Intact corneal epithelium is essential for the prevention of stromal haze after laser assisted in situ keratomileusis

AIMS

To determine the effect of intact corneal epithelium on stromal haze and myofibroblast cell formation after excimer laser surgery.

METHODS

Denuded epithelium alone, photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), or LASIK with denuded epithelium was performed in rabbit eyes. Postoperative anterior stromal haze was assessed employing a standard scale. Immunohistochemical methods were used to detect alpha smooth muscle actin (alpha-SMA), a marker for myofibroblastic cells, and type III collagen in subepithelial corneal tissue.

RESULTS

Three weeks after surgery, the presence of alpha-SMA positive long extended and spindle-shaped stromal cells, and synthesis of type III collagen were observed in the subepithelial stromal layer corresponding to corneal haze in PRK and LASIK with denuded epithelium, but not in denuded epithelium alone and LASIK.

CONCLUSION

The intact corneal epithelium may play an important part curbing subepithelial haze and differentiation of myofibroblasts in corneal wound healing.

Laser in situ keratomileusis: association with increased width of palpebral fissure

PURPOSE

To report the preoperative and postoperative palpebral fissure width in eyes undergoing laser in situ keratomileusis.

METHODS

In a prospective study, 165 consecutive eyes of 87 patients (41 men and 46 women with a mean +/- standard deviation age of 32.9 (+/-9.5) years) had laser in situ keratomileusis using a Summit (Waltham, MA) APEX PLUS excimer laser and a Moria (Antony, France) LSK microkeratome. The width of palpebral fissure was measured preoperatively, 3 months or 6 months after laser in situ keratomileusis. Patients were classified into three groups as follows: hard contact lens users group (n = 61), soft contact lens users group (n = 63), and non-contact lens users group (n = 41).

RESULTS

The average width of palpebral fissure increased after laser in situ keratomileusis in all three groups. The hard contact lens users group increased from 7.6 (+/-1.6) mm to 8.7 (+/-1.2) mm (P <.0001) and non-contact lens users group increased from 7.7 (+/-1.9) mm to 8.9 (+/-1.9) mm (P <.0001).

CONCLUSION

These results suggest that laser in situ keratomileusis may be associated with an increase in the width of the palpebral fissure.

A significant role of stromal fibroblasts in rapidly progressive dry eye in patients with chronic GVHD

PURPOSE

To elucidate histopathologic features of the lacrimal gland in chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation.

METHODS

Lacrimal gland specimens from five patients who had dry eye as part of the symptoms of chronic GVHD were examined by immunohistochemistry and transmission electron microscopy. Lacrimal gland specimens from five patients with Sjögren's syndrome (SS) were used as control samples.

RESULTS

Lymphocytes, predominantly T cells, were found primarily in the periductal areas of the lacrimal gland from patients with chronic GVHD, whereas B cells were the dominant infiltrating cells in the acinar areas of the lacrimal gland from patients with SS. Notable findings in the lacrimal gland from patients with chronic GVHD were marked fibrosis of the glandular interstitium and an increase in the number of CD34(+) stromal fibroblasts. These findings were more prominent in patients with severe dry eye than in those with mild dry eye. Electron microscopic observations of the lacrimal gland from patients with chronic GVHD revealed that stromal fibroblasts were attached to various inflammatory cells, especially T cells, through primitive or rudimentary contacts. In addition, the presence of a well-developed rough endoplasmic reticulum in the fibroblasts and newly synthesized collagen fibrils in the extracellular matrix indicated an active production of extracellular matrix components. Electron micrographs revealed multilayered and thickened basal laminae of blood vessels, ducts, and lobules in the lacrimal gland of patients with chronic GVHD; however, these observations were infrequently observed in the lacrimal glands of patients with SS.

CONCLUSIONS

The results suggest substantial differences in the lacrimal gland histopathology of patients with chronic GVHD and SS. In addition, it is likely that stromal fibroblasts are actively involved in the pathogenic process of chronic GVHD in the lacrimal gland by producing excessive extracellular matrix components.

Improvement of lacrimal function by topical application of CyA in murine models of Sjögren's syndrome

PURPOSE

The object of this study was to evaluate improvement of lacrimal gland (LG) function after topical cyclosporin A (CyA).

METHODS

Topical CyA (0.01% and 0.1%) was applied to two mouse models of Sjögren's syndrome, the NFS/sld after thymectomy and the nonobese diabetic (NOD) mouse, and the functional integrity of the lacrimal gland was evaluated by measuring basal and stimulated tear secretion and its histologic integrity by examining it for apoptosis and lymphocyte invasion.

RESULTS

After treatment with CyA at 0.1% in the NFS/sld mice, tear function increased, and there was a decrease in lymphocyte infiltration of the LG and a decrease in apoptotic figures among the acinar cells. In the NOD mice, tear function also improved, but there was no associated decrease in lymphocyte infiltration. However, the expression of Fas ligand (FasL) in NOD mice by infiltrating lymphocytes was suppressed with 0. 1% CyA eye drops.

CONCLUSIONS

CyA appears to improve tear secretion in mouse models of Sjögren's syndrome by preventing lymphocyte-induced apoptosis of acinar cells. In one model this was achieved by preventing lymphocyte infiltration and in the other by reducing expression of FasL expression on infiltrating lymphocytes.

Changes in ocular surface caused by antiglaucomatous eyedrops: prospective, randomised study for the comparison of 0.5% timolol v 0. 12% unoprostone

AIM

To study changes induced in ocular surface epithelia and the tear film by antiglaucomatous eyedrops. A beta blocker (0.5% timolol) and a novel prostaglandin F(2alpha) metabolite related drug (0.12% unoprostone) were examined in a prospective, randomised fashion.

METHODS

40 patients were randomly assigned to use either 0. 5% timolol (timolol group) or 0.12% unoprostone eyedrops (unoprostone group) twice a day for 24 weeks. In addition to routine ocular examinations, corneal epithelial integrity (vital staining tests, tear film break up time (BUT), anterior fluorometry, specular microscopy) and tear function (Schirmer's test, cotton thread test, tear clearance test (TCT)) were examined before and after the treatment.

RESULTS

Both eyedrops caused significant reduction in intraocular pressure from the baseline levels. No significant changes were noted in corneal integrity in both groups, except a decrease in BUT at 20 weeks in the timolol group. The timolol group demonstrated significant decreases in Schirmer's test, tear clearance test, and tear function index (Schirmer's test value multiplied by clearance test); however, no such changes were noted in the unoprostone group.

CONCLUSION

While unoprostone eyedrops caused no adverse effects on the corneal epithelial integrity and tear function, timolol caused significant impairments in tear production and turnover.

Combined medical and surgical treatment of severe vernal keratoconjunctivitis

PURPOSE

We report the efficacy of an alternative method of treatment for vernal keratoconjunctivitis (VKC) that consists of excision of the palpebral conjunctiva followed by supratarsal injection of corticosteroid and five times daily topical application of 0.05% cyclosporine A (CsA) and cromolyn sodium.

METHODS

We evaluated 10 patients with severe treat-resistant VKC with corneal complications. The patients were evaluated for symptoms and for signs, including conjunctival changes, corneal limbal infiltrates, vascularization, reduction of epitheliopathy, meibomitis, visual acuity, intraocular pressure, and pathologic evaluation, before and after treatment.

RESULTS

All patients showed marked improvement after 2 weeks of treatment. The symptoms (P <.01), signs (P <.02), and the visual acuity of all patients (P <.01) had significantly improved following treatment. Histological examination showed significant inflammatory cell decreases 4 weeks after surgery (P <. 05).

CONCLUSION

Surgery plus topical drug therapy may be useful in treating patients with very severe VKC.

Conjunctival epithelium expression of HLA-DR in dry eye patients

PURPOSE

To compare conjunctival epithelium expression of HLA-DR and ICAM-1 with tear dynamics and ocular surface parameters.

METHODS

Brush cytology and flow cytometry were used to quantitatively analyze HLA-DR and ICAM-1 expression in 28 dry eye patients.

RESULTS

HLA-DR was expressed in 66% of the conjunctival cells of dry eye patients. This expression correlates with that of ICAM-1, as well as with the Schirmer test results (p < 0.05).

CONCLUSION

This study confirmed that dry eye consists not only of ocular surface desiccation, but also of upregulation of the HLA-DR and ICAM-1 molecule in the conjunctival epithelium, possibly resulting in increased inflammation.

Association of preoperative tear function with surgical outcome in severe Stevens-Johnson syndrome

OBJECTIVE

To retrospectively study the surgical outcome in severe Stevens-Johnson syndrome (SJS).

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Twenty-nine eyes of patients with severe SJS associated with total conjunctivalization were examined.

INTERVENTION

Preserved human amniotic membrane grafting and keratolimbal allograft transplantation was performed. Intensive immunosuppression and epithelial management were continued postoperatively.

MAIN OUTCOME MEASURES

Successful ocular surface reconstruction was determined by epithelialization with corneal epithelium. The association between surgical outcome and preoperative tear function was studied.

RESULTS

The ocular surface was successfully covered by corneal epithelium in 13 eyes (44.8%). The mean corrected visual acuity recovered from 0.0039 to 0.017. Persistent epithelial defect was the most common complication. Eyes with successful ocular surface reconstruction had significantly better preoperative Schirmer's test values (P = 0.025) and tear clearance rates (P = 0.043) than those that failed.

CONCLUSIONS

In patients with severe SJS, preoperative tear function significantly influenced surgical outcome. Eyes with Schirmer's test value of >10 mm have a greater chance of successful ocular surface reconstruction.

Complications with one-piece lamellar keratolimbal grafts for simultaneous limbal and corneal pathologies

PURPOSE

To determine the efficacy of a one-piece lamellar keratolimbal graft for the treatment of ocular surface disorders involving the limbus and cornea.

METHODS

A retrospective study of a case series including eight patients with either Stevens-Johnson syndrome (four patients), ocular cicatricial pemphigoid (three patients), or familial subepithelial amyloidosis of the cornea (one case) was performed with a mean follow-up period of 18 months after surgery.

RESULTS

Of the eight cases, three patients retained a corneal epithelial appearance upon their latest visit. No statistically significant difference was observed between preoperative visual acuity (0.013) and postoperative acuity (0.082). Stromal neovascularization was observed in all cases. Seven of eight cases experienced persistent epithelial defects (PED), four of which evolved secondary infectious ulcers. Two cases required further surgical intervention to treat PED or infectious ulcers. None of the cases developed glaucoma.

CONCLUSION

A one-piece keratolimbal graft does not seem to offer any advantage over a two-piece limbal and corneal graft in the treatment of severe ocular surface disorders involving the limbus and cornea.

Trabeculectomy with mitomycin C for post-keratoplasty glaucoma

AIM

To investigate the effect of trabeculectomy with and without mitomycin C in post-keratoplasty glaucoma.

METHODS

A retrospective study was performed on patients who underwent trabeculectomy for glaucoma after penetrating keratoplasty. 34 eyes of 32 patients were included in this study. 26 eyes received trabeculectomy with mitomycin C and eight eyes without mitomycin C. The procedure was deemed successful if the intraocular pressure was maintained below 21 mm Hg with or without use of additional antiglaucoma medication (mean follow up time 22.3 (SD 10.3) months).

RESULTS

At the last examination trabeculectomy was successful in 19 of 26 eyes (73.0%) with mitomycin C (+) and two of eight (25.0%) without (p=0.0219). When the prognosis was analysed by Kaplan-Meier curve, the mitomycin C (+) group showed a better prognosis (p=0.0182). Mean intraocular pressure and average number of glaucoma medications improved in the group with mitomycin C without severe side effects on the graft. Graft rejection after trabeculectomy was seen in two eyes in the mitomycin C group. Final graft clarity rate was 69.2% (18/26) in the mitomycin C (+) group and 37.5% (3/8) in the mitomycin C (-) group. Complications such as persistent epithelial defect, cystoid macular oedema, choroidal detachment, leakage from bleb were seen in four eyes in the mitomycin C (+) group and in one eye in the mitomycin C (-) group.

CONCLUSIONS

Trabeculectomy with mitomycin C showed better results for glaucoma following keratoplasty.

Mikulicz's disease and Sjögren's syndrome

PURPOSE

To characterize lacrimal gland function and lymphocyte infiltration in patients with Mikulicz's disease (MD) and Sjögren's syndrome (SS).

METHODS

Four patients with MD and 5 with SS were recruited, on whom were performed Schirmer test I (Schirmer test without anesthesia), Schirmer test with nasal stimulation, and vital staining of the ocular surface. The lacrimal gland was then biopsied and the tissues stained with CD3, CD4, CD8, B220, APO2.7, Fas, and Fas ligand (Fas-L) antibodies.

RESULTS

Although regular Schirmer test results in the MD group were less than 10 mm, those with nasal stimulation, 38.1 +/- 3.4 mm, were significantly greater than the SS group. There were minimal ocular surface changes in MD. Morphologic staining with hematoxylin and eosin was identical in both groups, but the acinar cells were stained with APO2.7 only in the SS group. There was strong Fas and Fas-L staining in SS patients but not in those with MD.

CONCLUSIONS

Lacrimal gland acinar cells in those with MD maintained their function and were not programmed for cell death. The sicca syndrome was not observed in MD patients. Although the pathology is similar for MD and SS, the difference in acinar cell apoptosis and function can explain clinical differences.

Telomerase activity and p53 expression in pterygia

PURPOSE

To investigate tolomerase activity and p53 expression in pterygial tissue.

METHODS

Pterygia tissue was obtained during excisional surgery fr om 35 eyes of 35 patients, and superior bulbar conjunctival tissue from the same eye was also sampled as control when possible. Fluorescence telomeric repeat amplification protocol was used to measure telomerase activity in whole pterygium samples from 9 cases and in the epithelium and stroma of pterygium from another 10 cases. p53 protein content was measured by enzyme-linked immunosorbent assay (ELISA) in tissues obtained from 7 eyes, as well as in epithelial cell suspensions collected by brush cytology in 8 eyes. Six samples were also analyzed for UV-specific mutations in the p53 gene by the single-strand conformation polymorphism technique and DNA sequencing. A conjunctival epithelial cell line was irradiated with sublethal levels of UV-B to investigate whether telomerase activity can be induced in vitro.

RESULTS

In all, 63% of pterygia samples demonstrated telomerase activity, whereas all 10 paired conjunctival control samples were negative (P = 0.05, chi-square test). Of the 10 samples in which telomerase activity was measured separately in the epithelium and stroma of pterygia, 5 samples were positive in the epithelium, only 1 of which had activity in the stroma. Average telomerase activity in positive samples was 18.44 +/- 8.77 U/microg protein, compared with telomerase activity measured in a carcinoma in situ patient (33.73 U/microg), and in an immortalized conjunctival epithelial cell line (50.72 +/- 15.55 U/microg). Telomerase activity was not upregulated in this cell line by UV-B exposure. All 6 pterygia samples tested for p53 mutations did not reveal the UV-specific mutations in exons 5, 6, 7, or 8. No statistical significance was observed in the pterygium or conjunctiva p53 protein levels in epithelial cells collected by brush cytology, while p53 protein level was lower in pterygia when measured in whole tissue samples.

CONCLUSIONS

Telomerase activity was detected in some pterygia, mostly in the epithelium. Pterygia was not associated with an increase in epithelial p53 protein content measured by ELISA.

Formation of dioxins (PCDDs/PCDFs) by dioxin-free fly ash as a catalyst and relation with several chlorine-sources

Simplified thermal formation experiments have been conducted using dioxin-free fly ash as a catalyst with many kinds of combustible samples such as newspaper, kerosene, paraffin, PE (polyethylene), PP (polypropylene) and PVC. Chlorine sources were PVC, NaCl and HCl. The combustion of samples containing chlorine in the absence of dioxin-free fly ash produced dioxins at a low level although HCl was present in the gas stream. On the other hand, the combustion of samples without chlorine with dioxin-free fly ash increased dioxins formation to a level around 10 times higher than that upon heating dioxin-free fly ash alone. This result is considered to be due to the presence of metal chloride in the fly ash and hydrocarbons in the gas stream. The combustion of samples containing either an organic or inorganic chlorine source or using a HCl stream with dioxin-free fly ash increased dioxin level dramatically.

IL-4 induces eotaxin production in corneal keratocytes but not in epithelial cells

BACKGROUND

In severe allergic eye diseases, the breakdown of epithelial barrier function can lead to severe corneal damage such as erosions or ulcers which often resist treatment. Although eosinophils are thought to play a crucial role in corneal tissue damage in severe ocular allergy, the mechanisms of eosinophil recruitment to the cornea has not been fully clarified. Eotaxin has been found in tears of severe allergic patients with corneal ulcer. In this study, we investigated whether the Th2 cytokine interleukin-4 (IL-4) induces eotaxin production in human corneal epithelial cells and keratocytes.

METHODS

Primary cultures of human corneal epithelial cells and keratocytes were incubated with IL-4 and/or TNF-alpha for 48 h. Released eotaxin was measured by ELISA, and the eotaxin proteins were visualized by immunocytochemistry. Eotaxin mRNA expression in cultured cells was analyzed by RT-PCR.

RESULTS

IL-4 induced eotaxin production in keratocytes in a dose- and time-dependent manner which was enhanced by TNF-alpha. There was no detectable eotaxin produced by corneal epithelial cells (<5 pg/ml). The cytoplasm of keratocytes incubated with IL-4 stained positively against anti-eotaxin antibodies, while eotaxin mRNA was detected in keratocytes incubated with IL-4.

CONCLUSIONS

Human corneal keratocytes, but not epithelial cells, are capable of producing eotaxin by stimulation with IL-4. Our results suggest that eotaxin production in keratocytes induced by IL-4 may play an important role in eosinophil recruitment to corneal ulcers in allergic ocular disease. Eotaxin production by keratocytes may explain the severity of allergic disease involving the corneal stroma.

Clinical application of Er:YAG laser for the treatment of pterygium

BACKGROUND AND OBJECTIVE

To evaluate the clinical application of Er:YAG laser for the treatment of pterygium.

METHOD

Five patients (5 eyes) with pterygium, 2 primary cases and 3 retreatment cases, whose ages ranged from 44 to 68 years (mean 54.4 years), were treated with the Er:YAG laser. The optical system consisted of a fluorozirco-aluminate glass fiber and a handpiece tip made of quartz glass. The tip of the guiding probe was applied to the surface of the pterygium, where the laser beam was emitted. The radiant energy was set at 10 mJ with water spray.

RESULT

The removal of pterygium was accomplished under topical anesthesia with a laser output approximate range from 50 to 100 shots. Complications such as corneal erosion or thinning of the sclera were not observed. However, recurrence was seen in the 3 retreatment cases.

CONCLUSION

The Er:YAG laser system may be a clinically useful tool as a laser surgical knife for ocular tissue.

Ocular surface management in corneal transplantation, a review

PURPOSE

To discuss the importance of ocular surface management in corneal transplantation, especially in limbal transplantation.

METHODS

Since the corneal epithelium is not completely recovered after corneal transplantation, meticulous attention should be paid to the ocular surface to prevent infection and rejection, which are the major causes of corneal transplantation failure. Preoperative evaluations of the ocular surface should be carried out, followed by appropriate surgical procedures, depending on the condition of each patient. Vigorous immunosuppressive measures should be taken after surgery.

RESULTS

In both case reports presented in this study, each patient underwent successful surgery and his condition was controlled by medication suited to his needs.

CONCLUSIONS

For those patients with stem cell deficiency, limbal transplantation, possibly with the use of autologous serum drops, should be considered to reconstruct and maintain the ocular surface. Ocular surface management is necessary for the success of corneal transplantation, especially for limbal transplantation.

Surgical treatment of children blinded by Stevens-Johnson syndrome

PURPOSE

The surgical treatment of severe Stevens-Johnson syndrome is considered to be very difficult, especially in children. However, ocular surface reconstruction is possible in certain cases.

METHODS

We have performed ocular surface reconstruction by allogeneic corneal epithelial stem cell transplantation in four children blinded by Stevens-Johnson syndrome.

RESULTS

Two cases failed, and the other two had excellent results. The successful cases had good lacrimal function and conjunctival epithelium, with clear corneal stroma and pathology limited to the superficial ocular tissue, whereas the failures did not.

CONCLUSIONS

The successful ocular surface reconstruction has been stable for more than 1 year in two cases, suggesting that some patients with Stevens-Johnson syndrome are very good candidates for ocular surface reconstruction, especially when the patients have good tear function and healthy conjunctival epithelium.

Iatrogenic cataract after laser-assisted in situ keratomileusis

PURPOSE

To report a case of corneal opacity and iatrogenic cataract after laser-assisted in situ keratomileusis.

METHOD

Case report. A 44-year-old man was initially seen with a traumatic cataract, corneal stromal opacity, and defect of the endothelium in the right eye after laser-assisted in situ keratomileusis performed by a plastic surgeon who had no ophthalmologic training.

RESULTS

It was speculated that repeated ablations resulted in corneal perforation. We immediately performed phacoemulisification to remove the cataract and to prevent phacolytic glaucoma. However, visual acuity remained 20/200 because of the corneal stromal opacity, and penetrating keratoplasty was performed 2 months later, which improved best-corrected visual acuity to 20/30.

CONCLUSIONS

This case demonstrated that laser-assisted in situ keratomileusis can cause devastating damage to the eye.

Treatment of persistent corneal epithelial defect by autologous serum application

OBJECTIVE

To evaluate the efficacy of autologous serum application for the treatment of persistent epithelial defect.

DESIGN

Prospective, clinical, noncomparative case series.

PARTICIPANTS

A total of 16 eyes were studied.

INTERVENTION

Autologous serum was prepared from the patients and diluted to 20% by saline. The patients were instructed to use the autologous serum six to ten times a day. The concentration of vitamin A, epidermal growth factor (EGF), and transforming growth factor-beta (TGF-beta) was measured at 1 week and 1 month stored in the refrigerator and 1 month and 3 months in the freezer.

MAIN OUTCOME MEASURES

Time to closure of epithelial defect.

RESULTS

Vitamin A, EGF, and TGF-beta were stable during the 1 month in the refrigerator and 3 months in the freezer. Among 16 persistent epithelial defects, 7 (43.8%) healed within 2 weeks, 3 (18.8%) healed within 1 month, and the remaining 6 (37.5%) did not respond within 1 month. No apparent side effect of autologous serum application was observed.

CONCLUSIONS

Autologous serum application healed 43.8% of persistent defect within 2 weeks and 62.5% within 1 month.

Dry eye after haematopoietic stem cell transplantation

AIMS

To determine the incidence, natural course, and severity of dry eye occurring or worsening after haematopoietic stem cell transplantation (SCT).

METHODS

At a tertiary care hospital, 53 patients undergoing allogeneic or autologous SCT followed by at least 180 days of follow up were studied prospectively. Examination included grading of symptoms of dry eye, evaluation of ocular surface, tear break up time, and Schirmer tests with and without nasal stimulation. Meibomian gland secretion was also examined using a slit lamp while applying steady digital pressure.

RESULTS

Of the 53 patients, 44 received allografts. Half of these patients (22) developed dry eye or their pre-existing dry eye worsened after SCT, while none of nine autograft recipients did. Onset of dry eye was 171 (SD 59) days after SCT. Two types of dry eye occurred. One (n=10) was severe with ocular surface findings resembling Sjögren's syndrome and reduction of reflex tearing soon after onset. A mild type (n=12) had unimpaired reflex tearing. Meibomian gland dysfunction (MGD) was more frequent and severe in patients with dry eye and chronic graft versus host disease (GVHD), and overall severity of dry eye was greater in patients with MGD and chronic GVHD.

CONCLUSIONS

Dry eye after SCT occurred only in allograft recipients, and was not evident in autograft recipients. The severe form of dry eye had a tendency to develop rapidly. Further study on the prediction and treatment of severe dry eye after SCT is necessary.

IL-4 regulates chemokine production induced by TNF-alpha in keratocytes and corneal epithelial cells

BACKGROUND

Eosinophils are thought to play a major role in the pathogenesis of corneal lesions in ocular allergies. The regulation of chemokine production in corneal cells by the Th2 cytokine, interleukin 4 (IL-4), was examined in order to investigate its role in ocular allergies.

METHODS

Pure cultures of human corneal epithelial cells and keratocytes were exposed to tumour necrosis factor alpha (TNF-alpha) and/or IL-4. 24 hours after exposure, culture supernatants were removed and concentrations of IL-8 and RANTES were quantified by ELISA assay.

RESULTS

Simultaneous addition of IL-4 inhibited TNF-alpha induced IL-8 production in both corneal epithelial cells and keratocytes. TNF-alpha and IL-4 synergistically stimulated the production of RANTES in keratocytes.

CONCLUSION

Differential regulation of chemokine production from corneal cells by IL-4 may play a role in the selective recruitment of predominantly eosinophils to the ocular surface in ocular allergies.

Morphology and barrier function of the corneal epithelium after penetrating keratoplasty: association with original diseases, tear function, and suture removal

PURPOSE

To study changes in structure and barrier function of the corneal epithelium after penetrating keratoplasty.

METHODS

Sixty-nine eyes of 56 patients undergoing penetrating keratoplasty were studied. Fifty-six age-matched normal eyes served as controls. Corneal epithelial structure was studied by using specular microscopy. Barrier function of the corneal epithelium was examined by slit-lamp fluorophotometry. Vital staining, tear function, and corneal sensitivity also were examined.

RESULTS

Fluorescein and rose bengal staining scores, incidence of elongated cells, the mean epithelial area, and mean fluorescein uptake were significantly increased in postkeratoplasty eyes compared with controls. Original disease influenced the results of barrier function, where keratoconus revealed better function than bullous keratopathy or corneal scar. However, no such differences were noted in epithelial structure. Six eyes with absence of palisades of Vogt had revealed significantly increased epithelial area and fluorescein uptake. Removal of the running suture caused a decrease in elongated cells and epithelial cell area without significant changes in barrier function.

CONCLUSION

Corneal epithelial structure was significantly impaired in postkeratoplasty eyes. Epithelial barrier function of postkeratoplasty eyes was influenced by original diseases. Removal of sutures improves epithelial structure but not barrier function.

Preferential localization of CD8+ alpha E beta 7+ T cells around acinar epithelial cells with apoptosis in patients with Sjögren's syndrome

The T lymphocytes that infiltrate the exocrine glands in Sjögren's syndrome (SS) play a key role in damaging glandular epithelial cells, but the mechanisms of this damage by T lymphocytes are not fully understood. To determine the cellular basis of this phenomenon, we focused our attention on the T lymphocytes around acinar epithelial cells in SS. We showed that CD8+ but not CD4+ T lymphocytes were located around the acinar epithelial cells and that a majority of these CD8+ T lymphocytes possess an unique integrin, alpha E beta 7 (CD103). The acinar epithelial cell adherent with alpha E beta 7 (CD103)+ CD8+ T lymphocytes was apoptotic. Both the perforin/granzyme B and Fas/Fas ligand pathways were implicated in the process of programmed cell death in lacrimal glands. These results suggested that alpha E beta 7 integrin, by interacting with E-cadherin, mediates the adhesion between CD8+ T lymphocytes and acinar epithelial cells in SS and participates in inducing epithelial cell apoptosis, leading to secretory dysfunction of exocrine glands, a hallmark of SS.

Abnormal blinking of newscasters

When compared with a control group, blink rates of Japanese TV newscasters were increased, suggesting a possible reaction to reading the news under stressful studio conditions. Frequent blinking may be distractive to the viewing audience.