroid response was defined as an elevation of 10 mmHg or more above preoperative baseline or a single measurement of greater than 25 mmHg. Statistical analysis was performed with paired t tests.
Results
There were 10,789 eyes in the short taper group and 8,424 in the long taper group. Mean preoperative IOP and central corneal thickness were not significantly different. The difference in IOP elevation at 1 month was not significant (5.95% and 6.17% respectively), but was significant at months 2 (5.43% and 2.42%) and 3 (2.74% and 0.55%). By the month 6 visit persistent IOP elevation was uncommon in both groups (0.00% and 0.03%). The mean IOP elevation for steroid responders was greatest at month 1 for both groups (15.08 and 14.59)
Conclusion
IOP elevation due to postoperative fluoromethalone following PRK was more common with a long steroid taper than with a short, however, this difference did not persist at the six month postoperative visit. IOP compensation for the change in corneal thickness would likely reveal a greater change and warrants further evaluation.