An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells: the cornea and the sclera. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application.

Assessment of ocular hemodynamics is an important element in diagnosis of all forms of glaucoma. Existing methods, unlike the transpalpebral rheoophthalmography (TP-ROG), evaluate only the posterior eye segment. This study evaluates the opportunities of new TP-ROG technology to assess the effectiveness of the glaucoma treatment. The proposed TP-ROG method is characterized by ease of use and the lack of direct contact between the surface of the eyeball and the electrodes; this method is highly informative and quite accurate, which allows us to objectively assess the state of ocular hemodynamics in patients with primary open-angle glaucoma (Int J Biomed. 2016; 6(4):287-289.)

Experimental results on minimally invasive techniques of SXL allow to recommend them for further clinical investigation as a promising treatment of progressive myopia.

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Purpose:to evaluate, using transpalpebral rheoophthalmography (TP ROG), the effectiveness of sclera-strengthening and trophic treatment of progressive myopia with a new biologically active chitosan-containing transplant.Patients and methods. 40 children and adolescents with moderate or high progressive myopia, averagely aged 12.6 ± 0.38 years, were examined after receiving low invasive sclera-strengthening surgery on one eye with a biologically active chitosan-containing transplant. The initial refraction of the operated eye was — 6.25 ± 0.23 D, while that of the fellow eye was — 5.85 ± 0.28 D. The yearly gradient of myopia progression averaged 1.10 ± 0.04 D. Hemodynamic parameters were measured using TP ROG) prior to intervention, then 1, 6 and 12 months after intervention. At the same time points, scleral acoustic density (SAD) was determined by analyzing tissue histograms obtained with a multipurpose ultrasound device, VOLUSON 730 Pro «GE».Results. One year after sclera-strengthening treatment, a 4.4-fold reduction of myopia progression rate on the operated eye was noted, supplemented by a 2.2-fold reduction of same on the fellow eye. Stabilization of refraction was accompanied by an increase of SAD: 6 months after the surgery, SAD was averagely 19.7 conventional units higher than the original figure in the posterior pole of the operated eye, and 16.2 conventional units higher in the equatorial area. One year after the surgery, the figures were, respectively, 15.9 (p < 0.05) and 14.0 conventional units (p < 0.01). The rheographic index of TP ROG increased with regard to the initial value by 139 % after one month, by 69.8 % after 6 months, and by 34.6 % after 1 year. On fellow eyes, the index also tended to increase: by 123.3 % after 1 month, by 65.2 after 6 months, and by the end of the follow-up period it exceeded the original value by 28.7 %, which is an evidence of a pronounced trophic effect of sclera-strengthening myopia treatment with chitosan not only on the operated eye but also (to a lesser extent) on the fellow eye.Conclusion. TP ROG is an effective evaluation method of sclera-strengthening treatment of progressive myopia. This method can also be used to study eye hemodynamics in a variety of ophthalmic pathologies, including those managed in pediatric clinical practice.