PurposeTo estimate the effectiveness of complete corneal ring (MyoRing) implantation compared with MyoRing implantation combined with corneal collagen crosslinking (CXL) for keratoconus treatment for 36 months follow-up.DesignRetrospective cohort study.Materials and methodsMyoRing implantation was performed in a series of 78 patients (80 eyes) with keratoconus II–III Amsler classification, of these 39 eyes had MyoRing implantation combined with CXL. Implantation of a MyoRing in the corneal pocket was performed using a PocketMaker microkeratome and corneal intrastromal implantation system. During CXL, riboflavin solution 0.1% was injected into the corneal pocket through the incision tunnel and standard surface UVA irradiation (370 nm, 3 mW/cm2) was then applied from 5-cm distance for 30 min.ResultsSignificant improvements in uncorrected distance visual acuity and corrected distance visual acuity were observed for both groups, which was relatively better 12 months after procedure in MyoRing alone group; however, in 36 months there was no difference between groups. Keratometry was reduced in both groups; after MyoRing implantation for 8.45 D and MyoRing + CXL for 9.43 D, the spherical equivalent decreased from 8.45 to 7.72 D and from 9.43 to 6.25 D, respectively. The cylinder decreased to 3.33 D with MyoRing alone and to 3.31 D with MyoRing + CXL. Corneal thickness remained nearly unchanged (from 433.69 ± 38.76 to 434.21 ± 34.98) in MyoRing group and decreased from baseline (from 426.93 ± 46.58 to 401.24 ± 39.12 µm) in MyoRing + CXL group 36 months postoperatively, which corresponds with pachymetry reduction after conventional CXL.ConclusionBoth MyoRing implantation and MyoRing combined with CXL were effective for treating keratoconus. At 36 months, there were slightly better outcomes in MyoRing + CXL group; however, in MyoRing alone group visual and refractive outcomes were stable overtime.

Во всем мире ежегодно отмечается значительный рост заболеваний роговицы, сопровождающихся деструктив-ными изменениями коллагена в ее составе, что связывают с ухудшением экологии, интенсификацией глазной хи-рургии, травмами глаза, а также с увеличившимся числом офтальмоинфекций [1]. В Российской Федерации на больных с заболеваниями роговицы приходится до 18% общего числа слепых и слабовидящих [2].В основе кератоэктазий, в частности кератоконуса, лежит прогрессирующая деградация коллагеновой струк-туры роговицы и, соответственно, снижение ее прочност-но-механических свойств, приводящие к помутнению, нередко рубцеванию и значительному снижению остроты зрения. Как правило, это билатеральный патологический процесс, чаще наблюдаемый у лиц молодого трудоспо-собного возраста. Качественные и количественные из-менения состава коллагена органа зрения, отрицательно сказываясь на его структуре, проявляются в различных сочетаниях симптоматики болезни.Этиология кератоконуса считается многофакторной и наряду с вышеуказанными причинами включает также наследственную, эндокринную, аллергическую, имму-нологическую и другие теории, среди которых наиболее признанной у специалистов считается генетическая ги-потеза [3]. Несомненно, в пользу этого свидетельствуют семейные случаи заболевания, а также их сочетание с некоторыми наследственными синдромами. Так, по дан-ным мультицентрового проспективного исследования CLERK (США), генетические формы кератоконуса были выявлены в 13,5% случаев [4].В последнее десятилетие так называемый инжини-ринг тканей, базирующийся на процессах фотополи-меризации, стали использовать для лечения широкого спектра заболеваний. В частности, с целью укрепления роговой оболочки глаза при хронических дегенеративных процессах успешно применяется ультрафиолетовый (УФ) кросслинкинг роговицы (UV Corneal Crosslinking, CXL), основанный на ее облучении при длине волны 370 нм с использованием светочувствительного рибофлавина [5].Кросслинкинг (перекрестное связывание, или сши-вание) способствует стабилизации биомеханических свойств роговицы за счет увеличения количества свя-зей между фибриллами стромального коллагена, кера-тоцитами и белками межклеточной адгезии посредством рибофлавин-УФ-индуцируемых фотохимических реак-ций [5−8]

One month after treatment, there was a slight decrease in uncorrected and best corrected visual acuity (UCVA and BCVA) - from 0.08±0.03 and 0.4±0.15 preoperatively down to 0.06±0.02 and 0.3±0.07, respectively, caused by pseudohaze of the cornea. Keratometric parameters (the average refractive power of the cornea, corneal astigmatism, and corneal thickness) did not change significantly. The demarcation line was identified in 56% of cases. By the 3-month follow-up, UCVA and BCVA improved up to 0.1±0.07 and 0.52±0.1, respectively. The refractive power of the cornea decreased by 2.0 diopters and corneal astigmatism - by 0.7 diopters reaching 46.8±2.7 and 5.1±1.3 diopters, respectively (p≤0.04). Central corneal thickness decreased by an average of 29 microns. The demarcation line remained visible in 25% of cases. At 6 months, BCVA averaged 0.58±0.13, at that, 56% of eyes gained 1 line and 31% - 2 lines. The refractive power of the cornea decreased down to 45.7±1.6 diopters, corneal astigmatism - down to 4.8±1.5 diopters. The demarcation line was not detected. At 1 year, there were no significant changes in the average values of optometric indices as compared to the 6-month period. Сonclusion. Pellucid marginal corneal degeneration should be regarded as a kind of primary ectasia, often bilateral and notable for its characteristic clinical picture and late onset. In progressive disease, photochemical crosslinking of the cornea contributes to the improvement of optometric parameters and stabilization of the process.

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Purpose To evaluate anatomic and functional results of ALK using different technics for end‐stage keratoconus. Methods Anterior lamellar keratoplasty was performed in 21 eyes with progressive keratoconus of IV stage of disease according to the Amsler classification. In 1st group (12 cases) keratoplasty was performed using a femtosecond laser LDV8. Removed corneal disc diameter ‐ 7.5‐8.0 mm, thickness ‐ 250‐300 mc. In 2nd group (9 cases) manual dissection of anterior stroma was performed. Partial trepanation without penetration of anterior chamber (diameter 7.5‐8.0 mm) was done at depth 250 mc using Barron trephine. Corneal graft was fixated by 10/0 sutures. The follow‐up was 6 months. Results Significant improvements of UCVA and CVA was up to 0.2 and 0.5, respectively, in 1st group. In 2nd group UCVA and CVA improved up to 0.08 and 0.3 in early postop period. Mean corneal astigmatism was 4.6±1.2 D in 1st group and 7.7±2.4 D in 2nd, respectively. In 1 case after manual technic (2nd group) hazing and graft rejection was observed in 2 months after surgery. Conclusions The use of femtosecond technologies in anterior lamellar keratoplasty increases the efficiency of the operation due to the greater predictability and accuracy of the procedure and the optimal donor‐recipient juxtaposition. This leads to better visual and refractive outcomes by reduction of corneal astigmatism due to good wound apposition, biomechanical stable incision.

The article presents the study results of the local antioxidant status in patients with progressive keratoconus and its dynamics after the ultraviolet corneal crosslinking. Purpose: to study the oxidative activity in the tear of the patients with keratoconus and its dynamics after ultraviolet cornea crosslinking. Patients and methods. To assess the local level of oxidative activity in keratoconic patients according to the levels of total antioxidant status (TAS) and superoxide dismutase (SOD) in the tear fluid, as well as their dynamics after UV crosslinking were investigated. The study included 38 patients (38 eyes) with keratoconus stage I–II (classification according to Amsler), men — 24 (63.1 %), women — 14 (36.9 %). The standard UV crosslinking group (S-CXL) was 20 eyes, and the pulsed accelerated protocol (I-CXL) — 18 eyes. The average age of patients was 32.4 ± 6.8 years. As a control group, 12 practically healthy individuals were selected. The time of observation is before the operation, on the 3rd, 7th, 14th and 30th days after the procedure. Results: On the basis of the conducted studies, it was revealed that keratoconus patients showed a statistically significant decrease in the initial indicator of TAS by 40 % and amounted to 1.68 ± 0.21 mmol/l, compared to healthy people — 2.82 ± 0.15 mmol/l. The SOD level in tears in patients with keratoconus was also lower by 19 % — to 96.7 ± 11.3 ng/ml, compared to the control — 119.1 ± 16.5 ng/ml. The use of S-CXL of the cornea caused a decrease in TAS during the first 3 days with the subsequent restoration of its level. The use of pulse A-CXL also showed a decrease in this indicator, but by the end of 1st month the level of TAS was higher than preoperative and better than when using the standard protocol. A decrease in SOD level after treatment was noted during the first 3 days, however, the use of S-CXL caused a more significant collapse of this indicator compared to the pulsed accelerated corneal crosslinking protocol. Conclusion. TAS data and SOD level had shown a decrease in local antioxidative status in patients with keratoconus. Ultraviolet corneal crosslinking causes the maximum decrease in SOD and TAS on the 3rd day after the procedure, and from the 14th day their gradual recovery to the initial level is observed. The standard protocol contributed to a more pronounced development of local cross-linking damage in patients with keratoconus. It manifests itself in the antioxidant status reduction of the tear compared to the pulsed accelerated method.