ABSTRACT
PURPOSE: To investigate the effects of various 5-fluorouracil (5-FU) concentrations, exposure times, and application techniques on in vitro-cultured human corneal cells. METHODS: Human corneal epithelial cell (HCEC) and human corneal keratocyte (HCK) cultures were exposed to different 5-FU concentrations (0.025%-1%) and incubation durations (5 minutes to 2 hours). The cytostatic effect was evaluated as the percentage of inhibition of migration relative to the control. The evaluation of cytotoxic effect included both phase contrast microscopic observations and viability measures performed using an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] colorimetric assay. The results are expressed as ratio of optical density (OD) reduction 24 hours after exposure. RESULTS: The cytostatic effect was time and dose dependent. The 50% inhibiting dose was 0.55% after 1 hour of incubation for HCECs and was 0.5% after 2 hours of incubation for HCKs. A 100% inhibitory effect was never observed at any concentration or incubation duration. No cytotoxic changes were observed using an 5-FU concentration of <1%; 1% 5-FU showed time-dependent cytotoxic changes in HCEC cultures only. MTT analysis showed no OD reduction at 5-FU concentrations of <1%, whereas 1% 5-FU showed OD reduction <50% at any tested exposure time. HCECs showed higher reduction in OD than HCKs. CONCLUSIONS: 5-FU formulations topically used in clinical practice showed limited toxicity in normal cultured corneal epithelial cells and keratocytes.
Subject(s)
Antimetabolites/toxicity , Corneal Keratocytes/drug effects , Epithelium, Corneal/drug effects , Fluorouracil/toxicity , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Survival , Cells, Cultured , Colorimetry , Dose-Response Relationship, Drug , Humans , Microscopy, Phase-Contrast , Time Factors , Tissue DonorsABSTRACT
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes. DESIGN: Prospective, double-masked, randomized clinical trial. PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia. METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months). MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH. RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively). CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Subject(s)
Antibiotics, Antineoplastic/therapeutic use , Cornea/drug effects , Corneal Opacity/prevention & control , Mitomycin/therapeutic use , Myopia/surgery , Photorefractive Keratectomy , Wound Healing/drug effects , Administration, Topical , Adult , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/adverse effects , Contrast Sensitivity/drug effects , Double-Blind Method , Female , Follow-Up Studies , Humans , Intraoperative Care , Lasers, Excimer , Male , Microscopy, Confocal , Middle Aged , Mitomycin/administration & dosage , Mitomycin/adverse effects , Ophthalmic Solutions , Prospective Studies , Visual Acuity/drug effectsABSTRACT
The influence of duration of diabetes and metabolic control on phalangeal quantitative ultrasound (QUS) was evaluated in a group of children and adolescents with type 1 diabetes. Eighty-six patients (mean age 11.9 years; mean duration 4.3 years) were studied. Daily calcium intake was assessed by means of a questionnaire. Amplitude-dependent speed of sound (AD-SoS) was measured at the phalanxes of the non-dominant hand and expressed as a z-score. Linear and multivariate correlations with duration of diabetes and, short term and long term metabolic control were sought. AD-SoS z-score was -0.43+/-1.4 (95% CI, -0.73; -0.13). Nine subjects had values below -2S.D. Daily calcium intake was 1042+/-456 mg/day; 47 subjects (54.6%) were below the recommended levels. A negative correlation was found between AD-SoS z-score and duration (r, -0.33, P=0.002) or metabolic control (HbA1c-last year r, -0.32, P=0.002; HbA1c-whole duration, r, -0.40; P=0.003). Negative AD-SoS z-scores depended significantly and directly on duration and quality of metabolic control, even when controlled for calcium intake. In conclusion, the architectural organization of bone was impaired in 10.5% patients. Duration of diabetes and poor metabolic control were the main determinants affecting AD-SoS. QUS may be a useful tool in the screening of bone disturbance in young patients with diabetes. Optimization of metabolic control is required to prevent osteoporosis.
