Biomedical subjects
Publications and source records attributed to M Lazar.
A case of proliferative vitreoretinopathy that spontaneously regressed, leading to reattachment of the retina, is presented. The importance of such a spontaneous resolution in terms of understanding the pathogenesis, and planning a treatment, is discussed.
A 64-year-old patient with open-angle glaucoma was treated with timolol following two unsuccessful filtering procedures. While on timolol therapy, she developed three episodes of choroidal detachment, hypotony and shallow anterior chamber. These findings resolved upon cessation of timolol and reappeared on 3 occasions shortly after reinstitution of the beta blocker therapy.
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Oculab Tono-Pen tonometry was compared with Goldmann applanation tonometry in 82 eyes of 82 patients with normal corneas and in 54 eyes of 54 patients who had undergone penetrating keratoplasty and whose corneas did not preclude the use of Goldmann tonometer. We found that the intraocular pressure (IOP) in 48% of the eyes with normal corneas and in 57% after keratoplasty has different measurements with Goldmann and Tono-Pen pressures of 3 mm Hg or more. Despite the correlation between the Goldmann tonometer and the Tono-Pen in the group of eyes with normal corneas (r = 0.83) as well as in the group of eyes after keratoplasty (r = 0.79) the Tono-Pen tended to significantly overestimate the Goldmann tonometer reading (p < 0.0001). The mean difference between the two instruments was highest across the lower IOP range (< 9 mm Hg) in the group of eyes after keratoplasty. Because the mean absolute values of the paired differences between Goldmann and Tono-Pen measurements varied significantly across all IOP intervals it was not possible to establish a correction factor which could be used when comparing the two measurements. Based on this study the Tono-Pen consistently overestimated the actual IOP in an unpredictable manner. Where possible Goldmann measurements of the IOP are still to be preferred.
Retinoblastoma is the most common intraocular malignancy of childhood. Trilateral retinoblastoma is a syndrome characterized by bilateral ocular retinoblastoma in conjunction with an intracranial neuroblastic neoplasm in the pineal body, or in supraseller or parasellar location. We report the case of a three year old girl with trilateral retinoblastoma and review the literature on this subject.
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The Viviparous-1 (Vp1) gene of maize is specifically required for expression of the maturation program in seed development. We show that Vp1 encodes a 73,335 dalton protein with no detectable homology to known proteins. An acidic transcriptional activation sequence was identified by fusion to the GAL4 DNA-binding domain. Expression of VP1 in maize protoplasts resulted in strong activation (greater than 130-fold) of a reporter gene fused to the promoter of a presumptive target gene. The acidic domain in VP1 was essential for transactivation and could be functionally replaced by the activator sequence of the herpes simplex virus VP16 protein. Our results indicate that VP1 is a novel transcription factor possibly involved in potentiation of a seed-specific hormone response.
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We prospectively studied all deaths in this hospital from July 1, 1989 through December 31, 1989 for possible eye donations. During this period 539 patients died, of whom, 219 were suitable candidates for donation, and 61 donations were obtained (11.3%). In the course of the study the procurement rate increased progressively as a result of a higher level of effort and awareness by the medical staff.
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A case of intraocular lens implantation in a patient with Behçet's uveitis is presented. During a 12-month follow-up the uveitis did not flare up and no other complication developed.
A prospective study of 83 eyes in 76 consecutive patients undergoing keratoplasty for keratoconus is presented in which 1% atropine was routinely given at the end of surgery. No case of permanent mydriasis was seen. The syndrome described in the literature of fixed, dilated pupil after the use of atropine in keratoplasty no longer seems to exist and the warning against strong mydriatics appears unwarranted.
Detachment of the host's Descemet membrane inadvertently occurred while removing the decompensated graft in a patient undergoing rekeratoplasty. The membrane was purposefully left intact and the new graft sutured on top of it. In this way, opening of the anterior chamber was avoided and the operation completed as an 'extraocular' procedure. The graft and the membrane have remained clear during 3 years of follow-up.
We studied the ability of topical clonidine, an alpha-agonist, to suppress the acute rise in intraocular pressure (IOP) following neodymium-YAG posterior capsulotomy (YPC). In a randomized controlled trial 63 eyes were pretreated with one drop of either 0.25% clonidine or saline 1 h before performing YPC and immediately following the procedure. The greatest IOP rise in the saline treated eyes occurred in the second hour after YPC, when the mean (+/- SD) IOP rose from a baseline pressure of 12.7 +/- 3.2 to 18.7 +/- 10.7 mmHg. In clonidine treated eyes, the IOP fell from a mean of 11.9 +/- 3.4 to 9 +/- 3.3 mmHg 2 h postoperatively. In the saline treated group 9 eyes (27%) developed an IOP rise greater than 10 mmHg. Clonidine proved to be highly effective in preventing the rise in IOP following YPC.
A pseudophakic pilot of the Israeli air force flying an F-15 (Eagle) aircraft was followed up for three years. He experienced about 100 flying hours, 5% of the time under high g stress. The intraocular lens did not dislocate and no complications were observed. It seems that flying high performance fighter aircraft is not contraindicated in pseudophakic pilots.
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Periocular injections of corticosteroids play an important role in the management of various ophthalmologic diseases. The Depo-Medrol vehicle, injected into the vitreous, was shown to be toxic to the lens and to the retina when applied at double strength. The authors examined the effects of Depo-Medrol and one of the components of its vehicle, myristyl-gamma-picolinium chloride (MGP), on the functional integrity of the rabbit visual system. Visual function was assessed objectively from the electroretinogram (ERG) and the visual evoked potential (VEP). The experimental drugs were injected into the vitreous humor of one eye while saline was injected into the fellow eye for control. Depo-Medrol did not produce any measurable effects on the ERG or the VEP. When MGP solutions were injected in concentrations at least twice as large as that in the Depo-Medrol, significant reductions in the light- and dark-adapted ERG responses were seen. The effects of the drug on the ERG responses was seen as early as 3 days postinjection and developed to its maximal level within 1-2 weeks. No ERG recovery was seen over a period of more than 2 months. The VEP, elicited by applying light stimuli to the experimental eye, was characterized by low amplitude and delayed implicit time compared with the response obtained from the control eye.
We prospectively studied all the deaths that occurred in Sourasky Medical Center (Ichilov Hospital), Tel Aviv, from 1 July through 30 September 1989 for possible eye donation. Of the 135 suitable candidates 29 donations were obtained (21.5%). In the course of the study the procurement rate progressively increased as a result of a higher level of effort and awareness by the hospital medical staff.