Corneal Refractive Therapy (CRT) or Orthokeratology is a non-invasive temporary myopia correction via special rigid contact lenses. The special structure of these lenses offers a visual acuity of 100% for an extensive period of time (for 24 hours and longer) without any other correction procedures, as a result of applying them on the eyeballs during night, for 6 to 8 hours.
According to specialized literature, CRT is a progressive method which stops the development of myopia, removes the spasms of the ocular muscles and stabilizes their activity.
The mechanism: Wearing lenses causes modification in the corneal thickness, especially in the epithelial layers (Greenberg, Will, Holden, Wang). Refractive therapy causes the thinning of the epithelia in the center and its thickening on the medium periphery. The joint effect of these slight modifications of the shape leads to obvious changes of the corneal power. (M.Ladage, 2004; O.S.Averianova, 2007).
INDICATIONS FOR CRT :
· Elimination of the need to wear eyeglasses and contact lenses;
· Stops the progression of myopia;
· Age: from 6 to 40-50-60 years old;
· Myopia: up to "-" 6.5 D;
· Astigmatism: up to "-" 2.5 D;
· Thin cornea: patients are not suitable for LASIK;
· Lifestyle: sports, hobbies.
CONTRAINDICATION FOR CRT :
· Pathologies of the cornea: inflammations, dystrophy;
· Keratoconus or keratoglobus;
· Deviations from average limits of the central corneal curvature of < 40,00 and > 50,00 D;
· Corneal astigmatism of >2,5 D: relative contraindication;
· Increased rigidity of the upper eyelid;
· Inflammatory pathologies of the eyelids and conjunctivitis;
· The dry eye syndrome;
· Simultaneous pathology of the eyeball: cataract, glaucoma, uveitis.
Is it possible to treat myopia with the help of orthokeratological lenses?
According to the statistics of Western companies, 90% of children who were treated by orthokeratologists obtained positive results. The positive effect is conditioned by the fact that Corneal Refractive Therapy reshapes the corneal surface, stabilizes the intraocular tension and eliminates all refractive errors.
What do I do if I don’t like this method?
The best thing about this method is that the effect of the orthokeratological lenses is temporary if the procedure is stopped, all modification will disappear within 72 hours.
Will I be able to see when using the lenses?
Of course! By applying the lenses you will have a much clearer vision with them and without.
For how many years should I wear the orthokeratological lenses?
Thanks to a modern material with 100% oxygen permeability, this method is absolutely non-invasive. This is why there aren’t any side effects after applying lenses. These lenses offer you a new quality of life.
What are the complications that might occur while wearing lenses?
In very rare cases wearing orthokeratological lenses can cause dry eyes, edema of the superficial layers of the cornea, which is visible within the first stage of the therapy. Infectious diseases are quite uncommon. According to international research, the possibility of infections during Refractive Therapy is 0,0006%. When applying soft daily contact lenses, the possibility of infections is 0,0039%. This research confirms the safety of the orthokeratological lenses.
How do the orthokeratological lenses get adjusted?
Adjusting the lenses is a process which requires a meticulous approach of the cornea parameters, adjusting the lenses on an individual basis. The quality of this therapy depends on several factors, like the professionalism of the ophthalmologist, the modern equipment, the diversity of lenses. The orthokeratological lenses are the only orthokeratological lenses in the world that can be adjusted depending on 3 parameters and their adjustment can last up to 1 month. During this month, the patient visits the “Oculus Prim” ophthalmologist 3-4 times.
The first visit lasts from 1,5 to 2 hours. During the consultation, the patient is examined by following the screening procedures:
· Refractive error, by using an autorefractor;
· Corneal pachymetry;
· Corneal topography;
· Computerized investigation of the quality and quantity of the tear film;
· Computerized perimetry;
· Non-contact tonometry;
· Investigation of the accommodation reflex function;
· Slit lamp biomicroscopy;
When there are no contraindications, the doctor adjusts the parameters of the lenses in compliance with the data obtained after examinations. Subsequently, the placement of the lenses is analyzed and the visual acuity is assessed.
After the first night of using the lenses, the patient comes for a second visit at the doctor. The ophthalmologist analyzes the placement of the lenses and evaluates the visual acuity in order to confirm that it corresponds to the refraction of minus 2 diopters, which should disappear during the first night.
After one week of applying the lenses every night, the patient comes for a standard examination procedure. During this period, the patient can experience double vision, clouded vision, decreased acuity in the evening.
The fourth visit takes place after 3 to 4 weeks of wearing lenses. The vision already becomes as good as it can be and stable. Subsequently, the doctors of “Oculus Prim” examine the patient every 3 months.