[Changes in accommodation in children with hyperopic anisometropia and unilateral amblyopia after laser refractive surgery and pleoptic treatment]

PURPOSE

This study comparatively analyzes the state of accommodation in children with hyperopic anisometropia and amblyopia after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) combined with pleoptic treatment, and after conventional pleoptic treatment.

MATERIAL AND METHODS

The first group consisted of 30 children with medium and high hyperopia, high and medium amblyopia, and anisometropia greater than 3.0 diopters, who underwent Femto-LASIK in the amblyopic eye. The second group consisted of 28 children with similar local status, who were prescribed traditional correction and received conservative treatment. The follow-up period was 1.5 years.

RESULTS

After 1.5 years, higher visual acuity (p<0.05) was achieved in the first group. A significant increase in the coefficient of accommodative response (CAR) was observed in the operated amblyopic eyes in group 1 - by 0.1±0.02 c.u. compared to the control group (p<0.05). In both groups there was an upwards trend for the coefficient of microfluctuations (CMF) in the amblyopic eye, but in the first group CMF increased more significantly (p<0.05). The objective accommodative response (OAR) and positive relative accommodation (PRA) of the amblyopic eye showed a double increase - by 1.0±0.23 and 0.9±0.38 diopters, respectively, at the end of treatment in the first group. The increase in similar indicators in the second group was insignificant (p<0.05). In children of the first group the difference in ciliary muscle thickness (CMT) of the amblyopic eye with disabled and enabled accommodation increased by 0.04±0.01 mm (p<0.05) in the anterior part of the ciliary muscle at the levels of CMTmax and CMT1.

CONCLUSION

The data obtained in this study indicate the strong effect of refractive laser surgery in combination with pleoptic treatment on improving the visual acuity and the state of accommodation of the amblyopic and paired dominant eyes in children with hyperopic anisometropia, in contrast to conventional methods of treatment.

[Justification for the use of modular intraocular lens (experimental study)]

The rising number of cases requiring intraocular lens (IOL) exchange, including those for refractive reasons, drives the search for methods to minimize the trauma of the procedure. Lens implants with modular optics may lower complication risks.

PURPOSE

To test the use of modular IOL on a laboratory animal in an experiment.

MATERIAL AND METHODS

A novel modular IOL was implanted into rabbit eyes in disjointed form with subsequent intraocular assembling. Presence of long-term side effects of implantation and possibility of atraumatic optical disk exchange were evaluated 4 months after the surgery.

RESULTS

A total of 3 rabbit eyes underwent IOL implantation surgery, no technical difficulties were encountered. Postoperatively two eyes were quiet with proper central IOL position and no deformations in the haptic and optical parts. Epithelial cell proliferations did not hinder intraocular disassembly/assembly of the modular IOL. Optical disk spontaneously dislocated into anterior chamber in one eye, with subsequent chronic inflammation and corneal edema. In the late postoperative period, no difficulties were observed in disconnecting the optical part from the haptic ring and their coupling. Optical disk exchange did not require extensive handling of the haptic, except that of fixation leaflets during release/capture of the optics. Mechanical impact of the procedure on the lens capsule and Zinn's zonule fibers was minimal.

CONCLUSION

The experiment has validated the functionality and feasibility of the modular IOL principle designed to lower the threshold for decisions on IOL exchange in postoperative correction of clinical refraction. In most cases, rabbit eyes were demonstrated to exhibit long-term stable fixation, relative ease and safety of optical disk exchange eliminating the need for traumatic capsular bag manipulations.

[Clinical value of CT-perfusion in patients with ureteric stones]

INTRODUCTION

Urinary stone disease is one of the most significant urologic diseases, since its prevalence increases annually, which makes it necessary to study and improve effective preventive measures, diagnostic methods and to implement new treatment interventions.

AIM

to study changes in blood flow in the renal cortex and medulla in patients with ureteral stones using CT perfusion.

MATERIALS AND METHODS

From 2017 to 2019, a total of 53 patients with upper ureteric stones were evaluated at the Russian-Japanese Center for Imaging and the Institute of Urology and Reproductive Health of the FGAOU VO I.M. Sechenov First Moscow State Medical University. Preoperatively, all patients underwent CT perfusion. The study was performed on a Toshiba Aquilion One 640 in volume mode with a slice thickness of 0.5 mm. In this study, blood flow changes were evaluated depending on the degree of dilatation of collecting system.

RESULTS

In patients without dilatation of the collecting system, the average values of cortical and medullary blood flow and blood volume were within normal values. In patients with a dilatation of collecting system, there were significant differences cortical and medullary blood flow between the affected renal unit and contralateral side (27% and 34%, respectively). A decrease in cortical and medullar perfusion by 55% and 58%, respectively, in patients with the dilatation of calyxes was more pronounced in comparison with a decrease in perfusion in patients with the dilatation of only the ureter and pelvis.

CONCLUSION

CT perfusion performed on the 640-slice CT scan allows an objective assessment of changes in renal blood flow in patients with ureteric stones.

[Dual-energy computed tomography in the diagnostics of urolithiasis]

THE AIM

To assess the diagnostic performance of dual-energy computed tomography (DECT) in the evaluation of the composition of urinary stones "in vivo".

MATERIALS AND METHODS

A total of 91 patients aged from 20 to 70 years old (mean 42.7) with urinary stone disease were examined at Sechenov University, including 68 men (75%) and 23 women (25%). Prior to surgery, all patients underwent DECT (Canon, Japan) in order to predict the chemical composition of urinary stones in vivo. Extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS) was performed in 53 (58.2%), 18 (19.7%) and 20 (22.1%) patients, respectively. Postoperatively, all stones or stone fragments (n=91; 100%) were examined using a comprehensive physical and chemical analysis (X-ray phase analysis, electron microscopy, infrared spectroscopy).

RESULTS

In 6 patients (6.6%) staghorn stones were diagnosed, while in 15 (16.5%), 17 (18.7%), 22 (24.2%) and 31 (34.1%) stones were located in ureteropelvic junction, pelvis and ureter, respectively, including 24 patients with lower ureteric stones (26.4%). Prediction of the stone composition in vivo was carried out on the basis of the one indicator, the dual energy ratio (DER). The threshold values of DER for different types of stones were taken from the literature. All stones were divided into 4 groups according to the DECT results: vevellite stones (n=40, 43.9%), Ca-containing stones without vevellite (n=34, 37.3%), uric acid stones (n=10, 10.9%) and struvite stones (n=7, 7.9%). Thus, when comparing the results of DECT and physical and chemical analysis, in the first group four stones were incorrectly assigned by DECT to the group of Ca-containing stones without vevellite and three stones were incorrectly assigned to the group of struvite stones; in the second group four stones were incorrectly assigned to the group of vevellite stones; in the third group one stone was incorrectly assigned to the group of struvite stones; in the fourth group one stone was incorrectly assigned to the group of vevellite stones and one stone in the group of uric acid stones. In order to increase the diagnostic efficiency of DECT, we performed a comprehensive analysis of five specific DECT indicators (stone density at 135 kV, Z eff of the stone, DER, DEI, DED) using discriminant analysis. Thus, the sensitivity, specificity and overall accuracy of DECT with the use of just one indicator (DER) were 83.3%, 89.8%, 86.8% for vevellite, 88.2%, 92.9%, 91.2% for Ca-containing stones without vevellite, 90%, 98.8%, 97.8% for uric acid stones and 60%, 95.3%, 93.4% for struvite stones, respectively. When using discriminant analysis with five specific DECT indicators, higher values of sensitivity, specificity and overall accuracy were seen: 95.2%, 89.8%, 92.3% for a vevellite, 85,3%, 96,4%, 92,3% for Ca-containing stones without a vevellite and 100%, 100% and 100% for both uric acid and struvite stones, respectively.

CONCLUSIONS

Dual-energy computed tomography is a highly informative method which allows to perform preoperatively the reliable assessment of the chemical composition. DECT in patients with urinary stone disease allows to optimize the treatment strategy and carry out preventive measures on individual basis, taking into account the stone type.

[Modern radiology diagnostics methods for assessment of renal perfusion in patients with urinary stone disease]

Urinary stone disease is the current issue for healthcare system worldwide. High prevalence of urinary stone disease (at least 5% of the population of developed countries) determines clinical significance of the studying of its etiology and pathogenesis, improving of diagnostic methods and novel treatment technologies. The development of endoscopic devices, creation of new eswl machines and improvement of endourology interventions under X-ray guidance allowed to solve the problem of surgical treatment. Therefore, one of the actual issue is the choice of X-ray method for predicting and evaluating of treatment efficiency in patients with urinary stone disease. The changes of renal blood flow depend on urodynamic disturbances, stone location and size, the duration of disease, complications, patients age. Therefore, for comprehensive studying of renal function the hemodynamics evaluation is needed. In this review the advantages, drawbacks and perspective on developing of different radiologic methods for renal hemodynamic assessment are given.