In a newly published study in the PLOS One journal entitled “Reliability of Intra-Retinal Layer Thickness Estimates“, researchers from Germany explored the precision and reliability of a medical imaging technique named optical coherence tomography (OCT) in measurements of thickness of different intra-retinal layers in patients with multiple sclerosis (MS). This parameter has been considered a good indicator to monitor neurological conditions.
MS is a condition characterized by damaged neurons that induces inefficient communication between parts of the nervous system. It is believed that MS is caused by an autoimmune disorder and also environmental factors like infections. Patients with MS are generally treated by numerous medications aimed to prevent new attacks and long-term disability. Alternative medicines including relaxation techniques, drugs like cannabis and oxygen therapy are also explored by MS patients despite the lack of scientific evidence. Patients with MS may suffer from various symptoms including muscle weakness/spasms, difficulty in moving and coordination, changes in sensation, depression, fatigue, bladder and bowel difficulties, and problems with speech.
Some of these symptoms may develop in isolated attacks and some strengthen with time resulting in permanent neurological problems. Among these, visual problems related to inflammation of the optic nerve have been associated with MS and they may lead to complete or partial loss of vision. Retina, which constitutes the third and inner coat of the eye, is reported to be an excellent site for monitoring neurological disorders like MS. OCT is a technique that is utilized to perform thickness measurements of the intra-retinal layers. Nonetheless, the approaches currently employed to determine layer thickness vary notably and published data concerning the reliability of OCT are not conclusive.
In the study, researchers evaluated the repeatability of different estimated thickness using OCT technique. After in-depth literature search, 27 articles related to OCT applied to MS patients have been identified. To explore the repeatability of previously published estimates, the researchers performed repeated measurements on 13 MS patients and 15 healthy controls using two OCT devices. The team estimated each layer thickness with repeated measurements and looked at repeatability using correlation/repeatability coefficients. The results of the simulated layer thicknesses showed excellent repeatability for all retinal layers except for the outer plexiform layer, which is characterized by a thinner thickness.
Given the reliable and repeatable estimates obtained in the study, researchers concluded that the use of OCT should be encouraged in clinical research studies with MS patients especially for thicker retinal layers. However, for thinner ones as the outer plexiform layer of the retina, the assessment generally looks weak and hence requires a further investigation in the future.