CONTACT LENSES

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.

By choosing to undergo this treatment, it is necessary to perform some preliminary tests, check the state of health of the eye and then a map of the cornea, using an instrument called Corneal Topographer.Once the specific data has been obtained, the problems and the visual defect assessed, the next operation performed by the Optometrist technician is the evaluation and technical processing of the possible feasibility of the contact lens application.Once all the necessary evaluations have been completed and after the first application for exploratory purposes, the technicians will give the correct answer on the feasibility of the application.

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 scleral 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.

Juvenile developmental myopia is an increasingly widespread condition and therefore requires careful management. Technical studies quantify that, by 2050, the subjects requiring myopic corrections in Europe will reach about 50% of young people. It is important and necessary to adopt all possible strategies.

The corrective methods are:
Orthokeratology (wearing night contact lenses)
The Menicon Bloom Night / Bloom Night Toric contact lenses
Soft contact lenses with defocus (specific)
Menicon Bloom Day contact lenses
Specific ophthalmic lenses
The Essilor Stellest lenses
Atropine (low dose medical drug)

The Essilor Stellest project (approved by the Bicocca University of Milan) for ophthalmic lenses and Menicon Bloom (CE Certification on the safety of the medical device) for Day contact lenses and Night Orthokeratology, demonstrate that research in the field of myopic progression is a subject of much attention of the technical companies of the sector.Each case must be evaluated, after an Ophthalmologist examination, to consider both, advantages and disadvantages.

Keratoconus is a degenerative disease resulting from a lower resistance of the corneal structure. The cause would be linked to a fragility of the collagen that constitutes the cornea associated and in some cases to repeated traumas.It occurs in childhood or puberty and progresses in most cases up to the age of 35-40, although in some subjects it can progress even further.Contact lenses for keratoconus are not recommended to slow down the evolution, but to provide the excellent vision that cannot be achieved with glasses due to the strong distortions of the corneal surface.