[Aberrometry results of a new IOL model with variable refractive surface].

The article presents the aberrometry results of a new intraocular lens (IOL) model with variable refractive surface of own design. By changing the pressure of silicone oil inside the artificial lens three levels of refractive power were achieved: 17.5D; 20.0D; 22.0D. The quality of the experimental optical system is comparable to that of a human eye after in vivo implantation of a ReSTOR multifocal IOL. Accommodating IOLs with refractive power varying within 4.5D are capable of maintaining the quality of retinal image, thus, ensuring high visual acuity.

[Aberrometry of a new artificial implanted lenses model with changeable refractive surface].

There was made an aberrometry of new IOL with changeable refractive surface. Different power of silicon oil inside the lens become changes in it refractive power. So, in this way we made three types of IOL refractive power: 17,5 D; 20 D; 22 D. The quality of experimental optical system may be comparative with optical system that made by ReSTOR IOL implantation in human eye. HOA and LOA, that generated by the new IOL, had no or small influence to the quality of optical system.

Capsule fixation device for cataract surgery.

PURPOSE: The authors present a patient with Marfan syndrome who underwent cataract surgery using a novel device for fixation of capsular bag. METHODS: The capsule fixation device (CFD) is poly(methyl methacrylate) arch with double-armed bent hook that can be introduced into the anterior chamber through the clear corneal incision, placed with a rest on the capsule equator, and sutured to the sclera without injury of the capsular bag. A 16-year-old patient with Marfan syndrome underwent consecutive phacoemulsification with in-the-bag intraocular lens and CFD implantation on both eyes. RESULTS: During the surgery handling the CFD was technically simple with good visualization. The preoperative best-corrected visual acuity was 0.3 and 0.1 and postoperatively 0.6 and 0.8 in the right and left eyes, respectively. The postoperative follow-up was over 9 months. CONCLUSIONS: Use of the CFD was successful in a case of lens subluxation with no complications observed during the period of follow-up.

Depth of focus: clinical manifestation.

PURPOSE: To assess depth of focus on the basis of measurements of the point spread function, which involve Stiles and Crawford phenomenon. SETTING: Department of Ophthalmology of National Academy of Postgraduate Education. METHODS: Gullstrand's schematic eye parameters and data of subjective measurement of size of diffusion circles were used for calculation of depth of focus. Data of 1171 eyes with visual acuity 1.0-2.0 were included in the study. RESULTS: Under condition of visual acuity 1.5 data of the depth of focus were 0.38 D, 0.64 D, and 1.92 D for pupil diameter 5.0 mm, 3.0 mm, and 1.0 mm, respectively. Visual acuity 1.0 is characterized by larger value and visual acuity 2.0 by lesser value of the depth of focus. CONCLUSIONS: Depth of focus and normal levels of visual acuity have a close relation: the higher the visual acuity, the smaller the depth of focus.

[Focusing strength and a subjective method for determining refraction].

Three hundred and seventy-four eyes were examined by a subjective method, by using trial lenses in natural accommodation. This yielded the following distribution of clinical refraction: hypermetropia (43.6%), emmetropia (30.8%), myopia (12.8%), and astigmatism (12.8%). The classical subjective method of refractometry is based on the schematic eye having no focusing strength. The currently available data by a number of authors show that the focusing strength of more than 0.5 diopters is typical of the human eye, which affects the results of refractometry. When the collecting glass +0.25 D or +0.5 D is applied, the eye with a visual acuity of 1.0 or more retains the level of vision due to the holding the focusing strength across the retina rather than the accommodation strength. By taking in account the correction, the distribution in the study group was as follows: emmetropia (73.0%), myopia (12.8%), astigmatism (12.8%), and hypermetropia (1.4%).

Accommodative function of eyes in persons exposed to ionizing radiation.

Results of a comparative study of accommodative capability of eyes in individuals exposed to various doses of ionizing radiation and in a control group are presented. The mean values for ranges of accommodation in the control group were consonant with previous data. However, the range of accommodation was found to be reduced in exposed patients from younger age groups. It has been established that the ranges of accommodation depended, besides the age, on the absorbed dose of ionizing radiation: the greater the dose absorbed, the lesser the range of accommodation in the same age group. The effect of ionizing radiation seems to be additive to that of age.

[Micro-trephination of the limbus in neovascular glaucoma]. / Mikrotrepanatsiia limba pri neovaskuliarnoi glaukome.

Microtrephination of the limb was carried out for neovascular glaucoma on 112 eyes. The technique of the operation is described and its results are analyzed. Electric microtrephine (0.6 mm) allows making perforations in the limb as oblique microchannels connecting the anterior chamber and the subconjunctival space. Mitomycin C, an antimetabolic drug, was used for neovascularization control near the channels and filtration pad. High efficiency, low invasiveness, and low incidence of postoperative complications recommend this operation as an alternative method for the treatment of neovascular glaucoma.

[Effects of monochromatic light on ocular hydrodynamics]. / Vliianie monokhromaticheskogo sveta na gidrodinamiku glaza.

Effects of green and red optic filters on ocular hydrodynamics was studied. The results indicate that monochromatic green light causes a decrease of the true intraocular pressure, improves intraocular fluid discharge, and decreases Becker's coefficient. Green filters (ZSP) can be used as an additional method for conservative treatment of glaucoma patients.

Forceps for capsulorhexis.

Conventional continuous curvilinear capsulorhexis (CCC) by forceps is connected with use of viscoelastics. A new model of forceps allows CCC without a viscoelastic and has the advantage of a bent-needle cystotome because the terminal part of the instrument is the size of a bent needle. The instrument retains the forceps' ability to grasp tissue firmly and prevents anterior chamber collapse during CCC. I performed the CCC using the new forceps without a viscoelastic in 198 eyes.

[Comparative characterization of the results of new and standard methods of keratotomy]. / Sravnitelnaia kharakteristika rezyltatov novoi i standartnoi metodikkeratotomii.

The authors compare the efficacies of the traditional "Russian" radial keratotomy and the new method of making radial keratotomic incisions with evenly deep profiles. Keratotomy was carried out in 60 patients (120 eyes) with similar binocular myopia. On one eye the traditional "Russian" method was used, on the other the new method. The new method enables the physician to make a radial incision with one movement of a knife with programmed increase of the depth from the center to periphery. The number of incisions was the same on both eyes. In remote periods after surgery (4.5 years, on average) corneal refraction on the eyes operated on using the traditional "Russian" method reduced from 43.2 to 39.5 D and eye refraction from -4.36 to -0.4 D. Corneal refraction on the eyes operated on using the new method reduced from 43.2 to 39.3 and eye refraction from -4.36 to -0.32 D. The new method of keratotomy is not inferior to the traditional method but is more rapid and convenient.

[Asymmetric radial keratotomy for low-grade myopia]. / Kératotomie radiaire asymétrique pour la myopie faible.

Thirty patients (47 eyes) underwent a radial keratotomy for low myopia (from -0.75 to -2.5 D). Surgical technique was as follows: optical zone between 3.0 and 4.5 mm according to the degree of the myopia; two radial incisions in vertical superior and nasal horizontal meridian. The incisions were full thickness, obtained either with the "Russian" (centripetal) technique or with a centrifugal technique, but using a special designed knife. Mean refractive result was 1.73 D. For low myopia, our technique seems less traumatic and the refractive effect more rapidly steady.

New technique for knife and radial keratotomy.

BACKGROUND: Radial keratotomy is the most popular method of surgical correction of myopia, but requires further improvements. This study presents a new knife design for radial keratotomy. METHODS: Radial keratotomy was performed on 120 eyes of 60 patients with myopia. We utilized two diamond knife designs. The new knife allows a surgeon to perform corneal incisions of varying programmed depth with one movement of the hand, deeper at the limbus. As a control, we used the standard Fyodorov knife. One eye was operated on with one type of knife, the other eye with the other type. The number of incisions was the same with both techniques. RESULTS: After a 2-year follow up of the group of eyes operated on with the new knife, the mean keratometric power changed from 43.20 diopters (D) to 39.30 D, and the mean amount of myopia from -4.37 to -0.32 D. In the group of eyes operated on with the standard knife, the mean keratometric power changed from 43.20 to 39.50 D, and the mean amount of myopia from -4.36 to -0.40 D. CONCLUSIONS: The final refractive effect of the new knife was equal to that of standard knives. However, the new knife was more convenient: duration of surgery was shorter, and there was no need to change the length of the blade to deepen the incisions during surgery.

[Prevention of postoperative inverse astigmatism during radial keratotomy]. / Prophylaxie de l'astigmatisme postopératoire inverse pendant la kératotomie radiaire.

Seventy eight patients (156 eyes) were treated by radial keratotomy. Patients with spherical axial myopia were selected (including 39% of physiological astigmatism cases). After radial conventional technique the against-the-rule astigmatism > 1.0 D is 31.6% and between 1.0 and 2.0 D is 3.4% versus 0.6% (< 1.0 D) and 0.1% (1.0-2.0 D) with the modified technique. To decrease the frequency of the against-the-rule postoperative astigmatism after RK procedure we performed 1 or 2 vertical additional flag-incisions on the horizontal meridian to counteract the effect of the corneal oedema on the superior incisions.

[Management of corneal microperforations during radial keratotomy]. / Conduite à tenir devant des microperforations cornéennes au cours de la kératotomie radiaire.

Corneal microperforations induce a corneal astigmatism since refractive effect is increased on the perforated meridian. To counteract this induced refractive error, we performed "flag" or tangenital incisions on the perpendicular meridian.

[Radial asymmetric keratotomy in mild-degree myopia]. / Radial'naia asimmetrichnaia keratotomiia pri miopii slaboi stepeni.

The suggested method for surgical correction of weak myopia involves two mutually perpendicular incision on the cornea in the major meridians. These two incisions result in but a slight alteration of the tissues, and a stable refraction effect of about 1.5 diopters is achieved at once; vision acuity improves to make 0.9-1.0.

[A phototopographic method of measuring the thickness of the cornea]. / Fototopograficheskii sposob izmereniia tolshchiny rogovitsy.

This method is based on asymmetric growth and distension of the cornea in various directions. One has just to ascertain the visual line projection site on the corneal surface and to measure the corneal thickness in but two points, in the centre and lower, near the limbus; then the thickness of the cornea at any site of the cornea may be calculated, for the cornea is the thinnest at sites where the limbus is the furthest from the centre. The accuracy of this method is not inferior to that of the known optic method.

[Crystalline lens alloplasty in childhood]. / Alloplastika khrustalika v detskom vozraste.

Alloplasty of the lens by means of the N. M. Sergienko's anteroposterior model of intraocular lens was made in 20 children, aged from 5 to 15 years, with traumatic or congenital cataracts. In 16 patients visual acuity after surgery was 0.3-1.0. In children, the postoperative period has some peculiarities, one of them being a longer course of postoperative uveitis with almost a 100% exudative reaction of different degrees. The N. M. Sergienko's anteroposterior model of intraocular lens can be effectively used for intraocular correction in children with traumatic and congenital cataracts, providing reliable fixation and producing no undesirable and specific complications for the construction.

[A method of surgical treatment of progressive and complicated myopia]. / Sposob khirurgicheskogo lecheniia progressiruiushchei, vysokoi i oslozhnennoi blizorukosti.

The paper describes a modification of scleroplastic operation combining a vertical bandage with simultaneous covering of posteroexterior segment of the eye ball and creation of a "depo-tissue". As a grafting material, preserved human dura mater was used. By the proposed method, 97 operations were made in 67 patients with myopia from 6.0 to 32.0 D. In 30 patients, the surgical results were observed within 3 years. In all of the patients operated on, the stabilization of the process was recorded. The proposed modification is technically simple and accessible to a wide circle of ophthalmologists.

[Arc-wedge keratoplasty as a method for correcting astigmatism]. / Dugovaia klinokeratoplastika kak metod korrektsii astigmatizma.

In view of low effectiveness of optic correction of astigmatism a problem of its surgical correction becomes urging. A new operation for correction of astigmatism--arc wedge-keratoplasty, worked out by the authors, was made in 19 eyes with mixed and complex myopic astigmatism. Before operation the degree of astigmatism was, on the average, 6.8 +/- 2.11D (4.5-14.0), after operation--2.2 +/- 0.18D (0.18-5.5). The refractive effect made up, on the average, 4.6D (from 2.0 to 12.5). A change of a refractive power of the cornea was seen in both main meridians. The follow-up period ranged from 6 months to 4 years. The operation is highly effective and less traumatic than the known ones because only two notches are made and the central free zone not less than of 5 mm is preserved. A conclusion is made that operation of arc wedge-keratoplasty is advisable for correction of mixed astigmatism.