Robert D. Stone

Monocular Axial Myopia Associated with Neonatal Eyelid Closure in Human Infants

We studied eight infants who developed unilateral axial myopia associated with neonatal eyelid closure. Clinical findings and ultrasonographic biometric measurements suggested that axial elongation of the eye may occur as a result of neonatal eyelid closure, a finding similar to that for experimental myopia produced in neonatal animals after eyelid fusion. Early treatment of eyelid occlusion in the neonate may prevent axial myopia and subsequent anisometropic amblyopia.

Epidemic Postsurgical Candida Parapsilosis Endophthalmitis: Clinical Findings and Management of 15 Consecutive Cases

Fifteen cases of postoperative Candida parapsilosis endophthalmitis occurring secondary to a contaminated lot of an irrigating solution were studied. All patients underwent a vitreous tap or diagnostic and therapeutic vitrectomy. Eleven of the 15 specimens were positive for the organism. Fourteen patients were treated with pars plana vitrectomy surgery. All patients were treated with intravitreal amphotericin B and systemic amphotericin B and 5-fluorocytosine. Two clinical recurrences were successfully treated with intravitreal amphotericin B, removal of the pseudophakos, and oral ketoconazole. The intraocular lens was retained in 11 of the 14 pseudophakic patients. Final visual acuities ranged from 20/25 to no light perception with eight of 15 patients having 20/60 or better visual acuities. Measurable levels of intraocular amphotericin B were found after systemic amphotericin B administration. Two patients with totals of 20 and 30 micrograms of intravitreal amphotericin B over 48 and 96 hours, respectively, had near normal ERGs one year later. Posterior capsulotomy and vitrectomy appear to decrease amphotericin B toxicity and allow sequential intraocular injection of this drug within a short time period.

Neovascular glaucoma after helium ion irradiation for uveal melanoma

Neovascular glaucoma developed in 22 of 169 uveal melanoma patients treated with helium ion irradiation. Most patients had large melanomas; no eyes containing small melanomas developed anterior segment neovascularization. The mean onset of glaucoma was 14.1 months (range, 7-31 months). The incidence of anterior segment neovascularization increased with radiation dosage; there was an approximately three-fold increase at 80 GyE versus 60 GyE of helium ion radiation (23% vs. 8.5%) (P less than 0.05). Neovascular glaucoma occurred more commonly in larger tumors; the incidence was not affected by tumor location, presence of subretinal fluid, nor rate of tumor regression. Fifty-three percent of patients had some response with intraocular pressures of 21 mmHg or less to a combination of antiglaucoma treatments.

Classification of Proliferative Vitreoretinopathy Used in the Silicone Study

The Silicone Study is a multicenter randomized clinical trial that compares a long-acting gas with silicone oil for the surgical treatment of proliferative vitreoretinopathy (PVR). As part of the study, a topographic classification of PVR has been developed that is based on the characteristic patterns of retinal distortion produced by the contraction of proliferative membranes on the retina or within the vitreous base. This classification is used to document the extent and anatomic distribution of PVR present preoperatively and to help standardize the surgical treatment. Experience has shown that this classification facilitates the identification of these membranes and their systematic dissection, and the authors therefore suggest that it be used to augment the Retina Society classification of PVR.

Uveal Melanoma Radiation: 125I Brachytherapy Versus Helium Ion Irradiation

The optimum radiation therapy for uveal melanoma is uncertain. Both helium ion irradiation and 125I brachytherapy have been used to treat this neoplasm. This investigation analyzed the control and complication rates of uveal melanomas treated with helium ions of 125I plaques. In both a retrospective and a prospective dynamically balanced study, the control rates appeared to be similar. There were more posterior segment complications after 125I plaques and more anterior segment complications, including neovascular glaucoma, after helium ion irradiation. The follow-up period is too short to draw definitive conclusions on the radiation complications. Overall, approximately 89% of eyes were retained and less than 4% of treated eyes were removed because of failure to control the tumor.

Effect of Various Doses of Radiation for Uveal Melanoma on Regression, Visual Acuity, Complications, and Survival

We reviewed 284 choroidal and ciliary body melanomas treated with 50, 60, 70, or 80 gray equivalents (GyE) of helium ion radiation. Multivariate methods of data analysis were used to adjust for differences between dose groups with respect to the characteristics of patients (and their tumors). Radiation dose level did not affect survival, complications, visual outcome, or tumor regression in this model. The minimum radiation dose necessary to achieve tumor control with charged particles may be less than 50 GyE.

Uveal Melanoma Necrosis After Helium Ion Therapy

A 71-year-old man underwent enucleation because of intractable pain ten months after receiving helium ion therapy for a uveal melanoma. There was no clinical or ultrasonographic evidence of tumor regression but histologically the tumor appeared almost entirely necrotic.

Effects of altered coronary perfusion pressure on function and metabolism of normal and cardiomyopathic hamster hearts.

The effects of a sudden decrease in coronary perfusion pressure from 140 to 0 cmH2O for a 10-second interval were analyzed in normal and cardiomyopathic hamster hearts to determine whether cardiomyopathy would affect the relationship between altered coronary perfusion pressure and left ventricular geometry, wall thickness, myocardial hydrodynamics, and hemodynamics. In normal hamsters, an acute reduction in coronary perfusion pressure resulted in a decrease in left ventricular short axis epicardial cross-sectional area, base to apex length, diastolic wall thickness, myocardial water content and developed pressure. In cardiomyopathic hamsters all results induced by lowering the hydrostatic pressure of the perfusing medium were the same except that diastolic wall thickness failed to decline, indicating a decrease in intramyocardial elasticity in dilated cardiomyopathy. In parallel studies, hearts were freeze clamped at end-diastole and high energy phosphates and energy metabolites analyzed. In both normal and cardiomyopathic hamsters no significant changes were observed in ATP, PCr, or Pi levels at 10 s following the decrease in perfusion pressure. However, during the abrupt decrease in coronary perfusion pressure adenosine increased and cAMP decreased in both groups of animals. The erectile effect of altered coronary perfusion pressure is partially attenuated in the cardiomyopathic hamster in which no change in diastolic wall thickness occurs during an abrupt change in the hydrodynamics of the heart.

Extramacular Disciform Lesions Simulating Uveal Tumors

PURPOSE The purpose of this study is to identify clinical, ultrasonographic, and fluorescein angiographic features of extramacular disciform lesions that allow differentiation from uveal tumors. METHODS This was a retrospective study of 19 patients referred to our ocular oncology unit with a possible malignancy who had a diagnosis of an extramacular disciform lesion made after complete evaluation. RESULTS The level of accuracy for each diagnostic technique alone was as follows: clinical (79%), ultrasonography (83%), and angiography (83%). Fluorescein angiography had limited utility because of severe media opacities in seven cases. No tumor developed an intraocular malignancy during the follow-up period. CONCLUSION A combination of the above, noninvasive techniques can be used to correctly diagnose extramacular disciform lesions.

Increased left ventricular diastolic stiffness in the early phase of hereditary cardiomyopathy

Isolated hearts from normal and cardiomyopathic hamsters (160 to 180 days of age) were perfused through the aorta and assessed by echocardiographic and 31P-NMR (nuclear magnetic resonance) techniques. A decreased left ventricular systolic pressure in cardiomyopathic hamsters was associated with diminished cardiac size and left ventricular wall thickness. However, the ratio of inner/outer cross-sectional area and estimated left ventricular volume at any given left ventricular weight was significantly higher, indicating relative left ventricular chamber enlargement in cardiomyopathic hamsters. Left ventricular volumes were increased with an intraventricular balloon. Gradual inflation of the balloon resulted in increments of left ventricular systolic and developed stress that rose to the same values in both groups. At this point, the normalized stress-strain relationship was approximately two times steeper for cardiomyopathic hamsters, while at lower strain values the diastolic stress in cardiomyopathic hamsters was less than in controls, possibly due to cardiac dilatation. Almost the same degree of dilatation was induced in control hearts by the acute addition of 1% alcohol, but it was not followed by increased diastolic stiffness. Examination of hearts by 31P-NMR techniques revealed a decreased phosphocreatine/inorganic phosphate (PCr/Pi) ratio in the cardiomyopathic hamsters that progressed further with balloon inflation and was associated with a relative fall in PCr and adenosine triphosphate (ATP) content. Results suggest increased diastolic stiffness in cardiomyopathic hamsters, which was not seen in acute cardiac depression with alcohol. Diastolic volume overload with increased wall stress is probably the major factor contributing to increased diastolic stiffness early in the cardiomyopathy.