Clinical assessment of a hand-held automated keratometer in cataract surgery.

PURPOSE

Pre-operative keratometry was performed on 32 eyes of 32 patients undergoing extracapsular cataract extraction with intraocular lens implantation, for calculation of intraocular lens power. In an additional 20 eyes of 20 patients post-operative keratometry was performed to guide selective suture removal. Readings from a manual keratometer and an automated hand-held keratometer were compared.

METHODS

Pre-operative measurements were repeated three times on each subject to assess the repeatability of each machine. Mean-difference plots were performed to define the limits of agreement of the two machines.

RESULTS

Repeatability was higher using manual keratometry (MK) than automated keratometry (AK). There was broad agreement between the two machines in pre-operative and post-operative assessment, although clinically significant differences are likely to occur in some cases.

CONCLUSIONS

MK should continue to be used for routine pre-operative keratometry, with the AK providing a useful alternative when MK is not possible. AK is sufficiently accurate to allow its use in post-operative assessment of suture-induced astigmatism.