Orthoptics is an important branch of ophthalmology whose objective is the evaluation and visual rehabilitation of muscular, sensory and innervation disorders affecting the visual system. Since September 2018 Humanitas has activated a dedicated clinic managed by Dr. Chiara Favilli, orthoptist and assistant in Ophthalmology. The center, which is under the direct supervision of Dr. Fabrizio Camesasca, ophthalmologist at the Eye Center of Humanitas Research Hospital in Rozzano, extends the wide range of services offered by HMC Milan.
How does an orthoptic examination work and what anomalies can it detect?
Under normal conditions, the eyes work together and in harmony, with the aim of allowing the perception of a single high-resolution image. The first part of the orthoptic examination consists in the evaluation of visual acuity, through the measurement of sight and the detection of the presence of refractive defects. This is followed by examinations to study binocular vision, i.e. the ability of the two eyes to work together, providing a correct perception of depth, and the examination of ocular motility, which allows you to assess the six ocular muscles, first individually (dutions), then together (versions).
The orthoptic examination therefore makes it possible to diagnose any anomalies in binocular vision. Among these there are:
Strabismus: a visible deviation of the eyes, or identifiable only by specific tests, caused by a deficit of the eye muscles. It generates a consequent loss of the ability to accurately assess the distance of objects (stereopsis).
Ocular paralysis, often resulting from trauma, caused by lesions of a single or multiple ocular nerves, sometimes associated with other signs and/or neurological symptoms.
Diplopia, understood as “double vision” of an object, during vision with both eyes. Causes include neurological or muscular problems, which alter the ability of both eyes to work together in the perception of a single image.
Amblyopia or “lazy eye”, a very common disorder in children, occurs when, often due to an optical problem, one eye sees better and is used more than the other. The lesser-used eye develops a lesser visual capacity and is, therefore, “neglected” by the brain. Diagnosis and treatment must be carried out by about 10 years of age; otherwise it will be impossible to develop a normal visual fineness.
Dyslexia and specific learning disorders, associated with problems of ocular motility and accommodation. The evaluation of the neuropsychiatrist and the work of the speech therapist should be associated with the evaluation of ophthalmology and orthoptics to assess and treat the visual problem. In the presence of a Specific Learning Disorder (SPD), already diagnosed by the speech therapist, a series of visuoperceptive tests are used to identify the presence of impairment of visual-motor and visuoperceptive abilities.
Alterations in ocular motility, linked to the presence of systemic, neurological or endocrine diseases. An example is hyperthyroidism (Basedow-Graves disease), which causes the protrusion of the ocular globes outwards (the so-called “protruding eyes”). This disease, even if well managed by the endocrinologist, can still cause problems of ocular motility.
Treatments for adults and children
In adults, in the presence of a post-surgical or post-traumatic strabismus or, even, linked to an ocular paralysis, there is a tendency to prescribe a prismatic lens that directs the light in particular to reduce the diplopia (double vision) that generally occurs as a result of these events. The most serious cases require surgical treatment by an ophthalmologist. In cases where the patient has fatigue in the ocular motility, he can carry out, under the guidance of the orthoptist, a series of sessions of orthoptic rehabilitative exercises (orthoptic training), to re-educate and strengthen the ocular musculature. In children, aged between 3 and 8-9 years, strabismus and amblyopia are treated, in 90% of cases with a rehabilitative therapy, called occlusive therapy, which consists in closing the eye that sees more (dominant) to force the more “lazy” eye (amblyopic) to work, thus developing the same visual acuity of the other. In the remaining 10% of cases the orthoptist can resort to other types of treatment.
The Hess-Lancaster test and corneal topography are among the available examinations
In Humanitas Medical Care Milan, in via Domodossola, in addition to the orthoptic examination, it is possible to perform the Hess-Lancaster test, to determine which muscles are involved in ocular motility problems.
The orthoptist can also perform corneal topography, an examination for mapping the anterior surface of the cornea, useful for assessing the optical quality and health of the anterior portion of the eye. It is prescribed in the presence of glaucoma, keratoconus (thinning of the cornea) and refractive defects.
