A matter of fact for many people - but a luxury for some others. We are speaking about life without glasses. In a significant part of the population, problems with vision appear early in childhood or at a very young age. This is mainly related to myopia, farsightedness or astigmatism. Normally, these defects are corrected with glasses, contact lenses, and since the 1990s by means of laser refractive surgery as well. Laser eye operations are nothing unusual for today's generation so some people interested in the surgery may be surprised that they are not suitable candidates for this kind of surgery. How is this possible? Leaving aside pathologic conditions in the eye, such as post-inflammatory state or degenerative changes in the cornea, the most frequent contraindication is a disproportion between the dioptric eye defect and the cornea thickness. The reason is that laser surgery reduces the cornea thickness at its central part. In this case, there is an obvious direct proportion - the more dioptres, the more tissue removed. Therefore, it is not always possible to perform surgery safely. What next? There is a solution - to remove as many dioptres as possible and keep the rest, wearing glasses or contact lenses afterwards as well.
Phakic intraocular lenses
Another solution is so-called phakic intraocular lenses. This idea is simple - hence brilliant. The original, natural patient's lens is kept in the eye - while another (artificial) lens is added to the patient's optical system. To put it simply, imagine that a contact lens is applied in the patient's eye but it is kept there permanently, without any additional care. At first, the implants used to be made of rigid materials and it turned out that, unfortunately, often they were not tolerated by the eye. Certain eye structures would become irritated, which led to complications.
Fortunately, scientific and medical research has brought new materials and new designs. The latest implant on the market is the Cachet lens made by Alcon. It was under development for 10 years but the result is worth the effort. The implant is made of special biocompatible material, known in ophthalmology since 1980s: it is shapeable yet is has excellent shape durability. Its design was improved in a systematic manner in order to reduce eye structure traumatization to the very minimum. The lens is permanently installed in the so-called front eye chamber and substitutes glasses or contact lenses. "The results achieved with this implant were a very pleasant surprise, mainly in regard to accuracy of post-operation refraction and implant stability in the eye. The surgery is patient-friendly and totally painless, and it takes only 5 minutes. And, first and foremost, this is an alternative solution available for patients who are not suitable for excimer laser correction," says head physician Petr Novák MD from Refrakční Centrum Praha. Neither post-surgery treatment nor care or attention by the patient are required. And when the eye gets older and cataracts appear, for example? The phakic lens may be removed while the patient's natural lens is replaced with a new, artificial one. It may be the modern, multifocal type, so that the person is not dependant on glasses again.