PubMed Health⌕ Search

Biomedical subjects

D R Korb

Publications and source records attributed to D R Korb.

At least 37 records · Page 2Linked to original sources
PubMed1983

Biomicroscopy of papillae associated with wearing of soft contact lenses.

We studied the topographical, macrostructural, and fluorescein staining characteristics of papillary changes of the upper tarsal conjunctiva associated with the wearing of hydrophilic (soft) contact lenses. Fifty soft contact lens wearers with elevated conjunctival papillae greater than 0.3 mm in diameter were studied. Topographic characteristics recorded were distribution and number of papillae; macrostructural characteristics recorded were diameter and morphology of papillae. The information collected included age of patient, duration of lens wear, average daily time of wearing lens, presence or absence of itching or mucus, refractive status, and atopic history. Papillae were found in most cases in the conjunctival zone adjacent to the tarsal fold and were never found in the zone adjacent to the eyelid margin without also occurring in the intervening zone. The diameter of the papillae ranged from greater than 0.3 mm to 2.0 mm. The number of papillae per eyelid ranged from 4 to over 100. The apices of the papillae were frequently flattened, and these flattened surfaces frequently stained with fluorescein. The vascular supply of individual papillae was observed to radiate from a vessel occupying the central core of each papilla.

Adult↗
PubMed1982

Human ocular mucus. Scanning electron microscopic study.

Twenty biopsy specimens of the human conjunctival epithelial surface with its associated mucus from normal subjects and contact lens wearers with biomicroscopic evidence of excess mucus were studied by scanning electron microscopy. Mucus existed in strands, sheets, and granules; each morphologic type of mucus was observed in all samples. No qualitative difference in morphologic features of mucus was found between normal subjects and those with excess mucus. Mucous forms observed by scanning electron microscopy closely resembled structures previously shown by biomicroscopic and light microscopic techniques, providing evidence that careful scanning electron microscopic preparation of biopsy specimens containing mucus may not greatly alter in situ morphologic characteristics of mucus.

Conjunctiva↗
PubMed1981

Biomicroscopy of papillae associated with hard contact lens wearing.

We studied the macrostructural characteristics of papillary changes of the upper tarsal conjunctiva associated with the wearing of polymethyl methacrylate (PMMA) contact lenses. Fifty subjects with elevated conjunctival papillae greater than 0.3 mm in diameter were studied. Macrostructural characteristics recorded were location, diameter, and number of papillae, presence or absence of staining at the apices of papillae, and degree of hyperemia of the upper tarsal conjunctiva. Patient information collected included age, duration of lens wear, average daily lens wearing time, presence or absence of itching or mucus, refractive status, and atopic history. The tarsal conjunctiva was divided into three zones of equal size. Papillae were present in various zones and combinations of zones; however, papillae were never confined exclusively to either (1) the zone adjacent to the tarsal folds or (2) the latter zone in combination with the zone adjacent to the eyelid margin without also occurring in the intervening zone. The diameter of the papillae ranged from greater than 0.3 mm to 2.0 mm. The number of papillae per eyelid ranged from two to over 100. The apices of the papillae were frequently flattened and craterlike, and often stained with fluorescein.

Adult↗
PubMed1981

Meibomian glands and contact lens wear.

A study of a syndrome characterised by deficient or inadequate Meibomian gland secretions, minimal or transient symptoms suggestive of ocular dryness, fluorescein staining of the cornea (often detected only after delayed observation or sequential instillation of stain), and contact lens intolerance is described. Clinical and cytological studies indicate that the syndrome is due to obstruction of the Meibomian gland orifices by desquamated epithelial cells that tend to aggregate in keratotic clusters, which results in alteration of the Meibomian glands' contribution to the precorneal tear film. Further complication may result from bacterial proliferation in the desquamated keratotic cells and the release of the bacteria and their toxic products into the precorneal tear film from these reservoirs in the excretory pathways of the Meibomian glands.

Adult↗
PubMed1980

Branching of microvilli in the human conjunctival epithelium.

Biopsy specimens were obtained from the upper tarsal and limbal conjunctivae of ten normal persons and from the upper tarsal conjunctivae of five asymptomatic contact lens wearers and five patients with giant papillary conjunctivitis (GPC) associated with contact lens wear. The microvillar surface of the conjunctival epithelium was studied by transmission and scanning electron microscopy. Branches often stemmed from the side of a straight tubular microvillus and formed an acute angle with the main process. Branches sprouted at various distances from the origin of the microvillus. The most common branching pattern was the bifurcated (bifid) form. Occasionally, both primary and secondary bifurcations were primary and secondary bifurcations were observed on the same microvillus. Some microvilli were branched in the normal conjunctivae, but the conjunctivae of asymptomatic contact lens wearers and patients with GPC had more branched microvilli and greater polymorphism, which correlated with the degree of alteration. This report demonstrates the presence of branched microvilli and describes the types seen in normal conjunctivae and compares the frequency with which branched microvilli are seen in altered conjunctival surfaces.

Cell Membrane↗
PubMed1980

Mucus secretory vesicles in conjunctival epithelial cells of wearers of contact lenses.

Biopsy specimens from the upper tarsal conjunctivae of ten patients with clinically evident contact-lens-associated giant papillary conjunctivitis (GPC) and eight asymptomatic contact lens wearers without clinically evident conjunctival changes were compared by light and transmission electron microscopy to determine the contribution of nongoblet epithelial cells to increased mucus. A control group consisted of five subjects who had never worn contact lenses. The apical cytoplasm of superficial nongoblet epithelial cells in specimens from all groups showed single-membrane-limited vesicular inclusions that stained metachromatically with toluidine blue and were positive with PAS staining, which indicated muco-protein content. Some vesicles appeared to discharge their contents into the conjunctival sac. More vesicles were found in the GPC subjects and the asymptomatic contact lens wearers than in the normal subjects. These observations, coupled with the sign of increased or excessive mucus discharge in GPC subjects and in asymptomatic lens wearers, support the premise that the superficial layers of non-goblet conjunctival epithelial cells can contribute to an increase in mucus production.

Adult↗
PubMed1980

Prevalence of conjunctival changes in wearers of hard contact lenses.

The prevalence of elevated papillae more than 0.3 mm in diameter was 10.5% in the conjunctivae of 200 subjects who had successfully worn polymethylmethacrylate hard contact lenses for eight hours or more daily for more than five years. Only three of 500 (0.6%) control subjects who had never worn contact lenses had these papillary changes. The prevalence of papillary changes for those with the so-called normal symptoms of mucus, itching, or both associated with wearing of hard contact lenses was 53% (16 of 21 subjects). The prevalence of these symptoms was 76% among subjects with polymethylmethacrylate contact lenses who had papillary changes and 8% among subjects with polymethylmethacrylate contact lenses who did not have papillary changes. We conclude that changes in the upper tarsal conjunctiva are associated with the wearing of hard contact lenses, occur in a significant percentage of patients wearing hard contact lenses for prolonged periods, and include a spectrum of papillary changes.

Conjunctival Diseases↗
PubMed1980

Meibomian gland dysfunction and contact lens intolerance.

A study of a syndrome characterized by deficient or inadequate Meibomian gland secretions, minimal or transient symptoms suggestive of ocular dryness, fluorescein staining of the cornea (often detected only after delayed observation or sequential instillation of stain), and contact lens intolerance is described. Clinical and cytologic studies indicate that the syndrome is due to obstruction of the Meibomian gland orifices by desquamated epithelial cells that tend to aggregate in keratotic clusters, which results in alteration of the Meibomian glands' contribution to the precorneal tear film. Further complication may result from bacterial proliferation in the desquamated keratotic cells and the release of the bacteria and their toxic products into the precorneal tear film from these reservoirs in the excretory pathways of the Meibomian glands.

Adolescent↗
PubMed1979

Corneal staining subsequent to sequential fluorescein instillations.

Liquid fluorescein (2%) was instilled into the inferior cul-de-sac and the precorneal tear film and the cornea were observed utilizing a specialized examination routine. Following the initial fluorescein instillation and observations, sequential fluorescein instillations were performed at five-minute intervals six additional times. The incidence of corneal staining (200 corneas) following the initial instillation of fluorescein was 19%. An additional 23% exhibited staining as a result of the sequential staining process. Five types of staining were classified; the most common forms were those associated with the lid margins. Severe degrees of staining appear to be clinically significant, as suggested by a correlation between severe degrees of staining and contact lens intolerance.

Contact Lenses↗
PubMed1978

Conjunctiva in asymptomatic contact lens wearers.

Biopsy specimens of the upper tarsal conjunctiva from 11 asymptomatic, biomicroscopically normal contact lens wearers (five hard and six soft) were studied by scanning electron microscopy. The conjunctiva in lens wearers showed areas of normal epithelial cell surfaces interspersed among areas of altered cells. The altered cell surfaces were characterized by centralized clumped microvilli and baring of that portion of plasma membrane around the cell periphery. The degree of centralization of microvilli varied widely, from a mild tendency to centralize accompanied by slight reduction in cell diameter, to an exteme centralization and dramatic diameter reduction. In some cells, the centralized microvillar structure had a unique mucuslike covering. Numerous altered cells were present in all 11 specimens from asymptomatic contact lens wearers. The number of these cells found by conjunctival biopsy of the hard contact lens wearers and the number in the soft contact lens wearers apparently did not differ. The upper tarsal conjunctiva in these asymptomatic contact lens wearers has an altered epithelial surface, different from that observed in normal subjects without contact lens-wearing experience and from subjects with contact lens-associated giant papillary conjunctivitis.

Adult↗
PubMed1978

Giant papillary conjunctivitis induced by hard or soft contact lens wear: quantitative histology.

Both hard and soft lens wearers develop a syndrome of decreased tolerance, increased mucus, mild itching, and giant papillary excrescences in the upper tarsal conjunctiva that resemble a varnal conjunctivitis. In the fully developed syndrome, the upper tarsal plate has an increase in stringy mucus and is covered by large papillae crowded together. The syndrome develops after months to years of otherwise successful lens wear and occurs in users of all types of soft and hard lenses. Histologic examination of tissues from 55 patients with well-developed giant papillary conjunctivitis compared with tissue from 15 normal people showed three findings characteristic of the syndrome: (1) mast cells in the epithelium, (2) eosinophils in the epithelium and substantia propria, and (3) basophils in the epithelium and substantia propria. Plasma cells and lymphocytes per cubic millimeter were not increased in detailed counts of 15 patients and 15 normal individuals. It is proposed that the number of plasma cells and lymphocytes cannot increase much beyond the level already present in normal conjuctiva and further influx of mononuclear inflammatory cells is the impetus for growth of the papillae. It is proposed that giant papillary conjunctivitis is a generalized response of the upper tarsal conjunctiva.

Adolescent↗
PubMed1977

Giant papillary conjunctivitis in contact lens wearers.

A syndrome that occurred in both hard and soft contact lens wearers was characterized by increased mucus, itching, decreased lens tolerance, and giant papillae in the upper tarsal conjunctiva. It developed in as few as three weeks with soft lens wearers but also occurred after months or even years of successful wear. The histology was characterized by basophils, eosinophils, and mast cells in the epithelium, and these cells as well as increased numbers of lymphocytes, plasma cells, and polymorphonuclear leukocytes in the stroma. The syndrome may be immunologic in origin with deposits on the lenses as the antigen, and the syndrome may be a major cause of difficulty in wearing contact lenses once they have been successfully fit.

Antigens↗