Abstract
Purpose: :
To evaluate the refractive exactitude of intraocular lens calculation power in patients with refractive surgery.
Methods: :
This is a case series. Patients with a history of phacoemulsification after refractive surgery (radial keratotomy or myopic keratomileusis in situ) were reviewed. The keratometric power, and the flattest keratometry by Axial Topography and Orbscan were registered. Keratometric power at 3 and 5 mm optical zone by Orbscan were studied. The calculation of IOL power was done with each parameters and 4 formulas: SRK II, SRK–T, Holladay and Hoffer. The postoperative spherical equivalent was compared with the IOL power implanted, then we matched results from formulas with keratometries. We analyzed which IOL could have been best adapted.
Results: :
Six eyes from 5 patients were included. The flattest keratometry was obtained by Orbscan Sim K minimum value. These Keratometries were correlated with SRK–T formula and gave us the highest IOL power. The flattest keratometric power in all patients with a history of radial keratotomy and one with myopic keratomileusis in situ were obtained from the flattest Orbscan value, and that with myopic keratomileusis in situ with an ectasia was from Orbscan at 5 mm optical zone. The highest IOL power was obtained in all patients with the flattest Orbscan value with SRK–T formula except in one patient with a history of keratomileusis in situ and ectasia
Conclusions: :
The flattest Keratometry with Orbscan and SRK–T, is the best combination, nevertheless, these values provide a general direction for the IOL power that should be placed. These parameters did not apply in our patient with a corneal ectasia.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • refractive surgery: complications • intraocular lens