Csaba L. Martonyi

Is There a Racial Difference in Physiologic Cup Size

Although many clinicians believe that there is a racial difference in the size of the physiologic cup, this premise has not been studied. To evaluate this, we prospectively examined 100 black and 100 white volunteers. Stereoscopic optic disc photographs taken of each subject were masked to block out the fundus pigmentation, randomized, and then evaluated by an experienced clinician. The average cup/disc ratio in blacks (0.35) was significantly greater (P less than 0.0001) than that in whites (0.24) for both right and left eyes. Forty percent of the optic discs of blacks and 14% of the optic discs of whites had a cup/disc ratio greater than or equal to 0.4.

Penetrating Keratoplasty in the Cat: A Clinically Applicable Model

A series of 28 consecutive penetrating keratoplasties were performed on adult cats. Donor corneas (n = 14) were maintained in culture medium for 14--24 hours prior to transplantation. Rotational autografts (n = 7) were used to control for cell loss caused by culture maintenance as well as for the effects of surgery. Additional homografts (n = 7) were transplanted following removal of the corneal endothelium to study the extent of host corneal endothelial cell regeneration. Pre- and post-operative endothelial cell counts of the homografts made from specular micrographs demonstrated an average cell loss of 30% one month following surgery. A similar 30% average cell loss was present in the rotational autografts. Clinically, both homografts and autografts remained clear and were near normal in thickness. Homografts lacking endothelium exhibited persistent, severe edema that correlated with the inability of the host corneal endothelium to resurface the graft. Clinical and morphologic evidence of mild homograft rejection as observed in 15% of the animals that received normal homografts. Corneal endothelial cell loss following penetrating keratoplasty in the cat approximates that observed following the same procedure in the human. Additionally, regenerative capacity of the corneal endothelium in the cat, like that of the human, is limited. These features suggest that this cooperative, hardy animal is an excellent model in which to study many aspects of corneal transplantation that have direct application to the treatment of human corneal disease.

Secular Microscopic Follow-up of Corneal Grafts for Pseudophakic Bullous Keratopathy

Pseudophakic bullous keratopathy (PBK) has become the leading indication for penetrating keratoplasty. In our initial fifty patients having keratoplasty for PBK there was gradual loss of clear grafts in patients with retained intraocular lenses (IOLs). Specular microscopy was performed on donor tissue, and periodically postoperatively, for 130 grafts for PBK. The highest cell loss at one year was in eyes with retained iris support (39.2%) or anterior chamber (37.2%) IOLs. Cell loss in grafts with removed iris support IOLs (21.3%) was significantly less. When iris support IOLs were exchanged for anterior chamber (AC) IOLs, the cell loss at one year (27.1%) was intermediate. We recommend that iris support IOLs be removed at keratoplasty. Exchange for an AC IOL should be considered depending on the visual needs of each patient. Removal of AC IOLs should be based on consideration of prior tolerance and position of the implant.

REGRESSION OF KAYSER-FLEISCHER RINGS DURING ORAL ZINC THERAPY : CORRELATION WITH SYSTEMIC MANIFESTATIONS OF WILSON'S DISEASE

Fourteen patients presenting with neuropsychiatric manifestations of Wilsons disease were treated with oral tetrathiomolybdate (TM) for 8 weeks followed by oral zinc (Zn) maintenance therapy. The patients were evaluated prospectively at baseline and at yearly intervals for up to 5 years by slit-lamp biomicroscopy and photography, quantitative neurologic and speech pathology examinations, 24-h urine copper collection, and a quantitative scoring of magnetic resonance imaging (MRI) of the brain. Kayser-Fleischer (KF) ring size decreased significantly during the 5-year study period (p < 0.0001). Although results of neurologic examination, speech pathology examination, and 24-h urine copper level analysis in symptomatic Wilsons disease patients improved during the study period, KF ring regression did not correlate with the improvement in these clinical parameters (p > 0.05). However, there was a correlation between MRI scores and KF ring regression (p = 0.02). Anticopper therapy with TM followed by zinc maintenance therapy is a safe and effective treatment for patients with neurologically symptomatic Wilsons disease. This treatment leads to reduction in KF ring size; however, KF ring reduction is not a good predictor of clinical improvement for patients with neuropsychiatric manifestations of Wilsons disease.

Size variation of the lacrimal punctum in adults

This is the first reported study on accurate computerized measurements of lacrimal punctal size in normal adults. There was a wide variation found between patients. The lower lid puncta were consistently noted to be larger than those of the upper lids. This is clinically significant in dry-eye patients who may need to be treated with punctal plugs of various sizes.

Recombinant Tissue Plasminogen Activator to Lyse Experimentally Induced Retinal Arterial Thrombi

We evaluated the efficacy of intravenously administered recombinant tissue plasminogen activator to lyse laser-induced arterial thrombi in the stroke-prone, spontaneously hypertensive rat model. The arterial thrombi were confirmed histologically, and assessed by color photographs and fluorescein angiography before and after intravenous tissue plasminogen activator or saline therapy. Experimental animals received tissue plasminogen activator (1 mg/kg of body weight) given intravenously over one hour, and control animals received similar volumes of normal saline. Tissue plasminogen activator was effective in lysing experimental retinal arterial thrombi.

Complement-induced retinal arteriolar occlusions in the cat.

Purpose: To develop an animal model of complement‐induced retinal vasculopathy and determine whether it resembles Purtschers retinopathy. Methods: Intravenous cobra venom factor was used to achieve intravascular activation of the complement system in cats. After a single bolus of cobra venom factor (75 units/kg), retinal blood flow was monitored at regular intervals by fluorescein angioscopy and angiography. Results: Multiple small retinal arteriolar occlusions were present during the initial fluorescein transit of the immediate postinjection fluorescein study in 12 of 12 animals. Small, rapidly moving gaps in the fluorescein column were seen in two thirds of the animals observed continuously by fluorescein angioscopy. Angiographically, the obstructions were transient, and filling of the associated patches of capillary nonperfusion occurred within 3 minutes. Purtschers‐like ischemic retinal infarcts did not develop in any eye. Histopathologic analysis failed to demonstrate the nature of the transient vascular obstructive lesions, but indirect evidence suggested the possibility of granulocyte aggregates. Conclusion: Intravascular activation of the complement system produces transient microembolic retinal arteriolar occlusions in the cat. Although this model may represent a mild form of Purtschers retinopathy, factors in addition to complement activation appear necessary to induce ischemic retinal infarcts.

Wilson's disease: Presymptomatic patients and Kayser-Fleischer rings

PURPOSE We evaluated patients with Wilsons disease to determine (1) whether presymptomatic patients who have Kayser-Fleischer (K F) rings demonstrate a more significant alteration of copper metabolism than those who do not have K F rings, and (2) whether presymptomatic patients have smaller K F rings than symptomatic Wilsons disease patients. METHODS Thirty-two patients with presymptomatic Wilsons disease were retrospectively analyzed. Sixteen of these had received no prior anti-copper therapy and underwent testing for baseline copper metabolism (24-hour urine copper, liver copper, and plasma ceruloplasmin). Quantitative measurements of K F rings were made for the group of untreated presymptomatic patients and a control group of symptomatic Wilsons disease patients. RESULTS We hypothesized that the 24-hour urine copper, in particular, would correlate with the presence of a K F ring. However, no significant difference was found between any of the baseline copper variables for presymptomatic patients who had K F rings compared to those who did not. K F rings of presymptomatic patients were found to be significantly smaller than K F rings of patients with symptomatic Wilsons disease (p < 0.05). CONCLUSIONS While this study does not show any relationship between urinary copper excretion and the presence of K F rings, it suggests that the larger K F ring size correlates with Wilsons disease severity.

Effect of Age and Keratoplasty on the Postnatal Development of Feline Corneal Endothelium

Unilateral autologous rotational penetrating keratoplasties were performed on 10 4-week-old kittens. Three eyes were lost to glaucoma secondary to anterior synechiae formation, four eyes were examined histologically 2 weeks to 1 month postoperatively, and the three remaining eyes were examined serially for 9 months by slit lamp observation, specular microscopy, and pachometry. Contralateral unoperated control eyes demonstrated a rapid decline in endothelial cell density during the first 8 weeks of life (6000 cells/mm2 to 3800 cells/mm2), a change which correlated with the growth of the cornea to its adult size. Thereafter, the endothelial density declined more gradually (2800 cells/mm2 at 6 months). Transplants exhibited a 50% endothelial cell loss 2 weeks postoperatively that related to the keratoplasty procedure, and the endothelial cell density subsequently declined gradually with age. Corneal thickness comparisons of unoperated and postkeratoplasty eyes suggests that the endothelium of the infant kitten has less functional reserve than the adult endothelium. Corneal endothelial cell counts made from infant and adult dogs, rabbits, and humans indicate that the high postnatal endothelial cell density observed in the cat also occurs in other mammalian species.

Unexplained heterochromia. Intraocular foreign body demonstrated by computed tomography

Standard radiographic techniques are often inadequate in demonstrating the presence and location of intraocular foreign bodies. Computerized axial tomography was used to confirm the presence of a metallic foreign body in a patient with heterochromia iridis and suspected ocular siderosis in whom no foreign material was found by conventional examination methods.