PURPOSE: We investigated the incidence of exposure keratopathy, cornea protective changes in tear film such as corneal sensitivity, tear film stability, and tear secretion after frontalis suspension, and the correlation of these with lagophthalmos. METHODS: The corneal sensitivity test, tear film break-up time (tBUT) measurement, and basic secretion test were performed prospectively in patients who had undergone frontalis suspension. RESULTS: The mean lagophthalmos was highest at postoperative 1 week and then gradually decreased. There were no significant changes in corneal sensitivity, tBUT or tear secretion after surgery. No significant differences were found in those parameters between eyes with lagophthalmos of 3 mm or more and those less than 3 mm, nor did these parameters differ between eyes with clear cornea and exposure keratopathy. Only tBUT at postoperative 1 week was significantly shorter in eyes with lagophthalmos 3 mm or more than those less than 3 mm. The average level of lagophthalmos in eyes with exposure keratopathy (15/33 eyes, 45.4%) was more than 3mm at every follow-up period, which was significantly higher than for eyes with a clear cornea. CONCLUSIONS: Tear physiology tends to maintain normal function despite poor blinking induced by lagophthalmos. The cornea is thought to be protected by these functions of tear film. The factor most influential on cornea status was the level of lagophthalmos, and exposure keratopathy should be carefully examined during postoperative period in eyes with higher lagophthalmos, especially more than 3 mm.
Blinking ; Cornea ; Follow-Up Studies ; Humans ; Incidence ; Physiology ; Postoperative Period ; Prospective Studies ; Tears*

PURPOSE: To evaluate the changes of higher order aberrations (HOAs) before and after laser subepithelial keratomileusis (LASEK) and to analyze the influence of tear film instability on HOAs of the corneal surface after LASEK. METHODS: In this cross-sectional study, 31 patients who underwent LASEK were divided into dry eye (16 patients, 32 eyes) and non-dry eye groups (15 patients, 30 eyes). Uncorrected distance visual acuity, spherical equivalent refraction, ablation depth, tear film parameters and Ocular Surface Disease Index (OSDI) questionnaire scores were evaluated in both groups. Total HOA root mean square (RMS), third-order coma, third-order trefoil and fourth-order spherical aberration (SA) of the corneal surface immediately and at 10 seconds after blinking were measured before and after surgery. RESULTS: The total HOA RMS, coma, trefoil and SA significantly increased after LASEK compared with preoperative values in both groups. In the dry eye group, total HOA RMS, coma and trefoil significantly increased except for SA at 10 seconds after blinking compared with those measured immediately after blinking. In addition, the changes of total HOA RMS, coma and trefoil were negatively correlated with tear film break-up time (R = -0.420, -0.473 and -0.439, respectively), but positively correlated with OSDI score (R = 0.433, 0.499 and 0.532, respectively). In the non-dry eye group, there were no significant differences between HOAs measured at 10 seconds after blinking and those measured immediately after blinking. CONCLUSIONS: The HOAs including coma, trefoil and SA significantly increased after LASEK. The tear film instability in the dry eye can be associated with more deterioration of the optical quality after LASEK, due to more significant increase of total HOA RMS, coma and trefoil.
Adult ; Cornea/*physiopathology ; Corneal Wavefront Aberration/*etiology/physiopathology ; Cross-Sectional Studies ; Dry Eye Syndromes/*physiopathology ; Female ; Humans ; Keratectomy, Subepithelial, Laser-Assisted/*adverse effects ; Lasers, Excimer/*therapeutic use ; Male ; Surveys and Questionnaires ; Tears/*physiology ; Visual Acuity/physiology ; Young Adult

The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a doubleedged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration.
Animals ; Apoptosis/drug effects/physiology ; Aqueous Humor/metabolism ; Blood Proteins/pharmacology ; Cell Survival/drug effects/physiology ; Cells, Cultured ; Epithelium, Corneal/*cytology/*enzymology ; Fibroblasts/cytology/enzymology ; Humans ; Nitric Oxide/biosynthesis/*physiology ; Nitric Oxide Donors/pharmacology ; Nitric Oxide Synthase/metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Penicillamine/*analogs & derivatives/pharmacology ; Peroxynitrous Acid/biosynthesis ; Rabbits ; Tears/metabolism ; Uveitis/metabolism

The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1beta, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1beta in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1beta and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders.
Acari/drug effects/physiology ; Adolescent ; Adult ; Aged ; Animals ; Blepharitis/drug therapy/*immunology/parasitology ; Chemokine CCL4/analysis ; Female ; Granulocyte Colony-Stimulating Factor/analysis ; Humans ; Interleukin-12/analysis ; Interleukin-13/analysis ; Interleukin-17/analysis ; Interleukin-1beta/analysis ; Interleukin-5/analysis ; Interleukin-7/analysis ; Male ; Middle Aged ; Tea Tree Oil/therapeutic use ; Tears/metabolism