Timing is always important when it comes to health and early diagnosis, but in the case of vision there is a time when parents need to be very careful not to miss the opportunity to detect a visual defect that – if discovered in time – can be corrected with good results. This is amblyopia, more commonly known as ‘lazy eye’, which has a prevalence between 1.5% and 2.5%. A visual defect that can be corrected as long as you intervene in time and no later than 6-7 years of life.
What is amblyopia
The ‘lazy’ one is an eye that cannot reach the value defined as ‘normal visual acuity’, the so-called 10/10. “Of all the cases of amblyopia – explains Andrea Piantanida, ophthalmologist surgeon of the Lariano Ophthalmology Center, Cernobbio-Como and member of the Scientific Committee of the Salmoiraghi & Viganò Foundation – it is conceivable that between half and one third have visual acuity equal to or less than 2/10. The impact on the quality of life of an amblyopia existing in adulthood depends both on whether it is an amblyopia involving one eye or both, and on the degree of residual visual acuity ”.
The risk of onset decreases as you get older
The younger children are and therefore their visual system is immature, the more rapidly and deeply the amblyopia develops. In fact, as the years go by, the risk of developing a lazy eye decreases. “Beyond 10-11 years, the age in which the development of the visual cortex is to be considered complete, it is practically impossible for amblyopia to develop”, says the ophthalmologist.
The impact on the quality of life
All of us will have happened to know someone who has a lazy eye and who normally carries out all his activities wearing glasses, but in reality the impact that this defect can have on the life of those who suffer from it is by no means negligible. “An amblyopia in adulthood – explains Piantanida – not only limits the possibility of accessing those professions and careers that require the possession of specific visual requirements, but also determines the risk of a serious condition of low vision if a disease or an event that irreversibly penalizes the non-amblyopic eye “.
The signals to be intercepted
Unfortunately, lazy eye recognition is nearly impossible for the parent in daily life. It is difficult for the child to report the visual difference of one eye compared to the other, or that both eyes see out of focus. But there are some signs that can raise doubts about the baby’s visual abilities: “A newborn who does not follow the lights, an abnormal red pupillary reflex in photographs, a child who gets very close to objects or the television, who uses a position abnormal to focus the images or that often stumbles “, emphasizes the ophthalmologist who specifies:” These signals are not, however, always connected to amblyopia alone: absolutely important to be able to intercept this clinical condition is to perform an eye examination in the first year of life “.
The Bruckner Test
The guidelines of the International Scientific Societies and the Italian Ophthalmological Society indicate the first compulsory eye examination at birth, at the year of life, at the age of three and six at the beginning of school. Within the first few days of life, among the tests to be carried out by the pediatrician, the analysis of the red reflex of the pupil, also known as the Bruckner test, is particularly important. “It is a simple examination – explains Piantanida – which allows the early diagnosis of ocular pathologies which, if discovered late, can cause severe amblyopia such as congenital cataract, congenital glaucoma, retinoblastoma, corneal anomalies. The finding of dark spots, a markedly reduced reflex or its total absence represent conditions for which it is necessary to urgently send the child to an ophthalmologist “.
The ophthalmologist’s evaluation
During the visit, the ophthalmologist carries out a series of evaluations thanks to which it is possible to determine the extent of the amblyopia present. Contrary to popular belief, the ophthalmologist is able from the first months of life to realize if a child has visual problems, also based on the way in which he fixes and follows objects and lights, and on the presence of characteristic shadows present in the field. pupillary. “Older children, who do not yet know the numbers or letters of the alphabet – explains Piantanida – are presented with tables with easy-to-understand symbols in decreasing size, in order to detect the degree of visual acuity developed. It is important to examine the two eyes separately as often the vision is different between one eye and the other ”.
Examination of the anterior segment and fundus
The examination of the anterior segment using a biomicroscope can also be performed in the youngest or uncooperative children: nowadays there are a whole series of portable instruments that facilitate the execution of the visit. Pupil dilation is also fundamental for a correct diagnosis. “The eye drops – explains the ophthalmologist – act both by dilating the pupil and by relaxing the ability to focus, that is, the accommodation of the eyes. The eye drops allow, in fact, the ophthalmologist to accurately measure refractive defects, that is myopia, hyperopia and astigmatism and to examine the inner part of the eye: the retina, the optic disc and the blood vessels “.
How to ‘awaken’ the lazy eye
Once amblyopia is identified, is there a solution? “To obtain the functional recovery of the amblyopic eye – replies Piantanida – it is necessary to associate the optical correction with the occlusion of the best eye of such an extent as to force the patient to use the amblyopic eye. There are different methods of occlusion ranging from penalization, to the use of opacifying filters for the lenses up to the occlusive bandage “. The pharmacological penalty (through eye drops with atropine or cyclopentolate) prevents the accommodation of the good eye, thus promoting fixation with the amblyopic eye for nearby objects. The optical penalty for far, on the other hand, consists
hypercorrection of the good eye (in practice a deliberately wrong pair of glasses) in order to favor the use of the amblyopic eye for distant objects. If a bandage is used, the degree of occlusion depends on the extent of the amblyopia and the early diagnosis.
The role of the family
The earlier lazy eye is diagnosed and the more promptly therapeutic measures are taken, the shorter both the degree of occlusion and the duration of therapy. Of course, it is difficult for children to accept the bandage that can be experienced as a heavy limitation, but it is a sacrifice that can solve the visual problem. “At the basis of therapeutic success – concludes the ophthalmologist – is adherence to therapy and family motivation. A therapy performed correctly and with appropriate timing prevents relapses that can occur until the end of the child’s visual development period, up to about 10/11 years “.
For more information visit the page dedicated to visual prevention of the Salmoiraghi & Viganò Foundation.