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Biomedical subjects

H Zauberman

Publications and source records attributed to H Zauberman.

At least 19 recordsLinked to original sources
PubMed1998

Limbal cell autograft transplantation for severe ocular surface disorders.

BACKGROUND: Limbal cell transplantation may improve the visual outcome after chemical trauma and ocular surface diseases. METHODS: Nine eyes of nine consecutive patients (eight males and one female, age 9-60 years), underwent limbal autograft transplantation (LAUT). In five cases LAUT was done for severe chemical burns in the acute stage (group 1). In four patients with old chemical trauma LAUT was performed years after the trauma (group 2). Penetrating keratoplasty (PKP) was carried out within 6 months after LAUT in three patients of group 2. Preoperatively, the visual acuity in all the patients except one was counting fingers. Postoperatively, patients were treated with topical antibiotics, topical corticosteroids and oral steroids. Oral cyclosporin was used after penetrating keratoplasty. RESULTS: No complications were observed during the surgical procedure. Postoperatively, the epithelialization was complete between days 7 and 12. The inflammatory response subsided within 3 months and the stromal neovascularization decreased. Visual acuity improved in all the nine cases, ranging from 6/6 to 6/30. The decreased visual acuity was due to corneal haze, scars and vascularization. Following PKP, the three grafts remained clear with intact epithelium. No complications were observed during the follow-up period from 7 to 60 months. CONCLUSIONS: Limbal cell transplantation is an efficacious procedure for rehabilitation of visual acuity after severe chemical trauma.

Acids↗
PubMed1997

Vitreoretinal surgery assisted by the 193-nm excimer laser.

PURPOSE: Ablating and cutting vitreoretinal membranes using a 193-nm excimer laser-based microsurgical system. METHODS: A 193-nm microsurgical system enables delivery of the beam into a fluid medium to cut preretinal and subretinal membranes. Two patients with proliferative diabetic retinopathy and one patient with proliferative vitreoretinopathy were treated with this new device. RESULTS: Gentle ablation and cutting of the preretinal and subretinal membranes without exerting any traction on or apparent damage to the neighboring tissue was achieved. CONCLUSIONS: The technology is applicable to a variety of intraocular vitreoretinal surgical procedures.

Aged↗
PubMed1995

Efficacy of topical gentamicin treatment after 193-nm photorefractive keratectomy in an experimental Pseudomonas keratitis model.

BACKGROUND: The treatment of Pseudomonas keratitis has many limitations, and further investigation to identify more effective approaches is required. We therefore studied the possible contribution of the debridement effect of 193-nm excimer laser on Pseudomonas keratitis in rabbit eyes. METHODS: Pseudomonas keratitis was induced in 30 rabbit eyes by inflicting controlled central corneal scratches and applying a drop of Pseudomonas aeruginosa suspension. After 24 h, one cornea of each animal was photo-ablated (excimer laser: fluency 90 mJ/cm2, 10 Hz, 213 pulses), yielding 50 microns of tissue ablation, while the follow cornea served as control. Five groups of six animals each were formed and received: a subconjunctival injection of gentamicin 20 mg (group 1), topical 14 mg/ml gentamicin hourly (group 2) or every 2.5 h (group 3), or NaCl 0.9% hourly (group 4) for 8 h. In group 5, animals were sacrificed without additional treatment. After 9 h corneas were excised, homogenized, serially diluted, and plated on agar blood plates. The numbers of colony-forming units (CFU) per cornea were statistically evaluated (Mann-Whitney test). RESULTS: In control eyes, a greater decrease of CFU was observed in group 2 than in group 3 (P = 0.03). In laser-ablated eyes, there was no difference in CFU between groups 2 and 3. Comparison of the excimer-treated and control eyes revealed a greater number of bacteria (CFU) in controls only in group 3 (P = 0.02). CONCLUSION: Our study suggests that controlled debridement of cornea with excimer laser may improve the effect of topical antibiotics.

Administration, Topical↗
PubMed1994

Vitreoretinal ablation with the 193-nm excimer laser in fluid media.

PURPOSE: To ablate retina and vitreous membranes using the 193-nm argon fluoride excimer laser in a fluid medium. METHODS: A special delivery system for the 193-nm excimer laser was developed that enabled the delivery of the laser into high-absorption liquid environments. The system was tested on the retina in an in vitro cup preparation of cow's eyes, and also in vivo on retina and vitreous membranes of rabbit eyes. The depth of cut as a function of laser energy was determined for an ablating needle with a 0.25-mm exit diameter. RESULTS: Gentle cutting of retinal tissue and of vitreous membranes was obtained in an energy range of 0.075 to 0.25 mJ/pulse. At the energy level of 0.075 mJ/pulse, four pulses were required for full-depth cut formation in rabbit retina, whereas at energy levels greater than 0.17 mJ/pulse, one pulse was sufficient for full-depth cut formation. The maximal rate of cutting achieved for the bovine retina was 2 mm/sec at a 20-Hz repetition rate of the laser. Ablation occurred only when the tip was held in contact with the tissue. CONCLUSIONS: The technology described herein appears to be advantageous and applicable to a variety of vitreoretinal surgical procedures.

Animals↗
PubMed1993

The effect of the ArF excimer laser on Candida albicans in vitro.

Candida albicans colonies in Sabouraud agar plates were irradiated with the excimer laser as follows: (a) at 10 Hz, power densities of 115-300 mJ/cm2 and 200-3000 pulses, and (b) power density of 115 mJ/cm2 and 200 pulses at 10-50 Hz. Additional colonies were irradiated with a power density of 200 mJ/cm2 at 10 Hz and 500 pulses. Each colony was cultured and the visible colony forming units were counted after 24 h. The cultures remained sterile at: 115 mJ/cm2, 1500 or 3000 pulses; 200 mJ/cm2, 400 or 500 pulses; and 300 mJ/cm2, 300 or 400 pulses. They decreased significantly in other groups. Photoablation with a power density of 115 mJ/cm2 and 200 pulses significantly decreased the number of yeast colonies in the culture plates at 30 Hz (p < 0.029) and 50 Hz (p < 0.02). Photoablation did not affect the counts in colonies located 1 or 2 mm from the treated colonies. Various energies of the excimer laser may significantly reduce or eliminate yeast in vitro.

Candida albicans↗
PubMed1993

Silicone oil tamponade for retinal detachment and delayed treatment of retinal tears.

Four patients underwent a vitrectomy procedure for retinal detachment associated with anterior and posterior proliferative vitreoretinopathy (D-1 type). In each patient, an internal tamponade was achieved with 1000-centistoke silicone oil. Preretinal and/or subretinal hemorrhage that was difficult to remove during surgery, as well as remnants of subretinal fluid, prevented complete intraoperative treatment of the retinal tears or the retinotomy with endolaser photocoagulation. The silicone oil tamponade kept the retina flat until laser treatment was applied to the retinal tears several weeks later, when the retinal blood and subretinal fluid had reabsorbed. When circumstances make achieving intraoperative laser marks difficult, silicone oil tamponade appears to be superior to a long-lasting gas tamponade. It provides a more permanent tamponade than gas and excellent visualization of the fundus several weeks after surgery, at which time laser marks can be completed.

Adult↗
PubMed1992

The effect of indomethacin on prostaglandin E2 in human cornea and conjunctiva.

We studied the inhibitory effect of topical 1% indomethacin aqueous suspension on prostaglandin E2 in 20 conjunctivae extracted during cataract surgery and 16 corneas extracted during penetrating keratoplasty. Thirty minutes before each surgical procedure, indomethacin or placebo (0.9% sodium chloride solution) was instilled into the eye to be operated on in a masked fashion for conjunctiva and selectively for cornea. The excised corneal buttons and conjunctival tissue were homogenized and assayed for prostaglandin E2 concentration using radioimmunoassay. The levels of prostaglandin E2 in the conjunctiva significantly decreased (P less than .0033) after administration of indomethacin (203.7 +/- 219.5 pg/mg) compared with the placebo-treated tissues (849.8 +/- 564.1 pg/mg). The levels of prostaglandin E2 in the corneas significantly decreased (P less than .0157) after administration of indomethacin (522.5 +/- 570.2 pg in the cornea) compared with the placebo-treated tissues (1636.3 +/- 1344.1 pg in the cornea). Indomethacin may serve as a potent anti-inflammatory agent in conjunctival and corneal inflammatory disorders.

Adolescent↗
PubMed1992

Extreme deepening of the anterior chamber during phacoemulsification.

An unusual deepening of the anterior chamber during a phacoemulsification procedure was observed in 3 patients with cataracts: 1 with high myopia, 1 with a lens opacification following a vitrectomy procedure, and 1 with pseudoexfoliation syndrome. This deepening hindered emulsification of the nucleus in the posterior chamber. Early delivery of the nucleus from the capsular bag allowed phacoemulsification to proceed at the pupillary level. The "sinking" of the lens toward the vitreous cavity appears to be related to a lack of vitreous pressure due to liquefaction, or to loosening of the zonular support in the pseudoexfoliation syndrome.

Aged↗
PubMed1992

Microsurgery of the retina with a needle-guided 193-nm excimer laser.

This article presents a method used to guide the beam from an argon fluoride excimer laser to make it suitable for microsurgical purposes and confine it to areas that can be varied in dimension from 1 micron to tens or hundreds of microns. This approach guides the excimer laser beam with an articulated mechanical arm and confines it with variable-diameter tapered tubes, possibly allowing the use of this laser in in vitro retinal surgery with endolaser techniques. Currently, because of the lack of a delivery and focusing system for the 193-nm argon fluoride beam and its absorption by biologic liquids, this laser is used exclusively in ophthalmology for topical applications, such as corneal sculpting. This new method resolves these problems in a unique way with impressive results. Specifically, it was shown that, with this needle-guided excimer laser, it is possible to remove retinal tissue accurately without detectable damage to surrounding cells. Applications of this new technique in retinal surgery are discussed.

Animals↗
PubMed1991

The effect of topical administration of indomethacin on symptoms in corneal scars and edema.

We conducted a masked randomized study of 50 patients to evaluate the effect of administration of topical indomethacin 1% suspension on symptoms in corneal scars, edema, infiltrates, and erosions. Patients with symptoms (photophobia, pain, itching, burning sensation, foreign-body sensation, and tearing) were treated with topically administered indomethacin 1% or placebo and monitored for eight weeks. The severity of the complaints was rated and the scores were evaluated (Wilcoxon rank-sum test). Of the 25 patients treated with indomethacin, 21 (84%) had improvement in symptoms and the severity of each of the symptoms was significantly decreased. Of the 25 patients treated with placebo, one (4%) had improvement in symptoms without statistical change of the severity of the symptoms. However, when the placebo-treated patients received indomethacin drops, the symptoms were significantly decreased (P less than .002). This study suggests that topical administration of indomethacin 1% may reduce ocular symptoms in patients with corneal scars, edema, or erosions.

Administration, Topical↗
PubMed1989

Assessment of intraocular lens power on the basis of precataract refractive measurements.

Assessment of intraocular lens (IOL) power may rely, when biometric measurements of the eye are not available, on refraction previous to cataract development. Such an assessment, however, is generally considered unreliable. To improve the predictability of this method, we correlated refraction measurements with predictions of IOL power. In contrast to previous studies which used retrospective assessment of precataract refraction, this study included only noncataractous eyes and correlated the direct refractive measurements obtained with hypothetical IOL power values. These values were calculated by placing axial length and corneal power measurements of the same eyes in the SRK formula. We conclude that the regression formula obtained may improve the clinical judgment required for predicting lens implant power in cataractous eyes, on the basis of precataract refractive measurements.

Adolescent↗
PubMed1989

[Age-related macular degeneration after retinal detachment surgery].

We studied a group of 157 patients who had retinal detachment surgery in one eye with successful anatomical reattachment and a fellow eye without a retinal detachment. In a group of 7 out of 8 patients who had a retinal detachment that included the macula and who underwent surgery, we found that the development of macular degenerative changes was much less pronounced in the operated eye than in the fellow, control eye. In a group of 3 patients who had retinal detachment without macular involvement, the appearance of macular degenerative changes appeared to be rather symmetric in the operated and in the fellow eye. The presence of a circling buckle did not appear to have an influence on the ARMD changes. It appears that the presence of a macular detachment is a factor in modifying the natural history of age-related macular degeneration. The diminution of signs of ARMD could be related to a degree of atrophy in the retinal pigment epithelium occurring after a retinal detachment with the macula off.

Aged↗
PubMed1988

Correlations between ocular optical components, height and head circumference.

Correlations between the ocular optical components, height and head circumference were investigated in 144 subjects. Refraction had a higher correlation with axial length than with corneal curvature. On the other hand, height and head circumference had a higher correlation with corneal curvature than with axial length. These results express the dependence of refraction on the axial length and suggest a similarity between corneal and skeletal growth, compared with the relatively independent elongation of the eye. Refraction correlated significantly with head circumference but not with height, relations which may be explained by considering some of the optical components that determine refraction, rather than treating refraction as a single factor.

Adolescent↗
PubMed1988

Use of fibrin glue in ocular surgery.

Cryoprecipitate and thrombin were used to prevent bleeding and induce permanent conjunctival attachment in ten cases of retinal detachment, 40 cases of extracapsular cataract extraction, and ten cases of strabismus. This method proved to be a good alternative to suturing the conjunctiva in each of the above-mentioned surgical procedures, and appears to result in a better and more comfortable postoperative course.

Adhesives↗
PubMed1987

Prevention of clot formation in cat retinal vein by systemic and subconjunctival urokinase.

The thrombolytic effect of urokinase was tested on cat retinal vein thrombus induced by argon laser photocoagulation. At various time intervals after thrombosis, intravenous infusion or subconjunctival injections were given. Subconjunctival normal saline injections were used for controls. In vitro subconjunctival urokinase prevented thrombus organization if given within six hours of thrombosis. Subconjunctival injections of urokinase vs normal saline were also studied in vivo in a masked fashion. At intervals of three to 24 hours following thrombosis, 11 cats were treated with subconjunctival urokinase in one eye and normal saline in the 11 fellow eyes. Within ten days after thrombosis, the vein was patent in eight (72%) of the 11 eyes treated with urokinase and in one (9%) of the 11 control eyes.

Animals↗
PubMed1987

Promoting effect of n-decylmethyl sulfoxide on the penetrability of the optic nerve for lidocaine HCl in cats.

We examined the effect of n-decylmethyl sulfoxide (n-decylMSO) on the resistance of the optic nerve sheath to the penetration of lidocaine hydrochloride. Three series of experiments were carried out in living cats, administering lidocaine with and without n-decylMSO. The visual evoked potential (VEP) and optic nerve response (ONR) were measured. The results obtained indicated that n-decylMSO increased the penetration of lidocaine. The presence of lidocaine (1%) and n-decylMSO (2.5%) decreased the ONR amplitude from 120 to 15 microV after a time lag of 105 min, and VEP decreased from 9.0 to 5.5 microV. This effect was preserved during the experiment. Histological examination showed only minimal changes in the optic nerve and the eye globe and its contents. Some infiltration of mononuclear cells was found around the optic nerve sheath.

Anesthetics, Local↗
PubMed1987

The choice of a syringe for manual cortex aspiration.

The friction force of 5-ml, 2-ml, and 1-ml syringes used for manual aspiration of cortex material in extracapsular cataract extraction (ECCE) were compared. It was found that for a 5-ml syringe the force was 500 g, for a 2-ml syringe it was 250 g, and for a 1-ml tuberculin-type syringe it was only 50 g. The ease and duration of cortex aspiration in 30 cases of ECCE were compared using each of the above syringes partially filled with fluid, connected to a 25-gauge Gill's type cannula, and a closed anterior chamber technique. It was found that with the help of a 1-ml tuberculin syringe, cortex material was removed faster and with less finger fatigue than with the 5-ml or 2-ml syringe.

Cataract Extraction↗