Reizo Manabe

Fibronectin appears at the site of corneal stromal wound in rabbits

Fibronectin (FN) is present both in plasma and in extracellular matrix, and is postulated to be involved in wound healing. The appearance of FN was investigated in the wounded rabbit cornea after corneal stroma was injured with a sharp knife or after lamellar keratoplasty was performed. An indirect immunofluorescence technique was employed to detect the presence of FN. Normal, unwounded rabbit cornea showed an intensive fluorescence at Descemets membrane. Strong specific fluorescence was observed at the edge of a stromal wound and beneath the sliding epithelial cells after non-perforating incisions. These could be detected as early as 3 hours after injury. The fluorescence became the strongest at 6 hours, and and then gradually decreased in its intensity, disappearing by about 7 days when epithelial cells entirely filled the stromal wound. In case of lamellar keratoplasty, FN was detected at the interface of the graft and the recipient cornea. These results suggest that FN plays an important role in the stromal wound healing.

Serial alterations in endothelial cell shape and pattern after intraocular surgery

We serially examined the endothelial cellular pattern and thickness of the central cornea after intracapsular cataract extraction and penetrating keratoplasty. The endothelial cellular pattern was analyzed with a computer-assisted digitizer. We used the frequency of hexagonal cells as the index to describe the degree of hexagonality in the cellular pattern. In the intracapsular cataract extraction group (20 eyes), the frequency of hexagonal cells was 68% preoperatively. During the first four weeks this frequency decreased rapidly to a significantly lower level (52%). The corneal thickness was significantly increased within the first week (0.57 mm) and steadily decreased to preoperative values at four weeks (0.53 mm). During the period from four to 24 weeks, the frequency of hexagonal cells increased gradually to 64%. In the penetrating keratoplasty group (ten eyes), the frequency of hexagonal cells and the thickness at one month were 62% and 0.64 mm respectively. During the next six months the frequency of hexagonal cells decreased significantly to 53%, and the thickness decreased to 0.53 mm. There was a gradual increase in the frequency of hexagonal cells to 62% during the two years after penetrating keratoplasty.

Quantitative Analysis of Endothelial Mosaic Pattern Changes in Anterior Keratoconus

The corneal endothelia of 21 eyes with anterior keratoconus and 15 eyes of age-matched controls were investigated with a specular microscope. Of the 21 eyes, 15 had definite keratoconus while six apparently normal fellow eyes were designated as latent. The corneal endothelial photographs were subjected to a computerized digitizer analysis of the area and shape of individual cells. The endothelium in keratoconus showed a significant increase in the extent of polymegethism (the coefficient of variation in cell area; 0.36 +/- 0.07) as compared with controls (0.24 +/- 0.03), with the mean cell area staying within normal limits. The relative frequency of hexagonal cells in keratoconus (50.5 +/- 5.7%) was significantly lower than that of controls (70.6 +/- 5.5%). Additionally, an increase of various cell shapes was noted, indicating that there was also a significant increase in cellular pleomorphism. In the latent group, alterations in cellular structure could not be detected by analysis of cell area when compared to controls. However, when these eyes were subjected to cell shape analysis and compared to fellow keratoconic eyes, both eyes showed similar pleomorphic characteristics. These results suggest that in the fellow eye in unilateral keratoconus, even when there are no ocular signs and symptoms, diagnosis can be made early with specular microscopy and computerized cell shape analysis.

Demonstration of Herpes Simplex Virus DNA in Idiopathic Corneal Endotheliopathy

A 56-year-old man developed idiopathic corneal endotheliopathy. The lesion consisted of severe stromal edema at the lower half of the cornea along with a number of associated keratic precipitates and steadily progressed to the upper half of the cornea. By polymerase chain reaction, herpes simplex virus DNA was demonstrated in the aqueous humor of this patient. Corneal stromal edema was resolved in response to treatment with topically applied and systemic acyclovir. Herpes simplex virus DNA was repeatedly demonstrated in the aqueous humor when the endothelial lesion recurred later. This evidence strongly indicates that this unique endothelial disorder is of viral origin.

Sodium and chloride transport across the isolated rabbit ciliary body

Unidirectional Na+ and Cl- fluxes were determined in the isolated rabbit ciliary body under short-circuited conditions. A statistically significant net Cl- flux towards aqueous was detected in the standard bathing solution (HCO3- = 115 mM), but no net Na+ flux was demonstrated in this solution. The net Cl- flux exceeded the short-circuit current, suggesting the existence of a net flux of other ion(s). In a bathing solution containing 5 mM HCO3-, the net Cl- flux was abolished, suggesting that HCO3- in the bathing solution enhances the net Cl- flux.

Clinical Evaluation of Fibronectin Eyedrops on Epithelial Disorders After Herpetic Keratitis

The clinical efficacy was investigated of fibronectin eyedrops on the nonhealing corneal epithelial defect after herpetic keratitis. Fibronectin eyedrops were prepared from the patients own blood plasma by an affinity chromatography using gelatin-coupled agarose gel and by gel filtration technique. Twenty eyes with metaherpetic trophic ulcer with persistent epithelial defect that had not responded to conventional therapy were treated by the instillation of fibronectin eyedrops 6 times a day. The mean +/- standard deviation duration of epithelial defect was 61.5 +/- 66.1 days. The epithelial defects healed within 15.6 +/- 12.4 days. These results suggest that fibronectin eyedrops are a possible effective therapeutic approach in nonhealing corneal epithelial defect after herpetic keratitis.

Vitamin A eyedrops for superior limbic keratoconjunctivitis.

We treated 12 patients with superior limbic keratoconjunctivitis with topical vitamin A (retinol palmitate) eyedrops. After a follow-up period of at least three months, this therapy was found to be effective, to a varying extent, in ten patients (83%). Superior limbic keratoconjunctivitis lesions did not recur in these patients as long as topical application was continued.

Aldose reductase inhibitor (CT-112) eyedrops for diabetic corneal epitheliopathy.

We treated two diabetic patients with corneal epithelial disorder that resisted conventional medical therapy with topical CT-112 (5-[3-ethoxy-4-pentyloxyphenyl]-2,4-thiazolidinedione), a newly synthesized aldose reductase inhibitor. One patient had developed recurrent corneal erosion after vitrectomy and the other had spontaneously developed superficial punctate keratopathy. The corneal lesion in each patient responded to topical CT-112 in two to four weeks and was almost cleared within two months. A similar corneal lesion recurred in both patients soon after CT-112 was discontinued, but it disappeared again when the drug was resumed.

Distribution of epidermal growth factor in rat ocular and periocular tissues.

Using a sensitive radioimmunoassay (RIA) specific for rat epidermal growth factor (rEGF), we investigated the presence of rEGF in a variety of rat ocular and periocular tissues. Immunoreactive rEGF (IR-rEGF) was present in tear fluids (25.5 ± 5.8 ng/ml), exorbital lacrimal gland (6.73 ng/g wet weight), intraorbital lacrimal gland (2.80 ng/g wet weight), Harderian gland (1.90 ng/g wet weight), and conjunctiva (0.16 ng/g wet weight). EGF was not detectable in aqueous humor, cornea, iris and ciliary body, lens, or the posterior part of the globe (retina, choroid, and vitreous body). Gel exclusion chromatography and reverse-phase high-performance liquid chromatography revealed that IR-rEGF in the above ocular fluids and tissues was indistinguishable from standard rEGF. Using enzyme-linked immunohistochemistry, rEGF was demonstrated to be localized in the duct epithelial cells of lacrimal glands. These findings reveal that EGF is preferentially localized in the ocular surface and lacrimal apparatus.

Co-existence of glucagon- and substance P-like immunoreactivity in the chicken retina

This immunohistochemical study of chicken retina using flat-mounts shows that pancreatic glucagon- and substance P-like immunoreactive amacrine cells have more heterogeneous subpopulations than was previously understood to be the case. Using double-staining immunohistochemical procedures we demonstrate that a substantial proportion of all subtypes of glucagon-like immunoreactive cells contain substance P-like immunoreactivity and that the ratio of the amacrine cells containing both peptides to total immunoreactive cells varies according to position in the retinal and cell type. These results suggest that retinal cells may have different functions according to position or cell type.