[Scanning electron microscopy results of the vitreous body in asteroid hyalosis]. / Rezul'taty skaniruyushchei elektronnoi mikroskopii steklovidnogo tela pri asteroidnom gialoze.

PURPOSE: To evaluate the structure of vitreous body in asteroid hyalosis by low vacuum scanning electron microscopy. MATERIAL AND METHODS: The material of the study was samples of the vitreous body obtained from 7 patients aged from 62 to 72 years with vitreomacular traction syndrome during vitrectomy. In all cases, clinical manifestations of asteroid hyalosis (the presence of multiple point-like echo-positive inclusions) were identified during the preoperative examination. Samples for scanning electron microscopy and chemical microanalysis were prepared without using fixation elements, total dehydration, staining or centrifugation, and according to the so-called principle of bougienage, which consists in partial separation of fractions of the gel-like tissue with a stream of saline. RESULTS: The conducted examinations made it possible to identify various types of local accumulations of mineral elements in the vitreous body in asteroid hyalosis - called asteroid bodies - that is, multiple complex rounded formations consisting of needle-shaped crystals of a radial fibrous structure. CONCLUSION: The developed algorithm, which includes intraoperative sampling of the vitreous body in conditions of its minimal hydration and a special technique for preparing samples for scanning electron microscopy and chemical microanalysis, provides the capability for the in vivo assessment of morphological changes in hyaloid elements of the vitreous body. With that, asteroid bodies can be considered as markers of the vitreous structures that are difficult to visualize.

[Current approach and the role of laser photocoagulation in the treatment of retinal vein occlusions]. / . Sovremennye podkhody i mesto lazernoi koaguliatsii v lechenii okkliuzii ven setchatki.

Despite the emergence of new approaches in the treatment of retinal vein thrombosis and post-thrombotic complications, namely, intravitreal pharmacotherapy and surgical treatment, laser photocoagulation continues to play a significant role in the management of patients with this pathology. Although the method of laser photocoagulation has been used for quite a long time, different views exist on its indications and execution in specific clinical situations. At that, not all opinions regarding the use of laser photocoagulation in thrombosis are based on convincing clinical studies. The aim of this work was to summarize current literature data on the use of laser photocoagulation in the integrated treatment of retinal vein occlusions and, also, to show which aspects of the treatment of thromboses can be considered well-established and reasonable and which remain a subject of debate.

[Biometric parameters of vitrectomized eyes]. / Biometricheskie parametry avitreal'nykh glaz.

AIM: To analyze changes in various biometric parameters after vitrectomy. MATERIAL AND METHODS: A total of 50 patients (50 eyes) were followed up. All of them underwent vitrectomy for idiopathic epiretinal fibrosis and macular hole. In addition to the standard ophthalmic examination, we performed a combined ultrasound study and ultrasound biomicroscopy before and after the surgery (at 2-3 weeks and 6 months). Variation statistics was applied to assess the results using the SPSS Statistica 20 software. RESULTS: According to ultrasound biomicroscopy, the following parameters increased: anterior chamber depth, trabecular-ciliary process distance, posterior chamber maximal depth and volume, and fiber length within the zonule of Zinn. In the late postoperative period (6 months after the surgery), there was an increase in lens volume and anterior-posterior ocular axis by the average of 0.15±0.04 mm. Against this background, clinical refraction shifted toward myopia by the average of 0.68±0.05 diopters in the early postoperative period and 1.7±0.15 diopters at 6 months. CONCLUSION: With the help of modern ultrasound examinations we have identified biometric changes in the anterior segment of vitrectomized eyes. We have also established a myopic shift of clinical refraction, which is most likely to be due to the increase in axial eye length and lenticular changes.

[Combined transscleral and transpupillary thermotherapy in large vasoproliferative retinal tumors].

Three cases (two patients) of large vasoproliferative retinal tumor treatment by an original method, which includes intraoperative non-contact transscleral thermotherapy and subsequent transpupillary thermotherapy, are described. Positive anatomical results were achieved in all three cases.

[Visual fixation features after treatment of exudative age macular degeneration].

Changes of visual fixation in patients with choroidal neovascularitation (CNV) associated with age macular degeneration (AMD) after bevacizumab are studied. 45 patients (45 eyes) with active CNV treated with intravitreal bevacizumab were enrolled into the study. Visual fixation was studied before and 3-6 months after treatment using original method that included fundus foto and fluorescein angiography. Fixation relative to fovea and lesion was evaluated. Foveal fixation beyond lesion was found in 9%, foveal fixation within lesion--in 47%, extrafoveal fixation beyond lesion--in 18%, extrafoveal fixation within lesion--in 26% of patients. Changes of fixation localization after treatment was found in 24% patients. Examination of visual fixation may be useful for prognosis of anti-VEGF treatment efficacy in patients with CNV.

[Surgical treatment policy using recombinant prourokinase for submacular hemorrhages].

An immunofluorescence technique was used to study the transretinal penetration of intravitreal fibrinolytic agent Hemase (a recombinant urokinase) in an experiment on 4 rabbit eyes. Hemase (54 kD) was proved to be able to penetrate across all retinal layers 2 hours after intravitreal administration. The efficacy of Hemase was tested in the treatment of submacular hemorrhages (SMH) of various etiology. Thirteen patients with SMH associated with age-related macular degeneration or ophthalmic injury were enrolled in the study. Hemase 500 IU was intravitreally injected 24 hours before pneumatic dislocation of SMH in 10 patients. In 3 patients with massive SMH, the proposed vitrectomy procedure was employed, by epiretinally injecting the fibrinolytic agent under a gas bubble, followed by drainage of the subretinal space. The operation was ended, by administering air and Hemase, and then by putting the patient in the supine position for 3-4 hours, thereafter his/her position was recommended to be changed to the prone position to realize the mechanism of pneumatic dislocation. The studies suggest that pneumatic SMH dislocation in combination with Hemase administration permits visual acuity to be increased in 80% of cases. The efficiency of manipulation and the functional outcome of treatment depend on the etiology of hemorrhage. The proposed vitrectomy technique using Hemase reduces neuroepithelial injury, effectively drains SMH, and dislocates its remnants from the foveal area.