Orthokeratology, promoted by EurOK (European Academy of Orthokeratology), is a non-surgical technique which makes it possible to correct a defect of sight through the programmed application of contact lenses.
This technique consists in the application of rigid gas permeable lenses (RGP) with a particular conformation, called inverse geometry, to modify the shape of the cornea for optical purposes. Night orthokeratology lenses are made with extremely oxygen permeable materials and are put only while sleeping: in this way they produce a temporary reduction of the visual defect by changing the shape of the surface of the cornea, which has a certain degree of plasticity. When the lens is on the eye it is clearly seen as with a conventional lens; when the lens is removed in the morning, the cornea retains its modified shape and continues to look good to the naked eye all day, without glasses and without contact lenses. After an initial period of adaptation, clear vision with the naked eye lasts until evening. Replacing the lenses every night maintains a stable effect over time. This treatment is completely reversible: if you want to stop using these lenses, a short period of suspension is sufficient for the cornea to return to its original shape.
Why Orthokeratology is worth doing?
The main objective is to free the ametrope from the use of glasses, but given the treatment of the subject by researchers and ophthalmologists it has also come to the conclusion that, even for children and young people of developing age, using glasses or traditional contact lenses, the deterioration is three times higher than for Orthokeratological use.
It is however to always keep in mind that, F.D.A. and C.E. had, the Orthokeratological technique is aimed at the myopic up to -6.00 / -8.00 diopters (in extreme cases, under direct Ophthalmological control). Excellent results are also obtained for Hypermetropia up to +5.00; Cylinder up to -5.00; Presbyopia up to +3.50.
Scleral lenses are lenses that, depending on their position, cover both the cornea and the sclera (mini-scleral and scleral). The main use of scleral lenses is the correction of irregular corneas in order to restore vision. The major use in this category is corneal ectasias, which can be divided into two groups. The main group of corneal ectasias includes keratoconus, kerato globe and pellucid marginal degeneration.
The second group includes post-refractive surgery ectasias (LASIK, LASEK, PRK) post radial keratotomy (RK), and trauma.
A scleral lens can be indicated in many of these cases and also for other types of irregular corneas. For example, eyes with corneas that have significant and severely irregular scars due to trauma can obtain optimal vision with them.
A large group of patients presenting with expository keratitis (diseases of the ocular surface) is particularly favored in the use of scleral lenses for the maintenance of a reservoir of liquid behind the lens.
A situation in which it is advisable to use sclerar lenses is Sjögren’s syndrome and is a chronic autoimmune inflammatory disease that affects hundreds of thousands of people worldwide (80% – 90% are female). In Sjögren’s syndrome, the immune system, not recognizing its own cells, tissues and organs, mainly attacks the exocrine glands (salivary, lacrimal) destroying them and creating considerable disorders of dry mouth (xerostomia) and dry eye (keratum dry conjunctivitis).
This category also includes conditions such as persistent corneal epithelial defects, Steven Johnson syndrome, neurotrophic corneal diseases and kerato atopic conjunctivitis. A scleral lens may be a good indication if the eyelid closure is incomplete, such as in the palpebral coloboma, exophthalmos, ectropion, nerve palsy and after palpebral retraction surgery.
WARNING: we declare that the visual examinations and professional services provided by Occhial House s.r.l. and by his collaborators, they are not medical-oculistic activities.