This article discusses modern approaches in the development and production of materials for contact lenses – rigid gas permeable and soft, including silicone-hydrogel. Special attention is paid to obtaining high Dk materials.

Corneal topography has been widely used in medical practice over recent years and it has helped to detect keratectasias of various genesis more often and in the earlier stages. The emergence of the new polymer materials with high oxygen permeability made it possible to wear scleral contact lenses safely, that also resulted in their popularization. Scleral gas permeable lenses are an effective method of vision correction not only for various ectasias, but also for ametropia, presbyopia and other refractive pathologies. Scleral contact lenses do not directly touch the cornea and the limbus area, whereas tear firm under the lens physically smoothes out all of the existing defects and irregularities of the corneal surface, thus creating a “cornea-tear-lens” unified optical system. As a result, visual acuity increases significantly. In addition, scleral lenses ensure excellent comfort starting from the first minutes of wearing due to a larger diameter, no direct contact with the cornea and relatively low mobility. Scleral lenses ensure high visual functions and comfort owing to their specific self-supporting design, which is rested on the sclera. Selection and fitting of scleral contact lenses is simple and can be mastered by any ophthalmologist.

Purpose: A cytological assessment of the effectiveness of eye burns complex treatment using low-intensity infrared laser radiation (LILR) was performed.

Material and methods. 42 patients (64 eyes) with eye burns of different etiology and severity were examined. For the patients of the main group (21 patients, 30 eyes) low-intensity infrared laser radiation was added to the traditional treatment methods.

Results. Decrease in the number of basophils and the amount of exudation during the inflammatory process indicated the suppression of the initial forms of inflammatory mediators – histamine and serotonin; the disappearance of leukocytes and restoration of the cytoplasm structure and epithelial nuclei was the result of the prostaglandins and leukotrienes suppression by LILR. An increase in the nuclear cytoplasmic ratio (NCR) was the result of the metabolic processes activation and the increase of their regenerative ability.

Conclusion. Therefore, the use of LIRL is considered to be an effective method of the eye burn treatment since it triggers and prolongs the effect of the primary therapy.

Purpose: The purpose of the study is to determine the correlation between the incidence of giant papillary conjunctivitis induced by the use of contact lenses (CLPC) and contact lens material, replacement schedule or wearing time. The emergence of new materials and designs of contact lenses along with modifications in the replacement and wearing schedule have changed the structure of complications in users of soft contact lenses (SCLs). At present, infectious and hypoxic complications are extremely rare; on the other hand, toxic-allergic reactions that arise in users of contact lenses (CLs) have come to the fore.

Material and methods. A retrospective cohort clinical study involved 1 668 users of SCL of various materials and with different replacement and wearing schedules. Patients were monitored from 2008 to 2018.

Results. As a result of the study, it was found that the CLPC incidence correlate with the wearing time and replacement schedule of the SCLs.

Conclusion. Any SCL user, regardless of the SCL material and lens replacement schedule may potentially have CLPC. The severity of the CLPC process depends on SCLs wearing time and replacement schedule. Daily disposable SCLs are safer as opposed to 2-week disposable and monthly contact lenses. In case of wearing daily SCLs, the risk of CLPC is the same for hydrogel and silicone-hydrogel lenses. Focusing on compliance with the rules of SCLs, use and care is the major measure that helps to prevent the formation of CLPC.

The review covers the issue of hybrid contact lenses application as one of the modern contact correction methods in patients with ametropias of various genesis. Hybrid contact lenses consist of a rigid central optical part made of highly gas-permeable material and a flexible peripheral part made of hydrophilic material. These lenses combine the optical correction qualities of gas-permeable corneal lenses with the comfort and stable fit usually provided by soft contact lenses. Compared to gas-permeable corneal lenses, hybrid lenses are more comfortable, often have better centration and more stable fit on the eye. Hybrid contact lenses successfully correct both types of astigmatism: regular and irregular. This type of lenses is a good alternative method of contact correction for patients who place heavy demands in terms of the quality of vision.

Purpose: Comparison of dry eye syndrome stages with intensity of changes in peripheral retina in patients undergoing medical therapy.

Material and methods. The clinical study involved 94 patients with mild and moderate dry eye syndrome (DES). Group 1 and Group 2 were both comprised of 25 patients; group 3 was comprised of 44 patients. The observation period was 6 months. Parameters of the anterior eye surface and intensity of changes in the peripheral retina were subjected to evaluation and comparison.

Results. The study has shown, that the radius of the tear meniscus, surface tension coefficient and the number of areas stained with fluorescein significantly correlate with the probability of changes in the peripheral retina. The interrelation between the probable formation of changes in the peripheral parts of the retina and the indicators of tear production was revealed in all patients. After 3 months the performed treatment led to the disappearance of the initial correlation between the factors: on visits 3 and 4 logit-models appeared to be unreliable, that meant the absence of interrelation between the probability of formation of changes in the peripheral retina and indicators characterizing the condition of the anterior ocular surface or tear production.

Conclusion. The correlation between changes in the peripheral parts of the retina and tear production was described.

Topicality. In recent years, dry eye syndrome has become increasingly important in clinical practice. Disturbance of the wettability of the eye surface occurs due to external factors influence, one of which are contact lenses. The review presents the literature data analysis covering possible impact of contact lenses made of different materials (hydrogel, silicone hydrogel, soft and rigid gas permeable) on the development of dry eye symptoms, as well as the role of tear substitutes use when wearing contact lenses. Due to a great variety of different studies on this topic, the literature review on the tear substitutes instillation when wearing contact lenses in patients with dry eye syndrome is relevant and crucial for doctors in outpatient departments.

Conclusion. The research has shown that, it is possible to identify unmodifiable and modifiable risk factors for dry eye syndrome with reliable and probable factors. In addition, the therapeutic use of HYLO-COMOD and PARIN-POS is accompanied by minimum possible negative side effects and their use can increase the amount of tear film, as well as reduce the severity of eye discomfort.