The OCT test has, in recent times, become an irreplaceable and advanced technology used in ophthalmology. 

So, how does an OCT test work? The machine examines the retina or optic nerve using a laser beam. As the light waves move through the examined area, the light reflected off of the individual layers is projected into a detailed image of the retina structure. This process captures even the slightest changes in the eye structure, that would otherwise be impossible to detect during a routine examination. 

Advantages of OCT

Meticulous examination and analysis of the imaging obtained by the OCT test helps detect early signs of ocular diseases such as glaucoma or age-related macular degeneration. The test is so precise that it is often able to detect changes in the ocular tissues even before the patient notices any deterioration in their eyesight. This is a feature that doctors consider to be the biggest advantage. Studies suggest that prevention and early implementation of treatment is the best strategy to avoid irreversible eye damage. At the same time, the OCT test is a useful tool for monitoring the effectiveness of treatment. 

The OCT test is:

• SHORT- the examination takes less than 5 minutes per each eye
• PAINLESS- non-invasive examination
• TOLERABLE- there is no sharp light involved, just an invisible infrared laser
• COMFORTABLE- no need to use dilating eye drops
• EFFECTIVE- detects changes at an early stage

Glaucoma - the silent thief of sight

Glaucoma is the term used to refer to diseases affecting the optic nerve. The optic nerve transmits visual information from the eye to the brain, and damage can in the early stages result in partial loss of vision, but in advanced stages can even lead to blindness. Glaucomas are a painless disease, and initially, don’t tend to cause any issues for the patient, and are therefore often referred to as “the silent thief of sight”.

There are several risk factors that share the burden for the cause of glaucoma, one of which is high intraocular pressure which is measured as a part of the eye examination. Another significant risk factor is genetics, and therefore patients with a family history of glaucomas are advised to attend regular preventative eye examinations.

Glaucomas develop very gradually, over the span of many years. Patients in the early stages don’t notice any significant signs of visual impairment. An integral part of diagnosing glaucoma and its stage of progression is an examination of the visual field (perimeter) and an OCT test. These examinations should be repeated at least once a year.

Monitoring the decreasing thickness of the nerve fiber layers allows for early diagnosis of glaucoma in the early stages, also known as pre-perimetric glaucoma (before there are any changes in the visible field). There are several effective methods for treating glaucomas: medicative (eye drops), laser or operation. 

Macular Degeneration

The macula is a small spot on the retina which is the region of our sharpest vision. It has a very high concentration of photoreceptor cells that detect light and send signals to the brain, which interprets them as images. Age-related macular degeneration (AMD) is a degenerative change in this area of the eye which can lead to deteriorating vision or blindness. 

Macular degeneration presents in two forms: dry or wet. Dry AMD is a metabolic disruption causing the light-sensitive cells to atrophy. This form comes on gradually and progresses slowly, however it eventually leads to a serious and permanent visual impairment. 

On the other hand, wet AMD is fast onset, and often causes sudden changes or disturbances in vision, such as blurriness or distortions. Out of the many possible treatment options of wet AMD, currently, the most preferred treatment is injections of so-called anti-VEGF antibodies into the vitreous humor. 

One of the most used methods for early detection and routine monitoring of macular degenerations is the OCT test.