Basil H. Bloom BSc(Hons) FCOptom

Optometrist

Orthokeratologist.

Do you want to see all day without Spectacles or Contact Lenses?           ORTHOKERATOLOGY is the NEW Contact Lens alternative to Laser Surgery.

Corneal Topography provides a computerized surface map of the cornea for  evaluation of the cornea for Orthokeratology, Contact Lens and pre-surgical proceedures.

EyeSys System

The corneal surface has 75% of the refractive or light focusing ability of the eye. The EyeSys System utilizes placido disk technology (see below) to acquire images of the corneal surface. Placido disk technology is based on a technique that captures the reflection of rings of light off the surface of the cornea and measures the different distances between the ring reflections. Current software technology captures the reflected images with a digital camera, processes the data, and displays the information in multiple formats.

A Placido device is made up of many concentric light rings. The exact arrangement and number of rings may vary with different manufacturers.	Light rings are projected on the cornea above. This image is captured on a CCD and analyzed as thousands of computations are performed instantly.

The EyeSys System pictured measures approximately 8000 points on the front surface of the cornea and generates color-coded curvature topographical maps that identify specific areas where varying degrees of corneal curvature and irregularities occur. It also detects the location and degree of any astigmatism that may be present.

It produces a computerized surface map of the cornea and can show the difference between two maps.

The one below is the effect of an Orthokeratology lens, worn at night and removed in the morning, showing a -3.00D change.

It also allows computerised contact lens fitting where I can design a custom lens without having to insert trial contact lenses on the patients eyes.

Copyright © 1999 Basil H. Bloom Optometrist                                    
Last modified: June 26, 2005