[State-of-the-art of trans-vitreal surgery of the eye]. / Sovremennoe sostoianie transvitreal'noi khirurgii glaza.

The modern condition of endo- and transvitreal surgery of the eye was demonstrated with regard for surgical approaches, technical outfit, expendables and medical preparations. Variants of clinical application of vitreal surgery methods at different pathologies of the vitreous body and retina, e.g. haemophthalmos of various etiologies, opacity of the vitreous body (including that of the uveal origin, proliferative diabetic retinopathy) diabetic macular edema, proliferative vitreoretinopathy of other etiologies (including complicated retinal detachments, posttraumatic vitreoretinopathy), complicated cataract extraction, macular pathology (including traction deformation of the retinal surface, senile macular holes and sub-retinal neovascular membranes) are discussed.

[Pathological basis for clinical stages of the proliferative process in diabetic retinopathy]. / Patologicheskoe obosnovanie klinicheskikh stadii proliferativnogo protsess pri diabeticheskoi retinopatii.

In order to elucidate the relationships between posterior ocular structures, 48 samples of epiretinal membranes were examined, which were obtained during transcilliary vitrectomy for proliferative diabetic retinopathy of different stages (29 patients with type I diabetes mellitus and 19 with type 2). The findings of morphological analysis and preoperative ophthalmoscopy (color photographs) demonstrated clinical and morphological correlations of stages of proliferative diabetic retinopathy. Impossibility of differential diagnosis between posterohyaloid membrane and newly formed tissue by clinical methods and impossibility of their mechanical intraoperative separation allow us to regard the stages of proliferative process as stages in changes of the posterohyaloid membrane proper. The posterohyaloid membrane is detected clinically and morphologically only in the presence of pathological changes, including diabetic retinopathy. We detected the following clinical histological correlations of proliferative process stages in diabetic retinopathy: 1) glial; 2) glio-vascular; 3) glio-vascular-fibrous; 4) fibrovascular; 5) fibrous (cicatricial). The histology of stages of proliferative diabetic retinopathy and correlation of histological findings with the clinical (ophthalmoscopic) picture of the process are described in detail. Recommendations on the treatment of each of these stages are offered.

[Formula for estimating the optic force of elastic intraocular lenses]. / Formula rascheta opticheskoi sily élasticheskikh intraokuliarnykh linz.

Formula for estimating the optic force of intraocular lenses made from elastic materials has been tried in 106 patients. The formula takes account of forward deflection of the elastic intraocular lens in the posterior chamber of the eye. The proposed method for estimation more than threefold decreases the mean error in estimation of optic force of elastic intraocular lenses in comparison with calculations with the use of known formulas. The mean error is 0.78 +/- 0.13 diopters, which corresponds to modern requirements to the accuracy of formulas for calculating the optic force of intraocular lenses.

[Contribution of posterior hyaloid membrane to pathogenesis and transciliary surgery of proliferative diabetic retinopathy]. / Rol' zadnei gialoidnoi membrany v patogeneze i transtsiliarnoi khirurgii proliferativnoi diabeticheskoi retinopatii.

Results of 276 transcilliary vitrectomies in patients with proliferative diabetic retinopathy are analyzed. The indications for surgery were traditional in 180 patients and early in 98. The object of surgical manipulations in early surgery for proliferative diabetic retinopathy is the posterior hyaloid membrane, which should be detached from the retina and removed at an area as larger as possible. New vessels or fibrovascular tissue are left intact. After removal of the posterior hyaloid membrane they do not proliferate. Early surgery on the posterior hyaloid membrane in patients with proliferative diabetic retinopathy helps attain more stable and better functional results and involves a lesser number of serious intra- and postoperative complications. Fibrovascular proliferation does not progress after removal of the posterior hyaloid membrane at the site of the posterior pole of the eye, and therefore, we did not carry out panretinal laser coagulation during or after surgery. The only exceptions were cases with neovascularization of the iris in the postoperative period.

[A pathohistological study of newly formed subpigment epithelial tissue in patients with senile macular dystrophy]. / Patogistologicheskoe issledovanie subpigmentno-épitelial'noi novoobrazovannoi tkani u bol'nykh s senil'noi makuliarnoi distrofiei.

Efficacy and possibility of direct operations on the macular area of the retina in humid (exudative) maculopathies (senile maculodystrophy) is validated theoretically, morphologically, and clinically. A hypothesis on the mechanism of exudative process development in the macular area in degenerative diseases is formulated on the basis of pathohistological analysis of removed subpigmental material. Indications for such operations are defined.

[Posterior hyaloid membrane as structural base of growth of neovascular tissue in proliferative diabetic retinopathy]. / Zadnegialoidnaia membrana kak strukturnaia osnova rosta novoobrazovannoi tkani pri proliferativnoi diabeticheskoi retinopatii.

Morphologic study of 38 specimens of epiretinal membranes obtained during transciliary vitrectomy in 26 patients with type I diabetes mellitus and 12 with type II diabetes with proliferative diabetic retinopathy of different stages was carried out. In proliferative diabetic retinopathy, new vessels grow mainly along the posterior (retinal) surface of the posterior hyaloid membrane. Sometimes, if there are defects in the posterior hyaloid membrane, proliferative tissue stratifies it and appears on the anterior (hyaloid) surface. We observed no growth of new vessels outside the posterior hyaloid membrane. The impossibility of clinical and mechanical separation of the posterior hyaloid membrane and tumor tissue permits us to regard the stages of proliferative process in diabetic retinopathy as stages in the alteration of the posterior hyaloid membrane proper. Five variants in the structure of proliferative tissue can be distinguished in diabetic retinopathy; we consider that these variants are stages in its development: 1) glial--with predominance of cell-free or hypocellular glial tissue; 2) glial vascular--with growth of thin-wall vessels into glial tissue; 3) glial vascular fibrous--with growth of porous fibrovascular membrane in glial tissue; 4) fibrovascular--with predominance of fibrovascular tissue; and 5) fibrous (cicatricial) hypocellular compact connective tissue with just few vessels or none at all. Reduction of new vessels, involution of proliferative tissue, and development of traction detachment of the retina are associated with the beginning of fibrous proliferation.

[On the role of the posterior hyaloid membrane in the pathogenesis of and surgery for proliferative diabetic retinopathy]. / O roli zadnegialinovoi membrany v patogeneze i khirurgii proliferativnoi diabeticheskoi retinopatii.

A total of 278 patients subjected to transciliary vitrectomy for proliferative diabetic retinopathy (PDR) were followed up. Thirty preparations of epiretinal membranes removed in surgery were examined under an optic microscope. Vessels newly forming in PDR were found to grow mainly along the external surface of the posterior hyaloid membrane; they ceased their growth after its removal. The posterior hyaloid membrane is the anatomical object of surgical intervention of PDR. The proliferative form of diabetic retinopathy is never seen in the presence of a naturally occurring or vitrectomy-induced complete posterior hyaloid detachment, that is why if the posterior hyaloid membrane is well detached from the retina in the course of operation, panretinal laser coagulation in the postoperative period is not recommended.

[First experience with transvitreal surgery of central chorioretinal dystrophy complicated by exudative detachment of the sensory retina and pigment epithelium]. / Pervyi opyt transvitreal'noi khirurgii tsentral'noi khorioretinal'noi distrofii, oslozhnennoi ékssudativnoi otsloiko sensornoi setchatki i pigmentnogo épiteliia.

Transvitreal removal of viscous exudate from under the detached sites of the pigmented epithelium and sensor retina results in a gradual stable adjoining of these sites, associated with improvement of the visual function, this improvement depending on the period of the existence of a central retinal detachment. Intra- and subretinal solid exudates resolve within several months postoperation.