Biomedical subjects
Publications and source records attributed to S Zonis.
We examined five members of a highly inbred kinship who had isolated microphthalmia associated with colobomatous cysts and various other ocular lesions. They were all offspring of consanguineous (first cousins) and unaffected parents. Microphthalmia in this kindred was transmitted as an autosomal recessive trait. Ultrasonography was effective for prenatal diagnosis in two pregnancies at risk.
A 20-year-old man developed myopia immediately after blunt trauma to the eye. The main finding was a shallow anterior chamber. Ultrasonography revealed anterior displacement of the iris lens diaphragm without change in lens thickness or axial length of the eye. After 1 week intraocular pressure decreased to a very low level, and edema of the optic disc and macula developed. Since hypotony and shallowness of the anterior chamber persisted for many months, we assume the cause to be detachment of the ciliary body. This is an uncommon mechanism for traumatic myopia, spasm of the ciliary body being more common.
Twenty-seven patients with vernal conjunctivitis who remained symptomatic following treatment with corticosteroid drops and/or Opticrom drops (sodium cromoglycate 2%, benzalkonium chloride 0.01%) were treated with aspirin. Aspirin produced marked improvement in all patients apart from three. The possible mechanism of the efficacy of aspirin in vernal conjunctivitis is discussed.
The histological and structural features of Bitot's spots are described. Light microscopy revealed squamous metaplasia with keratinization. Electron microscopy showed severe loss and attenuation in height of microvilli as well as widening of the intercellular spaces. The amorphous material overlying the conjunctiva was composed of cellular debris containing edemetous endoplasmic reticular membranes and lysozomes.
In this case report the authors present a patient in whom loss of vision developed in the left eye in the early stage of herpes zoster ophthalmicus. He suffered from optic neuropathy followed by central retinal artery occlusion. Ophthalmologists should be aware of this rare and early complication of herpes zoster.
Argon laser is widely used to coagulate the diabetic retina in order to inhibit the proliferative stage of diabetic retinopathy. Ten pigmented rabbits underwent retinal photocoagulation with argon laser. Retinal function was assessed electroretinographically before treatment and at different time intervals after treatment. The ERG responses measured 4-7 days after treatment were reduced in amplitude by a degree which was proportional to the number of laser applications. In five eyes that were treated with at least 1000 applications the ERG responses were very small when measured 4 days post-treatment. However, a gradual recovery was observed and within 2 months the ERG responses approached the normal pretreatment amplitudes. Histological findings from light and electron-microscopy suggested that the ERG recovery could not be solely explained by healing of the coagulated areas. Structural differences were seen in the pigment epithelial layer between a retina obtained immediately after treatment and one studied after ERG recovery. It is suggested that changes in the electrical resistance of the pigment epithelium may contribute to the ERG reduction seen immediately after laser treatment in the rabbit and to the increase in the ERG amplitude observed during the apparent functional recovery of the retina.
Serum carcinoembryonic antigen levels were measured in nine patients with choroidal malignant melanoma prior to enucleation and at three-month intervals thereafter for three years. Raised levels were found preoperatively in four of the nine patients. One of these patients had persistent and progressive elevation of serum carcinoembryonic antigen levels postoperatively, and clinical evidence of metastases subsequently became apparent. In the remaining eight patients, carcinoembryonic antigen levels remained at or returned to normal values and no clinical evidence of progression of the disease was detected. These results suggest that although serum carcinoembryonic antigen estimation is not a reliable diagnostic screening test for choroidal malignant melanoma, it may be useful for follow-up and monitoring of recurrences of the disease.
Electron microscopic study of conjunctiva in two cases of Sjögren's syndrome showed decrease in height and number of microvilli and lack of branching. Following immunosuppressive treatment, an increase in height, number and branching of conjunctival microvilli was observed. Notwithstanding the lack of influence on tear secretion, immunosuppressive drugs are of benefit in the treatment of ocular manifestations of Sjögren's syndrome. The increase in number, height and branching of microvilli enlarge the surface of the conjunctiva and thus improve the efficacy of artificial tears.
Infarction of the occipital cortex usually causes loss of the contralateral half of the visual field in both eyes. Although cases with complete transient loss of vision have been described, this is due to involvement of the second half of the cortex in the pathologic process. We report a case of a one-eyed patient with almost complete loss of vision in her only eye because of an infarction of the ipsilateral occipital cortex. During the patient's hospitalization, the temporal half of the visual field recovered. The case is of interest because of the difficulties in diagnosing cortical blindness in a one-eyed patient.
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Electroretinographic (ERG) responses were measured in diabetic patients before, during, and after panretinal photocoagulation treatment with argon laser. The laser applications reduced considerably the amplitudes of the a and b waves of the ERG. Moreover, the relationship between the amplitude of the b wave and that of the a wave was severely affected, resulting in ERG responses of abnormal pattern. The b waves were smaller than expected from the a waves. These findings indicated that the photocoagulation treatment not only destroyed the retinal areas directly illuminated by the laser beam, but also affected the functional integrity of adjacent areas. These additional effects resulted in subnormal signal transmission from the photoreceptors to the proximal retina.
Conjunctival biopsies of 11 patients with sicca syndrome were studied under light and transmission electron microscopy. The notable findings were vasculitis of the conjunctival vessels. There were severe changes in the microvilli, namely a loss of microvilli and decrease in their height, measuring approximately 1,000-2,000 A, in comparison with microvilli of the control conjunctiva, measuring 4,000 A in height. There was no branching yet or fusion of microvilli.
The retinal function of patients with high refractive error was studied electroretinographically. Thirty-one hypermetropic patients, 7 myopic patients, and 7 patients with either unilateral or bilateral aphakia participated in the study. The ERG responses were measured in the light- and dark-adapted states. It was found that myopic eyes were characterised by subnormal amplitude but normal pattern, expressed by normal relationship between the b-wave amplitude and the a-wave amplitude. In aphakia the ERG responses were of normal amplitude and pattern. However, the hypermetropic patients could be divided into 3 groups. One group included subjects with a subnormal b-wave to a-wave relationship. The second group was characterised by a normal b- to a-wave relationship, while patients belonging to the third group exhibited supernormal b-wave to a-wave relationship. This classification of hypermetropic subjects did not correlate with the axial length of the eye or the refraction of the ocular media.
Biopsy material from primary and secondary overacting inferior oblique muscles were examined by light and electron microscopy. Most muscle fibres were in different stages of atrophy. A high variation of alterations was encountered in all muscles. The most striking abnormalities were huge accumulations of mitochondria and muscle vacuolisation related mainly to the enlargement of the tubules of sarcoplasmic reticulum. The mitochondrial aggregates and vacuolisation occupied more muscle surface in the inferior muscles of primary overaction than those of secondary overaction.
The prevalence of pseudoexfoliation among patients of Sephardic origin was more than twice the expected when compared with the ethnic distribution of the population consulting the Rambam Medical Center eye clinic. A strong association between brown irises and pseudoexfoliation was noted. No uniform scanning electron microscope pattern was seen of the pseudoexfoliation.
The medial rectus, external rectus and inferior oblique muscles were examined by electron microscopy in Möbius syndrome. The electron microscopic findings of the medial rectus and inferior oblique were of degenerative and inflammatory nature, whereas the lateral rectus showed complete fibrosis. The fibrotic lateral rectus could explain the absence of abduction in Möbius syndrome.
An infant with congenital agranulocytosis (Kostmann's syndrome) presenting with necrosis of the eyelids and lacrimal apparatus is reported. Although the disease is rare, its presence should be considered in infants with severe localized pyogenic infections.
The permeability of newly formed blood vessels in proliferative diabetic retinopathy at different stages of development was correlated with their ultrastructural features. The young proliferating vessels were much more permeable to fluorescein than were the older vessels. Transmission electron microscopy revealed that the blood vessels within the young intravitreal proliferating fronds had intermediate interendothelial junctions, whereas the blood vessels within the old neovascular preretinal membranes had tight interendothelial junctions of the macula occludens type. Fenestrations were observed only rarely in the endothelial wall of either the young or the older proliferating vessels. We conclude that the principal route of fluorescein leakage from the newly formed blood vessels in proliferative diabetic retinopathy is via the interendothelial clefts.