By optic atrophy in medicine we mean an abnormal decrease in the size of the ” optic papilla “, which represents thepoint where the optic nerve emerges in the eyeball collecting the axons that originate from the photoreceptors of the retina. The papilla corresponds to a physiological scotoma called the blind zone of Mariotte : a small object positioned in that area will not be visible even in the case of a normal visual field. This blind zone can expand in some pathologies such as in glaucoma.
There are two forms of optic atrophy:
- primary optic atrophy: the papilla is whitish showing an abnormally enlarged depression;
- secondary optic atrophy: the papilla is greyish and its margins are no longer as sharp as in the primary one; the depression is completely filled.
The causes of an optic atrophy can be different, including:
- anterior ischemic optic neuropathy (optic nerve head infarction);
- retinal infection;
- retinal inflammation;
- arsenic poisoning;
- excessive alcohol consumption;
- genetic causes, in this regard read:
Atrophy can also be related to:
- pernicious anemia;
It presents with an acute reduction of vision, generally in the central part of the visual field, in the upper or lower half (altitudinal defect). In the latter case, looking horizontally, you no longer see the floor or you no longer see the ceiling of the room (if you have lost the upper visual field). However, in some cases, the central vision may be maintained.
The diagnosis is mainly carried out with a visual field examination generally performed during an eye examination , associated with a retinal fluorangiography . Other diagnostic investigations that could be performed in the eye field are:
- fundus examination ;
- visual acuity exam (eye exam) ;
- computerized optical tomography (OCT) ;
- slit lamp examination (or biomicroscopy) ;
- traditional and fluorescent retinography ;
- self-refractometry ;
- visual evoked potentials ;
- electrooculography (EOG) ;
- electroretinography (ERG) ;
- ocular ultrasound ;
- Ishihara tables ;
- tonometry .
Examination of the ocular fundus may show the presence of edema of the optic papilla with swelling due to the accumulation of retinal fluid, associated with hemorrhages, with a flame appearance ( intraretinal hemorrhages ) and exudates. Localized or diffuse pallor of the optic nerve ( atrophy and optic subatrophy ) can be observed . The “pale” optic nerve is so called when the optic nerve appears pinched and thinner than normal. Based on the suspected diagnosis, the ophthalmologist may request other tests, such as a CT scan or magnetic resonance imaging or seek advice from a neurologist and / or neurosurgeon.
The treatment of an optic atrophy varies according to the disease or condition upstream that determined it: there is no single cure capable of solving all types of atrophy. This should therefore make the patient understand how important a precise diagnosis is, in order to set up a treatment as effective and rapid as possible. In the case of non-arteritic ischemic optic neuropathy, in the acute phase the pathology can be treated with the administration of oral steroids, which serve to reduce the edema of the optic disc. Of particular importance is the prevention of ischemic neuropathy in the healthy eye. In these cases the use of platelet aggregation inhibitors and the control of cardiovascular risk factors such as systemic arterial hypertension is recommended, diabetes and dyslipidaemias (changes and increases in fats and lipids in the blood). The arteritic form is treated in acute with boluses (steroids) intravenously and then orally, until scaling in maintenance, in the chronic form. The collaboration of the internist and immunologist is important for patient management