Undetected development of glaucoma after radial keratotomy.

PURPOSE: To report a case of advanced glaucomatous optic atrophy years after bilateral radial keratotomy.

METHODS

Multiple intraocular pressure (IOP) measurements of both eyes in a 40-year-old woman who underwent previous bilateral radial keratotomy were obtained using Goldmann applanation tonometry as well as air-puff and Schiotz tonometry. In addition to regular eye examinations, corneal thickness, surface, and shape were examined using Orbscan and C-Scan.

RESULTS

The cornea of both eyes did not show signs of corneal thinning, but flattening of the corneal surface was observed. The decreased corneal curvatures precipitated a misjudgment of IOP readings measured by central applanantion tonometry (12 to 18 mmHg), whereas impression and non-contact tonometry revealed elevated IOP values (21 to 27 mmHg).

CONCLUSIONS

Changes of the corneal shape without corneal thinning can lead to falsely low IOP values. Therefore, in eyes that have undergone corneal refractive surgery, non-Goldmann measurement of IOP and continued examination of the optic nerve and possibly visual fields are recommended.