Search Results

Abstract

PURPOSE: To assess the reliability and penetration depth of an automated micropuncture system using a tattoo machine.
METHODS: Twenty human corneas were obtained and subjected to intrastromal micropuncture using a tattoo machine. Each cornea was divided into two halves: one received pigment, while the other received saline solution as a control. The Cheyenne tattoo machine was operated at 60 Hz, with standardized needle exposure (six passes per application). The machine used cartridges containing five microneedles. The study was registered with Agência Nacional de Vigilância Sanitária ANVISA (numbers 80281110015, 80281110016, and 80281110019). The pigment used was Electric Ink black ink, with a density of 1,271,460 μg/mL. Puncture depth was measured before and after the procedure using both anterior segment optical coherence tomography and histopathological analysis. Puncture depth measurements were analyzed using ImageJ software. Each cornea was measured thrice, and the results were subsequently compared.
RESULTS: No corneal perforations were observed with the use of the tattoo machine, and puncture depth measurements ranged from 107 to 486 µm.
CONCLUSIONS: The use of a tattoo machine represents a viable and accessible approach for keratopigmentation, with potential for both cosmetic and therapeutic applications. Its adaptation for controlled intrastromal drug delivery may enable the targeted treatment of deep infectious keratitis, corneal neovascularization, and stromal inflammatory disorders, representing a promising approach for corneal stromal diseases. Further research is needed to optimize techniques and evaluate long-term safety and efficacy, particularly for the delivery of antimicrobial, anti-inflammatory, and anti-vascular endothelial growth factor agents.

Keywords: Eye banks; Cadaver; Cornea; Corneal stroma; Drug delivery systems; Tissue donors; Tattooing/instrumentation; Punctures

Abstract

PURPOSE: This study evaluated the proportion of corneas discarded by the Eye Bank of Londrina, Paraná, due to positive serology over a 5-year period and its impact on transplant availability.
METHODS: A cross-sectional study was conducted, analyzing 1,968 corneas from 1,056 donors collected between January 2014 and December 2018 at the Eye Bank of Londrina. Serological tests for hepatitis B (HBsAg and anti-HBc), hepatitis C (anti-HCV), and HIV (anti-HIV 1 and 2) were performed using chemiluminescent microparticle immunoassays. Data were analyzed descriptively and presented in tables and graphs.
RESULTS: Of the 1,968 corneas processed, 897 (45.57%) were discarded. Among these, 333 (37.12%) tested positive for serological markers. Hepatitis B accounted for 34.67% of positive cases (15% of total donations), hepatitis C for 1.11% (0.50% of total), and HIV for 0.89% (0.4% of total). Hepatitis cases remained stable between 2014 and 2016, with a marked decline in 2017 and 2018. Most discarded corneas were positive for anti-HBc (31.88%) and negative for HBsAg; however, the anti-HBs test was not performed to confirm immunity to the hepatitis B virus.
CONCLUSION: The findings highlight the importance of serological testing to identify and eliminate contaminated corneas, thereby preventing the transmission of infectious diseases to recipients. Positive serology for hepatitis, particularly hepatitis B, was the leading cause of corneal disposal.

Keywords: Cornea; Corneal transplantation; Corneal donation; Eye banks; Hepatitis B virus; Hepatitis C virus; HIV infections; Seropositivity; Serologic tests

Abstract

Objetivos: Dimensionar o impacto da pandemia da COVID-19 nas doações e transplantes de córnea no Brasil e obter indicadores confiáveis para o embasamento de proposições de medidas efetivas para a manutenção e o aperfeiçoamento do sistema de obtenção, processamento, distribuição, utilização e controle dos tecidos oculares doados.
Métodos: Um questionário foi enviado, pelo escritório Brasil da Associação Pan-Americana de Bancos de Olhos (APABO), aos Bancos de Olhos brasileiros. Dados de janeiro a agosto de 2020 foram coletados para gerar indicadores confiáveis sobre o impacto da pandemia da COVID-19 nas doações e transplantes de córnea no Brasil.
Resultados: Dados de 37 Bancos de Olhos mostraram que 76,1% das 3.060 doações e 74,5% dos 3.167 transplantes aconteceram no período pré-pandemia. Das 6.052 córneas processadas 71,8% foram disponibilizadas para fins terapêuticos: 72,9% foram transplantadas, 26,1% acabaram sendo inviabilizadas (45% destas, classificadas para indicações ópticas) e 1%, em glicerina, permanecia em estoque. Das 1.706 córneas que não puderam ser disponibilizadas para uso terapêutico, 47,9% foram excluídas por fatores relacionados às condições dos tecidos, 43,6% por fatores sorológicos, 6,7% por contraindicações constatadas em histórico clínico após a captação e 1,8% por outros fatores.
Conclusões: O impacto negativo da pandemia nas doações e transplantes de córnea no Brasil se deveu à recomendação do Ministério da Saúde de suspender, por quase seis meses, as captações de doadores em parada cardiorrespiratória. Os indicadores tornam evidente a necessidade de atualização dos critérios de classificação e disponibilização das córneas pelos Bancos de Olhos e do sistema nacional de distribuição destes tecidos.

Keywords: Bancos de Olhos; Córnea; Doação de tecidos; Transplante de Córnea; COVID-19; Política pública; Brasil.

Abstract

OBJETIVOS: As características físico-químicas e o baixo custo da água de coco foram fundamentais para o este estudo. Analisar o uso de solução a base de água de coco como meio de conservação de córneas humanas em banco de olhos.
MÉTODOS: Estudo experimental e controlado realizado no Banco de Olhos do Hospital Geral de Fortaleza. Utilizou-se solução à base de água de coco preparada no laboratório de Tecnologia de Sêmen de Caprinos do Departamento de Medicina Veterinária da Universidade Estadual do Ceará. Foram usadas córneas de descartes divididas em dois grupos: G1 (Conservante com água de coco) - grupo experimental e G2 (grupo Conservante com OPTISOL GS^®) grupo controle, em experimentos sequenciais. A osmolaridade do G1 foi analisada sequencialmente com 275, 300, 325, 345, 365 e 400 mOsm/L. A viabilidade das córneas foram realizadas por microscopia especular e biomicroscopia nos 1º, 3º e 7º dias.
RESULTADOS: As córneas em solução de 365 e 345 mOsm/L apresentavam transparência nos 8mm centrais até o 3º dia, com edema em toda periferia, dobras centrais e edema 2+, com perda parcial do epitélio até 7º dia, sendo o de maior osmolaridade com melhor transparência durante o seguimento. Grupo com 275, 300 e 400 mOsm/L, córnea opaca, edema difuso, perda total do epitélio no 3º dia. As córneas em Optisol mantiveram seus aspectos.
CONCLUSÕES: O conservante à base de água de coco manteve em parte a transparência corneana e a integridade epitelial, especialmente nos primeiros 3 dias de seguimento. A solução conservante com água de coco nas formulações utilizadas não se mostrou eficaz para o uso em banco de olhos humanos.

Keywords: Córnea; Água de coco; Preservação de órgãos/métodos; Solução para preservação de órgãos; Biotecnologia

Abstract

MÉTODOS: Córneas humanas de treinamento disponibilizadas foram randomizadas em quatro grupos: Pachy-100 (profundidade de incisão = espessura corneana central - margem de segurança de 100 µm), Pachy-50 (margem de segurança de 50 µm), Pachy-0 (sem margem de segurança) e Pachy+50 (profundidade de incisão = espessura corneana central + 50 µm). Todas as lamelas foram dissecadas através um método padronizado e já publicado (Pachy-DSEK). As espessuras das lamelas (centro, zona de 3,0mm e zona de 6,0mm) foram medidas com tomografia de coerência óptica. A razão de espessura centro-periferia foi calculada aos 3,0 e 6,0 mm de diâmetro.
RESULTADOS: Perfuração endotelial ocorreu apenas no grupo Pachy+50 (n=3, 30%). A espessura central da lamela nos grupos Pachy-100, Pachy-50, Pachy-0 e Pachy+50 foi de 185 ± 42 µm, 122 ± 29 µm, 114 ± 29 µm, e 58 ± 31 µm, respectivamente (p<0,001). As razões C/P aos 3,0 e 6,0 mm foram de 0,97 ± 0,06 e 0,92 ± 0,14, respectivamente. Os parâmetros de características do doador não se correlacionaram com os resultados de espessura de lamela. A profundidade planejada de incisão se correlacionou com a maioria dos parâmetros de espessura de lamela (p<0,001). A espessura de lamela se correlacionou negativamente com a profundidade planejada da incisão (p<0.001, r=-0,580). O melhor resultado foi observado no grupo Pachy-0, em que 75% das lamelas mediram abaixo de 130 µm e não houve perfuração endotelial.
CONCLUSÃO: Através de um método padronizado de dissecção, a maioria das lamelas endoteliais apresentou uma configuração planar. O planejamento de profundidade de incisão igual à espessura corneana central resultou em alta porcentagem de lamelas ultrafinas sem ocorrência de perfuração.

Keywords: Transplante de córnea; Ceratoplastia lamelar; Endotélio corneano; Dissecção; Tomografia de coerência óptica

Abstract

PURPOSE: To evaluate the impact of the COVID-19 pandemic and characterize the serological profile of discarded corneal donations in the coverage area of the Banco de Olhos de Londrina, through reverse transcription-polymerase chain reaction testing for COVID-19 and serological screening of cornea donors excluded because of positive test results.
METHODS: This observational retrospective study included 776 cornea donors who’s serological and reverse transcription-polymerase chain reaction test results were processed at the Hospital of Universidade Estadual de Londrina between May 2020 and 2022. The number of corneal donations and tissue utilization rates throughout the years of operation of the Banco de Olhos de Londrina were also analyzed.
RESULTS: The mean donor age was 53.14 years; 332 donors (43%) were female, and 444 (57%) were male. Positive results were identified in 15.76% of donors for hepatitis B core antibody antibodies, 0.65% for hepatitis B surface antigen, 1.03% for hepatitis C antibodies, and 0.52% for human immunodeficiency virus and human T-lymphotropic vírus. Positive reverse transcription-polymerase chain reaction results for SARS-CoV-2 were observed in 2.7% of cases. Older adults were 2.6 times more likely to test positive for SARS-CoV-2 (95% CI, 1.06-6.34) and 3.0 times more likely to test positive for hepatitis B core antibody (95% CI, 1.95-4.41) than younger individuals. A 75.2% reduction in corneal donations was observed in 2020 compared with 2019, accompanied by a 5% increase in tissue utilization, possibly associated with the effectiveness of donor screening during the pandemic.
CONCLUSION: The COVID-19 pandemic had a profound impact on the number of corneal transplants worldwide, in Brazil, and at the Banco de Olhos de Londrina because of the substantial decline in donations during this period. Hepatitis B was the leading cause of corneal tissue discard due to positive serology in both this study and previous reports, highlighting the importance of prevention programs and improved vaccination coverage. Strict legislation, comprehensive serological screening, and appropriate processing of donated tissue remain essential to eliminate potential sources of infection and ensure transplantation safety.

Keywords: Cornea; Corneal transplantation; COVID-19; Eye banks; Serology

Abstract

PURPOSE: To investigate the association of pre-photorefractive keratectomy Schirmer-1 test value with post-photorefractive keratectomy central corneal epithelial thickness, ocular surface disease index score, and uncorrected distance visual acuity.
METHODS: Patients were categorized according to preoperative Schirmer-1 value: the normal Schirmer Group (n=54; Schirmer-1 test value, >10 mm) and the low Schirmer Group (n=52; Schirmer-1 test value, between 6 and 10 mm). We analyzed ablation depth, visual acuity, result of Schirmer-1 test (with anesthesia), tear film break-up time, ocular surface disease index score, central corneal epithelial thickness, and spherical equivalent refraction.
RESULTS: We found significant differences between the groups in Schirmer-1 test value, tear film break-up time, and ocular surface disease index score, both preoperatively and postoperatively (p<0.001). The preoperative central corneal epithelial thicknesses of the two groups were similar (p>0.05). After photorefractive keratectomy, the Schirmer-1 test value and spherical equivalent refraction decreased in both groups (p<0.05), and ocular surface disease index scores and central corneal epithelial thickness values increased in the low Schirmer Group (p<0.001) but not in the normal Schirmer Group (p>0.05). The postoperative central corneal epithelial thicknesses of the low Schirmer Group were significantly higher than those of the normal Schirmer Group (p<0.001). Postoperative uncorrected distance visual acuity did not differ significantly between the two groups (p>0.05).
CONCLUSIONS: In patients with low Schirmer-1 test values before photorefractive keratectomy, the corneal epithelium thickened and ocular surface complaints increased during the postoperative period. However, changes in the corneal epithelium did not affect the postoperative uncorrected distance visual acuity. To reduce postoperative problems on the ocular surface in these patients, we recommend that dry eye be treated before photorefractive keratectomy.

Keywords: Epithelium, corneal; Cornea; Photorefractive keratectomy; Schirmer test; Visual acuity

Abstract

PURPOSES: This study aims to assess and compare the postoperative visual and topographic outcomes, complications, and graft survival rates following deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with macular corneal dystrophy.
METHODS: In this study we enrolled 59 patients (23 male; and 36 female) with macular corneal dystrophy comprising 81 eyes. Out of these, 64 eyes underwent penetrating keratoplasty, while 17 eyes underwent deep anterior lamellar keratoplasty. The two groups were analyzed and compared based on best-corrected visual acuity, corneal tomography parameters, pachymetry, complication rates, and graft survival rates.
RESULTS: After 12 months, 70.6% of the patients who underwent deep anterior lamellar keratoplasty (DALK) and 75% of those who had penetrating keratoplasty (PK) achieved a best-corrected visual acuity of 20/40 or better (p=0.712). Following surgery, DALK group showed lower front Kmean (p=0.037), and Q values (p<0.01) compared to the PK group. Postoperative interface opacity was observed in seven eyes (41.2%) in the DALK group. Other topography values and other complications (graft rejection, graft failure, cataract, glaucoma, microbial keratitis, optic atrophy) did not show significant differences between the two groups. The need for regrafting was 9.4% and 11.8% in the PK and DALK groups, respectively (p=0.769). Graft survival rates were 87.5% and 88.2% for PK and DALK; respectively (p=0.88 by Log-rank test).
CONCLUSION: Both PK and DALK are equally effective in treating macular corneal dystrophy, showing similar visual, topographic, and survival outcomes. Although interface opacity occurs more frequently after DALK the visual results were comparable in both groups. Therefore, DALK emerges as a viable surgical choice for patients with macular corneal dystrophy without Descemet membrane involvement is absent.

Keywords: Macular corneal dystrophy; Corneal dystrophies; Hereditary; Keratoplasty; Penetrating; Corneal transplantation

Abstract

PURPOSE: Wet bio-amniotic membrane plugging combined with transplantation is a novel option that combined amniotic membrane plugging with amniotic membrane transplantation for the treatment of small corneal perforations. This study aimed to evaluate the efficacy of wet bio-amniotic membrane plugging in the treatment of small corneal perforations and compared it with that of the penetrating keratoplasty procedure.
METHODS: Forty patients (41 eyes) with small corneal perforations <3 mm in diameter treated at our hospital between July 2018 and January 2021 were retrospectively included. Among them, 21 eyes were treated with wet bio-amniotic membrane plugging (wet bio-amniotic membrane plugging group), and 20 eyes were treated with penetrating keratoplasty procedure (penetrating keratoplasty procedure group). The best-corrected visual acuity, anterior chamber formation, corneal thickness, primary disease control, postoperative complications, and graft survival rate were assessed.
RESULTS: No significant difference in baseline characteristics was found between the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups (p>0.05). The postoperative control rates of primary diseases in the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups were 95.2% and 90.0%, respectively (p=0.481). Visual acuity was improved 6 months after the operation in the wet bio-amniotic membrane plugging group and was improved at postoperative 1 month in the penetrating keratoplasty procedure group. The formation time of the anterior chamber in the wet bio-amniotic membrane plugging group was significantly shorter than that in the penetrating keratoplasty procedure group (p=0.023). The corneal thickness of the two groups significantly increased 12 months after the operation; however, the degree of thickening in the penetrating keratoplasty procedure group was higher than that in the wet bio-amniotic membrane plugging group (p<0.001). During the follow-up, postoperative complications were not different between the two groups (p>0.999).
CONCLUSION: The results suggest that wet bio-amniotic membrane plugging is effective and safe in the treatment of small corneal perforations. Thus, it can be used as an emergency treatment alternative to penetrating keratoplasty procedure for small corneal perforations.

Keywords: Amnion; Transplantation; Amniotic membrane; Keratoplasty, penetrating; Corneal perforation; Wet bio-amniotic membrane plugging; Wet bio-amniotic membrane transplantation

Abstract

PURPOSE: To evaluate the clinical results of cryopreserved amniotic membrane transplantation as a treatment option for refractory neurotrophic corneal ulcers.
METHODS: This prospective study included 11 eyes of 11 patients who underwent amniotic membrane transplantation for the treatment of refractory neurotrophic corneal ulcers at Hospital de Clínicas da Universidade Federal do Paraná, in the city of Curitiba, from May 2015 to July 2021. Patients underwent different surgical techniques in which the amniotic membrane was applied with the epithelium facing upward to promote corneal re-epithelialization.
RESULTS: The median age of the patients was 60 years (range, 34-82 years), and 64% were men. The predominant etiology of corneal ulcers was herpes zoster (45% of cases). Approximately one-third of the patients (27%) were chronically using hypotensive eye drops, and more than half (54%) had previously undergone penetrating corneal transplantation. At the time of amniotic membrane transplantation, 18% of the eyes had corneal melting, 9% had corneal perforation, and the others had corneal ulceration without other associated complications (73%). The time between clinical diagnosis and surgical treatment ranged from 9 days to 2 years. The corrected visual acuity was worse than 20/400 in 90% of the patients preoperatively, with improvement in 36% after 3 months of the procedure, worsening in 18% and remaining stable in 36%. Of the patients, 81% complained of preoperative pain, and 66% of them reported total symptom relief after the surgical procedure. In one month, 54.6% of the patients presented a closure of epithelial defect, and half of the total group evolved with corneal thinning. The failure rate was 45.5% of the cases.
CONCLUSION: Cryopreserved amniotic membrane transplantation can be considered a good alternative for treating refractory neurotrophic corneal ulcers, as it resulted in significant improvement in pain (66%) and complete epithelial closure (60%) in many patients at 1 month postoperatively. Notably, the high failure rate highlights the need for further studies to identify patient- and ulcer-related factors that may influence the outcomes of this procedure.

Keywords: Amnion/transplantation; Corneal ulcer; Anterior eye segment; Keratitis

Abstract

O presente trabalho traz uma revisão das abordagens terapêuticas para a cegueira da córnea. O estudo detalha as etapas e os elementos envolvidos na cicatrização da córnea. Ele mostra as limitações das estratégias cirúrgicas e farmacológicas usadas para restaurar e manter a transparência da córnea em termos de sobrevida a longo prazo e alcance geográfico. As perspectivas dos agentes anabólicos, incluindo vitamina A, hormônios, fatores de crescimento e novos moduladores pró-mitóticos e anti-inflamatórios para auxiliar a cicatrização da ferida na córnea, são revisadas criticamente. Aqui, apresentamos estudos envolvendo nanotecnologia, terapia gênica e reengenharia de tecidos como possíveis estratégias futuras para atuar de maneira isolada ou combinada com a cirurgia da córnea para prevenir ou reverter a cegueira corneana.

Keywords: Cegueira; Doenças da córnea; Transplante de córnea; Terapia genética; Terapia baseada em transplante de células e tecidos; Células-tronco

Abstract

Os bancos de olhos utilizam procedimentos estéreis na manipulação dos olhos, medidas antissépticas para a descontaminação da superfície ocular e critério rigoroso de seleção do doador. Essa seleção é feita por meio do prontuário médico e de testes sorológicos específicos post mortem. Para orientá-la e uniformizá-la, as associações de bancos de olhos e órgãos governamentais fornecem listas de contraindicações absolutas e relativas de uso do tecido, baseadas nas condições prévias de saúde do doador. Essas listas são as guardiãs do princípio de Hipócrates "primum non nocere" e, como tal, são conservadoras. Entretanto, cada transplante traz o risco de transmissão de agentes potencialmente nocivos ao receptor. O objetivo não é eliminar esse risco, mas limitá-lo a um nível razoável. Existe um equilíbrio entre a segurança e a disponibilidade de córneas. A sabedoria está em manter esse equilíbrio, exercendo a prudência sem rigor exagerado.

Keywords: Bancos de olhos/normas; Transplante de córnea; Seleção do doador; Coleta de tecidos e órgãos

Abstract

Em decorrência de complicações, da biocompatibilidade e da escassez de tecido doador para transplantes de córnea natural, foram elaboradas córneas artificiais que são potenciais para reabilitar funções ópticas. Nessa perspectiva, objetivou-se a análise da eficácia da reabilitação visual entre os implantes: Boston tipo I, Boston tipo II, Aurolab, osteo-odonto-ceratoprótese e ceratoprótese de Osso Tibial. De modo geral, a princípio observou-se uma tendência de melhoria da Best-corrected visual acuity em todos os tipos de lentes, mas considerável queda durante acompanhamento a longo prazo. O dispositivo com melhor reabilitação visual em pacientes com superfícies oculares úmidas é a Boston tipo I, seguida pela Aurolab, que é economicamente viável em países emergentes. Ao considerar pacientes com olhos secos, o implante de Boston tipo II apresenta maior reabilitação visual. Por fim, em virtude de não apresentarem dados equiparáveis, as lentes osteo-odonto-ceratoprótese e de osso tibial não puderam ser analisadas.

Keywords: Transplante de córnea; Próteses visuais; Córnea; Reabilitação; Acuidade visual