"Following the launch of i-GO Overnight Vision Correction, Chris Bennett takes another look at reverse geometry optics and charts his progress this time around."
"Starting Out
My first consultation, which lasted about one hour, consisted of a sight check, refraction and then a slit-lamp examination. As far as the Ortho-K goes, the meat of the appointment is the topography readings upon which the shape of the final lens will depend. This is achieved by taking four readings, which are then run through software, which compares the repeatability of the result to ensure a true measurement has been taken. As this was a trial and I am familiar with Ortho-K and RGP insertion and care, I requested that the lenses were posted to me for the first night's wear.
Following the first night of wear I was to return to the practice for a check with the lenses in. I found the lenses quite comfortable to wear and on waking the vision was noticeably better with the lenses still in than I had expected or that I had experienced with the Ortho-K lenses. I did notice some mistiness in the right lens. By the time I got to the consultation I had been awake for two and a half hours and was happy for the lenses to come out. My VA at this point was 6/6 with the single night's wear. Bansal expressed surprise at the size of the flattened area of the cornea, around 7mm, and was very pleased with the results. A slit lamp and flourescein examination showed no signs of wear whatsoever. The right lens required a bit of cleaning, which was the cause of the mistiness. I was ready to start in earnest.
On the third visit a week later the same flourescein and VA tests were conducted. I had another line of acuity, although at near I was still over-corrected by +0.75, which Bansal said he would review after my vision had stabilised at the one-month check. The key he said was making the lenses powerful enough for the correction to last throughout the day, without ‘over cooking it' to the extent that close vision was still an issue in the evening. A further fortnight of wear in I found that my near vision was more of an issue than when I use glasses and contact lenses.
At my last consultation Bansal had suggested he might reduce the power of the lenses if this persisted once the lenses and correction had settled down. One feature of orthokeratology is that the effect does build momentum, so two weeks in I really began to notice my emergent presbyopia rather more than before.
A double benefit could be achieved by missing the odd night's wear. There were a couple of occasions at weekends when I decided to give myself a night off from wear. This had the dual benefit of taking the edge off the correction, thereby making close vision more comfortable and giving me a night without lenses.
Otherwise my vision was fine and I found the freedom of not having to wear glasses and contact lenses when doing activities such as swimming and running the biggest life change. This proved an apposite time of year for the trial. The nights were drawing in and the weather swung from bright sun to cloud and rain, just the kind of conditions when choosing the right eyewear becomes an issue. I found night vision with the i-GO lenses excellent and general day vision, apart from close work, excellent. I had become to all intent and purposes emmetropic.
I found it an ideal method of vision correction for an active myope, offering a post-Lasik effect without the risk of surgery. I will continue to use orthokeratology on a period basis as my chosen method of correction."