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The authors made a mathematical and clinical analysis of the cribriform lamina (CL) of the optic nerve and nerve fiber bundles passing through its foramens in glaucoma-induced optic neuropathy. It was shown that in elevated intraocular pressure, there was a significant CL deformity leading to the compression and deformity of nerve fibers. The important biomechanical characteristic of CL deformity is the tangent of the angle between the longitudinal axis of the scleral canal and the perpendicular to the CL surface. An increase in the inner radius of the scleral canal of the optic nerve due to its dissection at decompression surgery is one of the ways of diminishing CL flexure and nerve fiber deformity. A small increase in the scleral canal radius (by approximately 10%) was demonstrated to eliminate significant CL flexure.

The ocular drainage system in normal intraocular-pressure glaucoma was studied by fluorescence lymphoangioscopy of the anterior ocular segment on 24 eyes and by histomorphological analysis of the drainage zone on 12 eyes. The study revealed the increased volumetric lymph flow in the drainage zone, which suggests the higher tissue drainage that correlates with intraocular pressure and agrees with the histomorphological findings. Patients with normotensive glaucoma were found to have ischemic and destructive changes in the drainage zone and vascular system of the anterior ocular segment. The histomorphological and lymphoangioscopic findings suggest the destruction of the drainage system, the retention of intraocular fluid, and the possible periodic unrecorded ophthalmic tone increase in normotensive glaucoma.

A procedure is proposed to contrast a clear solution of the cytostatic agent 5-fluorouracil during subconjunctival administration early after surgery for glaucoma in order to prevent hyperscarring. For this, after dissolution of 5-fluorouracil with 0.1% dexamethasone solution, 0.05 ml of 0.08% trypan blue solution was added to an injection syringe until the mixture produced a uniform light blue color. 0.1-0.2 ml of the mixture was subconjunctivally injected. The proposed procedure makes it possible to visualize the site of injection with a high degree of reliability: the penetration of the agent into the given area, the area of its spread, and the volume of the agent's administration, to view external filtration and possible intrachamber flux, and to provide information on the topography of formed outflow tracts.

The authors made a morphological study of the early proposed and clinically tested revascular optic nerve decompression operation developed to improve blood supply to the initial portion of the optic nerve in glaucoma-induced optic neuropathy. An experiment was carried out on 11 rabbits. The operated and control eyes were enucleated 1, 4, and 6 months after surgery. The experiment has established that muscle autografting into the retroscleral and paraneural space of the optic nerve is followed by a number of cellular reactions with the active participation of satellite cells, some of which may be associated with regenerative processes and presumably regarded as one of the cell autotherapy modalities.

Intraocular fluid contrasting is achieved via subconjunctival injection of 0.1 ml of 1% sodium fluorescein solution then diffusing along the outflow tract through the anterior chamber. Then the area concerned of the drainage tracts is photographed by means of a slit lamp completed with a digital camera operating in the infrared photographing mode and with a system of special filters, which makes it possible to enhance the sensitivity of the system to the spectrum of fluorescein irradiation. A series of the images made before and at a certain temporal interval after administration of the contrast substance is analyzed by using the original computer program "Digital Differential Fluorescein Study of the Ocular Drainage Tract". The result of the analysis is the possibility of functional characterization of the intraocular fluid outflow tract in the area under study. The procedure yields a picture of the relative hydrodynamic activity of drainage collectors located in any perisuperficial structures of the eye.

The causes of ineffectiveness of primary non-penetrating profound sclerectomy were analyzed on the basis of filtration-zone biopsy materials obtained in repeatedly made antiglaucomatous procedures. The authors believe that the above ineffectiveness is preconditioned by inconsistency of the drainage-zone internal wall resulting from its dystrophic changes due to tissue ischemia, cell apoptosis, collagen changes with fiber's degradation and fibers' colliquative necrosis. It was demonstrated experimentally that the monofilament suture, when applied to the filtration zone, enhances the hypotensive effect of the non-penetrating procedure due to the ability of filtration canals (shaping around sutures) to dose the outflow of lachrymal fluid through the anterior chamber into the subscleral and subconjunctival spaces as well as by activation of the uveoscleral outflow paths.

Possibilities, conditions and outlooks of using a 5% fluorouracil solution, as subconjunctival injections after antiglaucomatous interventions and as intraoperative applications in the trabecular area, were studied in 131 patients (143 eyes) with uncompensated developed and advanced glaucoma. The results of clinical examinations showed a high efficiency of using fluorouracil after antiglaucomatous interventions to ensure a long-lasting hypotensive effect. Two injections made in the early postoperative period did not entail any complications and were sufficient to maintain the surgical effect.

On the basis of ocular perfusion pressure a new method was suggested for determining an individually endurable intraocular pressure (IOP), i.e. pressure of target. A total of 390 eyes (232 patients with primary open-angle and normal-tension glaucoma) were examined before and after conservative and surgical treatment. The pressure of target was found, in a progressing worsening of visual functions, to be significantly lower versus the stabilized glaucoma, which was due to a low ocular perfusion pressure. The maximally tolerable IOP in a progressing glaucomatous optic neuropathy concomitant with a normalized IOP amounts to 13-15 mm Hg; while, in the stabilized glaucoma it can exceed the mean statistic norm. The pressure of target was shown to be a non-permanent value, which changes depending on the dynamics of the ophthalmic perfusion pressure and IOP. The sensitivity of the suggested method is 77.4%. It can be used in prognosticating the glaucomatous-process clinical course and in choosing an optimal tactics for the treatment of open-angle and normal-tension glaucoma.

A total of 45 patients (45 eyes) were operated on by using the technique of non-perforating deep sclerotomy (NDST). A conclusion on the action mechanism, efficiency and indications for NDST was made on the basis of determining the retention degree and of the intraoperative monitoring of tonometry and tonography parameters. Perforations of various scopes were proven to have an impact on the surgical hypotensive effect; finally, intraoperative measures were suggested in case of NDST inefficiency.

The visual functions and hemodynamics of the optic-nerve and retina were examined before and after decompression surgeries in the optic nerve. The methods of ophthalmodynamometry and ultrasound dopplerography were used to study the optic-nerve hemodynamics. The results showed an essential improvement in the visual field and blood circulation of the optic nerve in 80.7% of operated patients. The obtained data are indicative of that a disturbed blood circulation in the optic-nerve initial portion plays an important role in the development and progressing of glaucomatous optic neuropathy. Decompression surgeries in the optic nerve in cases of a progressing worsening of the visual functions are pathogenetically substantiated for glaucomatous patients.

A new operation on the optic nerve scleral canal, revascularization compression of the optic nerve, was carried out in 21 patients (21 eyes) in order to improve the visual functions and stabilize the glaucomatous process. The operation combines the advantages of decompression of the optic nerve by dissection of the posterior scleral ring with creation of an additional source of blood supply to the optic nerve from the myovascular bundle of the internal rectal muscle. Good functional effect and notable improvement of hemoperfusion of the optic nerve and retina were attained (period of observation up to 2 years). The degree of visual field extension correlated with the degree of increase in hemoperfusion values. Comparative analysis showed a higher functional efficiency of revascularization decompression of the optic nerve in comparison with optic nerve decompression, which is due to a more essential improvement of ocular hemoperfusion.

Retrospective analysis of the efficiency of optic nerve decompression in progressive glaucomatous optic neuropathy in patients with normalized intraocular pressure showed widening and/or stabilization of the visual field in remote periods (6-11 years) in 83.3% patients. Study of the hemodynamics after optic nerve decompression showed a significant improvement of the hemodynamic parameters in the orbital artery-central retinal artery system: increased bloodflow velocity in the central retinal artery, increase of ophthalmic blood pressure and perfusion pressure, dilatation of the arteries, and constriction of veins, which indicates improvement of hemoperfusion in the initial portion of the optic nerve and retina after decompression surgery on the optic nerve. Extension and stabilization of visual field correlated with positive changes in circulation.

Comparative evaluation of the significance of hemodynamic factors of risk of progress of glaucomatous optic neuropathy has been carried out: blood flow velocity, blood flow resistance, blood pressure in the orbital artery-central retinal artery system, perfusion ocular pressure in connection with stabilization of glaucomatous process, and intraocular pressure were analyzed for a period of up to 16 years. The most significant factors were blood pressure in the orbital artery-central retinal artery system and perfusion ocular pressure, but not blood flow velocity. The leading factor indicating the risk of progress of optic neuropathy in primary glaucoma is ocular perfusion pressure. Measurements of opthalmodynamometric pressure can be used for evaluation of perfusion pressure and recommended for wide clinical application for predicting the course of primary glaucoma.

The efficacy of surgical treatment of low (normal)-pressure glaucoma is validated on the basis of analysis of the disease progress risk factors. The risk factors are inadequate intraocular pressure (IOP) and insufficient blood supply to the optic nerve and retina. For stabilizing the glaucomatous process, IOP is to be reduced below 14 mm Hg. After antiglaucoma surgery, IOP decreases by 35% on average (to 13.9 mm Hg), and visual field is retained in remote period in 81.2% patients. Antiglaucoma operation with simultaneous decompression of the optic nerve results in a greater increase of visual field due to improvement of blood supply to the optic nerve and retina; visual functions are stabilized for a long time in 77.8% cases at a higher IOP (16.14 mm Hg) in patients with worse initial status. Functional results of surgery for normotensive glaucoma depend on ophthalmic tone and optic nerve and retinal hemodynamics.

The authors analyze the causes of the progress of glaucomatous atrophy of the optic nerve in normal ophthalmic tone. Ninety-four patients (105 eyes) with different stages of glaucoma were examined; intraocular pressure in them was normalized by drug therapy or surgery. In additional to functional studies, hemodynamics was assessed in all the patients by fluorescent angiography of the optic disk, vacuum ophthalmodynamometry, and ultrasonic dopplerography of the carotid artery, orbital artery, and central retinal artery. Perfusion pressure in the orbital and central retinal arteries depends on the total-systems arterial pressure, and disorders of systemic circulation are hypothesized as one cause of decreased perfusion of the optic nerve and retina. Therapy for glaucomatous atrophy of the optic nerve and retina should include, along with normalization of intraocular pressure, measures aimed at maintaining a high level of perfusion pressure and volumic bloodflow.

Thirty-three conjunctival and iridial biopsy specimens obtained during surgery from 23 patients with glaucomas and 10 with cataracts were examined by functional morphologic and morphometric methods. Fluorescent angiography of the anterior segment of the eye was carried out in 15 patients. Conjunctival and iridial biopsy specimens were embedded in epon, ultrathin sections stained with 1% toluidine blue and polychromic stains. Counts of obliterated, studged, dilated, and normal blood vessels and mast cells per mm2 were estimated. The degree of fibrosis was taken into account as well. The number of pathologically changed vessels in glaucoma patients was 1.5 times higher than in those with cataracts. The counts of sludged and obliterated vessels in the conjunctiva and iris were in strict positive correlation. Early degree of intercellular matrix fibrosis was observed in all glaucoma patients and was 2.3 +/- 0.2, whereas in cataract patients this value was 1.3 +/- 0.3. Two forms of fibrosis were distinguished: with active fibroblast proliferation and sclerosis with depositions of coarse fibrous tissue. Mast cell index in glaucoma patients surpassed twofold that in controls. The microcirculatory bed status and intercellular matrix fibrosis in glaucoma may be due to increased count of mast cells and their precursors basophils which may be the modulators of the above processes.

Anti-cicatricial cytostatic therapy with 5-fluorouracil and prospidin was carried out after antiglaucoma surgery in 78 eyes of 67 patients aged 6 to 42 (2/3 of the patients were aged from 21 to 40). Half (34) of the patients suffered from open-angle (pigmented in 3 cases) and 6 from closed-angle glaucoma, the rest patients presented with common hydrophthalmia, the Frank-Kamenetsky, Sturdge-Weber, Riger's syndromes, etc. The cytostatics were injected subconjunctivally. The results of 67 surgeries were followed up for 6 months to 3 years. Stable normalization of the ophthalmic tone and stabilization of the process were achieved in 60 eyes (89.2%). The authors emphasize that cytostatics may be recommended for children and young subjects after surgery involving fistulization, on condition of thorough biomicroscopic monitoring in the postoperative period, because of a possible disadaptation of the edges of the mucosal incision and corneal diseases.

Clinical trials of the hypotensive effect of 0.5% betoptic, an antiglaucoma drug manufactured by Alcon (USA), were carried out at three ophthalmologic hospitals. Similar results obtained in all the trials permit a conclusion on a high hypotensive efficacy of this drug in patients with primary open-angle glaucoma. The drug was well tolerated by the patients.

The technique of decompression surgery on the optic nerve in vascular atrophy has been developed. Optic disk staining grew more intensive, visual field widened, and vision acuity improved after such surgery. Results of fluorescent angiography of the fundus oculi and ultrasonic dopplerography evidence an essential improvement of the blood stream in the central retinal artery after the operation. The positive effect of surgery persisted over the entire follow-up period (8 months). The authors consider that enlargement of the inner diameter of the posterior scleral ring permits a more loose disposition of the vessels and fibers of the optic nerve in this ring, this being conducive to better circulation in the optic disk and retina.

The mechanism of action of helium-neon laser stimulation has been studied in 26 eyes of 15 patients with dystrophic diseases of the eye and on the ground of 63 lymphangiographic investigations of the same patients. It was found that low-energy helium-neon laser stimulation (0.05-0.5 mWt/cm2) has a positive effect on restoration of visual functions. Lymphangiographic investigations have revealed a new biological phenomenon--activation of disturbed lymphatic flow under the action of a specially organized laser radiation. The results obtained confirm the earlier hypothesis (M. M. Krasnov et al., 1982) that under the action of laser radiation a normal physiologic system purifying the retina from disintegrated products is engaged into action.

The authors give theoretical grounds and experimental validation for surgery on the optic nerve to eliminate its atrophic changes in glaucoma. They suggest a technique of the direct intervention at the site of the optic disk, approaching it from the side of the eye cavity. A method for the optic nerve decompression at the site of its stem portion via an extraocular approach is suggested. Experimental studies have demonstrated the possibility of enlarging the volume of the optic nerve scleral canal by discission of its narrowest section, the scleral ring; this operation essentially decreases twisting and deformation of the nerve fibers and main vessels of the retina. Clinical results of decompression surgery in 32 patients with far-progressed glaucoma are analyzed. Improvement of the visual function and stabilization of the glaucomatous process were observed in all the patients both in the immediate and late postoperative periods. The retinal and optic nerve blood microcirculation were found to improve after the suggested decompression surgery.

Lymph microcirculation in the bulbar conjunctiva at the site of surgery was studied by fluorescent lymphangiography in 217 patients with primary glaucoma before and in various periods after trabeculectomy. Lymph vessels are changed after the operation; the pattern and intensity of these changes reflect the activity of cicatrization at the site of the operation and are closely related with the hypotensive effect in remote periods postoperation. In cases with the complete compensation of ophthalmic tone without extra hypotensive therapy a moderate narrowing of the lymph vessels was observed, parallelled by a compensatory increase of their quantity and of the volumic rate of the lymph flow. If the hypotensive effect of surgery was insufficient, an essential decrease of all the lymph flow parameters was observed, the most manifest in the patients with intraocular pressure still increased after extra drug therapy. A regular lowering of the lymph flow in 2-4 years after surgery was recorded; this lowering anticipated the deterioration of the hydrodynamic parameters. Noteworthy that ophthalmic tone failed to normalize when the mean diameter of the lymph vessels decreased more than twofold vs. the preoperative value. A conclusion is made that fluorescent lymphangiography holds good promise as a method for the assessment of the intensity of cicatrization processes after antiglaucoma surgery in order to timely prescribe preventive anticicatricial therapy. Administration of cytostatics in the postoperative period helps considerably increase the number of satisfactory outcomes of surgery due to suppression of cicatrization processes at the site of intervention. A lesser rate and intensity of cicatricial deformations of the lymph vessels was recorded in the patients administered cytostatics.