Lysis of vitreous strands with neodymium: YAG laser

Eighteen eyes with vitreous strands adherent to the corneoscleral wounds of previous cataract surgery were treated with neodymium: YAG laser to lyse those strands. Twelve eyes were treated for management of cystoid macular edema (CME group); six eyes were treated for prophylaxis of possible CME (prophylactic group). In the CME group, visual acuity improved two or more lines in nine eyes (75.0%), and seven eyes had a post laser visual acuity of 0.5 or better (One eye had a pre-treatment visual acuity of 0.5 or better). In the prophylactic group, visual acuity was either maintained at the pre-treatment visual acuity of 0.5 or better. In the prophylactic group, visual acuity was either maintained at the pre-treatment level or improved in five eyes (83.3%) 18 months later following laser treatment. This procedure was complicated by retinal detachment in one case and the elevation of intraocular pressure over 10 mmHg in another case.     

Effect of intense pulsed light using acne filter on eyelid margin telangiectasia in moderate-to-severe meibomian gland dysfunction

Lasers in Medical Science - Evaluate the improvement in clinical signs and symptoms in patients with moderate-to-severe meibomian gland dysfunction (MGD) treated with intense pulsed light (IPL)...     

Neodymium: YAG laser vitreolysis for treatment and prophylaxis of cystoid macular oedema

Eighteen eyes with vitreous strands adherent to the corneoscleral wound of previous cataract surgery were treated with neodymium: YAG laser to achieve vitreolysis. Twelve eyes were treated for management of cystoid macular oedema (CMO group) and six eyes were treated for prophylaxis of possible CMO (prophylactic group). In the CMO group, visual acuity improved two or more Snellen lines in 10 eyes (83.3%) and seven eyes had a post–laser visual acuity of 20/40 or better (one eye had a pre–treatment visual acuity of 20/40 or better). In the prophylactic group, visual acuity was either maintained at the pre–treatment level or improved in five eyes (83.3%) eighteen months after laser treatment. This procedure was complicated by retinal detachment in one case and elevation of intraocular pressure over 10 mmHg in another case.     

A femtosecond laser creates a stronger flap than a mechanical microkeratome

PURPOSE: To compare corneal flaps made with a femtosecond (FS) laser with those made with a mechanical microkeratome (MM) in rabbits, measuring early postoperative inflammation and apoptosis and late postoperative adhesion strength. METHODS: Study 1 involved four treatment groups: one with flaps made only with the FS laser (FS group), one with flaps made with the FS laser followed by excimer laser ablation (FS+LASIK), one with flaps made with the MM, and one with flaps made with the MM followed by excimer laser ablation (MM+LASIK). The eyes were analyzed by histology and TUNEL staining for apoptosis at 4 and 24 hours. Study 2 involved two reference groups: an FS group and an MM group. Adhesion strength was measured with a tension meter 1 and 3 months later. RESULTS: Study 1: Inflammatory cell infiltration in the central cornea was significantly greater in the FS group than in the MM group at 4 and 24 hours (P < 0.05) and was significantly greater in the FS+LASIK group than in the MM+LASIK group at 24 hours (P < 0.05). Infiltration at the peripheral interface was significantly greater in the FS group than in the MM group and was significantly greater in the FS+LASIK group than in the MM+LASIK group at 24 hours (P < 0.05). Study 2: At 1 and 3 months, 126.7 and 191.3 grams of force (gf) were needed to detach the flaps in the FS group, compared with 65 and 127.5 gf in the MM group, respectively. The grams of force needed was significantly higher in the FS group than in the MM group at 3 months (P < 0.05). CONCLUSIONS: The FS laser produces greater corneal stromal inflammation than the MM early postoperatively without any increase in apoptosis and stronger flap adhesion late postoperatively. Therefore, it may require stronger anti-inflammatory drugs to be administered.     

Mitomycin C, ceramide, and 5-fluorouracil inhibit corneal haze and apoptosis after PRK

PURPOSE: To investigate the effects of mitomycin C (MMC), ceramide, and 5-fluororacil (5-FU) on haze after photorefractive keratectomy (PRK) and exposure to ultraviolet B (UVB) radiation. METHODS: The right eyes of 42 New Zealand white rabbits were treated with PRK to correct -10 diopter with a 5-mm optical zone. Sponges soaked in 0.02% MMC, 10 or 40 micromol/L ceramide, or 0.5% 5-FU were applied to the right eyes of 6 rabbits each, and a tarsorrhaphy was performed. Eight weeks after complete healing, topical 0.02% MMC or 0.5% 5-FU was applied twice daily to the right eyes of 6 rabbits that had previously received PRK but no topical medication. The control group of 6 rabbits was treated only with PRK. Three weeks after PRK, all the laser-treated eyes were exposed to 100 mJ/cm UVB radiation. Corneal haze was assessed biomicroscopically every 2 weeks using the Fantes scale. Eyes were enucleated 2, 7, and 13 weeks after PRK, and tissue specimens were stained with hematoxylin and eosin and with Apostain. RESULTS: Corneal haze was observed in all rabbits after PRK and was aggravated by UVB irradiation. When applied immediately after PRK, MMC induced corneal opacity and apoptosis of keratocytes, but, at later times, this reagent significantly suppressed opacity, Apostain-positive keratocytes and reactivation of keratocytes, even after UVB irradiation. In contrast, ceramide and 5-FU suppressed corneal opacity after PRK, but this effect was not sustained after UVB irradiation. CONCLUSIONS: MMC is a potent inhibitor of haze induced by PRK and UVB irradiation. Throughout the process of corneal wound healing, the severity of apoptosis and reactivation of keratocytes was closely correlated with haze formation.     

Non-contact tonometry: an ideal method for mass screening

We evaluated one of the new non-contact tonometers, the Pulsair non-contact tonometer, to assess its accuracy and reliability. Measurements on 101 eyes were used to assess its accuracy against Goldmann tonometry measurements, and another 24 eyes were used to assess its reliability (reproducibility). The results showed the instrument to be highly accurate and reliable in measurement.     

Regulation of 1-cys peroxiredoxin expression in the process of stromal wound healing after photorefractive keratectomy

PURPOSE: To investigate 1-cys peroxiredoxin (1-cysPrx) expression during the corneal wound-healing process after PRK and the effect of growth factors on 1-cysPrx expression in cultured bovine keratocytes (BKs). METHODS: Rat corneas were excised at 4 hours, 12 hours, 1 day, 3 days, and 7 days after PRK. Expression of 1-cysPrx in the corneas was examined by immunohistochemical, Northern blot, and immunoblot analyses. Keratocytes were isolated from bovine corneas and subcultured to study the effects of TGF-beta1, keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and H2O2 on 1-cysPrx expression at different concentrations and time intervals. Generation and proliferation of intracellular reactive oxygen species (ROS) in cultured BKs stimulated by these growth factors were measured by the DCF (2',7'-dichlorofluorescein) assay, the CCK-8 assay, and immunoblot analysis with a polyclonal proliferating cell nuclear antigen (PCNA) antibody, respectively. RESULTS: Intense staining of 1-cysPrx was observed in the epithelia and the anterior stromas of wounded corneas 4 hours after PRK and had extended to the entire stroma by day 3. By day 7, the expression almost returned to nonsurgical control level in epithelia, although notable expression was still detectable in the stroma. Concomitant augmentation of 1-cysPrx mRNA and protein was seen in the corneas at 12 hours to 7 days. Growth factor treatment in cultured BKs resulted in 1-cysPrx induction in a dose- and time-dependent manner. Growth factor-stimulated cells showed strong DCF fluorescence and increased proliferation during a 24-hour incubation, during which an upregulation of 1-cysPrx occurred. CONCLUSIONS: These observations provide new information for the regulation of 1-cysPrx expression during the corneal wound-healing process.