[Results of corneal lenticule extraction for correction]. / Rezul'taty ekstraktsii lentikuly rogovitsy dlya korrektsii miopii srednei i vysokoi stepeni.

One of the main methods for correcting moderate and high myopia is corneal lenticule extraction. Ziemer is adding a new application to the FEMTO LDV Z8 platform - Lenticule CLEAR, designed to treat myopia by corneal lenticule extraction.Purpose - to study the safety and effectiveness of corneal lenticule extraction using the Ziemer LDV Z8 device for the correction of moderate and high myopia. MATERIAL AND METHODS: The prospective study included 24 patients aged 26.8±4.6 years (24 eyes) who underwent surgeries for moderate and high myopia on the Ziemer LDV Z8 device at the S.N. Fyodorov National Medical Research Center «MNTK «Eye Microsurgery¼ in January 2020. RESULTS: After correction of moderate and high myopia using the Ziemer LDV Z8 device, patients showed stable improvement in visual acuity one week after surgery, which remained throughout the postoperative period. Dynamic 1-month follow-up of patients operated on the Ziemer LDV Z8 platform for moderate and high myopia showed that the median value of uncorrected visual acuity one week after surgery was 0.9 [0.7; 1.0], and after one month - 1.0 [1.0; 1.0]. Patients operated on the Ziemer LDV Z8 platform had no intra- or postoperative complications, 79.2% of patients also had no loss of maximum corrected visual acuity. The mean corneal thickness before surgery was 555.9±28.2 µm, it significantly decreased to an average value of 464.8±26.9 µm one week after surgery (p<0.05). The cost of tissue was 17 microns per 1 diopter. CONCLUSION: The obtained results indicate the high effectiveness of the correction of moderate and high myopia using the Ziemer LDV Z8 device.

[Clinical and functional outcomes of correcting low to moderate myopia with FemtoLASIK performed with Russian and Swiss femtolaser platforms]. / Kliniko-funktsional'nye rezul'taty korrektsii miopii slaboi i srednei stepenei metodom FemtoLASIK s ispol'zovaniem otechestvennoi i zarubezhnoi femtolazernykh ustanovok.

PURPOSE: To compare the effectiveness, safety, predictability and stability of FemtoLASIK procedure in low to moderate myopia using Femto Visum and Femto LDV Z6 femtosecond laser platforms and to evaluate the effect of these procedures on corneal higher-order aberrations. MATERIAL AND METHODS: Russian femtolaser platform (1 MHz) was used to form the corneal flap in the main group consisting of 98 patients (98 eyes) with mean spherical equivalent (SE) of -3.73±1.42 D. Swiss femtolaser platform (5 MHz) was used in the control group (94 patients, 94 eyes; mean SE -3.81±1.44 D). Excimer laser ablation was performed using the Russian platform (500 Hz) in both groups. All patients underwent complete ophthalmological examination. The follow-up period was 12 months. RESULTS: Twelve month postoperatively, in the '1 MHz' group uncorrected visual acuity (UCVA) of 1.0 or better was achieved in 91.8% of patients, and in the '5 MHz' group - in 90.4% (p>0.05). There were no registered losses of 2 or more lines of best-corrected visual acuity (BCVA) in either group. In the '1 MHz' group, predictability of targeted refraction within ±0.5 D was achieved in 91.8% of patients, within ±1.0 D - in 99.0%; in the '5 MHz' group - in 91.5% and 98.9% of patients, respectively (p>0.05). Root-mean-square (RMS) deviation of corneal higher-order aberrations in the 6-mm optical zone was increased by 0.072 µm (by 1.21 times) and by 0.077 µm (by 1.22 times) in the '1 MHz' and '5 MHz' groups (p>0.05), respectively. CONCLUSION: The FemtoLASIK procedures performed using Russian (1 MHz) and Swiss (5 MHz) femtosecond laser platforms are effective, safe, predictable, have stable postoperative visual and refractive outcomes, and lead to increase in RMS of corneal higher-order aberrations using both platforms in patients with low to moderate myopia. There were no statistically significant differences between the two femtolaser platforms (p>0.05) for all examined parameters.

[SMILE keratorefractive surgery technique]. / Keratorefraktsionnaia tekhnologiia SMILE.

Small incision lenticule extraction (SMILE) keratorefractive surgery technique is a laser surgery alternative to common methods that doesn't require laser ablation of the cornea. Despite its novelty, SMILE technique has already demonstrated positive clinical results comparable to Photorefractive Keratectomy (PRK) and Laser-Assisted in Situ Keratomileusis (LASIK), which led to its widespread application in clinical practice. Compared with other keratorefractive techniques, SMILE has a number of distinct advantage including high biomechanical stability of the cornea, low risk of dry eye syndrome, absence of a corneal flap and associated complications, preservation of corneal epithelium. The article describes the most common SMILE modifications, its weak points and possible complications, as well as methods of additional correction of remaining ametropy.

[Causes, prevention and correction of refractive errors after phacoemulsification with intraocular lens implantation]. / Prichiny, profilaktika i korrektsiia refraktsionnykh narushenii posle fakoémul'sifikatsii s implantatsiei intraokuliarnykh linz.

PURPOSE: To evaluate the influence of dry eye disease (DED) in cataract patients on refractive results of phacoemulsification with implantation of intraocular lenses (IOLs). MATERIAL AND METHODS: The study included 24 patients (24 eyes) with early cataract or phacosclerosis who planned to undergo phacoemulsification with implantation of multifocal IOL. Inclusion criteria was preoperative presence of DED. During the initial visit, all patients first had IOL power calculated, received comprehensive treatment to address DED, and then repeated the IOL power calculation. Accuracy of achieving target refraction was evaluated by the amount of residual spherical equivalent one months after the surgery. RESULTS: In patients with cataract and DED, the following statistically significant changes were noted after ocular surface normalization: reduction of the cylindrical component of refraction, reduction of corneal irregularity and its asymmetry, as well as normalization of eye surface. The average difference in the calculation of IOL power before and after DED treatment was 0.87±0.11 D, maximum error was 2.25 D. Control examination one month after the operation showed high visual functions in all operated patients. Deviation from the planned refraction was minimal (41.2% of cases were within in ±0.25 D of the planned refraction, 76.5% of cases in ±0.5 D, 100% of cases in ±1.0 D). CONCLUSION: Preoperative detection of DED and its correction in patients with cataract increases calculation precision of IOL power and improves clinical and functional results.

[Effect of corneal refractive surgery on optical coherence tomography measurements]. / Vliianie keratorefraktsionnykh operatsii na pokazateli opticheskoi kogerentnoi tomografii.

The effect of significant changes in corneal power after refractive surgery on the parameters of optical coherence tomography (OCT) has not been sufficiently studied. PURPOSE: To study effects of corneal refractive surgery on optical coherence tomography (OCT) measurements in patients with moderate and high myopia. MATERIAL AND METHODS: OCT was performed in 62 patients (62 eyes) with myopia over 4 D before and one month after LASIK. The changes in 14 parameters of the thickness of the retina, ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) were analyzed. RESULTS: The mean refractive effect was 7.07±2.02 D (4.0 to 11.75 D). Postoperative changes in the parameters analyzed were insignificant, averaging not more than 1.3% of the baseline value with the exception of pRNFL thickness in the temporal quadrant (2.2%). Only six of the 14 parameters were statistically significant - retinal thickness in the central subfield and the inner nasal quadrant, average and minimum thickness of GCIPL, and pRNFL thickness (mean and in the temporal quadrant). Individual changes of the parameters in most patients did not exceed the error of method. CONCLUSION: In patients with moderate to high myopia, LASIK operation has only a slight effect on the OCT parameters of the retina and pRNFL. Only in patients with very high myopia, the decrease over 10 D in corneal refractive power creates an optical effect of increasing the average thickness of pRNFL and GCIPL by 2-3 µm. This should be taken into account when examining such patients for glaucoma.

[Differential diagnostic OCT-criteria of acute and chronic central serous chorioretinopathy]. / Differentsial'no-diagnosticheskie OKT-kriterii ostroi i khronicheskoi form tsentral'noi seroznoi khorioretinopatii.

Principal differences in natural history, therapeutic approaches, and functional prognosis of acute and chronic central serous chorioretinopathy (CSC) requires that they were distinguished. AIM: to define differential diagnostic criteria for acute and chronic CSC basing on the chorioretinal complex analysis by EDI-optical coherence tomography (OCT). MATERIAL AND METHODS: A retrospective analysis was performed that included data of 112 patients with CSC, who were assigned to either the 'acute' (52 patients) or 'chronic' (60 patients) group depending on symptoms duration (3 months) and fluorescein angiography findings. With the enhanced depth imaging (EDI) module mounted on OCT (Spectralis, Heidelberg, Germany), the structure of the chorioretinal complex was studied. RESULTS: In acute CSC, the height of the neuroepithelium detachment (310.73±113.63 µm) was greater than that in chronic CSC (205.68±90.80 µm), p=0.03. The frequency of subretinal deposits also differed (17.3% and 100% of cases, respectively), p<0.01. The subfoveal choroidal thicknesses were similar (462.7±110.7 and 494.7±132.1 µm, respectively, p=0.6), however, in acute CSC, diffuse thickening of the choroid was noted (39 patients, 75% of cases), while chronic CSC was marked by local dilatation of the Haller's layer (39 eyes, 65% of cases). The diameter of hyporeflective pockets in the Haller's layer in the 'acute' (324±98.1 µm) and 'chronic' (352.0±84.3 µm) groups correlated with choroidal thicknesses (r=0.68, r=0.75). Hyperreflective intrachoriodal dots were more common in the 'chronic' group (acute - 1.9%, chronic - 68.3%), so did hyperreflective vascular walls -13.5% and 68.3%, respectively, p<0.01. Dome-shaped RPE detachments were observed equally often in both groups (acute - 67.3%, chronic - 68.3%, p=0.9), while the 'double-layer sign' was only characteristic of chronic CSC (86.7%). CONCLUSION: OCT criteria of acute CSC include a dome-shaped detachment of neuroepithelium and diffuse thickening of the choroid in the absence of deposits; of chronic CSC - subretinal deposits, local dilatation of the Haller's layer vessels, hyperreflective vascular walls, intrachoroidal dots, and the 'double-layer sign'.

[Visual rehabilitation of patients with large post-traumatic defects of the anterior eye segment through iris-lens diaphragm implantation]. / Sistema zritel'noi reabilitatsii patsientov s obshirnymi defektami struktur perednego otrezka glaznogo iabloka na osnove implantatsii iridokhrustalikovoi diafragmy.

The diversity of methodological approaches and lack of pathogenetically reasonable tactics for patients with combined ocular injuries became the basis for the development and systematization of surgical rehabilitation stages of patients, in whom post-traumatic cataract is combined with post-traumatic aniridia and corneal scarring. AIM: to construct a visual rehabilitation approach to patients with post-traumatic defects of the anterior eye segment following optical-reconstructive surgery that involved implantation of an iris-lens diaphragm (ILD). MATERIAL AND METHODS: We have analyzed 80 reconstructive cases with ILD implantation in patients with post-traumatic aniridia and corneal damage. These patients constituted the first study group (Group 1). We have also investigated 58 eyes with residual ametropy and stable visual function 1 year after ILD implantation before and after conducting a laser keratorefractive surgery. These patients were assigned to the second study group (Group 2). RESULTS: Rehabilitation approach to patients after anterior segment injuries that has been proposed allows to achieve high clinical and functional results and reduce the risk of intra- and postoperative complications. CONCLUSION: The proposed approach to patients after optical-reconstructive surgery with iris-lens diaphragm implantation followed by keratorefractive surgery is an effective method of visual rehabilitation of anterior eye segment post-traumatic defects.

[Laser thermokeratoplasty: clinico-functional aspects of postoperative eye condition].

Laser thermokeratoplasty (LTK) induces postoperative inflammation of the cornea. Its clinical manifestation as well as the degree of endothelial cell loss depend on laser irradiation energy and the number of coagulates. The refractive effect of LTK is most stable in a hyperopia of up to 3.0 D and a laser energy value of up to 170 mJ; in this case, endothelial cell loss dose not exceed 2.2%. According to biomicroscopy, ultrasound pachimetry, and optical coherent tomography of the anterior segment of the eye, LTK results in corneal thickening, after which the volume of the coagulant gradually decreases and stabilizes by the end of the first year after LTK. Two types of scar, biomicroscopically different in size and optical density, form after LTK. The authors distinguish four clinical periods of healing after LTK, which makes it possible to evaluate and systematize physiological and biomechanical processes taking place in the cornea during refraction formation.