Russian biophysicists developed revolutionary techniques for diagnostics, prevention and treatment of age-related eye pathologies.

A paradox: light, which gives us information, can also cause eye pathologies, such as cataract or degenerative changes of eye retina. This phenomenon has an explanation: photochemical reactions, which take place in retina, and perception of visual signals depend on light and oxygen. However, various parts of an eye contain substances, mainly, fatty acids and proteins, which are easily oxidized by light of certain wavelength. Oxidation changes molecular structure of these substances, thus vision becomes less acute. Human organism can resist these negative processes, but when it gets older, resistance becomes less effective, and eyesight pathologies start accumulating.

Among other tasks, the researchers tried to create new photosensitive optical material, able to protect eyes from damage by light. This material will help making special glasses and intraocular lenses. New material has organic nature – it is made of spiropyrans and their derivatives. These molecules can rearrange under the influence of short wave light and add colour to colourless material, containing these molecules. When short wave radiation disappears, the material again loses colour. Such mechanism of “photocolouration” provides protection from light with most dangerous wavelength. Authors claim that they have enough data to make experimental samples of this material for further serial production.

 

 

Researchers also worked on creating new agents for preventing cataract development. Oxidation processes, caused by light, lead to aggregation of lens proteins (crystallins) and, finally, to lentoid opacity and poor eyesight. In normal situation, other proteins, known as chaperons (these proteins are responsible for normal folding of other proteins and prevent protein denaturation under stress), prevent lentoid opacity. New agent will also demonstrate anti-oxidant properties, and authors have already patented their invention.

In addition, researchers are concerned about increasing effectiveness of a new non-surgical diagnostic technique of age-related changes and degenerative diseases of eye retina. The technique is based upon detecting changes in absorption characteristics and intrinsic radiation (intrinsic fluorescence or auto-fluorescence) of light, having a certain wavelength, by pigments of eye retina (also known as fluorophores). These pigments usually change structure, when a pathology develops, thus they can show how severe the disease is, and help choosing treatment in order to avoid retinitis pigmentosa or retina dystrophy. Particular attention is paid to identification of certain substances, responsible for auto-fluorescence of eyecup bottom, and detection of their spectral characteristics.

All innovations are based on fundamental knowledge about molecular mechanisms of eyesight.

Source: Science News

Kizilova Anna