Biomedical subjects

Yair Morad

Publications and source records attributed to Yair Morad.

26 records · Page 2Linked to original sources

PubMed2003

Nonophthalmologist accuracy in diagnosing retinal hemorrhages in the shaken baby syndrome.

Nonophthalmologists did not attempt to (36%) or were "unable to" (19%) examine the fundus in 72 children with shaken baby syndrome. When the retina was examined, nonophthalmologists were accurate in recognizing the absence or presence of retinal hemorrhage in 87%. However, false-negative examinations occurred in 13%. Ophthalmology consultation should be an integral part of the evaluation of children with suspected abuse.

Child, Preschool↗

PubMed2003

Injury induced by chemical warfare agents: characterization and treatment of ocular tissues exposed to nitrogen mustard.

PURPOSE: Mustard agents are highly toxic and abundant warfare chemicals, primarily affecting ocular tissues, with no specific treatment antidote. The purpose of the present study was to examine the efficacy of novel metallocomplexes, known to inhibit the formation of highly reactive free radicals, to reduce ocular injury induced by nitrogen mustard (NM). METHODS: One eye in each of 72 rabbits was exposed to 1% to 2% NM. Topical treatment with eye drops of a metallocomplex--either zinc- or gallium-desferrioxamine (Zn/DFO and Ga/DFO)--was compared with treatment with saline, zinc (chloride), or DFO alone. Examiners masked to the treatment groups assessed the extent of ocular injury and the response to treatment using clinical, histologic, and biochemical criteria. RESULTS: Exposure to NM followed by administration of carrier alone (saline) caused severe and long-lasting injury to ocular anterior segment structures. Treatment with either Zn/DFO or Ga/DFO yielded marked protection (52%-64%), including faster healing of corneal epithelial erosions, less scarring and neovascularization, decreased inflammation in the anterior chamber, better maintenance of intraocular pressure, and less severe changes in the iris and lens. These were also associated with better preservation of systemic antioxidant status. Zinc or DFO alone afforded lower levels of protection. No toxic effects of these complexes were observed. CONCLUSIONS: It is suggested that Zn/DFO or Ga/DFO, by virtue of their enhanced ability to infiltrate cells and inhibit transition metal-dependent formation of free radicals through the combined push-pull mechanism, be considered as a basis for treatment of mustard injuries.

Administration, Topical↗

PubMed2002

Caruncle abnormalities in the oculo-auriculo-vertebral spectrum.

Goldenhar syndrome (GS) is a congenital disorder believed to be caused by the defective development of the first and second brachial arches and the first brachial clefts during the fourth through eighth weeks of embryologic development. It is characterized by epibulbar dermoids and/or lipodermoids, preauricular tags, pretragal fistulas, hemifacial microsomia, and vertebral anomalies. Other ocular and nonocular symptoms have also been described. To our knowledge there are only three previous reports of abnormal caruncles in GS. We have reviewed our experience with a consecutive series of seven GS patients with caruncular malformations. Caruncular abnormalities included dysplatic and/or bilobed caruncles (two cases), ectopic caruncles (three bilateral cases and one unilateral case), and ectopic plus dysplastic caruncles (one case). Our experience suggests that the incidence of caruncular malformations in GS anomalies is higher than previously reported. This may be clinically important in differentiating GS from other first- and second-arch syndromes. Additionally, linking abnormalities in the first and second months of gestation that cause the typical stigmata of GS with malformation of the caruncles, which normally develop in the third month of gestation, could provide clues to the pathogenesis of GS.

Abnormalities, Multiple↗

PubMed2002

Endoscopic photocoagulation of the ciliary body after repeated failure of trans-scleral diode-laser cyclophotocoagulation.

PURPOSE: To report the successful control of intraocular pressure with endoscopic cyclophotocoagulation after repeated failure of trans-scleral diode-laser cyclophotocoagulation. DESIGN: Interventional case report. METHODS: A 3 1/2-year-old child had intraocular pressure around 30 mm Hg in one eye despite full medical treatment and three procedures of trans-scleral diode laser photocoagulation. RESULTS: Endoscopic view of the ciliary body revealed many misplaced laser burns in the pars plana region. Using direct endoscopic visualization of the ciliary body, precise, confluent burns were applied to the ciliary body. Six months after the procedure, intraocular pressure has remained under 20 mm Hg. CONCLUSION: Endoscopic cyclophotocoagulation can effectively lower intraocular pressure after recurrent external diode-laser photocoagulation has failed to do so. The direct visualization during the endoscopic procedure is particularly advantageous in cases with atypical ciliary body morphology, such as in pediatric glaucoma.

Child, Preschool↗

PubMed2002

Correlation between retinal abnormalities and intracranial abnormalities in the shaken baby syndrome.

PURPOSE: To report correlation between retinal and intracranial abnormalities and to evaluate pathogenesis of retinal hemorrhages in the shaken baby syndrome (SBS). DESIGN: Observational case series. METHODS: Seventy-five children with apparent nonaccidental head trauma consistent with SBS had complete physical examination, complete ophthalmologic examination, neuroimaging by CT or MRI, or both, and skeletal radiographic survey. In this retrospective review, ophthalmoscopic and intracranial abnormalities were correlated. RESULTS: The age of patients ranged from 2 to 48 months (mean - SD, 10.6 +/- 10.4 months). Neuroimaging was abnormal in all 75 cases. Findings included subdural hematoma (70 children, 93%), cerebral edema (33 children, 44%), subarachnoid hemorrhage (12 children, 16%), vascular infarction (nine children, 12%), intraparenchymal blood (six children, 8%), parenchymal contusion (six children, 8%), and epidural hemorrhage (one child, 1%). Sixty-four (64/75, 85%) children had retinal abnormalities, mostly (53/64, 82%) confluent multiple hemorrhages that were subretinal, intraretinal, and preretinal in 47/64 (74%) and bilateral in 52/64 (81%). No association was found between anatomic site (left, right, or bilateral) of intracranial and retinal findings (McNemar test kappa = -0.026-0.106) or between any of the intracranial findings mentioned above and the following retinal findings: normal or abnormal retinal examination, multiple (>10) or few retinal hemorrhages (< or =10), symmetric or asymmetric retinal findings, or retinoschisis (kappa = -0.127-0.104). Signs of possible increased intracranial pressure were not correlated with any retinal abnormality (kappa = -0.03-0.073). There was no correlation between evidence of impact trauma to the head and retinal hemorrhages (kappa = 0.058). Total Cranial Trauma Score and Total Retinal Hemorrhage Score, both indicating the severity of injury, were correlated (P =.032). CONCLUSIONS: Our study supports previous observations that the severity of retinal and intracranial injury is correlated in SBS. We cannot support the suggestions that in most children with SBS retinal bleeding is caused by sustained elevated intracranial, elevated intrathoracic pressure, direct tracking of blood from the intracranial space, or direct impact trauma. The correlation in severity of both eye and head findings may suggest, however, that retinal abnormalities are the result of mechanical shaking forces.

Battered Child Syndrome↗

PubMed2002

Angiogenesis in pterygium: morphometric and immunohistochemical study.

OBJECTIVE: To evaluate the role of angiogenesis in the pathogenesis of pterygium by comparing the expression of von-Willebrand factor (vWF) and vascular endothelial growth factor (VEGF) in pterygium, and in normal superior bulbar conjunctiva. METHODS: 23 human samples from pterygium and the superior bulbar conjunctiva were stained using rabbit anti-vWF and anti-VEGF antibodies. The density of vWF and VEGF positive vessels, VEGF staining intensity and the number of VEGF positive stromal, epithelial and vascular endothelial cells were evaluated. RESULTS: Pterygium specimens had higher average vWF and VEGF positive microvascular counts per high power field (P = 0.0012), higher average VEGF staining intensity scores in epithelial, stromal and endothelial cells (p < 0.0001) and higher VEGF positive cell counts (P < 0.0001) than normal conjuctiva. CONCLUSIONS: Over-expression of VEGF in pterygium tissue, together with the abundance of vWF-stained new vessels, may support previous suggestions that angiogenesis may play a role in the formation of pterygium.

Adult↗

PubMed2002

Correlation between reading skills and different measurements of convergence amplitude.

PURPOSE: To find correlations between convergence amplitude and reading ability, as assessed in various methods. METHODS: Convergence of 66 children aged 8-10 years was evaluated using 1) Non-accommodative target at near and distance; 2) A near computerized stereogram; and 3) Measurement of near point of convergence (NPC). Reading ability was examined by: 1) a reading comprehension test and 2) the Developmental Eye Movement Test (DEM), which evaluates saccadic speed and accuracy. RESULTS: Convergence amplitudes on a distant target and on a near stereogram were correlated with the DEM score (P = 0.005/0.02, r = -0.38/-0.32 and P < 0.001/0.002, r = -0.53/-0.53 for break/recovery respectively), while NPC and convergence on a near non-accommodative target did not. Reading comprehension test score was not correlated with any of the convergence measurements. CONCLUSIONS: Convergence amplitude measured while accommodation is controlled was correlated with the DEM score, which evaluates saccadic speed and accuracy. Further study to evaluate whether improvement in vergence control improves DEM scores is needed.

Accommodation, Ocular↗

PubMedDate not supplied

Does photorefractive keratectomy alter the effect of topical medications?

INTRODUCTION: The influence of photorefractive keratectomy (PRK) on drug penetration into the eye is not yet established, as this procedure may alter the barrier function of the cornea as well as the blood ocular barrier. Pupillary response to topical tropicamide depends on its penetration into the anterior chamber. The purpose of this study was to examine the influence of PRK on pupillary response to topical tropicamide, and hence to evaluate whether PRK alters drug penetration into the eye. METHODS: Pupillary diameter was measured using infrared pupillometer at 0, 15 and 30 min after instillation of 0.1% tropicamide to both eyes of 28 patients 4 weeks after PRK in one eye. The untreated eye served as control. RESULTS: Pupillary diameter before and 30 min after dilation was 7.4 +/- 1.2 and 8.0 +/- 1.0 mm in the treated eyes and 7.5 +/- 1.2 and 8.1 +/- 1.0 mm in the untreated eyes, respectively (p = 0.45). Percentage of pupillary dilation (delta pupillary diameter/pupillary diameter at 0 min x 100) was also similar in treated and untreated eyes for the entire study group (12.5 and 10.5%, respectively, p = 0.17). A trend for greater dilation was seen in patients with myopia above 6 diopters (13.7 and 10.5% in treated and untreated eyes, respectively, p = 0.11) and cornea thinner than 540 microm (14.2 and 10.1% in treated and untreated eyes, respectively, p = 0.1). DISCUSSION: Our results confirm animal and human studies that found restoration of the ocular drug barrier at 4 weeks following PRK. The trend for greater penetration in patients with high myopia and thin corneas warrants further study on a larger cohort of this subgroup.

Administration, Topical↗