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Posterior corneal curvature measurements with peripheral fitting zones before and after myopic LASIK using Orbscan II
Arthur C K Cheng1, Thomas Ho, Srinivas K Rao
1Dept of Ophthalmology, Hong Kong Sanatorium & Hospital, 5/F Central Block, 2 Village Rd, Happy Valley, Hong Kong. artcheng@netvigator.com
Purpose:
To compare pre- and postoperative posterior corneal curvature measurements in peripheral fitting zones using the Orbscan II topographer in patients undergoing myopic LASIK.
Methods:
Retrospective analysis of preoperative and 3-month postoperative Orbscan II data of 194 eyes that underwent myopic LASIK at a university eye center. Posterior corneal power was estimated using the peripheral 7- to 10-mm fitting zones. The pre- and postoperative values were analyzed and compared.
Results:
The mean difference in estimated pre- and postoperative power of the posterior cornea was -0.04 +/- 0.16 diopters (P < .01).
Conclusions:
The difference in posterior corneal curvature measurement following myopic LASIK using the peripheral fitting zone with the Orbscan II, as compared to the preoperative values, is clinically insignificant.