[The effect of keratoconus-associated refractive errors on the results of tomographic methods of studying the posterior structures of the eye]. / Vliyanie opticheskikh narushenii pri keratokonuse na rezul'taty tomograficheskikh metodov issledovaniya struktur zadnego segmenta glaza.

PURPOSE: The study assesses the potential influence of refractive errors in keratoconus (KC) on the results of tomographic methods of studying the structures of the posterior eye segment. MATERIAL AND METHODS: The study included 30 patients with bilateral stabilized KC of stages I-IV in classification by M. Amsler. Spherical and cylindrical components of refractions were determined using automatic refractometry, keratometry measurements - based on scanning keratotopography with Scheimpflug analyzer. Aberrometry was performed to evaluate corneal wave front according to the following parameters: root mean square for lower order aberrations (RMS LOA), root mean square for higher order aberrations (RMS HOA), vertical trefoil, vertical coma, horizontal coma and spherical aberrations. Optical coherence tomography (OCT) and laser confocal scanning ophthalmoscopy (HRT 3) data was used in morphometric analysis of the optic nerve head and peripapillary retina. The following morphometric parameters were analyzed: optic nerve head (ONH) area, optic disc cup area, optic disc cup volume, ratio of optic disc cup area to ONH area, neuroretinal rim area, neuroretinal rim volume, peripapillary retinal nerve fiber layer (RNFL) thickness. All studies were performed first without correction, and 30 minutes after installing customized scleral hard contact lenses (SHCL). RESULTS: Compensation of the refractive errors characteristic for KC was achieved as expected with contact correction. OCT revealed a general trend for reduction in the area and volume of the optic disc cupping, ratio of area to volume of the optic disc cupping, as well as an increase in other parameters. As such, with correction the values for area and volume of the neuroretinal rim according to OCT were 2.2 and 13%, HRT 3 - 18 and 51.6%; comparable increase in mean RNFL thickness - 2.8 and 28.5%, respectively (p<0.001). According to HRT 3 data, the area and volume of optic disc cupping statistically significantly decreased (by 21 and 28%, respectively), while OCT showed statistically significant decrease only in cupping area (by 5.7%). The ratio of cupping to ONH area decreased by 6.6 and 23% relative to the initial data obtained with OCT and HRT 3, respectively. Significant decrease in ONH area amid SHCL correction was observed only with HRT 3. The revealed changes in morphometric parameters were analyzed using the fundamental principles of physiological optics. Changes in interference pattern and, consequently, morphometric parameters of structures of the eye fundus in KC are of multifactorial nature, and are mostly associated with refractive and wave artefacts occurring when the rays pass through the irregular corneal surface and cannot be optically compensated by the device. The use of SHCL as means for making the optic system relatively regular can significantly decrease the artefacts in morphometric measurements. CONCLUSION: The results obtained in this study demonstrate the practicality of tomographic examination in KC with contact correction. The optimal choice is custom-fit SHCL, which along with proper correction of refractive errors also ensures stable position of the lens on the cornea. In standard examination specialists should take into account the «false¼ decrease in parameters of the peripapillary retinal nerve fiber layer and increase in ONH cupping.

[Thermography of ocular surface tissues in the assessment of aseptic postoperative inflammation]. / Termografiya tkanei glaznoi poverkhnosti v otsenke asepticheskogo posleoperatsionnogo vospaleniya.

PURPOSE: To determine the thermographic parameters of ocular surface tissues in various types of anti-glaucoma operations. MATERIAL AND METHODS: The study included 70 patients with glaucoma (140 eyes) and 28 patients (56 eyes) with cataract and planned phacoemulsification. All patients underwent dynamic infrared thermography of the eye surface to evaluate the aseptic inflammatory response before and after surgery. RESULTS: The increase in the temperature of the ocular surface tissues was longer after penetrating glaucoma surgery than after the non-penetrating type, which indicates a more prolonged inflammatory aseptic reaction in response to surgical intervention. CONCLUSION: The obtained results allow the development of a rational tactic of preoperative drug preparation and more effective postoperative management.

[New visual field testing possibilities (a preliminary report)]. / Novye vozmozhnosti issledovaniia polia zreniia (predvaritel'noe soobshchenie).

There are currently no portable mobile perimeters that allow visual field testing outside ophthalmologist's examination rooms. PURPOSE: To develop a mobile perimetry technique based on use of a virtual reality headset (VR). MATERIAL AND METHODS: The study involved 26 patients (30 eyes) with II-III stage primary open-angle glaucoma (POAG) with compensated IOP. Perimetry was performed for each patient twice - on Humphrey analyzer (test 30-2, 76 points) and employing similar strategy on a perimeter integrated into VR headset (Total Vision, Russia). Visual field testing was performed with an interval from 1 hour to 3 days. The results were comparatively analyzed. RESULTS AND CONCLUSION: Patients tolerated the examination well. Comparative analysis of preliminary perimetry results obtained with both methods showed high degree of identity, so the results were concluded to be comparable. By visually isolating the wearer, VR headset achieves elimination of distractions and stable light conditions for visual field testing. The headset-perimeter is compact, mobile, easily transportable, can be used in the work of visiting medical teams and for examination at home.