Corneal reshaping: an experiment with a type I collagen-based vitrigel for remodeling porcine corneas / Remodelamento corneano: relato de um experimento com um vitrigel a base de colágeno tipo I para remodelamento de córneas porcinas

ABSTRACT Purpose: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea. Methods: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes. Implants were inserted into a manually dissected stromal pocket at a depth of approximately 200 μm. Three treatment groups were defined: group A (n=3), maximal ablation depth 70 μm; Group B (n=3), maximal ablation depth 64 μm; and group C (n=3), maximal ablation depth 104 μm, with a central hole. A control group (D, n=3) was included, in which a stromal pocket was created but biomaterial was not inserted. Eyes were evaluated by optical coherence tomography (OCT) and corneal tomography. Results: Corneal tomography showed a trend for a decreased mean keratometry in all four groups. Optical coherence tomography showed corneas with implants placed within the anterior stroma and visible flattening, whereas the corneas in the control group did not qualitatively change shape. Conclusions: The novel planoconcave biomaterial implant described herein could reshape the cornea in an ex vivo model, resulting in the flattening of the cornea. Further studies are needed using in vivo animal models to confirm such findings.

RESUMO Objetivo: Relatar um experimento projetado para determinar alterações anatômicas em córneas porcinas após a colocação de um novo implante de polímero na córnea. Métodos: Foi utilizado olho de porco ex vivo. Um novo agente modelador biocompatível, de colágeno tipo 1, com 6mm de diâmetro foi moldado com excimer laser em sua face posterior, para criar três formatos planocôncavos. Os implantes foram inseridos dentro de um bolsão, dissecado manualmente, a 200 micrômetros (μm). Foram definidos três grupos de tratamento: grupo A (n=3), teve a profundidade máxima de ablação de 70 μm; o grupo B (n=3), profundidade máxima de ablação de 64 μm; e o grupo C (n=3), profundidade máxima de ablação de 104 μm, com buraco central. O grupo controle, D (n=3), foi incluído, com a criação do bolsão estromal, porém sem inserir o material. A avaliação desses olhos foi realizada por tomografia de coerência óptica (OCT) e por tomografia corneana. Resultados: A tomografia corneana mostrou uma tendência para diminuição da ceratometria média em todos os 4 grupos. A tomografia de coerência óptica mostrou córneas com implantes localizados no estroma anterior e aplanamento visível, enquanto as córneas não mudaram qualitativamente o formato no grupo controle. Conclusões: O novo implante de biomaterial planocôncavo descrito aqui foi capaz de remodelar a córnea em modelo de animal ex vivo, resultando no aplanamento corneano. Novos estudos são necessários usando modelos animais in vivo para confirmar tais achados.

Corneal reshaping: an experiment with a type I collagen-based vitrigel for remodeling porcine corneas.

PURPOSE: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea. METHODS: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes. Implants were inserted into a manually dissected stromal pocket at a depth of approximately 200 µm. Three treatment groups were defined: group A (n=3), maximal ablation depth 70 µm; Group B (n=3), maximal ablation depth 64 µm; and group C (n=3), maximal ablation depth 104 µm, with a central hole. A control group (D, n=3) was included, in which a stromal pocket was created but biomaterial was not inserted. Eyes were evaluated by optical coherence tomography (OCT) and corneal tomography. RESULTS: Corneal tomography showed a trend for a decreased mean keratometry in all four groups. Optical coherence tomography showed corneas with implants placed within the anterior stroma and visible flattening, whereas the corneas in the control group did not qualitatively change shape. CONCLUSIONS: The novel planoconcave biomaterial implant described herein could reshape the cornea in an ex vivo model, resulting in the flattening of the cornea. Further studies are needed using in vivo animal models to confirm such findings.

Conjunctivitis Related to not Severe COVID-19: A Case Report.

PURPOSE: The purpose of this article is to report a bilateral conjunctivitis case in a patient with confirmed 2019 novel coronavirus disease (COVID-19). CASE REPORT/OBSERVATIONS: A 24-year-old healthy man developed severe conjunctivitis in his right eye, followed by his left eye 4 days after fever and myalgia. He reported yellowish conjunctival discharge, foreign body sensation, redness, and tearing, and those symptoms were resolved in 10 days. Analyses of nasopharyngeal secretions identified SARS-CoV-2 by polymerase chain reaction (PCR). CONCLUSION: Mild COVID-19 can cause severe bilateral conjunctivitis. The ophthalmologist may be aware of conjunctival secretions, a possible path of infection, during eye checkup.

Vogt-Koyanagi-Harada Syndrome in Brazilian Children.

Purpose To evaluate the characteristics of Vogt-Koyanagi-Harada (VKH) syndrome in Brazilian children.Methods Clinical data were obtained from the medical records of six children with VKH disease from March 2014 to June 2018 at the Federal University of São Paulo, Brazil.Results Six patients met the diagnostic criteria for VKH. The patients, who ranged in age from 5 to 8 years, all presented with chronic disease. The most common ocular finding was abnormal fundus pigmentation in five patients followed by band keratopathy in four. Two patients had glaucoma, cataract, and subretinal neovascularization. The final visual acuity was less than 20/40 in 50% of the eyes.Conclusion Visual outcomes were favorable in half of patients depending on the long-term sequelae. VKH is rarely reported in children and it may be sight-threatening, and requires careful attention, being an important differential diagnosis.

Pediatric Corneal Transplants: Review of Current Practice Patterns.

PURPOSE: To facilitate development of standardized guidelines for management of pediatric patients undergoing keratoplasty, particularly the youngest cohort, through a comprehensive survey assessing recent trends in practice patterns of corneal specialists and pediatric ophthalmologists. METHODS: A cross-sectional, observational study of current practices pertaining to pediatric keratoplasty was performed by designing a 20-question survey focused on preoperative indications, surgical techniques, and postoperative management. This survey was sent electronically to corneal specialists and pediatric ophthalmologists. Results were compared with the findings of previous studies regarding pediatric keratoplasty. RESULTS: Of the 80 ophthalmologists who responded, 51.3% currently perform pediatric keratoplasty; only 20% have performed >50 cases. The majority (73.8%) completed solely corneal fellowships; all perform penetrating keratoplasty, 35.2% also perform endothelial keratoplasty, and 37% also perform lamellar keratoplasty. Peters anomaly was the most common indication for transplantation (34.3%). The majority believe that 1 to 3 months is the optimal age range to perform keratoplasty for both monocular and binocular congenital corneal opacities, although 13% stated that they would never perform keratoplasty in a patient with a monocular opacity. All surgeons report modifying their intraoperative techniques for pediatric patients, but specific practices and postoperative management protocols vary. There is a consensus regarding the importance of amblyopia therapy in these patients. CONCLUSIONS: Our results were consistent with the published literature regarding the indication and types of surgery performed. Variability among surgical techniques and postoperative management protocols highlights the necessity of creating standardized guidelines to optimize management of pediatric patients undergoing keratoplasty. Collaborative efforts between corneal and pediatric specialists are crucial for defining visual rehabilitation protocols to enhance visual outcomes.

Inner retinal vasculopathy in Zika virus disease.

PURPOSE: Zika virus infection is associated with vision-threatening ocular complications including uveitis and outer retinopathy. The aim of this report is to describe a case of an adult patient with serologically confirmed Zika infection who presented with retinal vascular abnormalities that coincided with systemic post-viral neurological manifestations of the disease. OBSERVATIONS: A 34-year-old white female presented with symptoms of peripheral neuropathy following serologically confirmed Zika virus infection that was acquired in Puerto Rico four months prior to presentation. Ocular evaluation revealed perifoveal microaneurysms which were not associated with visual symptoms. CONCLUSIONS AND IMPORTANCE: These data potentially expand the phenotypic spectrum of Zika virus retinopathy. In addition to outer retinal abnormalities which are well-described in infants and adults, inner retinal vascular abnormalities may also occur and may be temporally associated with post-viral neurological sequelae of Zika virus infection. Clinicians should be aware of potential retinal involvement in affected patients who present with neurological symptoms after recovery from acute Zika virus infection.

Ocular effects of Zika virus-a review.

Zika virus was considered an innocent pathogen while restricted to the African and Asian population; however, after reaching the Americas in March 2015, it became a global threat. Despite usually causing mild or no symptoms in infected adults, Zika virus displays a different behavior toward fetuses. When infected during gestation, fetuses have their immature neural cells killed by the virus and consequently have devastating findings at birth. In the past year the drastic effects of Zika virus infection in newborns include neurological, ophthalmological, audiological, and skeletal abnormalities. These findings represent a new entity called congenital Zika syndrome. We summarize the ocular findings of congenital Zika Syndrome, as well as the current understanding of the illness, systemic manifestations, laboratory investigation, differential diagnosis, prophylaxis, and treatment for this disorder.

Uveitic band keratopathy: child and adult.

BACKGROUND: Calcified band keratopathy is a chronic degenerative disease characterized by the deposition of gray to white opacity in superficial layers of the cornea that typically develops over months or years. It is associated with a variety of conditions, including chronic uveitis. PURPOSE: The objective of this study is to assess visual acuity and corneal changes in patients with band keratopathy secondary to uveitis who underwent phototherapeutic keratectomy (PTK). SETTING: The place where this study was performed was in the Department of Ophthalmology and Visual Sciences, Federal University of Sao Paulo. DESIGN: This is a retrospective study. METHODS: Patients with uveitic band keratopathy were submitted to PTK. The PTK was performed using Allegreto Wave EX500, with the ablation area of 6 mm. RESULTS: Twelve patients (13 eyes) diagnosed with band keratopathy secondary to chronic uveitis were analyzed. Of the 12 patients, 8 patients were female (66 %), aged 22 years (7-53 years). From the 12 patients (13 eyes) evaluated in this study, only one patient (one eye) did not have visual improvement, due to epithelial deposits 2 weeks after PTK, and all the others benefited with the procedure. In the children group, all eyes had visual improvement, and quantitatively speaking, the children had a more significant improvement than adults. CONCLUSIONS: PTK is a safe and effective procedure even for children. However, the improvement in visual acuity was restricted due to other ocular changes secondary to uveitis, such as cataract and retinal changes, or even the corneal irregularity.

Effect of Topical Tacrolimus in the Treatment of Thygeson's Superficial Punctate Keratitis.

PURPOSE: To evaluate topical tacrolimus ointment for treating Thygeson's superficial punctate keratitis (Thygeson SPK). DESIGN: Retrospective interventional case series. METHODS: setting: Institutional practice. PATIENT POPULATION: The medical records of 14 patients (9 women; age range, 9-65 years) with Thygeson SPK were reviewed retrospectively. Diagnosis was based on the history and clinical examination. INTERVENTION: Patients were treated with tacrolimus 0.03% eye ointment instilled into the lower fornix twice daily for the first 2 weeks, followed by nocturnal application. The clinical signs and symptoms were assessed after 1 month of treatment. The drug was tapered with disease improvement. MAIN OUTCOME MEASURE(S): Treatment efficacy and side effects. RESULTS: All patients had bilateral disease (average duration, 6 years). All patients, except 2 who used the medication irregularly, had improved visual acuity (VA), symptoms, and signs as long as the medication was applied. Before treatment 28.57% of patients had VA between 20/30 and 20/50, with improvement after treatment to 20/25 or 20/20. Attempts to withdraw the medication resulted in recurrent disease, and, therefore, treatment was not curative during the study period. No significant local medication side effects were reported. CONCLUSION: Tacrolimus eye ointment 0.03% was effective for controlling Thygeson SPK for a long period with good patient tolerance and no noticeable local or systemic side effects. During the average 6-year follow-up, treatment was not curative. Randomized studies are difficult to conduct because of the disease rarity.