Калужский филиал ФГУ МНТК "Микрохирургия глаза"

Articles and publcations/2005

Fabrikantov O. Power Density of Infrared Divergent Laser Beam in Macular Area // 5th Euretina Congress 2005: Abstract Book. – Barcelona, 2005. – P. 163.

The purpose: to define the divergent beam lowlevel laser power density radiation in macular area of human eye in experiment.
Materials and methods. Experiment was made on six phacic cadaver's eyes. Clinical refraction was 1,92 ± 1,42 D, pupil diameters were 3 – 6 mms. The 2,5 mms hole was formed through sclera, horioidea and retina in macular area. The special calibrated photodiode was inserted in that hole. Laser irradiation was realized through the cornea and pupil to the posterior pole (wavelength - 890 nm, pulse power – 5,6 Wt, pulse duration – 70 ns, beam divergention – 25-30 degrees, frequency of pulses - 10000 Hz).
Results: Pulsed power density in macula was 2,1-2,7 mWt/mm2 at 3 mms pupil diameter and increased to 4,0-4,7 mWt/mm2 at 6 mms pupil diameter (irradiating distances – 5 mms). No energy was registered in macula, when laser was situated at the distance more than 200 mms from the cornea. When laser was removing from a cornea, power density of laser radiation in macula fell on the exponential law.
Conclusion: The power density levels of infrared lowlevel divergent laser beam can be dangerous for macular area in short distances.

Belyy Yu.A., Tereshchenko A.V., Yudina N.N. Intravitreal sodium hypochlorite electrolyzed solution during vitrectomy in the treatment of experimental exogenous bacterial endophthalmitis // 5th Euretina Congress 2005: Abstract Book. – Barcelona, 2005. – P. 162.

Purpose: to prove an intravitreal application of sodium hypochlorite electrolyzed solution during vitrectomy in the treatment of experimental exogenous bacterial endophthalmitis.
Materials and methods: 12 Chinchilla rabbits aging 6 months and weighting 2,5-3,5 kg were used. Rabbit eyes were rendered aphakic. 4 weeks postoperatively St.aureus (1.0*105 colony forming units/0.1 ml) were injected into the vitreous cavity of the both eyes. The given culture was resistant to gentamicin. 12 hours after bacterial injection a surgical treatment was performed.
Rabbits were divided into 2 groups: group 1 (12 eyes) – vitrectomy with sodium hypochlorite electrolyzed solution (SHES), 70 mg/l, as irrigational solution (the given concentration possesses the expressed antibacterial activity and is harmless for intraocular structures) plus intravitreal gentamicin, 0,2 mg; group 2 (12 didymous eyes) – vitrectomy with saline solution (0.9%) as irrigational solution plus intravitreal gentamicin, 0,2 mg. 14, 30 day after treatment animals underwent biomicroscopy and indirect ophthalmoscopy. Then the eyes were enucleated for histopathological examination.
Results: Biomicroscopic, ophthalmoscopic and histopathological scores of inflammatory process of the group 1 were significantly lower than group 2 (р <0,01).
Conclusions: SHES is the donator of an active oxygen. SHES destructs the protein- lipide layer of the microorganism biological membrane, changes membrane permeability, causing death or reduction of the antibiotic resistance of the microorganism. That mechanism allows to increase the efficacy of the antibiotic the given culture was resistant to.
Intravitreal sodium hypochlorite electrolyzed solution during vitrectomy plus intravitreal antibiotic is the most effective strategy in the surgical treatment of experimental exogenous bacterial endophthalmitis.

Yu.A. Belyy, A.V. Tereshchenko, P.L. Volodin, S.N. Popov, D.O. Shkvorchenko, S.V. Novikov Combined Surgical Method (CSM) for Central Retinal Vein Occlusion (CRVO)

Purpose: to develop CSM for the treatment of CRVO, based on vitrectomy, neurotomy and polymer elastic magnetic device (PEMD) implantation onto optic nerve.
Technique: after three-port vitrectomy, posterior hyaloid membrane removal, dosed neurotomy on the nasal side of the optic disk with the use of special intravitreal blade with limiter, the tunnel into the direction to the optic nerve was created in the inferior-internal quadrant, and PEMD was implanted into the tunnel. Ring-shaped PEMD enveloped optic nerve, short ciliar arteries, and part of retrobulbar fat.
Discussion: CSM was performed on 9 patients with severe CRVO. Duration of symptoms was 1 to 3 months. There was also a control group where there were 7 patients without PEMD. Improvement of homodynamic, acceleration of retinal edema resorption and preservation of central vision in patients with PEMD were significantly better than in the control group due to the combination of decompression and revascularization effects, and local action of the magnetic field.

Yu.A. Belyy, A.V. Tereshchenko, P.L. Volodin, M.A. Plahotniy, D.O. Shkvorchenko, S.V. Novikov Combined Surgical Treatment for Diabetic Macular Edema (DME)

Purpose: to develop combined surgical method (CSM) with exstrascleral implantation of polymer elastic magnetic implants (PEMI) for the treatment of DME.

Technique: after three-port vitrectomy, posterior hyaloid membrane removal, and barrier endolasercoagulation of central retinal edema zone, the tunnel was created in the upper-external quadrant, and implant with magnet on its distal end was implanted extrasclerally into the tunnel to macular edema projection zone. Implant was removed in 3 to 4 weeks. During edema resorption additional transpupillary lasercoagulation was performed.

Discussion: CSM was performed on 22 patients with DME (diffuse and cystoid). There was also a control group where there were 12 patients without PEMI. Acceleration of edema resorption and preservation of visial functions in patients with PEMI were highly significantly better than in the control group due to the smoothing of vitreomacular tractions, and local anti-edema, anti-inflammatory and magnetic orientation actions of implanted magnets.

Tereshchenko A, Belyy Y, Trifanenkova I. Use of the retinal pediatric system RetCam-120. The first experience in Russian Federation // XXXI Meeting of the Eurorean paediatric ophtalmological society EPOS. – Warsaw, Poland, 2005. – P. 25-26.

Purpose: to evaluate the capability of retinal pediatric system RetCam-120 in diagnosis and dynamic screening of retinopathy of prematurity (ROP) early stages.
Materials and methods: since 2003 in Kaluga region of Russian Federation on the basis of Kaluga Branch of S.N. Fyodorov Eye Microsurgery Complex was organized the ophthalmologic service for premature children. Detailed diagnostic examination with use of RetCam-120 was performed in 850 premature children at high risk for ROP. In case of ROP, series of RetCam examinations was carried out (from 4 to 20 photos depending on ROP stage). Examination results were recorded with account of recommendation of International ROP committee and International ROP classification.
In case of threshold stage, diode transconjunctival or argon laser transpupillary photocoagulation of the avascular retina was performed according to accepted recommendation with subsequent assessment of treatment effectiveness.
Results: ROP was detected in 180 (21,2%) premature children at high risk for ROP. Stage 1 was revealed in 99 (55,4%) children, stage 2 – in 52 (29%) children, stage 3 – in 27 (15%) children, stage 4 – in 1 (0,6%) child.
Argon laser photocoagulation was performed in 22 (12,2%) children (39 eyes), from theirs diode transconjunctival – in 20 eyes, argon transpupillary – in 19 eyes. No eyes demonstrated progressing of ROP. It was confirmed by long-lasting RetCam screening.
Conclusion: RetCam-120 digital images allow objective and analyzed data, whereas ophthalmoscopy is subjective and depend on doctor qualification.
Analysis of RetCam images allowed to evaluate objectively the length and the localization of the ROP, to determine exactly the moment of the disease transfer to threshold stage, and to estimate treatment effectiveness.

For more detailed information contact us, please E-mail:post@eye-kaluga.com