Biomedical subjects
Publications and source records attributed to V Boniuk.
We found an upper eyelid notch and posterior pole lens in a newborn anencephalic infant. An analysis of the development of the affected tissues helped localize the insult at the fifth to tenth week of gestation, probably close to the fifth week.
In a study of a selected age (greater than 60) and ocularly matched population requiring cataract extraction, a perfectly executed intracapsular cataract extraction followed by the introduction of a Fyodorov Type II ("Sputnik") lens did not lead to irreversible anterior or posterior segment changes different from those seen in a group followed for from 5 to 9 years. It did lead to an incidence of implant support dislocation and to membrane formation in about 10% of cases, reducible to about 2% with correctly made lenses and the appropriate use of postoperative drugs. The incidence of corneal degeneration (0), retinal detachment (2%), and intraretinal cystic maculopathy (3%) was equal in each group. Visual acuity levels were also equal. In appropriate cases, if the surgery is carried out with sufficient skill, the reward to risk ratio of implantation not only justifies but indicates the use of such lenses.
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The metabolism of cortisol and other steroids was studied in normal untreated rabbit iris-ciliary body and cornea as part of an investigation into the mechanism of glucocorticoid-induced glaucoma. Cortisol is readily converted to the inactive metabolite cortisone by these eye tissues indicating the presence of an 11beta-oxidoreductase system. This reaction is reversible with cortisone being converted to cortisol in the presence of appropriate cofactor. However, due to the absence of a (or as yet undetectable) cortisol-A-ring-reductase system (rate-limiting reaction) the steroid is not irreversibly metabolized to biologically inactive compounds. The 11beta-oxidoreductase system readily converts other C21-11beta-hydroxysteroids, such as corticosterone, to its appropriate C21-11-ketosteroid (11-dehydrocorticosterone). Some C21-steroids lacking the 11-hydroxyl group (11-deoxycortisol, 11-deoxycorticosterone) remain virtually unmetabolized (exception to this was found with progesterone). Evidence of a C21-steroid A-ring reductase system was found only when cortisone and progesterone were used as substrates. However, testosterone a C19 steroid was converted to clearly identifiable A-ring reduced and 17beta-and 3alpha(beta)-oxidoreduced metabolites, thus indicating the presence of testosterone A-ring reductase, 17beta-and 3alpha(beta)-oxidoreductase systems in the eye tissues studied. The presence of a steroid 5alpha(beta)-reductase for some steroids but not for cortisol indicates a distinct substrate specificity for this enzyme system in the eye tissues.
Two cases of GM1 type 1 gangliosidosis demonstrated microvascular abnormalities of the conjunctiva, as well as skin abnormalities in one case. This abnormality was studied by light and electron microscopy of a conjunctival biopsy; cytoplasmic vesicles were noted in the endothelial cells, producing a mechanical narrowing of the lumen. This storage material is similar to that seen in the fibroblasts of skin and of visceral organs in GM1 gangliosidosis, as well as to the material described in the systemic mucopolysaccharidoses. The material probably represents a keratan sulfate-like material. The conjunctiva provides a ready source for biopsy and diagnostic evaluation.
Clinical and histologic studies in 40 eyes of 35 patients with chronic open-angle glaucoma or chronic angle-closure glaucoma operated by various types of "trabeculectomies" were assessed to evaluate whether success was correlated with the surgical approach or with the presence of trabecular tissue in the pathologic specimen. It was clearly demonstrated that it is not necessary to localize or enter Schlemm's canal in order to perform successful trabeculectomies; it is not necessary to operate posterior to the scleral spur; and it is not necessary to excise either Schlemm's canal or trabecular tissue to achieve success. In essence, trabeculectomies primarily function as fistulizing operations carried out under scleral flaps substituting a scleral-conjunctival barrier to aqueous flow rather than the conjunctival barrier alone provided by standard glaucoma operations. This greater obstruction explains the absence of shallow chambers, the reduced incidence of polycystic bleb formation and, perhaps, an avoidance of long-term complications that often result from these two factors.
Experience with the vaccine can be summarized as follows: There were minimal problems with neuralgia and neuropathy as a result of the vaccine; vaccinated children were not a significant source of infection to the pregnant woman; the duration of immunity is similar to that obtained with natural rubella virus, but with lower antibody levels; and reinfection is more common with vaccination, but apparently no viremia develops. Several studies were reported regarding inadvertent vaccination in women who were pregnant at the time of vaccination. In one series [7], 19 pregnant women who were vaccinated were studied. Ten went to term and delivered normal babies and 9 aborted, 8 induced and 1 spontaneously. In one induced abortion, virus was demonstrable in fetal tissue including, notably, in the eye. Another case of CRS was diagnosed in utero amniocentesis [12], and the fetus was aborted at 12 weeks' gestation. Another evaluation of reinfection during pregnancy [1] confirmed that this was of little risk to the fetus, as there was no apparent viremia. In summary, then, in one ophthalmological generation, from Gregg until the present time, we have experienced the recognition, the observation, and, essentially, the conquest of the congenital rubella syndrome. However, if vaccination programs are not assiduously continued, we can expect a renewed upsurge of this difficult problem.
A randomized prospective study of 100 consecutive cataract operations was designed to ascertain the need for hospitalization for this procedure. The results clearly indicate that immediate ambulation and discharge of the cataract patient do not detract from the very high success rate of this operation. The random nature of this study adds strong support to those surveys that have similarly concluded that hospitalization and postoperative restrictions are not necessary for the great majority of cataract patients.