Early diagnosis of glaucoma will preserve vision
Researchers from the University of Iowa have developed a technique for the early diagnosis of glaucoma based on Raman spectroscopy and demonstrated its effectiveness in preclinical trials on animal models of glaucoma.
Glaucoma refers to a group of eye diseases that occur as a result of damage to the optic nerve, which delivers visual information from the eye to the brain. Increased intraocular pressure (the probability of which increases with age) is the main cause of the disease. Increased pressure of intraocular fluid on the optic nerve leads to its gradual destruction. There are about 70 million glaucoma patients worldwide, including about 2 million in the USA and about 1 million in Russia. Glaucoma is insidious because the onset of the disease is asymptomatic, and the disease progressing without treatment irreversibly leads to partial or complete loss of vision.
Currently, two main methods are used to diagnose glaucoma. The first of them is tonometry, which allows measuring intraocular pressure by the strength of the resistance of the eyeball to the force applied from the outside by carefully touching the eyeball with a special instrument. Using another technique – ophthalmoscopy – the doctor assesses the condition of the fundus and optic nerve, directly looking inside the eye through the pupil with an ophthalmoscope. Unfortunately, both methods make it possible to detect glaucoma at the stage of already begun degradation of the optic nerve. Often, more than one year passes from the beginning of the first biological changes characteristic of glaucoma to the diagnosis. For this reason, early diagnosis and timely treatment are of particular importance for the preservation of vision when glaucoma has begun.
The new technique is based on Raman spectroscopy, a method routinely used in chemical laboratories around the world to analyze the substances that make up a sample using the spectra of a laser beam of infrared light scattered by a sample directed at it. By directing a laser beam through the pupil into the fundus, using the spectrum of light scattered by retinal neurons, it is possible to obtain information about the chemical composition of cells and identify biochemical changes that occurred in retinal nerve cells during the development of glaucoma.
When testing the method on retinal tissue samples of dogs with glaucoma, the accuracy of detecting the disease was 90%.
The head of the work, Chenxu Yu (Chenxu Yu), does not hide his personal interest in the ongoing study: doctors attributed him to a high-risk group for glaucoma.
Currently, Yu's group is conducting preclinical tests of the diagnostic method on animals. In case of confirmation of the high efficiency and safety of the technique, specialists plan to start clinical trials of the new method in humans. Despite the fact that the analysis, according to scientists, will take about half an hour (modern glaucoma diagnostic procedures take less time), patients will undoubtedly benefit in the accuracy of diagnosis and in earlier detection of the disease.
Daria Chervyakova
Portal "Eternal youth" http://www.vechnayamolodost.ru / based on ScienceDaily: Developing a Test to Save Eyesight by Detecting Glaucoma Years Earlier.
29.03.2010