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Biomedical subjects

Hanna J Garzozi

Publications and source records attributed to Hanna J Garzozi.

14 recordsLinked to original sources

Relationship of cerebral blood flow and central visual function in primary open-angle glaucoma.

PURPOSE: To investigate the relations between middle cerebral artery (MCA) blood flow velocities and central visual function measured by foveal cone electroretinograms (ERG) and visual field. METHODS: Fifteen primary open-angle glaucoma patients were recruited. The eye with the more severe visual field defect (full threshold 24-2) and/or optic disc damage was chosen. Measurements included brachial arterial pressure, heart rate, visual acuity (logMAR), contrast sensitivity (CSV-1000), central visual field (Humphrey SITA 10-2), foveal cone ERG, and transcranial Doppler. Pearson correlation coefficients were estimated to assess the strength of the linear relationship between the MCA flow velocity and the other measured parameters. RESULTS: Visual field was successfully completed in 12 eyes. We were unable to obtain ERG responses and MCA velocity readings for 1 patient. A significant correlation was observed between MCA mean flow velocity and focal cone ERG amplitude [r=0.69, n=13, confidence interval (CI) 0.22, 0.90, P=0.009], but correlation between mean foveal cone ERG implicit time and middle cerebral was not statistically significant (r=0.011, n=13, CI 0.47, 0.63). A significant correlation was also observed between MCA mean flow velocity and mean sensitivity (r=0.76, n=12, CI 0.32, 0.93, P=0.005), and mean defect (r=0.73, n=12, CI 0.28, 0.92, P=0.007) of the central visual field, logMAR visual acuity (r=0.57, n=14, CI 0.05, 0.84, P=0.036), and contrast sensitivity (r=0.61, n=13, CI 0.09, 0.87, P=0.027). CONCLUSIONS: Our findings suggest that in certain primary open-angle glaucoma patients diminished central visual function may be one manifestation of widespread cerebrovascular insufficiency.

Blood Flow Velocity↗

The effects of droperidol in perforating keratoplasty.

PURPOSE: To evaluate the intraoperative and postoperative effects of droperidol administered with general anesthesia during perforating keratoplasty. METHODS: A prospective, randomized, double-masked clinical trial. Twenty-seven patients undergoing penetrating keratoplasty under general anesthesia were included. Patients were assigned randomly to two groups. Fifteen subjects received droperidol during induction of general anesthesia. Twelve control patients received general anesthesia without droperidol. RESULTS: Droperidol significantly reduced fellow eye intraocular pressure (p < 0.0001). Intraoperative anterior chamber depth was significantly deeper with droperidol (p = 0.0002). Iris bulging was observed in 25% of the control group and 0% with droperidol. There was significantly less postoperative nausea in the droperidol group (p = 0.038). There was less postoperative vomiting in the droperidol group, although the difference was not significant (p = 0.07). Postoperative wound gaping was observed in 2 patients; both of them did not receive droperidol. CONCLUSIONS: Droperidol effectively reduces intraoperative and postoperative complications in keratoplasty surgery.

Adjuvants, Anesthesia↗

Keratitis after implantation of intrastromal corneal ring segments.

A 53-year-old man had implantation of 2 intrastromal corneal ring segments (Intacs, Addition Technology Inc.) in the left eye. Several days after the lower segment was exchanged, an infiltrate was present at the corneal incision site. This progressed to a lower channel infection followed by diffuse keratitis. Culture from the conjunctiva was positive for Staphylococcus epidermidis, but cultures from the cornea were negative for microorganisms. Later, 2 gas bubbles appeared at the interface. The patient was treated with topical and subconjunctival antibiotics and channel irrigation. The keratitis resolved, leaving a neovascularized opacity at the nasal part of the lower channel.

Anti-Bacterial Agents↗

Intacs after laser in situ keratomileusis and photorefractive keratectomy.

PURPOSE: To evaluate the efficacy of intrastromal corneal ring segments (Intacs, Addition Technology) for the correction of residual myopia after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS: In this prospective noncomparative case series, Intacs were implanted in 5 eyes (4 patients) that developed myopic regression after LASIK or PRK. Intacs were implanted a minimum of 11 months after the laser procedure. The technique was identical to the standard procedure for myopic unoperated eyes. The Intacs thickness was based on the amount of residual myopia. RESULTS: Postoperative results revealed a reduction in the residual myopia and the mean K-reading. No eye lost best corrected Snellen visual acuity. No intraoperative or postoperative complications occurred. CONCLUSIONS: Implantation of Intacs in eyes with myopic regression after LASIK and PRK resulted in a good refractive outcome and an improvement in uncorrected visual acuity.

Adult↗

A nonsense mutation in the glucosaminyl (N-acetyl) transferase 2 gene (GCNT2): association with autosomal recessive congenital cataracts.

PURPOSE: To identify the genetic defect associated with autosomal recessive congenital cataract in four Arab families from Israel. METHODS: Genotyping was performed using microsatellite markers spaced at approximately 10 cM intervals. Two-point lod scores were calculated using MLINK of the LINKAGE program package. Mutation analysis of the glucosaminyl (N-acetyl) transferase 2 gene (GCNT2) gene was performed by direct sequencing of PCR-amplified exons. RESULTS: The cataract locus was mapped to a 13.0-cM interval between D6S470 and D6S289 on Chr. 6p24. A maximum two-point lod score of 8.75 at theta = 0.019 was obtained with marker D6S470. Sequencing exons of the GCNT2 gene, mutations of which have been associated with cataracts and the i blood group phenotype, revealed in these families a homozygous G-->A substitution in base 58 of exon-2, resulting in the formation of premature stop codons W328X, W326X, and W328X, of the GCNT2A, -B, and -C isoforms, respectively. Subsequent blood typing of affected family members confirmed the possession of the rare adult i blood group phenotype. CONCLUSIONS: A nonsense mutation in the GCNT2 gene isoforms is associated with autosomal recessive congenital cataract in four distantly related Arab families from Israel. These findings provide further insight into the dual role of the I-branching GCNT2 gene in the lens and in reticulocytes.

Arabs↗

Choroidal perfusion perturbations in non-neovascular age related macular degeneration.

AIM: Choroidal perfusion, affected in age related macular degeneration (AMD), is difficult to objectively assess given the overlying retinal circulation. This study more objectively compared choroidal perfusion parameters in a group with non-neovascular AMD to an unaffected age matched control group. METHODS: 21 non-neovascular AMD subjects and 21 age matched control subjects without evidence of AMD underwent assessment of their choroidal blood flow in a case-control study. Scanning laser ophthalmoscope indocyanine green (ICG) angiograms were analysed by a new area dilution analysis technique. Four areas in the perifoveal region and two areas in the temporal peripapillary retina were evaluated by producing a graph of intensity of fluorescence of each area over time. The mean of the filling times and the heterogeneity of the filling times were assessed. RESULTS: The means of the filling times within the perifoveal regions and the hetereogeneity of the filling times between regions within the same eyes were significantly greater in the AMD patients compared with the control subjects. CONCLUSIONS: Delayed and heterogeneous filling of the choroid was objectively demonstrated in eyes with non-neovascular AMD compared with age matched controls without evidence of AMD, using an area dilution analysis technique applied to ICG angiography.

Aged↗

Management of pellucid marginal degeneration with intracorneal ring segments.

PURPOSE: To present intracorneal ring segments for potential management of pellucid marginal degeneration. METHODS: A 41-year-old man with pellucid marginal degeneration with poor visual acuity due to irregular astigmatism was treated with Intacs microthin insert (KeraVision, Fremont, Calif) in the left eye. RESULTS: Uncorrected visual acuity improved from 2/60 to 6/60 following the procedure. The procedure completely eliminated myopia of -8.00 diopters and improved the irregularity of the astigmatism, although it did not change its magnitude. CONCLUSIONS: Insertion of the intracorneal ring segment improves visual acuity in pellucid marginal degeneration by flattening the central corneal protrusion, thus reducing myopia and improving the astigmatism irregularity.

Adult↗

Reactivation of ocular toxoplasmosis after LASIK.

PURPOSE: To report a reactivation of ocular toxoplasmosis after LASIK. METHODS: Case report of a 34-year-old man who underwent bilateral LASIK. The posterior segment examination revealed an old toxoplasmosis scar in the retinal periphery of the right eye. RESULTS: Uncorrected visual acuity improved postoperatively, and the patient was satisfied. However, 52 days after the procedure, he complained of loss of visual acuity in his right eye. Examination revealed signs of anterior uveitis, vitreitis, and active chorioretinal lesion satellite of the old toxoplasmosis scar. The patient was treated with a multidrug regiment with resolution of the vitreous and lesion activity. CONCLUSIONS: Toxoplasmosis reactivation may develop after LASIK.

Adult↗

Comparison of ocular hemodynamics measured by a new retinal blood flowmeter and color Doppler imaging.

BACKGROUND AND OBJECTIVE: To compare measurements of a new retinal blood flow device with central retinal artery blood velocity. MATERIALS AND METHODS: One randomly selected eye from each of 13 subjects was examined. Blood flow was measured by laser blood flowmeter and velocity by color Doppler imaging. The correlation between measurements was analyzed using regression analysis where a P value of less than .05 and coefficient of regression values of greater than .5 were considered significant. RESULTS: The laser blood flowmeter produced vessel diameter measurements of 90.1 +/- 18.7 microm (mean +/- standard deviation), velocity of 19.7 +/- 8.06 mm/sec, and flow measurements of 4.24 +/- 2.41 microL/min. Central retinal artery peak systolic velocity, end diastolic velocity, and mean velocity correlated significantly with laser blood flowmeter velocity (P = .01, r = .66; P < .01, r = .77; and P = .003, r = .76, respectively) and flow (P = .01, r = .71; P = .03, r = .6; and P = .01, r = .69, respectively). CONCLUSIONS: The laser blood flowmeter produces retinal artery flow and velocity measurements that correlate with central retinal artery peak systolic velocity end diastolic velocity, and mean velocity measurements. Further validation of the laser blood flowmeter's accuracy in measuring real flow warranted and likely requires more invasive in vivo studies (in animal models). However, this study supports the ability of the laser blood flowmeter to measure retinal blood flow.

Adult↗