[Wavefront characteristics in amblyopia of different etiologies in children]. / Osobennosti volnovogo fronta pri ambliopii razlichnogo geneza u detei.

Purpose. The study investigates corneal and higher-order internal aberrations in patients with amblyopia of different etiologies and their relationship with visual acuity, refraction, axial length, and fixation parameters. MATERIAL AND METHODS: Forty-five patients (90 eyes) were examined. All patients were divided into five groups: 1 - with dysbinocular amblyopia; 2 - with refractive amblyopia; 3 - with anisometropic amblyopia; 4 - with relative amblyopia due to congenital myopia; 5 (control) - fellow eyes without amblyopia. Aberrometry was performed using the OPD-Scan III device (Nidek, Japan). Fixation parameters were studied on the MP-3 microperimeter (Nidek, Japan). Correlation analysis was performed using Pearson's linear correlation coefficient (r). RESULTS: In amblyopia associated with congenital myopia, a significant increase in corneal and internal aberrations RMS, Total HOA, astigmatism (V) (0.65±0.26; 1.01±0.31; 4.22±1.17; -2.17±0.72; 0.86±0.3, respectively; control group - 0.44±0.19; 0.58±0.27; 1.0±0.75; -0.94±0.89; 0.47±0.65) and internal spherical aberration (0.06±0.02; control group - 0.04±0.03) was found. In dysbinocular amblyopia, a significant increase in internal aberrations Trefoil (V) and Coma (H) (0.75±0.52 and 0.17±0.35, respectively; control group - 0.05±0.28 and -0.07±0.21) was found, which correlated with a decrease in fixation density in the 2° ring (r= -0.40, r= -0.41). CONCLUSIONS: The increased level of higher-order aberrations in amblyopia associated with congenital myopia is due to the anatomical and optical features of the eyes. The increase in internal aberrations Trefoil (V) and Coma (H) in dysbinocular amblyopia is associated with a mismatch of the optical elements of the eye due to impaired fixation, i.e., it is not the cause, but the consequence of amblyopia.

[Changes in the wavefront and peripheral defocus profile after excimer laser and orthokeratology corneal reshaping in myopia]. / Izmeneniya volnovogo fronta i profilya perifericheskogo defokusa posle eksimerlazernogo i ortokeratologicheskogo resheipinga rogovitsy pri miopii.

PURPOSE: This study compares the trends of changes in corneal asphericity, corneal and total aberrations and peripheral refraction in myopic eyes after excimer laser and orthokeratology correction. MATERIAL AND METHODS: Aberrometry (OPD-Scan III; Nidek, Japan) was performed in 63 patients (126 eyes) with moderate and high myopia before and after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK; 88 eyes, group 1) and photorefractive keratectomy (PRK; 38 eyes, group 2). Peripheral refraction (Grand Seiko AutoRef/Keratometer) at 15° and 30° from the center of the fovea was observed in 12 patients of group 1 and in 18 patients with a background of orthokeratology correction (group 3). RESULTS: Corneal asphericity factor Q transitioned to positive values after PRK and Femto-LASIK. Corneal aberrations: root mean square higher order aberration (RMS HOA) increased in both groups, Tilt 1 increased in group 1 and became negative in group 2, Tilt 2 increased in group 2 and went negative in group 1. Trefoil 6 did not change in group 1 and decreased in group 2. Coma 7 and 8 increased synchronously in both groups. Spherical aberrations (SA) increased in group 1, and went negative in group 2. Total aberrations changed to a lower degree, and these changes were not synchronous with the corneal ones; RMS HOA decreased in group 1 (while corneal RMS increased significantly), and in the PRK group it increased, but much less than the corneal. Total SA increased in group 1 and did not change in group 2. Peripheral myopic defocus formed in all cases, after Femto-LASIK the maximum was in the zone of 30º, after orthokeratology lenses - in the zone of 15º. CONCLUSION: Using excimer laser and orthokeratology to reshape the cornea in full accordance with its different profiles have different effects on the wavefront and peripheral refraction of the eye. The internal optics of the eye partially compensates corneal aberrations induced by the excimer laser.

[Changes in subfoveal choroidal thickness in myopic children who wear bifocal soft contact lenses]. / Izmenenie tolshchiny khorioidei u detei s miopiei na fone nosheniya bifokal'nykh myagkikh kontaktnykh linz.

PURPOSE: To study the changes in subfoveal choroidal thickness in children with progressive myopia who have been wearing bifocal soft contact lenses (BSCL) with an ADD power of +4.0 D for 3 months. MATERIAL AND METHODS: The study included 40 patients (80 eyes) with progressive myopia of low and moderate degrees. The main group consisted of 23 patients aged 10.04±1.5 years with an average myopia of -3.06±1.17 D, they were examined before and 3 months after vision correction with bifocal soft contact lenses Prima BIO Bi-focal («OkVision Retail¼, Russia). The control group consisted of 17 patients (34 eyes) aged 9.29±0.92 years with an average myopia of -3.05±1.5 D using single vision spectacle lenses. Cycloplegic refraction, choroidal thickness and axial length were measured in all patients before and after 3 months. Choroidal thickness was measured using the semi-automatic method on the optical coherent tomography system RS-3000 Advance 2 («Nidek¼, Japan). Axial length was measured using the optical biometer IOL Master 500 («Carl Zeiss¼, Germany). RESULTS: In the main group, subfoveolar choroidal thickness increased on average by 15.3±24.3 µm after 3 months of wearing BSCL, and in the control group it decreased on average by 9.03±28.65 µm. Comparison of changes in choroidal thickness between the main and the control groups revealed a significant difference (p<0.001). Increase in axial length of the eye in the main group was significantly less than in the control group (0.005±0.08 mm vs 0.07±0.06 mm; p<0.001). A strong negative correlation was found between changes in the axial length and subfoveolar choroidal thickness in the main group (r= -0.67), but no similar relationship was found in the control group (r= -0.13). CONCLUSION: Subfoveolar choroidal thickness increases in children wearing bifocal soft contact lenses for myopia correction.

[Correlation of chorioretinal parameters with anatomical, optical and functional indicators of eyes with amblyopia of various origins]. / Korrelyatsiya khorioretinal'nykh parametrov s anatomo-opticheskimi i funktsional'nymi pokazatelyami pri ambliopii razlichnogo geneza.

Purpose. To measure thickness of the central retina and choroid, retinal nerve fiber layer and ganglion cell complex in the macular region, retinal nerve fiber layer in the peripapillary region in eyes with various types of amblyopia, and to analyze its relationship with best corrected visual acuity, refraction and axial eye length. MATERIAL AND METHODS: The study included 50 patients aged 5 to 16 years (mean age 10.04±3.01 years). All patients were divided into 6 groups: 1 - relative amblyopia with congenital myopia (23 eyes); 2 - dysbinocular amblyopia (14 eyes); 3 - refractive amblyopia (16 eyes); 4 - anisometropic amblyopia (7 eyes); 5 - paired eyes of patients with amblyopia (20 eyes); 6 - control group (20 eyes). Chorioretinal parameters were determined using the RS-3000 Advance 2 spectral optical coherence tomography system («Nidek¼, Japan). Correlation analysis was performed using the Pearson's linear correlation coefficient (r). The level of significance of the differences was determined by the standard Student's t-test. RESULTS: Morphological changes in the sensory and choroid membranes of the eye were revealed in groups with amblyopia of various origins compared to the control group, as well as in the fellow eyes. Intergroup comparison showed the presence of more significant disorders in refractive and relative amblyopia due to congenital myopia. Correlation analysis showed that structural changes in the posterior pole are more related to the anatomical and optical parameters of the eyes. CONCLUSION: Optical coherence tomography allows detection of microscopic structural anomalies in the posterior pole of the eye in amblyopia of various origins, assists in differential diagnosis of this condition with organic pathology, and - most importantly - helps peer deeper into the pathogenesis of this disease.

[Correlations between visual fixation parameters, photosensitivity of the retina and visual acuity in various types of amblyopia]. / Vzaimosvyaz' parametrov zritel'noi fiksatsii, svetochuvstvitel'nosti setchatki i ostroty zreniya pri razlichnykh vidakh ambliopii.

PURPOSE: To study the parameters of visual fixation, photosensitivity in the macular region of the retina, and their correlation with the best-corrected visual acuity (BCVA) for various types of amblyopia. MATERIAL AND METHODS: The study included 50 patients with an average age of 11.02±4.2 years. All patients were divided into 3 groups depending on amblyopia type; group 4 consisted of the paired eyes of patients with amblyopia; group 5 was the control group. Retinal photosensitivity and fixation parameters were studied on the Nidek MP-3 microperimeter (Japan). Correlation analysis was performed using the linear Pearson correlation coefficient (r). RESULTS: Retinal photosensitivity was the lowest in the groups with relative amblyopia with nystagmus (25.7±3.6 dB; group 3) and congenital myopia (26.1±2.9 dB; group 2), which is consistent with the partially organic nature of relative amblyopia. In the group with strabismic and refractive amblyopia (group 1), photosensitivity did not significantly differ from the control group (p>0.05). Fixation density was the lowest in the first (85.1±0.2% and 92.8±0.16% at 2° and 4°, respectively) and the third (62.6±0.16% and 89.3±0.05% in 2° and 4°, respectively) groups. In the first group, a strong correlation (r=0.77) of the fixation density and BCVA was revealed; no such correlation was observed in groups 2 and 3. No correlation of photosensitivity and BCVA was detected in group 1 (r=0.2). Fixation density in the group of paired eyes was significantly lower than in the control group (p<0.001). CONCLUSION: Microperimetry is an innovative tool for differential diagnosis, monitoring, method selection and evaluation of the effectiveness of treatment of various types of amblyopia.

[Optical aberrations of the eyes with various degrees of myopia]. / Aberratsii opticheskoi sistemy glaza pri miopii razlichnoi stepeni.

Purpose - to comparatively analyze the wavefront aberrations and biometric parameters of the eyes with various degrees of myopia. MATERIAL AND METHODS: The study included 134 eyes of 67 patients with mild, moderate and high myopia aged 7-28 (mean age 19.3±1.5 years). The following biometric parameters were examined: anterior chamber depth (ACD), lens thickness (LT), axial length (AL), as well as corneal and total aberrations. The parameters were studied on the Galilei G6 system (Ziemer Ophthalmic Systems AG, Switzerland) and the OPD-Scan III aberrometer (Nidek, Japan). Spherical aberration (SA) was estimated as the sum of Z4+Z8+Z12. RESULTS: As the refraction increased, the root mean square higher-order aberrations (RMS HOA) also increased significantly: from 0.24±0.02 µm in mild myopia to 0.45±0.03 µm in high myopia, and in eyes with AL of ≥27.0 mm - to 0.57±0.02 µm (p=0.01). An increase in vertical tilt, vertical coma and vertical trefoil were also observed. Total SA was positive and increased in eyes with moderate myopia compared to those with low myopia (from 0.02±0.01 µm to 0.06±0.02 µm, p=0.02), which coincided with changes in the internal optics of the eye: an increase in ACD and a decrease in LT. At the same time, no differences in corneal aberrations were observed among patients with low and moderate myopia. A significant decrease of SA occurred in high myopia (from 0.06 µm in low myopia to 0.015±0.02 µm in high myopia). The average value of SA was 0.005±0.01 µm in eyes with AL of ≥27.0 mm and appeared to be negative in 40% of cases. The average value of corneal SA was negative (-0.002±0.01µm) in eyes with AL of ≥27.0 mm. This group had predominantly patients with congenital myopia. CONCLUSION: An increase of total positive SA in patients with moderate myopia compared to those with low myopia is associated with changes in the internal optics of the eye (ACD, LT). Significant increase of higher-order aberrations and decrease of SA with the transition to negative values was observed in patients with high axial myopia.

[Comparative assessment of the parameters of visual fixation in amblyopia of different origin]. / Sravnitel'naya otsenka parametrov zritel'noi fiksatsii pri ambliopii razlichnogo geneza.

INTRODUCTION: Examination of visual fixation parameters is an important diagnostic method in patients with amblyopia of different origin. PURPOSE: To study the visual fixation parameters for various types of amblyopia. MATERIAL AND METHODS: The study included 108 patients (213 eyes) aged 5-11 years with moderate and high amblyopia: 27 patients (54 eyes) with strabismic amblyopia, 45 patients (87 eyes) with refractive and anisometropic amblyopia, and 36 patients (72 eyes) with relative amblyopia caused by deprivation nystagmus. All examinations were performed on the NIDEK MP-1 Microperimeter. RESULTS: Fixation density within 2° and 4°, the amplitude of the horizontal and vertical fixation point displacement, the averaged value of the fixation point displacement and the average velocity of displacement were evaluated. There was a positive correlation between visual acuity and fixation density for all types of amblyopia, the higher the visual acuity, the higher the fixation density in the area of 2° and 4°. The maximum values of the displacement point amplitude were registered in patients with nystagmus. In patients with strabismic amblyopia, hyperopia and myopia values of displacement point amplitude were lower. The highest average displacement and rate of displacement of the fixation point were found in the group of patients with nystagmus. The differences were much less significant in other groups. CONCLUSION: A comparative objective study of visual fixation parameters for various types of amblyopia was performed using the NIDEK MP-1 Microperimeter. There was a positive correlation between fixation density decrease, the increase of amplitude and average displacement of the fixation point, and visual acuity decrease for all types of amblyopia. There was no significant correlation between average rate of displacement and visual acuity. The maximum disturbance of fixation parameters, including the average rate of the fixation point displacement, was registered in nystagmus.

[Choroid and optical defocus]. / Khorioideya i opticheskii defokus.

The review summarizes experimental and clinical data attesting to the important role the choroid plays in the development of refraction through optically oriented thickness changes and the release of growth factors. Because of its unique anatomical position, the choroid can influence the transmission of a cascade of chemical signals from the retina to the sclera and thereby affect the growth of the eye. Understanding the relationship between the optical defocus and the response of the choroid to it will help uncover the fundamental mechanisms for controlling eye growth and develop new strategies for preventing the progression of myopia.

[Choroidal thickness in children with myopia and its changes after surgical strengthening of the sclera]. / Tolshchina khorioidei u detei s miopiei i ee izmeneniya posle khirurgicheskogo ukrepleniya sklery.

PURPOSE: To study the choroidal thickness (CT) in children with myopia and hyperopia and its changes after sclera reinforcement surgeries addressing the progression of myopia. MATERIAL AND METHODS: The study involved 133 patients: 78 children (average age 12.5±0.35 years) with mild hyperopia, low, moderate and high myopia and 55 children with moderate and high myopia who received low invasive scleroplasty (LSP, average age 12.31±0.49 years), or bandaging scleroplasty (BSP, average age 12.59±0.24 years) according to Snyder-Thompson technique and were examined prior to and after the procedure. All patients underwent standard ophthalmologic examination and had choroidal thickness manually measured with EDI-SD-OCT; 55 patients were examined before and 1 week after scleroplasty. RESULTS: A reduction of CT with refraction growth and axial elongation was found in 78 patients. Among the 55 patients, changes in CT were statistically significant: in the operated eyes, CT increased by 42.5±3.17 µm after LSP and by 62.1±1.06 µm after BSP. In fellow eyes, CT showed an increase of 26.1±1.79 µm after LSP and 33.7±0.55 µm after BSP. CONCLUSION: In the early period after sclera strengthening, CT significantly increased both in the operated and in the fellow eye. An increase of CT seems to stimulate the collagen biosynthetic activity of the scleral matrix and the collagen synthesis, and to boost the inhibitory effect that scleroplasty has on the myopia progression.

[Objective parameters of accommodation in concomitant strabismus]. / Ob''ektivnye parametry akkomodatsii pri sodruzhestvennom kosoglazii.

PURPOSE: To develop an objective method of determining binocular accommodative response (AR) and concomitant accommodation in patients with strabismus. MATERIAL AND METHODS: The study included 34 patients (68 eyes) with concomitant horizontal strabismus aged 6 to 32 years. The parameters of accommodation were measured using open field Binocular Auto Ref/Keratometer Grand Seiko WR-5100K (Grand Seiko Co. Ltd., Japan). The prism was placed in front of the deviated eye or the prisms were distributed evenly in front of both eyes until the deviation was eliminated. RESULTS: The addition of prisms had no effect on the refractometry results. In convergent strabismus monocular, binocular, direct and consensual accommodation responses were significantly higher than in divergent: -2.15±0.1 D and -1.66±0.12 D; -2.13±0.09 D and -1.33±0.14 D; -2,04±0,15 D and -1,16±0,1 D; -1.97±0.15 D and -1.06±0.09 D, respectively. In divergent strabismus and myopia, the binocular response was 2.8 times higher than in hyperopia (-1.8±0.09 D and -0.63±0.04 D, respectively). Resting tonus of accommodation (RTA) value was higher in patients with hyperopia, both with convergent (mean -2.27±0.41 D) and divergent strabismus (-2.36±0.47 D). Minimal RTA was observed in patients with convergent strabismus and myopia (mean -0.75±0.1 D). CONCLUSION: The study resulted in the development of a method of objective accommodometry of strabismic patients with deviation eliminated by prisms. Monocular and binocular AR were significantly higher in convergent strabismus compared to divergent, where consensual accommodation of the squinting eye is significantly reduced compared to the paired one. In patients with consensual strabismus, RTA is significantly higher in hyperopia than in myopia regardless of the form of strabismus.

[The influence of different means of myopia correction on peripheral refraction depending on the direction of gaze]. / Vliianie razlichnykh sredstv korrektsii miopii na perifericheskuiu refraktsiiu v zavisimosti ot napravleniia vzora.

INTRODUCTION: Peripheral defocus was experimentally found to control the development of refraction. PURPOSE: To evaluate peripheral refraction (PR) of myopic eyes in terms of different means of correction and the direction of gaze. MATERIAL AND METHODS: The study examined 128 patients (256 eyes) aged 8-14 years (average 11.07±0.39 years) with myopia from -1.0 to -7.0 (average -3.57±0.27 D). PR was measured without correction, in perifocal (PF), monofocal (MF), progressive glasses (PAL), monofocal soft contact lenses (ΜCL) and after orthokeratological (OCL) correction with the gaze directed straightforward or head angled outward, inward, upward and downward; all measurements were performed using binocular open-field auto ref/keratometer. RESULTS: PR profile without correction and with contact (OCL, ΜCL) correction does not depend on the direction of the gaze. In glasses, peripheral defocus is different with straightforward and skewed gaze directions. OCL forms a significant myopic defocus throughout the periphery of the retina. When using MCL, hyperopic defocus increases in all zones except the extreme temporal. In MF glasses, hyperopic defocus is formed and enhanced in all areas, significantly greater with skewed gaze than with straightforward. In PALs, myopic defocus is formed with gaze directed upward and downward, as well as at the extreme temporal periphery of the retina with straightforward gaze. In all other zones, hypermetropic defocus increases. In PF, in most zones myopic defocus is formed with all gaze directions. The greatest inhibitory effect on myopia progression is provided by OCL (YPR=0.28 D/year) and PF glasses (YPR=0.26 D/year). CONCLUSION: In contrast to correction with contact lenses, PR in glasses does depend on the direction of gaze. The inhibitory effect of the optics correlates with correction of hypermetropic defocus in myopic eyes.

[Long-term results of perifocal defocus spectacle lens correction in children with progressive myopia]. / Otdalennye rezul'taty ochkovoi korrektsii s perifokal'nym defokusom u detei s progressiruiushchei miopiei.

Peripheral defocus plays a significant role in the formation of refraction. Perifocal spectacles allow differentiating correction of central and peripheral refraction of the eye along the horizontal meridian and can correct or reduce peripheral hyperopia. PURPOSE: To study the long-term results of wearing perifocal spectacles on the refraction in children with progressive myopia. MATERIAL AND METHODS: Perifocal spectacles were assigned to children of 7-14 years old with progressive myopia from -1.0 to -6.0 D in terms of refractive spherical equivalent. The children were examined before the prescription of perifocal spectacles and after 6 months, 12-18 months, 2 years, 3 years and 4-5 years. We measured visual acuity, the character of vision, refractive error before and after cycloplegia, performed biomicroscopy, ophthalmoscopy and biometry. Peripheral refraction was studied at 15° and 30° points in the nasal (N15 and N30) and temporal (T15 and T30) meridians without correction and while wearing perifocal spectacles. RESULTS: In perifocal spectacles, in the 15° zone, 100% of the eyes formed myopic defocus, which averaged -0.05±0.1 D in T15°, -0.25±0.16 D in N15° and -0.44±0.03 D in T30°. In the N30° zone, the hypermetropic defocus decreased by 4 times and amounted to 0.38±0.03 D. The rate of progression of myopia decreased from 0.8 D of baseline values to 0.17 D at 4-5 years of follow-up. After 6 months of wearing perifocal spectacles, the refraction gain was -0.2±0.02 D (in the control group it was -0.38±0.04 D), after 12-18 months - (-)0.38±0.04 D (-0.63±0.09 D in the control group), after 2 years - (-)0,78±0,06 D (-1.18±0,15 D in the control group), after 3 years - (-)0.99±0.12 D (-1.65±0.20D in the control group). During the 4-5 years of the follow-up, the refractive error in the main group was -1.16±0.2 D, which is 60% less than in the control group (-1.95±0.2 D). CONCLUSION: Constant wearing of perifocal spectacles reduces the rate of myopia progression in children by 4.5 times compared with the initial rate, and by 1.6 times (by 60%) in comparison with the control group. Perifocal spectacles are recommended as optical means to slow the progression of myopia.

[Wavefront and accommodation parameters under different conditions of correction in myopia and hyperopia]. / V.V., Parametry volnovogo fronta i akkomodatsii v raznykh usloviiakh korrektsii pri miopii i gipermetropii.

PURPOSE: To compare the wavefront and accommodation parameters without correction and in soft contact lenses (SCL) in natural and cycloplegic conditions in eyes with myopia and hyperopia. MATERIAL AND METHODS: A total of 142 myopic (mean -5.6±1.4 D) and 48 hyperopic (mean +3.5±1.1 D) eyes were examined in 95 patients aged 5-32 years (mean age 16.9±0.9 years) to compare the wavefront aberrations without correction and with different SCL before and after cycloplegia (two drops of cyclopentolate hydrochloride 1%). The device was set up for 4 mm zone for both narrow and wide pupils. To compare the accommodation parameters under different correction conditions, 85 patients aged 8-23 years (mean age 14.9±0.6 years) with average myopia of (-)5.27±1.4D (123 eyes) and average hyperopia of +3.53±1.2 D (46 eyes) were chosen from the study group. Among the measured parameters are objective accommodative response (OAR), relative accommodation reserves (RAR), pseudoaccumulation amplitude (PA), higher-order aberrations: RMSHOAs, 6-9 Trefoil, 7-8 Coma, spherical aberration (SA). RESULTS: In myopic eyes with SCL Coma 7 decreases, Coma 8 increases with transition to positive values, and Trefoil 9 increases. In hyperopic eyes, trefoil 6 decreases, Coma 7-8 go negative. In myopic or hyperopic eyes with SCL, SA goes from positive to negative. In both myopia and hyperopia, accommodation and PA rates are higher in SCL than in glasses. CONCLUSION: SCL change certain wavefront parameters for myopia and hyperopia in different ways. The accommodation parameters in SCL are elevated in both myopia and hyperopia. The negative spherical aberration induced by contact lenses improves the accommodative response. The revealed features should be considered in the development of correction methods that target refractogenesis.

[Stabilizing effect of orthokeratology lenses (ten-year follow-up results)]. / Stabiliziruyushchii effekt ortokeratologicheskoi korrektsii miopii (rezul'taty desyatiletnego dinamicheskogo nablyudeniya).

The global prevalence of myopia in adults varies between 20-50% in Europe and the US and 60-90% in Asian countries. According to WHO, myopia is one of the five leading causes of blindness and low vision in the world. Prevention or deceleration of myopia progression is an important public health problem. In recent years, orthokeratology (ortho-k) contact lenses worn at night have been found effective in slowing down the progression of myopia, however, the follow-up period in related studies is no longer than five years. AIM: to investigate the effects of long-term (10 years) overnight wear of ortho-k lenses on the dynamics of axial eye growth in children and adolescents. MATERIAL AND METHODS: This is a prospective cohort study of the effects of ortho-k lenses on the dynamics of anterior-posterior elongation of the eyeball in 84 patients (168 eyes) aged 7 to 16 years and diagnosed with progressive myopia of 1.0 to 7.0 diopters. Patients were examined every three months, including the slit lamp examination to detect possible side effects of lens wear. RESULTS: The study proves the decelerating effect of the method on disease progression: the average 10-year increase in the axial eye length was 0.7±0.02 mm that corresponds to myopia progression of 2.4 diopters. A comparative analysis of the annual axial eye growth depending on patient age and the degree of myopia at baseline was performed. The increase was found to be generally greater in young children with higher initial myopia. CONCLUSION: Long-term wear of orthokeratology lenses is able to slow down the axial eye growth, i.e. the progression of myopia.

[Stabilizing effectiveness of orthokeratology and long-term minute-concentration atropine therapy in myopia (draft report)]. / Otsenka stabiliziruiushchego éffekta ortokeratologicheskoi korrektsii i dlitel'nykh instilliatsii atropina sverkhmalykh kontsentratsii pri miopii (predvaritel'noe soobshchenie).

The rational for the study was the high prevalence of myopia in the world. According to the World Health Organization (WHO), myopia is one of the five leading causes of blindness and low vision. Of recent reports on conservative measures for the stabilization of myopia, two areas of investigation deserve attention: methods of optical correction that affect peripheral refraction, orthokeratology lenses (OKL) in particular, and pharmacotherapy. The aim of the study was to evaluate the effectiveness and safety of myopia control in pediatric patients by combining two methods - OKL wearing and instillation of extra low doses of atropine (0.01%). MATERIAL AND METHODS: Within a prospective cohort study, 31 patients (62 eyes) aged 8 to 14 years with acquired myopia of low 14 (28), medium 11 (22), or high 6 (12) degree, were examined before and 6 months after adding 0.01% atropine instillations to OKL wearing. Refraction (Huvitz MRK 3100P), axial eye length (IOL-Master, 'CarlZeiss', Germany), absolute accommodation (Grand Seiko WRK-5100K), accommodative reserves, and pseudoaccommodation were assessed. RESULTS: The most significant effect on reducing the rate of disease progression was observed in patients with low and moderate myopia (1.5 and 1.7 times, correspondingly, p<0.05). In high myopia no reliable changes were noticed. Obviously, the inhibitory effect of OKL, which is conditioned by optical factors (peripheral myopic defocus in particular), even in combination with atropine, is not able to stop the progression of high myopia, which is based on structural and biomechanical changes of the sclera. CONCLUSION: Judging from these preliminary results, one should not claim 100% effectiveness of prolonged minute-concentration atropine use, however, the positive effect exists and the study continues.

[Peripheral refraction and retinal contour in congenital and acquired high myopia]. / Perifericheskaia refraktsiia i kontur setchatki pri vrozhdennoi i priobretennoi miopii vysokoi stepeni.

AIM: to perform a comparative study of peripheral refraction and retinal contour in patients with congenital versus acquired high myopia. MATERIAL AND METHODS: A total of 30 patients (60 eyes) with high myopia aged 8 to 18 years (11.2±0.32 years on average) were examined. The patients were divided into 2 groups. Group 1 consisted of 21 patients (42 eyes) with acquired myopia of -6.0 to -10.25 diopters (-7.55±0.17 diopters on average), group 2 - of 9 patients (18 eyes) with congenital myopia of -8.75 to -28.75 diopters (-16.39±1.24 diopters on average). Using the Grand Seiko WR-5100K binocular open-field autoref/keratometer (Japan), relative peripheral refraction was assessed with account to relative peripheral eye length measured by the IOL Master partial coherent interferometer ('Carl Zeiss', Germany) at 15° and 30° nasally and temporally from the foveal center along the horizontal meridian. RESULTS: In acquired myopia, relative peripheral refraction and relative peripheral eye length readings evidenced the formation of peripheral hyperopic defocus in all examined zones. Congenital high myopia cases were notable for myopic defocus at 15° of the nasal retina (N15 zone): -0.67±0.33 diopters against the eye length change of -0.33±0.13 mm. CONCLUSION: The research helped identify retinal contour changes characteristic of congenital myopia and indicative of posterior pole irregularity.

[АComparative analysis of the magnitude of the distance and lens-induced objective accommodative response in patients with different refraction]. / Sravnitel'nyi analiz velichiny distantnogo i lensindutsirovannogo ob''ektivnogo akkomodatsionnogo otveta pri razlichnoi refraktsii.

AIM: To study the magnitude of objective accommodative response (OAR) with account to the method of image defocusing. The latter can be realized by bringing the object nearer to the eye or by adding a minus lens in front of the viewer. MATERIAL AND METHODS: We examined 63 patients (126 eyes) with different refraction aged from 7 to 31 years. All patients underwent a series of OAR measurements on WR-5100K Grand Seiko Binocular Open-Field Autorefkeratometer under different conditions, including negative spherical lenses of -3.0 D and -5.0 D, test optotypes corresponding to visual acuity of 0.2 and 0.7 and presented at a distance of 5 m, and a set of variably sized optotypes presented at a distance of 33 cm and 20 cm. RESULTS: A disparity was found between the magnitude of accommodative responses evoked through different means: placing a negative lens in front of the viewer while he/she looks into the distance or bringing the object closer to the eye. In almost all cases lens-induced responses were less pronounced than distance-induced. In all myopic children, accommodative lag was longer at near than at distance. Generally, in all groups, OAR to distant objects as well as responses to a 3.0 D accommodative task at near did not depend on the size of the object. There was an insignificant and statistically unreliable difference for objects placed 20 cm away (5.0 D accommodative task): OAR to a smaller font was stronger than that to a larger one. CONCLUSION: In children and adults with emmetropia, hyperopic children, and myopic adults, longer accommodative lags were characteristic of lens-induced responses. In children with myopia, longer lags were observed at near. Moreover, at near, OAR to a smaller font was stronger than that to a larger one.

[Wavefront aberrations and accommodation in myopes and hyperopes]. / Aberratsii volnovogo fronta i akkomodatsiia pri miopii i gipermetropii.

AIM: to comparatively investigate accommodation, pseudoaccommodation, and higher-order aberrations in children and young adults with myopia and hyperopia. MATERIAL AND METHODS: A total of 39 myopic (the mean error of (-)5.2±1.5 diopters) and 53 hyperopic (the mean error of (+)3.1±1.15 diopters) eyes of 46 patients aged 5-20 years (11.6±0.6 years on average) were enrolled. Examination included evaluation of the objective accommodative response, relative accommodation reserves, pseudoaccommodation volume (calculated as the difference between the (+)3.0-diopter lens that is necessary for cycloplegic reading at a 33-cm distance and the weakest possible plus lens that enables reading), and higher-order aberrations (HOA), particularly the root mean square (RMS) value, vertical and horizontal trefoil, vertical and horizontal coma (coma7, coma8), and spherical aberration (SA). RESULTS: Both objective and subjective parameters of accommodation were reliably lower in myopia as compared to hyperopia, while wavefront aberrations (RMS HOA, vertical trefoil, coma7) and pseudoaccommodation - reliably greater. SA was found to be reliably more pronounced in those myopes, who demonstrated larger volume of pseudoaccommodation. At the same time, there was a mismatch in wavefront parameters of myopes and hyperopes at different levels of accommodation and pseudoaccommodation. In myopic eyes, vertical trefoil decreased down to negative values as the accommodative response improved. In contrast to that, in hyperopic eyes with large volume of pseudoaccommodation, SA decreased below zero. CONCLUSION: Myopia has been shown to be associated with reduced accommodation parameters as well as stronger HOA and pseudoaccommodation. Wavefront and accommodation parameters interrelations differ in myopic and hyperopic eyes. The nuances revealed should be taken into account when developing correction methods that purposefully influence refractogenesis.

[Peripheral refraction: cause or effect of refraction development?] / Perifericheskaya refraktsiya i refraktogenez: prichina ili sledstvie?

AIM: to study peripheral refraction and the shape of the eyeball in children with different clinical refraction. MATERIAL AND METHODS: Using an original method, peripheral refraction was measured at 10-12 degrees temporally and nasally from the fovea in 56 right eyes with different clinical, or axial, refraction of 20 boys and 36 girls aged 7 to 16 years (11.9±1.17 years on average). The shape of the eyeball was judged of by the ratio of its anterior-posterior axial length (AL) to horizontal diameter (HD). RESULTS: The incidence and value of peripheral myopic defocus in children appeared to decrease with clinical refraction increasing from high hyperopia to high myopia. This was the first time, mixed peripheral refraction was found in children, occurring more frequently in higher myopia. This mixed peripheral defocus, shown to be a transitional stage between relative peripheral myopia and relative hyperopia, indicates non-uniform stretching of posterior pole tissues in the course of refraction development and myopia progression. As ocular refraction increases from high hyperopia to high myopia, the growth of AL outpaces that of HD. CONCLUSION: Obviously, natural peripheral defocus results from changes in size and shape of the eyeball in the course of refraction development.

[Transpalpebral Tetrapolar Reoophtalmography in the Assessment of Parameters of the Eye Blood Circulatory System].

BACKGROUND: Quantitative assessment of hemodynamic parameters is an important element of ophthalmic diagnostics especially in early detection of myopia, glaucoma, diabetic retinopathy. The assessment of hemodynamic changes is essential in evaluating of the efficiency of treatment. Objective: Our aim was to determine the adequate of eye hemodynamics assessment using reoophtalmography in patients with various clinical refractions. METHODS: A controlled study was carried out. All tests were performed using transpalpebral tetrapolar method. Signal registration lasted for 20 seconds in the supine position, and then the diagnostic parameters were calculated. RESULTS: We present the results of examination of 76 patients aged 5 to 22 years (average age 13.0 ± 1.1). 32 patients had low myopia (62 reoophtalmography records), 23 patients had moderate myopia (42 records) and 5 patients had high myopia (12 records). The control group was composed of 16 patients. The main differences were found in the rheographic index, which is equal to 58.1 ± 4.1 mOhm in the control group. It is significantly reducing with refraction increase, from 47.8 ± 3.2 mOhm in low myopia to 34.0 ± 2.5 mOhm in high myopia (p = 0.050). This is an evidence of blood supply deficiency in the myopic eyes. CONCLUSION: Rheographic index was shown to differ in different breathing phases, which agrees with the known physiological regularities. The proposed method is highly informative and sufficiently accurate what allows assessing the eye blood supply state objectively. It is easy to apply and requires no contact with the eye surface, which is especially important in pediatric practice.