Keratoconus (KC) is a progressive, noninflammatory, bilateral (but usually asymmetrical) ectatic corneal disease, characterized by paraxial stromal thinning and weakening that leads to corneal surface distortion.
Visual loss occurs primarily from irregular astigmatism and myopia, and secondarily from corneal
Typically commences at puberty and progresses to the mid-thirties at which time progression slows
and often stops.
Between age 12 and 35, it can arrest or progress at any time and there is no way to predict how fast
it will progress or if it will progress at all.
In general young patients with advanced disease are more likely to progress to the point where they
may ultimately require some form of surgical intervention. Management.
Subclinical Keratoconus(KC) normally causes no visual impairment, the patient may require glasses
or nothing to achieve 20/20 vision.
Clinical Keratoconus is classified in several stages according to the conus severity.
The initial stages can be anticipated with contact lenses while the more advanced stages may need implantation of intracorneal rings, or laser combined with corneal cross-linking.
The final stage can be treated only with Keratoplasty(corneal transplantation).
A non-invasive treatment CXL (corneal collagen cross-linking riboflavin) treatment has been proven to strengthen the weak corneal structure in Keratoconus.This method works by increasing collagen cross-linking, which are the natural "anchors" within the cornea.These anchors are responsible for preventing the cornea from bulging out and becoming steep and irregular (which is the cause of Keratoconus).During the 30-minute, in-office treatment, custom-made riboflavin eyedrops are applied to the cornea, which are then activated by a special light. This is the process that has been shown in laboratory and clinical studies to increase the amount of collagen cross-linking in the cornea and strengthen the cornea.In published studies, such treatments were proven safe and effective in patients.
The next generation of multifocal intraocular lenses (IOL’s) – the Trifocal. This implant gives patients a better chance to enjoy clear vision at all distances with maintained contrast sensitivity and lower visual disturbance.
The older generation multifocal lenses offer clear distance and near vision, however they are least clear for intermediate vision and can result in glare and haloes especially with night driving. The trifocal implant has the advantage of offering clear intermediate as well as distance and near vision with minimal glare and haloes at night.
This lens enables patients to switch naturally between all distances. Studies have shown superior performance of the trifocal lenses for intermediate vision and overall image quality:
Outstanding intermediate visual acuity
The trifocal implant significantly improves intermediate visual acuity enabling patients to feel more comfortable performing their intermediate distances activities.
High resolution under all light conditions
The trifocal implant produces images with high resolution for all distances under all light conditions. You will be able to switch back and forth between targets at different distances without the need to put on corrective glasses.
The unsurpassed intermediate vision of the trifocal lens
becomes evident when compared with the performance of older generation multifocal lenses.
Trifocal implants display far better intermediate visual performance, even under poor light conditions.
U.S. Air Force Resolution Target Test (AFT) for the trifocal lens at near, intermediate and far distance at 3.0 mm pupil size.
Even poor light conditions have only a minimal influence on the good functional vision achieved by trifocal lenses at all distances.
Conditions related to this treatment:
Short / Long Sight
The applied method of anesthesia is called "Topical anesthesia with drops" and it is the most modern method of anesthesia in Cataract surgery.
It is completely painless because the anesthetic is administered in form of drops and no in painful injections.
The results are impressive, the patient may see few hours after surgery without any bruises or swelling of the eyelids.
The cataract is removed with a special instrument of ultrasounds and the utilized technique is named Phacoemulsification.
In normal eyes the transparent lens is located behind the iris, its functional purpose is to focus the emerged light from the surrounding space on the retina (fig. 1).
The progressive cloudiness of the normal transparent lens is called Cataract (fig. 2).
It starts as a whitish spot and in time ends up in a solid white lens named Mature Cataract.
The initial symptoms are: blurred images, halos around lights and poor color discrimination, which after some years leads to complete loss of vision.
The more frequent cause of Cataract is the aging of the human organism.
In rare cases, Cataract may present at birth (Congenital Cataract), after long-lasting reception of medication, after eye injuries and as consequence of chronic eye and systematic diseases.
The only effective way of treatment is the surgical removal of Cataract and the implantation of a synthetic lens at the same place, where it was located the blurred lens.
Today with the modern surgical methods that are in practice (phacoemulsification), the Cataract can be removed successfully at the initial stages, long before maturation.
The success rate of the surgery is very high and the re-establishment of vision approaches the physiological levels.
From a small incision of 3.0 mm, the Cataract is emulsified and aspirated through a small needle tip that is inserted inside the eye.(fig. 3) In the continuity without enlarging the incision, a special foldable lens is implanted inside the eye. The small incision is left without sutures and heals in most cases in two weeks. The intraocular lens remains in the eye forever.(fig. 4) The advantages of the method are very short time of hospitalization and quick recovery of vision, enabling the patient to regain his or her daily activities very soon.
There is no unique method to correct presbyopia at present. The most common available surgical treatment options are:
In this case, the doctor determines the dominant eye of the patient.
The nondominant eye is aimed to -1.0 myopic correction by laser and the dominant eye is fully corrected for far vision or left uncorrected if it can see far very well without correction.
It is the simplest and easiest approach to anticipate presbyopia, it is reversible and can be fully correct presbyopia on early stages and partially on advanced. In other words, in advanced presbyopia, the patient will need glasses only for small prints.
In this case, also the surgery is performed in the non-dominant eye. At first, a pocket is created in the corneal stroma with a laser or a microkeratome and than a small implant is inserted inside the corneal stroma centered on the patients' visual axes.
The procedure is also reversible.
MULTIFOCAL OR ACCOMODATING IOLs
Multifocal or accommodating IOLs.
In this case, the surgery is performed on both eyes and is based on the removal of the crystalline lens of the patient.
Then an artificial lens is implanted inside the eye in the place of the extracted crystalline lens.
The implant can be either multifocal or accommodating.
The pros and cons of each lens are variable for that reason the selection of the appropriate lens for every patient demands careful preoperative examination.
In contrary to the previous procedures this last one is not reversible.
The patients which are corrected with implants can see close and far with both eyes without glasses.