Biomedical subjects
Publications and source records attributed to H B Collin.
The prevalence of the corneal Hudson-Stähli line among 400 eyes was found to range from 5.3% of the eyes of patients aged 11-20 years to 100% of eyes of patients aged 81-90 years. In 87.3% of patients over 50 years of age corneas were affected; this percentage is considerably higher than previous estimates. Up to the age of 60 years it occurs more frequently in men than in women.
The characteristics, clinical appearance, and frequency of the rare corneal condition, keratoconus posticus circumscriptus, are discussed. A bilateral case of this condition, examined by use of techniques not previously employed, is described.
The presence of epicapsular stars (congenital epicapsular pigmentation) is a common occurrence, but it can become clinically significant when vision is impaired. A case history reporting such a condition is presented.
Four patients with symptomatic superior limbic keratoconjunctivitis underwent resection of the superior bulbar conjunctiva. One of these patients also underwent a tarsal conjunctival resection in the other eye. Three of the patients had previously been treated by various regimens without resolution; the fourth had had no prior treatment. All four patients had immediate and continued relief of the ocular symptoms after the superior bulbar conjunctiva was excised. The patient who underwent tarsal conjunctival resection experienced only short-term relief. We studied the conjunctival tissue by light and transmission electron microscopy. Both techniques revealed abnormalities related to the bulbar conjunctival surface with keratinization of the epithelium, acanthosis, degeneration of the nuclei, and intracellular accumulation of glycogen. Inflammatory cells were minimally present. The tarsal conjunctiva appeared essentially normal.
A prominent histological feature of superior limbic keratoconjunctivitis is the presence of keratinization of the superior bulbar conjunctiva. Ultrastructurally the affected conjunctival epithelium shows all of the characteristics of keratinization as described in skin. There is a superficial layer of horny cells with reduced organelles and thickened cell membrane. In the intermediate layers, the cells contain an increased number of cytoplasmic filaments which are sometimes aggregated into dense masses, keratohyalin granules, both in the cytoplasm and in the nucleus, membrane coating granules, lysosomes and various other types of membranous structures.
Superior limbic keratoconjunctivitis (SLK) is a condition of unknown etiology. Histological signs include acanthosis, dyskeratosis, keratinization, and ballon degeneration of the bulbar conjunctival epithelium. Ultrastructural examination of biopsy material from five eyes of patients with SLK shows numerous nuclear changes in the conjunctival epithelial cells. These include abnormal distribution and aggregation of nuclear chromatin, the presence of filaments within the nucleus, and dense accumulations of cytoplasmic filaments which surround the nucleus, resulting in "strangulation" and the formation of multilobed nuclei or multinucleated cells. These changes do not appear to have been described previously in any cell type.
The histopathological changes of vernal conjunctivitis comprise stromal infiltration by lymphocytes, plasma cells, and neutrophilic, eosinophilic, and basophilic leukocytes and epithelial invasion by mast cells and eosinophils. Blood vessels show swelling and death of endothelial cells and increased permeability with associated extravasation of erythrocytes and fibrin. The presence of basophils in ocular tissue has not been reported previously, and their occurrence in conjunction with the other pathological changes enables vernal conjunctivitis to be compared with, and classified as a manifestation of, delayed-type hypersensitivity of the cutaneous basophil type. Thus the mechanism is probably a mixture of both delayed and immediate immunological responses.
A case of recurrent herpes simplex virus keratouveitis was studied using both electron microscopic and viral culture techniques. We describe a patient who had a particularly violent course, including three failed grafts, endophthalmitis, and wound leak. We report the identification of virus in a quiescent failed corneal graft and retrocorneal membrane; persistence of virus enabling its culture from the vitreous; and electron microscopic identification in the cornea removed at the third transplant. The identification of cases in which viral proliferation occurs is necessary for a greater understanding of the pathogenesis of herpetic corneal disease and for determining in which particular patient steroid therapy should be avoided.