Cool Crosslinking: Riboflavin at 4°C for Pain Management After Crosslinking for Keratoconus Patients, A Randomized Clinical Trial.

PURPOSE: To explore corneal cooling as a method of pain management in corneal-accelerated collagen cross-linking. METHODS: This was a prospective and interventional randomized clinical trial registered in the National Institutes of Health Clinical Trials through the identifier NCT030760770. The research was conducted at the Institute of Ophthalmology "Conde de Valenciana." A total of 98 patients were randomly assigned to one of the following 2 groups: cold riboflavin (4°C) group or control group (riboflavin at room temperature). The inclusion criteria were patients of any sex, older than 18 years of age with keratoconus diagnosis who needed management with cross-linking in both eyes because of the evidence of progression. The exclusion criteria were patients who had cross-linking without epithelial debridement, unilateral cross-linking, or any other ocular pathologies besides keratoconus and any cognitive incapacity that would make the understanding of the pain test difficult. The main outcome measures were pain, tearing, photophobia, foreign body sensation, and irritation. RESULTS: At 2 hours post-op, pain in the case and control groups was 3.80 ± 3.00 and 8.08 ± 2.21 (P < 0.05), tearing was 1.56 ± 1.96 and 8.29 ± 2.42 (P < 0.05), photophobia was 5.44 ± 3.57 and 7.83 ± 2.64 (P < 0.05), foreign body sensation was 2.20 ± 2.78 and 6.54 ± 2.73 (P < 0.05), and irritation was 3.48 ± 2.98 and 6.79 ± 3.00 (P < 0.05), respectively. A statistical significant difference was maintained in pain values on day 1 (2.79 ± 3.09 and 4.91 ± 3.27 [P < 0.05]), 2 (2.54 ± 2.41 and 4.00 ± 2.43 [P < 0.05]), and 4 (0.45 ± 0.76 and 1.22 ± 1.67 [P < 0.05]). CONCLUSIONS: This study demonstrated that pain and associated symptoms decreased significantly in the riboflavin 4°C group.

Aplicação da mitomicina C na cirurgia refrativa / Mitomycin C application in refractive surgery

RESUMO A mitomicina C teve seu uso profilático e terapêutico estabelecido, ao longo dos anos, para diminuir o haze depois da ablação superficial. A mitomicina C é segura e eficaz como uma terapia adjuvante aplicada após um procedimento primário de ceratectomia fotorrefrativa ou após um retratamento com ceratectomia fotorrefrativa após o laser in situ keratomileusis LASIK. A mitomicina age modulando a cicatrização após a cirurgia. Constitui-se num potente inibidor de mitose, bloqueia a ativação e a profliferação dos fibroblastos e a diferenciação dos miofibroblastos. Embora existam muitos estudos apontando a segurança da mitomicina nas doses ultilizadas, ainda persistem dúvidas quanto à segurança, a longo prazo, do uso da mitomicina. Quando as córneas são examinadas com microscópios confocal, após depleção inicial dos ceratócitos, a densidade celular parece retornar ao normal seis a 12 meses após o uso de mitomicina C . A maioria dos estudos clínicos não encontrou diferença significativa entre a densidade endotelial celular préoperatória e pós-operatória quando a mitomicina C 0.02% foi aplicada durante a cirurgia com um tempo de exposição de 2 minutos ou menos. Em aproximadamente 14 anos, a mitomicina C mostrou-se eficaz na prevenção e tratamento do haze corneano.

ABSTRACT Over the years, mitomycin C has been used by refractive surgeons to prophylactically decrease haze after surface ablation procedures and therapeutically in the treatment of preexisting haze. Development of mitomycin C treatments has had a significant role in the revival of surface ablation techniques. We reviewed the literature regarding mechanism of action of mitomycin C, its role in modulating wound healing after refractive surgery, and its safety and efficacy as adjuvant therapy applied after primary photorefractive keratectomy surgery or after photorefractive keratectomy re-treatment after laser in situ keratomileusis and other corneal surgeries and disorders. The drug is a potent mitotic inhibitor that effectively blocks keratocyte activation, proliferation, and myofibroblast differentiation. Many studies have suggested that mitomycin C is safe and effective in doses used by anterior surface surgeons, although there continue to be concerns regarding long-term safety. After initial depletion of anterior keratocytes, keratocyte density seems to return to normal 6 to12 months after the use of mitomycin C when corneas are examined with the confocal microscope. Most clinical studies found no difference between preoperative and postoperative corneal endothelial cell densities when mitomycin C 0.02% was applied during refractive surgery,with exposure time of 2 minutes or less. After approximately 14 years of use, mitomycin C has been found to be effective when used for prevention and treatment of corneal haze.

Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas.

PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas / Alterações na espessura da córnea durante "cross-linking" do colágeno com irradiação UV-A e riboflavina hipo-osmolar em córneas finas

PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

OBJETIVO: Avaliar as alterações da espessura mínima da córnea durante e após o cross-linking do colágeno corneano com radiação ultravioleta A e solução hipo-osmolar de riboflavina em córneas finas. MÉTODOS: Dezoito olhos de 18 pacientes foram incluídos neste estudo. Após a remoção do epitélio, solução iso-osmolar de riboflavina 0,1% foi instilada a cada 3 minutos por 30 minutos. Solução hipo-osmolar de riboflavina 0,1% foi então aplicada a cada 20 segundos por 5 minutos ou até que a espessura mínima da córnea atingisse 400 µm. Irradiação UVA foi feita durante 30 minutos. Durante a irradiação, riboflavina iso-osmolar 0,1% foi aplicada a cada 5 minutos. Paquimetria ultrassônica foi realizada no ponto mais fino da córnea antes da cirurgia, após a remoção do epitélio, após a instilação de riboflavina iso-osmolar, após a instilação de riboflavina hipo-osmolar, após a irradiação com UVA e após 1, 6 e 12 meses do tratamento. RESULTADOS: Antes da cirurgia, a espessura mínima da córnea era de 380 ± 11 µm. Após a remoção do epitélio, este valor foi reduzido para 341 ± 11 µm e após 30 minutos de riboflavina iso-osmolar, caiu para 330 ± 7,6 µm. Após a riboflavina hipo-osmolar, a espessura mínima da córnea aumentou para 418 ± 11 µm. Após a irradiação com UVA, era de 384 ± 10 µm. Após 1, 6 e 12 meses do tratamento este valor era de 372 ± 10, 381 ± 12,7 e 379 ± 15 µm, respectivamente. Não foram observadas complicações no intra ou no pós-operatório precoce ou tardio. CONCLUSÕES: A solução de riboflavina hipo-osmolar 0,1% parece ser eficaz para edemaciar córnea finas. Este efeito é transitório e de curta duração. A espessura da córnea deveria ser monitorada durante todo o procedimento. Maior número de casos e seguimento prolongado são necessários para tirarmos conclusões quanto à segurança.

Early confocal microscopy findings after cross-linking treatment.

OBJECTIVE: To determine the effects of in vivo cross-linking treatment of the cornea. METHODS: Eighteen eyes of eighteen keratoconus patients underwent cross-linking treatment using a 0.1% riboflavin solution and ultraviolet A radiation at 370 nm at 3 mW/cm² for 30 minutes. In vivo confocal microscopy was performed before, and at 1 week and 1 month after treatment. RESULTS: At 1 week after treatment, keratocyte activation and collagen fiber organization showed as hyper-reflective structures and were observed from the first sub-epithelial image to a corneal stromal depth of 275.1 ± 85.9 µm. At 1 month after treatment, activated keratocytes and fiber organization were also observed from the first sub-epithelial image to a corneal stromal depth of 324.9 ± 66.0 µm. The deepest hyper-reflective structures at 1 month showed as thick, linear-shaped hyper-reflective structures. CONCLUSION: In vivo confocal microscopy in humans showed corneal stromal changes at 1 week and 1 month after cross-linking treatment, in some cases at depths in excess of 300 µm.

Topical use of rapamycin in herpetic stromal keratitis.

PURPOSE: To evaluate and compare the efficacy of rapamycin used topically in a mouse model of herpetic stromal keratitis. METHODS: The corneas were infected with herpes simplex virus type-1 strain KOS. Animals were divided into: control (CG), rapamycin (RAPA), cyclosporine (CsA), and dexamethasone (DEXA). The evolution of the disease was assessed clinically and histologically. RESULTS: On day 10 postinfection (pi), the RAPA group showed only a significantly lower angiogenic development than the CG. On day 14 pi, the treated groups had significantly lower scores for angiogenesis and necrosis than the CG. Also, on day 14 pi, the RAPA and DEXA groups showed significantly lower histopathological scores compared to the CG. CONCLUSIONS: The topical application of 0.05% rapamycin showed greater efficacy than 0.5% cyclosporine and similar efficacy to 0.1% dexamethasone to minimize the immuno-inflammatory process. Also, rapamycin showed early inhibition of the formation of new vessels.

Effect of genipin collagen crosslinking on porcine corneas.

PURPOSE: To evaluate the effect of genipin, a natural crosslinker, on porcine corneas. SETTING: Department of Ophthalmology, Universidad Nacional de Colombia, Bogota, Colombia. METHODS: Corneal strips (12.0 mm x 2.3 mm) were harvested from porcine eyes and treated by incubation with genipin at concentrations of 1.00%, 0.25%, and 0.10%. Parallel corneal strips from the same eye were used as untreated controls. After treatment at 20 degrees C for 40 minutes, tensile strain measurements were performed in a biomaterial tester. Porcine button corneas were treated with genipin 0.25% for 15 minutes and then digested by bacterial collagenase. Treated and untreated corneas were evaluated by light microscopy. RESULTS: Young modulus and stiffness in treated corneas increased in a concentration-dependent manner. Genipin increased resistance to corneal collagenase 5-fold in comparison with the controls. A decrease in the interlamellar space in treated corneas was also observed. CONCLUSIONS: Corneal collagen crosslinking induced with genipin produced a significant increase in biomechanical strength and resistance to bacterial collagenase. This crosslinker could be useful in treating corneal ectasia and corneal infectious and noninfectious diseases involving corneal melting.

Ultra B2 - Promoção de ligações covalentes do colágeno corneal (Corneal cross-linking) no tratamento de ceratocone: resultados preliminares / Corneal Cross-linking for the treatment of keratoconus: preliminary results

OBJETIVO: Apresentar os resultados visuais e ceratométricos, seis meses após tratamento foto-terapêutico com luz ultravioleta (UV) e vitamina B2 (Ultra B2), em pacientes com ceratocone progressivo. MÉTODOS: Vinte e cinco olhos de 20 pacientes (15 homens e 5 mulheres) com ceratocone progressivo, determinado pelo aumento de curvatura em exames seriados de topografia corneal, nos últimos seis meses foram avaliados. Acuidade visual não corrigida (UVA), acuidade visual melhor corrigida com óculos (BSCVA), equivalente esférico (SEQ), cilindro refrativo manifesto e a curvatura máxima (max K) pré e pós-operatórios (1, 3 e 6 meses) foram determinadas. Todos os pacientes foram submetidos ao tratamento Ultra B2 usando riboflavina (vitamina B2) e a luz ultravioleta (UV, 370 nm). O epitélio corneal foi removido após assepsia, colocação de blefarostato e anestesia tópica com proparacaína, por meio de solução de álcool hidratado (20 por cento) utilizada por 30 segundos. A córnea foi saturada com vitamina B2 por 15 minutos; em seguida, foi irradiada por luz UV por 30 minutos. Ao final do procedimento, foi colocada lente de contato terapêutica (LCT), mantida até a epitelização total. RESULTADOS: Houve melhora na UVA após o primeiro mês (de 0,15 ± 0,15 para 0,23 ± 0,20), com contínua mudança no terceiro e sexto mês pós-operatório, atingindo a diferença estatisticamente significante nesse período (p=0,025 e p=0,037 respectivamente). BSCVA melhorou de 0,41 ± 0,27 para 0,49 ± 0,29 no sexto mês, sem atingir a diferença estatisticamente significante. A progressão do ceratocone após o procedimento não foi notada em nenhum paciente, em comparação com o avanço topográfico nos 6 meses precedentes. Após 6 meses do procedimento, max K diminuiu em mais que 2,00 D (de 53,02 ± 8,42 para 50,88 ± 6,05 D), SEQ em menos que 1 D (de -3,27 ± 4,08 para -2,68 ± 3,02 D) e o cilindro refrativo em menos que 0,5 D (de -2,29 ± 1,77 para -1,86 ± 0,92), sem atingir diferença estatisticamente...

PURPOSE: To present early visual and keratometric results for corneal cross-linking with riboflavin and UV irradiation in patients with progressive keratoconus. METHODS: Twenty-five eyes of twenty patients (15 males and 5 females) with a progressive keratoconus in the previous 6 months were followed. Unaided visual acuity (UVA), best spectacle corrected visual acuity (BSCVA), spherical equivalent (SEQ), manifest cylinder, and maximal corneal curvature (max K) values were followed at 1, 3 and 6 months. All patients were submitted to corneal cross-linking using riboflavin (vitamin B2) as the photosensitizer and ultraviolet light (UV, wavelength 370 nm). Epithelium was removed with 20 percent alcohol, cornea was soaked with vitamin B2 for 15 min, and then irradiated with UV light for 30 min, after which a bandage contact lens (BCL) was placed. RESULTS: UVA increased after one month (from 0.15 ± 0.15 to 0.23 ± 0.20), and went on increasing at 3 and 6 months, reaching statistical significance (p=0.025 e p=0.037, respectively). BSCVA increased from 0.41 ± 0.27 to 0.49 ± 0.29 at month six, without reaching statistical significance at any time point. Progression of keratoconus stopped in all patients, in contrast with progression in all of them in the six-month period prior to the surgery. Max K decreased by more than 2 D (from 53.02 ± 8.42 to 50.88 ± 6.05 D), SEQ less that 1 D (from -3.27 ± 4.08 to -2.68 ± 3.02 D), while refractive cylinder decreased less than 0.5 D (from -2.29 ± 1.77 to -1.86 ± 0.92 D), without reaching a statistically significant difference. None of the eyes lost any line of BSCVA, 12 maintained the preoperative BSCVA, 7 gained one line, 5 gained two lines, and 1 patient gained three lines of BSCVA. CONCLUSIONS: Corneal cross-linking with riboflavin and UV light seems to be a safe (no loss of BSCVA) and effective (anatomical and optical properties maintained) procedure, which has shown to stop the progression of the keratoconus...

Effects of mitomycin C on infiltration of polymorphonuclear leukocytes after epithelial scrape injury in the mouse cornea / Efeito da mitomicina C na infiltração de leucócitos polimorfonucleares após lesão epitelial em córnea de camundongo

PURPOSE: To determine whether mitomycin C (MMC) alters appearance and disappearance of polymorphonuclear leucocytes (PMN) in the cornea stroma, using an epithelial scrape injury in eye mouse model. METHODS: Twenty-mice underwent mechanical epithelium debridement in the central cornea using 20 percent ethanol. After the scrape, the right eye received 0.02 percent MMC for one minute, while the left eye received physiological saline. The animals were sacrificed on days 1, 2, 5, and 14 after surgery, and corneal whole mounts were prepared for histology. PMN distribution was analyzed in digitized microscope images. Cell division in the cornea was determined by immunohistochemical detection of bromodeoxyuridine (BrdU), which was injected intraperitoneally before the mice were sacrificed. RESULTS: Epithelial scrape injury triggered infiltration of PMNs into the corneal stroma. An analysis of PMN distribution revealed that there was no difference between eyes treated with and without MMC at all time points. BrdU labeling showed that 0.02 percent MMC for one minute blocked keratocyte proliferation completely. CONCLUSION: MMC treatment regimen, which is common in clinical practice, inhibits keratocyte proliferation during wound healing, but when used at 0.02 percent for one minute, it does not affect PMN infiltration into the corneal stroma, and subsequent movement toward the injury site, or the disappearance of PMNs from the stroma, in the mouse epithelial injury model.

OBJETIVO: O objetivo do estudo foi determinar se a mitomicina C (MMC) altera o aparecimento dos leucócitos polimorfonucleares (PMN) no estroma corneano após abrasão epitelial central, utilizando olhos de camundongo como modelo. MÉTODOS: Vinte camundongos foram submetidos à abrasão epitelial em córnea central utilizando etanol a 20 por cento. Após a lesão, o olho direito recebeu MMC a 0,02 por cento por 1 minuto, enquanto o olho esquerdo recebeu solução salina. Os animais foram sacrificados em 1, 2, 5 e 14 dias após a cirurgia e a córnea foi preparada para histologia. A distribuição dos PMN foi analisada e digitalizada em imagens microscópicas. A divisão celular na córnea foi detectada pela imuno-histoquímica da bromodeoxirudina (BrdU), injetada intraperitonialmente duas horas antes dos animais serem secrificados. RESULTADOS: A lesão epitelial gerou infiltração de PMN no estroma da córnea. A análise da distribuição dos PMNs revelou que não houve diferença estatisticamente significante entre os olhos tratados e não tratados com MMC, em todos os tempos estudados. O estudo com BrdU mostrou que a MMC quando utilizada a 0,02 por cento por um minuto bloqueou completamente a proliferação de ceratócitos. CONCLUSÃO: O tratamento com MMC, que é utilizada comumente na prática clínica, inibe a proliferação dos ceratócitos durante a cicatrização corneana, porém quando utilizada a 0,02 por cento por um minuto, não altera a infiltração dos PMNs dentro do estroma corneano após lesão epitelial em córneas de camundongos.

Immunofluorescence confocal microscopy of porcine corneas following collagen cross-linking treatment with riboflavin and ultraviolet A.

PURPOSE: To assess ultrastructural stromal modifications in porcine corneas after riboflavin and ultraviolet A (UVA) exposure using immunofluorescence confocal imaging. METHODS: Twenty-five freshly enucleated porcine eyes were enrolled in the study. Five eyes served as control (group I). Twenty eyes had their epithelium removed (groups I, II, IV, and V) and five eyes had their epithelium intact (group III). Groups II and III were cross-linked with riboflavin 0.1% solution (10 mg riboflavin-5-phosphate in 10 mL 20% dextran-T-500) and exposed to UVA (365 nm, 3 mW/cm2) for 30 minutes. Group IV included five eyes soaked with riboflavin without posterior irradiation, and group V included five eyes irradiated, without previous exposure to riboflavin. Ultra-thin sections (8 microm) of the corneas were stained with anti-collagen I and DAPI and their fluorescence was revealed under confocal microscopy. RESULTS: Only the cross-linked corneas (group II) showed a pronounced, highly organized anterior fluorescence zone of 182.5 +/- 22.5 microm. Using DAPI staining, an anterior and concentrated displacement of cell nuclei due to collagen compaction was observed after crosslinking (group II). No structural changes were observed in all other groups. CONCLUSIONS: The cross-linking treatment effect can be directly visualized using confocal fluorescence imaging, allowing for a quantitative analysis. Cross-linked corneas showed a pronounced and limited anterior zone of organized collagen fibers, which was not observed in the other groups. Treatment of the cornea with riboflavin and UVA without previous deepithelialization did not induce any cross-linking effect. Consequently, to facilitate diffusion of riboflavin throughout the corneal stroma, the epithelium should be removed as an important initial step in the treatment.

[Corneal Cross-linking for the treatment of keratoconus: preliminary results]. / Ultra B2 - Promoção de ligações covalentes do colágeno corneal (Corneal cross-linking) no tratamento de ceratocone: resultados preliminares.

PURPOSE: To present early visual and keratometric results for corneal cross-linking with riboflavin and UV irradiation in patients with progressive keratoconus. METHODS: Twenty-five eyes of twenty patients (15 males and 5 females) with a progressive keratoconus in the previous 6 months were followed. Unaided visual acuity (UVA), best spectacle corrected visual acuity (BSCVA), spherical equivalent (SEQ), manifest cylinder, and maximal corneal curvature (max K) values were followed at 1, 3 and 6 months. All patients were submitted to corneal cross-linking using riboflavin (vitamin B2) as the photosensitizer and ultraviolet light (UV, wavelength 370 nm). Epithelium was removed with 20% alcohol, cornea was soaked with vitamin B2 for 15 min, and then irradiated with UV light for 30 min, after which a bandage contact lens (BCL) was placed. RESULTS: UVA increased after one month (from 0.15 +/- 0.15 to 0.23 +/- 0.20), and went on increasing at 3 and 6 months, reaching statistical significance (p=0.025 e p=0.037, respectively). BSCVA increased from 0.41 +/- 0.27 to 0.49 +/- 0.29 at month six, without reaching statistical significance at any time point. Progression of keratoconus stopped in all patients, in contrast with progression in all of them in the six-month period prior to the surgery. Max K decreased by more than 2 D (from 53.02 +/- 8.42 to 50.88 +/- 6.05 D), SEQ less that 1 D (from -3.27 +/- 4.08 to -2.68 +/- 3.02 D), while refractive cylinder decreased less than 0.5 D (from -2.29 +/- 1.77 to -1.86 +/- 0.92 D), without reaching a statistically significant difference. None of the eyes lost any line of BSCVA, 12 maintained the preoperative BSCVA, 7 gained one line, 5 gained two lines, and 1 patient gained three lines of BSCVA. CONCLUSIONS: Corneal cross-linking with riboflavin and UV light seems to be a safe (no loss of BSCVA) and effective (anatomical and optical properties maintained) procedure, which has shown to stop the progression of the keratoconus: a reduction, although not statistically significant, of the corneal curvature, spherical equivalent and refractive cylinder took place in patients where previous progression of keratoconus had been described.

Effects of mitomycin C on infiltration of polymorphonuclear leukocytes after epithelial scrape injury in the mouse cornea.

PURPOSE: To determine whether mitomycin C (MMC) alters appearance and disappearance of polymorphonuclear leucocytes (PMN) in the cornea stroma, using an epithelial scrape injury in eye mouse model. METHODS: Twenty-mice underwent mechanical epithelium debridement in the central cornea using 20% ethanol. After the scrape, the right eye received 0.02% MMC for one minute, while the left eye received physiological saline. The animals were sacrificed on days 1, 2, 5, and 14 after surgery, and corneal whole mounts were prepared for histology. PMN distribution was analyzed in digitized microscope images. Cell division in the cornea was determined by immunohistochemical detection of bromodeoxyuridine (BrdU), which was injected intraperitoneally before the mice were sacrificed. RESULTS: Epithelial scrape injury triggered infiltration of PMNs into the corneal stroma. An analysis of PMN distribution revealed that there was no difference between eyes treated with and without MMC at all time points. BrdU labeling showed that 0.02% MMC for one minute blocked keratocyte proliferation completely. CONCLUSION: MMC treatment regimen, which is common in clinical practice, inhibits keratocyte proliferation during wound healing, but when used at 0.02% for one minute, it does not affect PMN infiltration into the corneal stroma, and subsequent movement toward the injury site, or the disappearance of PMNs from the stroma, in the mouse epithelial injury model.

Cleaning solutions as a cause of diffuse lamellar keratitis.

PURPOSE: To assess the capability of two microkeratome cleaning solutions in causing diffuse lamellar keratitis (DLK) in a rabbit model of laser in situ keratomileusis (LASIK). METHODS: Two cleaning solutions (Palmolive 2:100 and Cidezyme 2:250) were tested. These solutions were diluted with balanced salt solution according to directions from the Hansatome microkeratome manual. Two additional solutions were prepared using an additional ten-fold dilution, creating a total of four study solutions. A LASIK flap was created in one eye each of 25 rabbits using the ALK Chiron microkeratome. The rabbits were divided into five study groups. The flaps were reflected and a drop of one of the study solutions (or BSS, control group) was placed on the interface. After 1 minute, the solution was washed out from the interface and the flap was repositioned. The eyes were examined at the slit lamp on postoperative days 1, 2, 3, 5, and 7. RESULTS: In 12 eyes, a flap displacement was identified. Four eyes showed flap retraction and five others, epithelial ingrowth in flap margins. The incidence of these events did not differ among groups. Thirteen eyes were then evaluated for DLK. No DLK-like interface inflammation was seen in the studied eyes. CONCLUSION: The cleaning solutions, when diluted as recommended by the microkeratome manufacturer, when in contact with the corneal stroma, and provided that the interface was washed with BSS did not cause DLK interface inflammation in rabbit LASIK models.

Transforming growth factor-beta stimulates collagen and fibronectin synthesis by human corneal stromal fibroblasts in vitro.

The effects of transforming growth factor-beta (TGF beta) and epidermal growth factor (EGF) on the synthesis of collagen and fibronectin, and on the proliferation of human corneal stromal fibroblasts in vitro, were evaluated. Human corneal stromal fibroblasts in culture were incubated for 48 hours with TGF beta or EGF in the absence of serum. Collagen and fibronectin in the culture media were measured by a collagenase-digestion assay and a competitive ELISA, respectively. The effects of the growth factors on proliferation were assessed by 3H-thymidine incorporation. Collagen synthesis was dose-dependently stimulated by TGF beta; at a concentration of 1 ng/ml of TGF beta, a 120% increase in collagen synthesis was seen over that of controls (p < 0.01). EGF, at a concentration of 10 ng/ml, induced a 40% increase in collagen synthesis over that of controls (p < 0.01). The maximum stimulation by TGF beta was greater than that by EGF (p < 0.05). Fibronectin synthesis was stimulated by TGF beta and EGF in a dose-dependent manner; 230% (p < 0.001) and 210% (p < 0.01) increases in fibronectin synthesis were caused by 10 ng/ml TGF beta and EGF, respectively. TGF beta and EGF dose-dependently stimulated 3H-thymidine incorporation. The maximum increases in 3H-thymidine incorporation reached 180% (p < 0.001) and 190% (p < 0.001) over that in controls, at 10 ng/ml concentrations of TGF beta and EGF, respectively. In conclusion, both TGF beta and EGF are potent stimulants of collagen and fibronectin synthesis and proliferation. Therefore, these two growth factors may be effective alternatives or additional choices for the treatment of corneal ulcer.

Penetraçäo de diferentes antimicóticos na córnea humana: estudo "in vitro" / Penetration of different antifungal agents human corneas: \"in vitro\" study

Este estudo compara a penetraçäo corneana de 6 antimicóticos na câmara anterior e no estroma corneano. Trinta córneas humanas desepitelizadas e recém enucleadas foram colocadas numa câmara de perfusäo e expostas as drogas a serem testadas por 6 horas. Agentes avaliados: anfotericina B 5%, natamicina 5%, diluída em DMSO, miconazol 1%, clotrimazol 5%, tiabendazol 5% e 5-fluorocitosina 1%. Dos antimicóticos avaliados a Natamicina diluída em DMSO, tiabendazol e 5-fluorocitosina apresentaram passagem através da córnea. A anfotericina B apresentou passagem em apenas 1 experimento. Após 5 horas de imersäo da córnea dos antimicóticos, foi possível detectar altas concentraçöes de todos antimicóticos no estroma profundo da córnea. O maior índice de penetraçäo foi o da anfotericina B