Based on device, the market is classified into slit lamp, biometer, perimeter, tonometer, optical coherence tomography (oct) scanner, fundus camera, autorefractor &
keratometer, and other devices.
Noninvasive tear break-up time test is usually performed by sophisticated and expensive instruments, Tearscope (21),
keratometers, or complicated computerized systems, topographic analysis systems including videokeratoscopy, ocular surface thermography, or lateral shearing interferometry.
Changes induced by surgery on the spherical equivalent and the average keratometry (measured with a manual
keratometer) Pre and Post-operative SE * Preoperative SE * Postoperative Measures.
Once cataract was diagnosed and surgery was planned, keratometry was done on Haag-Strait manual
keratometer and A-scan was done by applanation contact method on SonoMed machine.
The measurement is mainly done with the help of Bausch and Laumb
Keratometer. The value is then put on SIA calculator version 2.1 and the resultant SIA is found.
The
keratometer was placed at appropriate distance from the eye to be measured, forming the image of 3 rings and was brought into focus on the surface of cornea.
In both clinics keratometry (K) values were measured preoperatively and 1 month postoperatively using an autorefractometer/
keratometer (Nidek ARK-510A), followed by evaluation of SIA based on the method developed by Holladay et al.
At one week follow up an image was displayed in Retro Illumination Mode by Huvitz Auto Ref/
Keratometer Model HRK-7000 (Huvitz Co.
The relation of these values with CCT, ACD, AXL,
keratometer parameters, and refractive measurements were examined.
For example, I have found it useful to practice manual keratometry on most of my contact lens patients and get either my supervisor to check the technique or compare my findings with the auto
keratometer findings.