The transconjunctival oxygen monitor

The transconjunctival oxygen monitor, mounted on a polymethylmethacrylate conformer, continuously measures the tissue oxygen tension of the palpebral conjunctiva. It is preferable to transcutaneous monitors because it requires no heat and correlates arterial oxygen in cerebral blood flow by monitoring a tissue bed vascularized by the internal carotid artery. We used it on 19 adult patients. The monitor was valuable in correlating arterial oxygen in hemodynamically compromised and uncompromised patients. However, the measurements decreased abruptly when the conjunctival temperature fell below 33 C in the compromised patients. The only ocular complications were conjunctival chemosis and mild punctate keratopathy in some patients; these resolved within 48 hours. This device may be useful in monitoring tissue oxygen tensions in critically ill patients and neonates at risk for retinopathy.

Adolescent cystinosis, presenting with proteinuria

Isolated proteinuria preceding tubular dysfunction for years was the presenting laboratory sign in a patient with adolescent cystinosis, followed up to end-stage renal failure in the second decade of life. The renal biopsy showed the early characteristic features, multinucleated giant podocytes. The diagnosis was documented by slit lamp examination of the eyes and cystine determination in fibroblasts.

Episcleral and subconjunctival lipid deposits. One year follow-up

A series of 39 subjects, aged under 70, had the numbers of lipid globules counted in the slit lamp within 4 regions of the right eye and 4 regions of the left. The counting was repeated after an averaged period of 12 months (range 7-20 months). The investigation disclosed that the number of lipid globules rises. No instances were detected of a fall in their number, allowance being made for errors of measurement, assessed on the basis of blind double counting. The degeneration is not positively correlated to xanthelasma, diabetes mellitus, or presenile arcus.

Keratin-like proteins in corneal and conjunctival epithelium are different

Using SDS polyacrylamide slab-gel electrophoresis, water-insoluble (keratin-like) proteins in normal and regenerated ocular surface epithelium from rabbits were studied. The results indicated that keratin-like proteins from corneal and conjunctival epithelia in vivo distinctly different. Regenerated epithelia from either source retained their original keratin characteristics for at least 10 days after healing over the cornea, but at very early stages of healing migrating and regenerated epithelia showed either an extra band or a prominent band in addition to the original keratin-like proteins. Three months after healing, however, regenerated conjunctival epithelium on the cornea had changed its keratin characteristics, and resembled, but was not identical to, corneal epithelium.

Zinc, cobalt and selenium concentrations in the premature and full-term newborn eye

Zinc, cobalt and selenium concentrations were determined in tunics, vitreous and lens of the eyes of 17 infants who died during the neonatal period. Significantly higher concentrations of the measured elements were found in the vitreous. The tunics contained more zinc and cobalt than the lens, while the latter contained more selenium.

Limbal epithelium in ocular surface wound healing

The regenerated epithelium derived from limbal epithelium was histologically and biochemically compared with epithelia regenerated from corneal and bulbar conjunctival epithelia. The histologic results indicated that regenerated epithelium of limbal origin increased in thickness with time after healing and showed no goblet cell appearance on the cornea. This suggests that regenerated epithelium from the limbus is more like regenerated epithelium of corneal origin than that of bulbar conjunctival origin. However, the glycogen content and protein pattern profile showed that regenerated epithelium of limbal origin had characteristics intermediate between those of corneal and bulbar conjunctival origin. Thus it is proposed that there are three distinct types of ocular surface epithelia--corneal, bulbar conjunctival, and limbal--and that limbal epithelium behaves differently from corneal and conjunctival epithelia in ocular surface wound healing.

H2-receptors in the human ocular surface

Ten normal human volunteers participated in a two-part study of H2-receptor activity in the ocular surface. Dimethylaminopropylisothiourea (trivial name, dimaprit dihydrochloride), a highly selective H2-receptor agonist, produced vasodilation without itch. Pretreatment with the H2-receptor antagonist, cimetidine, significantly blocked the vasodilatory effect of dimethylaminopropylisothiourea, whereas pretreatment with the H1-receptor antagonist, antazoline phosphate, did not. We conclude that H2-receptors are present in the human ocular surface.

Human conjunctival surface mucins: a quantitative study of normal and diseased (KCS) tissue

The architecture and distribution of surface mucins were studied qualitatively and quantitatively by transmission electron microscopy in ruthenium red stained biopsies of the human conjunctiva. Six control specimens were compared with three from early keratoconjunctivitis sicca (KCS) and with three specimens from severe KCS cases. The area of the ruthenium red/OsO4/mucin reaction product on the conjunctival epithelial surface was measured by image analysis and the values were expressed in micron2 per micron length of epithelium. The total area of surface mucins was differentiated from the narrow zone of mucins in close contact with the microplicae. The value for total mucins in two cases of early KCS was higher (0.4 micron2/micron) than the control range (0.1-0.3 micron2/micron) due to the presence of large clumps of mucins on the surface. The values for microplical mucins in early and severe KCS were within the control range, but were an overestimate owing to the presence of abnormal structures, e.g. vesicles, and abnormal clumps on the surface. This morphometric technique has limitations, but with appropriate material it might be a useful tool for the identification of conjunctival surface mucins.

Corneal-conjunctival uptake of topical 3H-dexamethasone in the rabbit eye

Topically administered 3H-dexamethasone was localized radioautographically to the nuclei of several cell types in the cornea and conjunctiva. In the cornea, label was found in the epithelium and keratocytes. In the conjunctiva, label was found in the epithelium and in the connective tissue cells and blood vessel endothelial cells of the stroma. Prior administration of a 350-fold excess of nonlabeled hormone completely suppressed this localization, indicating that these cells are specific glucocorticoid target cells. There was no localization found in the corneal endothelium. Accumulation of silver grains between corneal stroma and Descemet's membrane suggests that this membrane acts as a partial barrier to diffusion of the steroid.

Glucocorticoid localization by radioautography in the rabbit eye following systemic administration of 3H-dexamethasone

Dexamethasone was localized radioautographically in the nuclei of target cells of the rabbit eye following intravenous administration of the labeled steroid. Specifically bound steroid was found in the nuclei of stromal and endothelial cells of the outflow pathway region. This suggests that the glucocorticoid-induced alteration in outflow facility may be mediated by specific effects in these target cells. Nuclear localization was also found in conjunctiva, iridial smooth muscle, choroidal stroma, retina, and sclera, suggesting a physiologic role for glucocorticoids in these tissues as well.

Lactoferrin in human ocular tissues

The main lacrimal gland and accessory lacrimal tissue from seven autopsy cases, lacrimal biopsy specimens from three patients, and conjunctival biopsy specimens from ten patients were examined for lactoferrin by an immunohistologic technique. Lactoferrin was identified and localized to acinar epithelial cells of both main and accessory lacrimal tissue. Lactoferrin was not found in conjunctival tissue except within conjunctival neutrophils. Other possible sources of human tear lactoferrin were considered, but we concluded from our data that the primary source of lactoferrin in normal human tears is the acinar epithelium of the main and accessory lacrimal glands.

Natural fat in external eye. Vital-stained by Sudan III powder

Examination of 113 eyes vital-stained by Sudan powder revealed that fat on the skin of outer canthus may pass onto the precorneal film (in 68%), and that the most reliable staining is obtained by application on the bulbar conjunctiva below the limbus corneae at 6 o'clock. In 41%, the precorneal film had stained drops or foam, with a tendency towards an increase among pathological cases (infectious conjunctivitis and blepharitis). An increased amount of fat was found in the mucous thread of eyes affected with infectious conjunctivitis and lagophthalmos. In a small number of pathological cases fat was also detected on cornea, bulbar conjunctiva, and inferior fornix. The fatty layer on the lower lid margin was stained more frequently and more intensely than that on the superior. The secretion of the meibomian glands was stained in no more than a scant one half of the glands (on an average 44%), independently of age, sex, site, and diagnosis.

Ultrastructural and histochemical studies of conjunctival concretions

Ultrastructural and histochemical studies were performed on conjunctival concretions (yellow spots in the tarsal conjunctiva) from two patients who had associated atopic keratoconjunctivitis and posttrachomatous degeneration. By electron microscopy, these concretions were composed of finely granular material and membranous debris accumulating in the conjunctival subepithelium. Histochemically, concretions stained strongly positive for phospholipid and elastin, weakly positive for neutral polysaccharides and lipid, and were negative for amyloid, collagen, glycogen, iron, mucopolysaccharides, RNA, and DNA. In view of the absence of both calcium and phosphate in the accumulated material, the use of the term "lithiasis" is misleading and should be avoided. These findings support a hypothesis that concretions that follow chronic conjunctivitis represent products of cellular degeneration.

Prelminary examination of rabbit conjunctival mucins

Conjunctival mucins from albino rabbits were fractionated using gel filtration and anion-exchange chromatography. Charge homogeneity of the various conjunctival mucin fractions was confirmed by polyacrylamide gel electrophoresis. The molecular weight characteristics of the isolated fractions varied with the analytical scheme employed. Two schemes yielded mucins with molecular weights of 10(4), 10(5), and 10(6). However, when anion-exchange chromatography was the first step in the fractionation scheme, the dominant mucin had a molecular weight of 1.7 x 10(5). In contrast, when gel filtration chromatography was the first step, the dominant mucin had a molecular weight of 5.7 x 10(4). It was postulated that during migration through the anion-exchange matrix, the low molecular weight conjunctival mucin underwent trimer formation. Comparison with the mucin fractions isolated from tear mucoid threads revealed that the scheme beginning with anion-exchange chromatography preserved the fractionation pattern seen in tear mucoid threads. This result implies that conjunctival mucins undergo an association prior to or after their entry into the tear film. The molecular event of interest in this process is self-association of the species with a molecular weight of 5.7 x 10(4), resulting in a trimer with a molecular weight of 1.7 x 10(5). This trimer appears to resist deaggregation on exposure to a medium of lesser ionic strength. Several explanations are offered for its formation as well as for its stability. The implication of multiple conjunctival (tear) mucins for tear film stability also is discussed.

Secretory component in human ocular tissues

Lacrimal tissue and accessory lacrimal tissue from seven autopsy cases, lacrimal tissue from three patients undergoing orbital exploration, and biopsy specimens from conjunctiva of 14 subjects were examined for the presence and distribution of secretory component by three anti-secretory-component antisera. Secretory component was present in all lacrimal and accessory lacrimal tissues but in no other ocular tissues. Over 60% of acinar cells stained for secretory component; about 5% of acinar cells stained brightly; about 30% of tubular cells stained brightly. Main and accessory lacrimal tissues appeared identical in their staining patterns. We concluded that the main sites of synthesis of secretory IgA in human ocular tissues are the lacrimal and accessory lacrimal tissues.

Keratopathy after oral administration of tilorone hydrochloride

Two patients given tilorone HCl orally for varying periods of time had clinical and histopathologic ocular changes. Retrospective study of 14 cancer patients who were taking tilorone HCl orally revealed that three patients had similar ophthalmic findings accompanied by the appearance of blue halos around pinpoint light sources. Examination revealed a diffuse clouding of the epithelium sometimes associated with subepithelial infiltrates. Abnormalities seen histologically included cloudy swelling of the epithelium and cytoplasmic inclusions. By electron microscopy these were found to be myelinoid bodies. Gas chromatography and mass spectrophotometry showed that tilorone HCl was present in the cornea and conjuctiva. Visual acuity was not affected and these changes were slowly reversible with the cessation of therapy. Biomicroscopic and conjunctival cytologic examination may serve to indicate the drug's storage and potential damage in the body.

Adult cystinosis. A case report

A 41-year-old man, referred because of the suspicion of retinal detachment, was found to have retinoschisis, moderately severe renal disease, and adult cystinosis with crystals in the cornea and conjunctiva. Conjunctival crystals were demonstrated by light and electron microscopy, and chemical analysis confirmed the presence of excessive amounts of cystine. Studies of renal tissue showed changes that were interpreted as being due to hypertensive vascular disease. Light and electron microscopic examination of kidney tissue showed no cystine crystals, and chemical analysis indicated only trace amounts of cystine.

Unusual intracytoplasmic inclusions in a case of idiopathic scleritis

Large cells containing prominent, refractile PAS-positive inclusions were found in cytological smears prepared from scrapings of the conjunctiva of an elderly diabetic patient with idiopathic scleritis progressing to scleromalacia perforans. Electron-microscopic study of these inclusions revealed them to be intracellular accumulations of dense, flocculent mucoid material within vacuoles whose interior surface was frequently decorated with microvilli. Similar inclusions have been reported in a number of neoplasms in nonocular tissue. The significance of these findings with regard to the patient's condition is not understood.

Congenital alacrima

A sixteen-year-old black male with congenital alacrima and deficient salivary secretion demonstrated evidence of keratoconjunctivitis sicca. The workup revealed elevated immunoglobulins and histologically normal lacrimal and salivary glands, but there was deposition of amyloid in the conjunctival stroma. The differential diagnosis of the dry eye is discussed.

IgE in limbal conjunctiva in Mooren's ulcer

A patient with a severe, progressive Mooren's ulcer was unsuccessfully treated by limbal conjunctival resection and cryotherapy. The excised conjunctiva demonstrated a band of IgE along the basement membrane.

Biochemical transformation of regenerating ocular surface epithelium

Several biochemical parameters, including glycogen levels, and the activities of hexokinase, phosphorylase, and lactate dehydrogenase have been compared in regenerating epithelium of conjunctival and corneal origin in rabbits. The study was designed to determine the extent of biochemical transformation of conjunctival into corneal epithelium completed within 6 weeks. Although histological transformation, especially in the case of the chemically damaged eyes, is not. Glycogen and lactate dehydrogenase levels remained well below normal corneal epithelial levels for the period of observation.

[Early alterations of the conjunctiva after alkali-burning (author's transl)]

Early alterations of the conjunctiva after alkaliburning (with 0.25 N NaOH) are described. After chemical damage, there is a nearly total loss of conjunctival epithelium, with simultaneous marked edema in the lower conjunctival parts. Alterations of the surface are examined by scanning electronic microscopy (SEM). Within 24 h marked infiltration of round cells into the conjunctival stroma takes place. After burning, we find a rapid decrease in the ATP level in the conjunctiva to about one-tenth of the normal value, whereas glucose and lactate showed only small alterations before and after chemical injury.