Biomedical subjects

A A Zubcov

Publications and source records attributed to A A Zubcov.

13 recordsLinked to original sources

PubMed1999

[Retroequatorial myopexy combined with bimedial recession for near-distance disparity esotropia].

PURPOSE: In cases of esotropia combined with a high AC/A ratio, partly accommodative convergence excess or with nonaccommodative convergence excess, two methods of surgical therapy are possible: recession of the medial recti (Parks) and retroequatorial myopexy (Cüppers). Our aim was to answer the question whether retroequatorial myopexy alone and in combination with bimedial recession are appropriate methods of reducing the strabismic angle at near and distant fixation to values under 10 PD and near-distance disparity to less than 10 PD to form the basis for single binocular vision without bifocals. PATIENTS AND METHODS: Eighty-three patients, aged 2-14 years (39 boys and 44 girls), were included in the study: 37 children (group A) with early-onset near-distance esotropia of 14-48 PD for distance and 26-65 PD for near objects and 46 children (group B) with acquired near-distance esotropia of 8-45 PD for distance and 26-70 PD for near objects. Inclusion criteria were a near-distanced disparity of at least 10 PD (range 10-33 PD), a follow-up of at least 3 months (median 5 months, range 3-69 months), retinoscopy in cycloplegia and full refractive correction. The amount of conventional surgery was chiefly based on the distance angle of esotropia. The myopexy was placed 12, 13 and 14 mm behind the insertion of the medial rectus. RESULTS: In 73 of 83 patients (88%) we were able to reduce the strabismic angle for distance and near fixation to less than 10 PD and in 73 cases even under 5 PD. In 77 of 83 patients (93%) the near-distance disparity was reduced to less than 10 PD and in 72 patients (87%) even under 5 PD. Postoperatively, 9 children had bifocals, but 3 of them have meanwhile discarded them. Two cases were slightly ocvercorrected and 1 case undercorrected. Seventy children (84%) attained grade of binocularity. CONCLUSION: Retroequatorial myopexy (fadenoperation) alone and combined with bimedial recession is an effective procedure in treating esotropia with abnormal near-distance disparity.

Adolescent↗

PubMed1999

Intraocular recombinant tissue-plasminogen activator fibrinolysis of fibrin formation after cataract surgery in children.

PURPOSE: To evaluate the efficacy and safety of intracameral recombinant tissue plasminogen activator (rt-PA) application for fibrinolysis of fibrin formation after cataract surgery in children. SETTING: Johann Wolfgang Goethe-University, Department of Ophthalmology, Frankfurt am Main, Germany. METHODS: This study comprised 11 eyes of 10 patients aged 3 to 13 years (mean 7.2 +/- 3.68 [SD]) who developed severe fibrin formation after cataract surgery and IOL implantation despite intensive topical steroid therapy. Under general anesthesia, fibrinolysis was performed with 10 micrograms of rt-PA 7.18 +/- 2.04 days after intraocular surgery. Follow-up included slitlamp examination, tonometry, visual acuity testing, and-ophthalmoscopy. Anterior chamber flare measurements could be performed in 6 eyes. RESULTS: Complete resolution of fibrin formations occurred in 90% of the patients in these cases, no recurrent fibrinous reaction or adverse effects were noted. In 2 eyes of the same patient with a history of juvenile rheumatoid arthritis and chronic uveitis, fibrin clot dissolution was incomplete. A recurrent fibrinous formation could be observed after 2 and 4 weeks, respectively. A beginning band keratopathy excluding the central and limbal cornea was noted after 6 and 8 weeks, respectively. CONCLUSION: Intraocular application of rt-PA appears to be a safe and efficacious therapeutic approach in the management of severe fibrinous reactions after pediatric cataract surgery.

Adolescent↗

PubMed1999

Stereopsis after primary in-the-bag posterior chamber implantation in children.

PURPOSE: The purpose of this study was to evaluate visual acuity and binocular function after primary posterior chamber intraocular lens (IOL) implantation in children. PATIENTS AND METHODS: A retrospective chart review of 39 eyes of 31 children was performed. Fifteen eyes with traumatic, 17 with developmental, and 7 with congenital cataracts without any other ophthalmologic problems were examined before and after cataract surgery (irrigation/aspiration procedure with implantation of a posterior chamber IOL). Twelve eyes also received a posterior capsulorrhexis and anterior vitrectomy. The mean age at surgery was 6.9 +/- 3 years (range, 3-12 years). RESULTS: Twenty (51%) of 39 eyes achieved a best-corrected postoperative visual acuity of 20/40 or better (range, 20/200-20/20). The mean postoperative visual acuity was 20/40 in the traumatic and developmental cataract groups and 20/100 in the congenital cataract group. There was a positive correlation between cataract morphology and visual acuity (P<.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (P <.005). Nineteen (70%) of 27 eyes in which no primary posterior capsulorrhexis had been performed had posterior capsule opacification. Stereopsis was found in 10 of the 31 patients: 43% of the traumatic cataract group, 30% of the developmental cataract group, and 14% of the congenital cataract group. CONCLUSIONS: After capsular bag-fixated IOL, visual acuity and binocular function in children older than 3 years were favorable and the complication rate, excluding posterior capsule opacification, was low.

Capsulorhexis↗

PubMed1998

[Capsular sack-fixed IOL implantation in pediatric cataract. Visual prognosis and complications].

BACKGROUND: The aim of the study was to evaluate results of visual acuity and binocularity and complications after cataract surgery with primary capsular bag-fixated IOL implantation in children. MATERIALS AND METHODS: Thirty-three children [mean age (+/- SEM) 6.9 +/- 2.9 years, range 3-12 years] accounting for 43 eyes, were examined before and after surgery (15 traumatic, 19 developmental, and 9 congenital cataracts, of the latter two groups 9 unilateral and 19 bilateral cataracts). RESULTS: All eyes had a best corrected postoperative visual acuity of 0.5 +/- 0.05. The postoperative visual acuity of the traumatic cataracts was 0.6 +/- 0.07, of the developmental cataracts 0.5 +/- 0.07, and of the congenital cataracts 0.2 +/- 0.05. Of the 43 eyes, 17 (40%) showed a best corrected visual acuity of 0.5 or better. There was a positive correlation between morphology (lamellar versus subcapsular opacification) and visual acuity (0.7 +/- 0.07 versus 0.5 +/- 0.05; P < 0.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (0.7 +/- 0.07 versus 0.2 +/- 0.05 P< 0.001) Stereopis was found postoperatively in 62% of the children. In one eye a capsular bag-fixated IOL implantation was not possible, and so the IOL was inserted in the sulcus. Four children presented with postoperative fibrin formation. Posterior capsule opacification occurred in 19% of the eyes in which a primary posterior capsulotomy had been performed. CONCLUSIONS: The prognosis of visual acuity and the results of stereopsis in children older than 3 years following capsular bag-fixated IOL implantation are very good. Both the intraoperative and postoperative complication rates were low.

Cataract↗

PubMed1997

Comparison of phacoemulsification and planned extracapsular extraction.

76% of cataract surgeons in German speaking countries use phacoemulsification (phaco) as the procedure of choice for cataract extraction while the other 24% still use the planned extracapsular extraction (ECCE). The opening technique of the anterior capsule is chosen accordingly: for phaco capsulorhexis is preferred, while for ECCE can opener or letter box technique is usually done. The length of the sclerocorneal incision is 3.2 mm in phaco, 6.2 mm for a PMMA posterior chamber lens implantation and 9-13 mm for the ECCE. We prospectively compared both procedures with each group including 100 consecutive patients. The mean irrigation volume was 96.6 +/- 48.8 ml in the phaco group as opposed to 48.1 +/- 26 ml in the ECCE group. The mean duration of irrigation was 130 +/- 67 s in the first versus 129 +/- 76 s in the second group; mean endothelial cell loss was 7.9 versus 7.1%. No correlation was found between endothelial cell loss and duration of irrigation. Mean postoperative astigmatism measured 1.0 +/- 0.49 in the first group as compared to 3.3 +/- 1.7 dpt in the second group. Except for the astigmatism, our study could not detect significant differences regarding the outcome between both procedures. There are advantages to the phacoemulsification procedure, however, such as a smaller incision (e.g. tunnel technique), a closed irrigation-aspiration system, controlled intraocular pressure and the more frequent use of capsulorhexis. Preferred indications are zonulolysis or previously performed fistulating surgery.

Astigmatism↗

PubMed1996

[Refractive errors and strabismus in premature infants].

AIM: We aimed to investigate the incidence of refractive errors and strabismus in premature infants relative to their individual birth weight. METHODS: We investigated 107 premature infants with birth weight < 1250 g (group A, n = 54) and > 1250 g (group B, n = 53). All children were evaluated at the ages of 6 and 24 months for their spherical equivalent and the presence of high myopia (< or = 6.0 D) and strabismus. RESULTS: At 6 months the spherical equivalent was -0.93 +/- 4.2 D in group A and 1.09 +/- 1.9 D in group B, at 24 months -0.75 +/- 5.0 D vs 1.44 +/- 1.9 D (P < 0.01). At 6 months the incidence of high myopia was 10% in group A and 0% in group B, at 2 years 12% vs 2% (P < 0.01). Low birth weight and a long period of artificial ventilation correlated with the development of high myopia. At 6 months 21% of group A and 8.5% of group B showed strabismus, at 2 years 25% vs. 8.5% (P < 0.01). CONCLUSION: Because of the increased incidence of high myopia and strabismus we recommend routine retinoscopy and orthoptic evaluation at the age of 6 months in every child weighing less than 1250 g at birth.

Birth Weight↗

PubMed1996

[Amblyopia, refractive errors and strabismus in congenital ptosis].

The incidence of amblyopia in the normal population is 2-6%, whereas among patients with congenital ptosis it can be as high as 50%. We reviewed 146 cases of congenital ptosis in patients aged between 5 months and 15 years and compared them to a control group of 34 age- and sex-matched patients. In 78 children (156 eyes) reliable optotype visual acuity could be obtained. Fifty-three eyes (34%) were amblyopic. Ametropia was responsible for 34% and anisometropia for 28.3% of the amblyopia cases. In 25.4% of cases strabismus, and in 11.34% stimulus deprivation, was the reason for the development of amblyopia. Children with congenital ptosis should have retinoscopy done in cycloplegia, and refractive errors should be corrected early. Controlled patching therapy should also be started early. Since stimulus deprivation amblyopia is rare, congenital ptosis need not be corrected early in life.

Amblyopia↗

PubMed1993

Improvement of visual acuity after surgery for nystagmus.

PURPOSE: The authors compared the preoperative and postoperative binocular visual acuities and eye movement recordings of patients who underwent eye muscle surgery consisting of the Anderson-Kestenbaum procedure or the artificial divergence procedure modeled after Cüppers, or a combination of both procedures, for the treatment of infantile nystagmus with head turn. METHODS: Binocular visual acuities and eye movement recordings by electro-oculography (EOG) were compared preoperatively with those done within 3 weeks postoperatively. Shifting and broadening of the minimal intensity zone and foveation time and changing of the waveform were measured. The treatment of 6 of 18 patients was based on the artificial divergence principle; for 7 patients, treatment was in accordance with the Anderson-Kestenbaum principle; and 5 patients had combined procedures. RESULTS: The improvement in binocular visual acuities was two Snellen lines or more in one of six patients in the artificial divergence group and four of five patients in the combined treatment group. The EOG recordings showed shifting of the minimal intensity zone toward the primary position in all three groups. A broadening of the minimal intensity zone occurred mostly in the artificial divergence and combined groups. Increases in foveation time and changes in waveforms from jerk to jerk with foveation were found in three of six patients in the artificial divergence group and in two of five patients in the combined group. CONCLUSION: With less muscle surgery, the artificial divergence and combined operations gave better vision improvement than the Anderson-Kestenbaum operation.

Adolescent↗

PubMed1992

Head nodding is compensatory in spasmus nutans.

BACKGROUND: Spasmus nutans is defined as asymmetric nystagmus with associated head nodding in childhood. It is not clear whether head nodding is a compensatory mechanism to control the nystagmus or an involuntary movement of pathologic origin. METHODS: The authors analyzed the relation between head and eye movements by simultaneous eye and head movement recordings of 35 patients with spasmus nutans. RESULTS: In 21 of these patients, the fine, fast, dissociated nystagmus changed during head nodding to larger and slower symmetric eye movements with both eyes oscillating at the same amplitude in phase and 180 degrees out of phase to the head movements, corresponding to a normal compensatory vestibulo-ocular reflex. CONCLUSION: These findings indicate that head nodding is compensatory in spasmus nutans.

Child, Preschool↗

PubMed1991

Visual-evoked cortical potentials in dissociated vertical deviation.

It is debatable whether chiasmatic misrouting of temporal optic-nerve fibers (similar to that found in ocular albinism) is also characteristic of dissociated vertical deviation. Pattern appearance, pattern reversal, and diffuse-flash, monocular full-field visual-evoked cortical potentials were recorded from albino and normal human subjects and subjects with dissociated vertical deviation. Pattern appearance was the most reliable stimulus for evaluating lateralization (albino-type misrouting) in adult albino patients, and diffuse-flash stimulation was almost as reliable in children. Pattern reversal was found to be an unreliable indicator. Lateralization was not evident among patients with dissociated vertical deviation, as determined by the three modes of stimulation. Our data supported earlier findings that pattern appearance is the most appropriate technique to detect lateralization. Our findings differed from those of previous reports in demonstrating that reliability of the lateralization phenomenon increases with age up to approximately 15 years. Pattern reversal stimulation was not reliable in patients with horizontal nystagmus.

Adolescent↗

PubMed1990

Treatment of manifest latent nystagmus.

Eight patients with manifest latent nystagmus, as noted by ocular movement recordings, were examined for nystagmus reduction after surgical or optical treatment. Seven of the patients had strabismus. Five patients underwent strabismus surgery, had no tropia postoperatively, and the manifest latent nystagmus converted to latent nystagmus. Four of these five patients subsequently showed improvement in binocular visual acuity. Three patients received optical treatment; one had accommodative esotropia and, with appropriate spectacle correction, the manifest latent nystagmus was converted to latent nystagmus with improved vision. In the other two patients the manifest latent nystagmus lessened after correction with appropriate spectacles; binocular visual acuity of one of these patients improved. The possibility of converting manifest latent nystagmus to latent nystagmus by strabismus surgery is a reasonable surgical goal. In patients with manifest latent nystagmus and strabismus, surgical or optical alignment of the eyes decreases the nystagmus intensity and may also improve binocular visual acuity.

Adolescent↗

PubMedDate not supplied

Visual acuity measurements by swept spatial frequency visual-evoked-cortical potentials (VECPs): clinical application in children with various visual disorders.

Previous studies have indicated that visual acuities of normal infants can be estimated with good accuracy using swept spatial frequency visual-evoked-potentials (VECPs). In this report we describe acuity measurements obtained with this technique from 304 examinations performed on 135 children having various visual disorders. When possible, two or more different stimulation frequencies (8, 12, 15 or 24 contrast reversals/sec) were used in each patient, and three to eight sweep VECPs were obtained from each patient under each simulation and recording condition. High correlation coefficients (0.94 - 0.96) between the acuity estimated on each patient from either the single sweep giving the best visual acuity (BSS) or from vector averages (VeA) of the EEG data obtained from several sweeps confirmed previous findings in normal infants. We also found high correlation coefficients among BSS recorded at different temporal frequencies (0.79-0.97) and among comparisons of BSS or VeA acuity to optotype visual acuity (0.6-0.89). Children with clinically undetectable optokinetic responses showed lower visual acuity estimated by BSS than those who demonstrated optokinetic nystagmus. We conclude that the sweep VECP is a valid method, giving estimates of acuity which correlate well with optotype acuity and correspond well to other clinical findings, and that it can be useful in the clinical management of nonverbal patients.

Child↗

PubMedDate not supplied

Asymmetric horizontal tropias, DVD, and manifest latent nystagmus: an explanation of dissociated horizontal deviation.

Four patients with dissociated horizontal deviation (DHD) are described and an explanation of their horizontal comitant deviations is offered. The patients had asymmetric comitant horizontal deviations dependent on the fixing eye. All of them had unequal visual acuity (VA) and asymmetric manifest latent nystagmus (MLN) documented with eye movement recordings. The subjects appear to use convergence to reduce their nystagmus when viewing with the eye having more severe nystagmus and hence poorer vision. When patients viewed with the eye having less nystagmus, little or no convergence was exhibited. We suggest that DHD may be the manifestation of an asymmetric nystagmus blockage syndrome (NBS). The dampening effect of convergence on nystagmus has been well documented in the past and seems to apply here. The patients demonstrate that a true, but asymmetric NBS, can be found with MLN.

Child↗