[Evaluation of the accuracy of modern intraocular lens calculation formulas when optical biometry is not possible]. / Otsenka tochnosti sovremennykh formul rascheta intraokulyarnykh linz pri nevozmozhnosti vypolneniya opticheskoi biometrii.

PURPOSE: This study evaluates the accuracy of modern intraocular lens (IOL) calculation formulas using axial length (AL) data obtained by ultrasound biometry (UBM) compared to the third-generation SRK/T calculator. MATERIAL AND METHODS: The study included 230 patients (267 eyes) with severe lens opacities that prevented optical biometry, who underwent phacoemulsification (PE) with IOL implantation. IOL power calculation according to the SRK/T formula was based on AL and anterior chamber depth obtained by UBM (Tomey Biometer Al-100) and keratometry on the Topcon KR 8800 autorefractometer. To adapt AL for new generation calculators - Barrett Universal II (BUII), Hill RBF ver. 3.0 (RBF), Kane and Ladas Super Formula (LSF) - the retinal thickness (0.20 mm) was added to the axial length determined by UBM, and then the optical power of the artificial lens was calculated. The mean error and its modulus value were used as criteria for the accuracy of IOL calculation. RESULTS: A significant difference (p=0.008) in the mean IOL calculation error was found between the formulas. Pairwise analysis revealed differences between SRK/T (-0.32±0.58 D) and other formulas - BUII (-0.16±0.52 D; p=0.014), RBF (-0.17±0.51 D; p=0.024), Kane (-0.17±0.52 D; p=0.029), but not with the LSF calculator (-0.19±0.53 D; p=0.071). No significant differences between the formulas were found in terms of mean error modulus (p=0.238). New generation calculators showed a more frequent success in hitting target refraction (within ±1.00 D in more than 95% of cases) than the SRK/T formula (86%). CONCLUSION: The proposed method of adding 0.20 mm to the AL determined by UBM allows using this parameter in modern IOL calculation formulas and improving the refractive results of PE, especially in eyes with non-standard anterior segment structure.

[Reasonability of accounting for gender in intraocular lens power calculation]. / O tselesoobraznosti ucheta gendernoi prinadlezhnosti pri raschete opticheskoi sily intraokulyarnykh linz.

PURPOSE: The study assesses the influence of gender on the accuracy of intraocular lens (IOL) power calculation by formulas SRK/T, Barrett Universal II (BUII), Ladas super formula (LSF), Hill RBF (RBF) and Kane. MATERIAL AND METHODS: The study enrolled 214 patients (106 men and 108 women) who underwent cataract phacoemulsification (PE). Optical biometry was performed on IOL-Master 500. IOL power calculation was performed either adjusting for gender (formulas SRK/T, BUII, LSF) or without such adjustment (formulas RBF, Kane). Calculation error (CE) was assessed one month after PE by comparing the achieved (autorefractometer Topcon-8800) and target spherical equivalent of refraction. RESULTS: Significant differences were found in mean IOL CE with gender-unspecific formulas (SRK/T, BUII, LSF) and no differences in gender-specific calculators (RBF, Kane). The Kane formula demonstrated the lowest CE between men and women (-0.01±0.43 versus -0.09±0.41 D; p=0.158), while the SRK/T formula had the highest CE (0.02±0.46 versus -0.21±0.44 D, respectively; p<0.001). Presence of a significant correlation between CE and gender was found for all formulas except Kane (R2=0.005, p=0.158). CONCLUSION: Patient's gender has a significant impact on IOL calculation accuracy. Using gender-responsive formulas could help achieve better refractive results with PE. The present study showed Kane formula to have the least CE dependence from gender. However, the CE difference (less than 0.25 D) was lower than the value of division (0.5D) in modern IOL models.

[Clinical features and treatment of endophthalmitis after cataract surgery]. / Klinicheskie osobennosti i lechenie endoftal'mita posle khirurgii katarakty.

PURPOSE: The study analyzes the frequency of acute endophthalmitis occurrence after cataract surgery, the risk factors, characteristic symptoms, and the effectiveness of peri-operative prevention measures. MATERIAL AND METHODS: The study retrospectively analyzed 59 670 cases of patients operated for cataract in 2017-2021. To prevent infections, patients received four instillations of third generation fluoroquinolone (quinolone antibiotic) in the course of two days prior to cataract phacoemulsification (PE), and two instillations immediately (1 hour and 30 minutes) before the surgery; three-minutes treatment of the cornea, conjunctival sac and periocular skin with 5% povidone iodine before the surgery; and as the last step of surgery, patients received subconjunctival injection of 0.05 g cefazolin with 2 mg dexamethasone. Follow-up after surgery included four injections of 0.5% levofloxacin in the course of 7-10 days, and 0.1% dexamethasone for two weeks, or fixed combination of tobramycin and dexamethasone four times per day for two weeks. The criteria for acute endophthalmitis are: loss of spatial vision, absence of red reflex, pronounced thickening of the choroid, suspended particulates in the retrovitreal space and the vitreous observed with ultrasonography in the early postoperative period (day 4-7 after surgery). RESULTS AND DISCUSSION: There were 32 patients (0.054%) diagnosed with acute endophthalmitis. Posterior capsule rupture was the main complicative risk factor of endophthalmitis development (OR=11.75, p=0.026). Main diagnostic criteria of acute endophthalmitis were hypopyon (OR=22.5, p=0.001) and absence of red reflex (OR=19.59, p<0.001). The use of the fixed combination of tobramycin and dexamethasone was associated with 5.8-times higher risk of acute endophthalmitis than separate application of levofloxacin and dexamethasone (p=0.042). CONCLUSIONS: Povidone iodine and third generation fluoroquinolone as a method of acute endophthalmitis prevention after cataract surgery demonstrate comparable efficacy to intracameral antibiotic injections.

[Alternative method of intraocular lens power calculation in eyes with short axial length]. / Al'ternativnyi sposob rascheta opticheskoi sily intraokulyarnykh linz pri korotkoi perednezadnei osi glaza.

PURPOSE: To develop an alternative method of intraocular lens (IOL) power calculation in eyes with mature cataract and axial length (AL) of less than 22.0 mm using modern formulas Barrett Universal II and Hill RBF. MATERIAL AND METHODS: The study enrolled 41 patients (41 eyes) who underwent phacoemulsification (PE). Ultrasound biometry (Tomey Biometer Al-100) and keratometry (Topcon-8800) were used for IOL power calculation by SRK/T and Haigis formulas. To calculate IOL power by Barrett Universal II and Hill RBF formulas, 0.2 mm were added to AL measured with ultrasonography (retinal thickness). One month after PE, spherical equivalent of refraction was compared with target refraction (calculated by the formulas listed above), and based on that a conclusion was made on the accuracy of calculations. RESULTS: Haigis formula was found to be the least accurate (IOL calculation error -0.39±0.79 D). The calculation error in SRK/T (0.04±0.79 D), Barrett Universal II (0.02±0.79 D) and Hill RBF (-0.05±0.73 D) formulas was much lower. However, among them Hill RBF had the lowest spread of the mean absolute IOL calculation error. Pairwise comparison revealed significant difference of mean IOL calculation error by Haigis formula versus the others. There was no significant difference in the following pairs: SRK/T - Barrett Universal II (p=0.855), and SRK/T - Hill RBF (p=0.167), but there was a significant difference (p=0.043) in the Barrett Universal II - Hill RBF pairdue to the tendency for slight hypermetropic calculation error in the former and the inherent slight myopic shift in the latter.. CONCLUSION: The proposed alternative method of IOL power calculation in eyes with mature cataract and short AL using modern formulas (Barrett Universal II and Hill RBF) shows higher accuracy compared to the formulas embedded in ultrasound biometer (SRK/T and Haigis), and can be recommended for use in everyday practice.

[Calculation of intraocular lens power after trabeculectomy]. / Osobennosti rascheta intraokulyarnykh linz posle sinustrabekulektomii.

PURPOSE: To assess biometric changes in eyes after trabeculectomy (TE) and its impact on refractive outcomes of phacoemulsification (PE) in order to determine the corrections for calculation of intraocular lens (IOL) power. MATERIAL AND METHODS: The study included two groups of patients: the 1st group consisted of 116 patients who were assessed by optical biometry (IOL-Master 500) for mean biometric values before and after TE; the 2nd group included 31 patients with history of TE (study subgroup) and 47 individuals without glaucoma (control subgroup) who underwent PE with subsequent comparison of IOL calculation accuracy. RESULTS: There was significant axial length (AL) shortening in the 1st group from 23.28±0.97 to 23.19±0.97 mm (p<0.001) 6 months after TE, which positively correlated (r=0.296, p=0.001) with intraocular pressure (IOP) decrease (from 25.4±5.34 to 17.2±4.42 mm Hg, p<0.001). Mean keratometry and anterior chamber depth values did not significantly change after TE. Mean IOL power calculation error after PE in the 2nd group was -0.05±0.47 D and 0.003±0.62 D for the control and study subgroups, respectively (p=0.697). However, significant impact of preoperative IOP on IOL power calculation error was discovered in the study subgroup (R2=0.526, p<0.001), but not in the control subgroup (R2=0.061, p=0.052). Based on linear regression, the expected IOL power calculation errors depending on the preoperative IOP were determined for patients with history of TE. CONCLUSION: AL shortening due to decrease in IOP in patients with history of TE leads to IOL power calculation errors. Expected IOL calculation error related to preoperative IOP level was determined, which could help improve refractive outcomes of PE in patients with history of TE.

[Optimization of intraocular lens power calculation in pseudoexfoliation syndrome]. / Optimizatsiya rascheta intraokulyarnykh linz pri psevdoeksfoliativnom sindrome.

PURPOSE: To assess the impact of pseudoexfoliation syndrome (PEX) on the accuracy of intraocular lens (IOL) power calculation. MATERIAL AND METHODS: The study included 243 patients who underwent phacoemulsification (PE); they were divided into the control (no PEX signs, n=131) and study (signs of PEX, n=112) groups. Barrett Universal II formula was used for IOL calculation by optical biometry (IOL-Master 500). Obtained refraction (autorefractometer Topcon-8800) was compared with target refraction to assess IOL calculation accuracy 1 month after PE. RESULTS: Patients with PEX had significantly shallower anterior chamber compared to the control group (2.86±0.43 versus 3.0±0.43 mm, p=0.003) and steeper corneal curvature (44.31±1.5 versus 43.7±2.59 D, p=0.052). There was significant difference in absolute error of IOL calculation between the groups (-0.02±0.45 versus 0.17±0.55 D for control and study groups, respectively, p=0.004). There was no difference in IOL calculation error depending on the implanted IOL models (AcrySof SA60AT and Akreos Adapt AO) in the control group. However, implantation of SA60AT in the study group showed significant difference in IOL calculation error compared with Akreos (0.3±0.57 versus 0.04±0.51 D, p=0.01). Using linear regression, optimized A-constants were suggested for these types of IOLs for patients with PEX (118.83 for SA60AT and 118.44 for Akreos).

[Gastrin-17 level in the omeprazole treatment of duodenal ulcer].

The article discloses the results of the duodenal ulcer treatment with a generic of omeprazole (Omizac) in the in-patient hospital and polyclinic conditions, dynamics of the serum gastrin level against the background of the drug application and after its withdrawal, and assessment of the intensity and duration of acid production inhibition in the stomach.