Corneal biomechanical features in patients with ankylosing spondylitis / Características biomecânicas da córnea entre pacientes com espondilite anquilosante

ABSTRACT Purpose: To evaluate the corneal biomechanical features and central corneal thickness in ankylosing spondylitis patients and to evaluate correlations of these parameters with disease activity. Methods: The study included 51 patients diagnosed with ankylosing spondylitis (mean age, 40.80 ± 13.15 years; range, 18-72 years) and 34 age- and sex-matched healthy controls (mean age, 42.00 ± 12.32 years; range, 18-60 years). All underwent a complete ophthalmological and physical examination, including visual acuity testing and biomicroscopic anterior and posterior segment examinations. Corneal hysteresis, corneal resistance factor, Goldmann-correlated intraocular pressure, and corneal compensated intraocular pressure were evaluated with an ocular response analyzer, and the central corneal thickness was measured with Sirius® corneal tomography. The Bath Ankylosing Spondylitis Disease Activity Index, Functional Index, and Metrology Index scores were recorded. Results: In the ankylosing spondylitis patients, the mean disease duration was 7.73 ± 6.05 (range, 1-30) years. There was no statistically significant difference between the patients and controls in the corneal biomechanical features. The Goldmann-correlated intraocular pressure and corneal compensated intraocular pressure both showed positive correlations with age (p=0.003 and p=0.001, res­pectively). There was a negative correlation between corneal hysteresis and disease duration (p=0.002), and between central corneal thickness and the Bath Ankylosing Spondylitis Metrology Index score (p=0.003). Conclusion: This study demonstrated a significant negative correlation between corneal hysteresis and disease duration in ankylosing spondylitis patients. Furthermore, the central corneal thickness value decreased with an increase in Bath Ankylosing Spondylitis Metrology Index score, which may result in an underestimate of intraocular pressure readings and thus an inaccurate risk assessment of glaucoma.

RESUMO Objetivo: Avaliar as características biomecânicas da córnea e espessura central da córnea em pacientes com espondilite anquilosante e analisar a correlação destes parâmetros no grupo de estudo com a atividade da doença. Métodos: Foram incluídos no estudo 51 pacientes com diagnóstico de espondilite anquilosante e 34 controles saudáveis com idade e sexo. Todos os sujeitos foram submetidos a um exame oftalmológico e físico completo, incluindo exames de acuidade visual, exames de segmento anterior e posterior biomicroscópicos. Foram avaliados o coeficiente de resistência da córnea, a pressão intraocular correlacionada com Goldmann e a pressão intraocular compensada da córnea com o analisador de resposta ocular, a espessura corneana central com a tomografia corneana pelo Sirius®. Se o índice de atividade da doença de espondilite anquilosante de banho, o índice funcional de espondilite anquilosante de banho, o índice de metrologia de espondilite anquilosante de banho. Resultados: Foram incluídos no estudo 51 pacientes com idade média de 40,80 ± 13,15 (intervalo: 18-72) anos e 34 casos de controle com idade média de 42,00 ± 12,32 (intervalo: 18-60) anos. No grupo espondilite anquilosante a duração média da doença foi de 7,73 ± 6,05 (1,00-30,00) anos. Não houve diferença estatisticamente significante entre dois grupos quanto às características biomecânicas da córnea. Na análise de correlação, no grupo de estudo; pressão intraocular correlacionada com Goldmann e pressão intraocular compensada da córnea estavam positivamente correlacionados com a idade (p=0,003, p=0,001, respectivamente). Houve uma correlação negativa entre a duração da doença e CH (p=0,002), e entre índice de metrologia de espondilite anquilosante de banho e espessura corneana central (p=0,003). Conclusão: Este estudo demonstrou correlação negativa significativa entre a duração da doença e a histerese corneal em pacientes com espondilite anquilosante. Além disso, com um aumento na pontuação de índice de metrologia de espondilite anquilosante de banho, o valor de espessura corneana central também estava di­minuindo o que pode causar uma diminuição nas leituras de pressão intraocular artificialmente e resultar em avaliação de risco imprecisa de glaucoma.

Corneal backscatter in insulin-dependent and non-insulin-dependent diabetes mellitus patients: a pilot study / Retroespalhamento luminoso das córneas de pacientes com diabete melito dependente e não dependente de insulina: estudo piloto

ABSTRACT Purpose: To compare central corneal backscatter obtained from Scheimpflug images between patients with insulin-dependent and non-insulin-dependent diabetes mellitus (IDDM and NIDDM, respectively) and healthy controls. Methods: Seven patients with IDDM (7 eyes), eleven patients with NIDDM (11 eyes), and sixteen healthy subjects (16 eyes) were included in this pilot study. Scheimpflug imaging system (Pentacam, Oculus Inc., Germany) was used to obtain optical sections of the cornea. Seven meridians were analyzed for each eye, oriented from 70° to 110°. Optical density values for the central 3-mm and 5-mm zones of the cornea were obtained by image analysis using external software. Results: Corneal backscatter was significantly higher in the diabetic patients than in the controls for the central 3-mm (p=0.016) and 5-mm (p=0.014) zones. No significant differences in corneal backscatter were found between the IDDM and NIDDM groups for either zone (both p>0.05). In the NIDDM group, significant correlations were observed for both central zones between corneal backscatter and age (3 mm: r=0.604, p=0.025; 5 mm: r=0.614, p=0.022) and central corneal thickness (3 mm: r=0.641, p=0.017; 5 mm: r=0.671, p=0.012); this was not found in the IDDM group (p>0.05). The presence of diabetes showed a significant effect on central corneal backscatter (Kruskal-Wallis test, p<0.001). Conclusions: Diabetic patients showed higher values of corneal light backscatter than healthy subjects. Corneal optical density analysis may be a useful tool for monitoring and assessing the ocular changes caused by diabetes.

RESUMO Objetivo: Determinar os valores de retroespalhamento luminoso central da córnea em pacientes diabéticos dependentes (IDDM) e não dependentes (NIDDM) de insulina, comparados com controles saudáveis, a partir de imagens de Scheimpflug. Métodos: Foram incluídos neste estudo piloto sete pacientes com IDDM (7 olhos), onze pacientes com NIDDM (11 olhos) e dezesseis indivíduos saudáveis (16 olhos). O sistema de Scheimpflug (Pentacam, Oculus Inc. Germany) foi utilizado para obter secções ópticas da córnea. Foram analisados sete meridianos para cada olho, orientados de 70º a 110º. A análise de imagem por meio de software externo permitiu a obtenção de valores da densidade óptica para os 3 e 5 mm centrais da córnea. Resultados: O retroespalhamento luminoso corneano foi significativamente maior em pacientes diabéticos para os 3 mm centrais (p=0,016) e para os 5 mm centrais (p=0,014) em relação ao grupo controle. Não foram encontradas diferenças significativas entre os grupos IDDM e NIDDM para cada zona analisada (p>0,05 em ambos os casos). No grupo NIDDM, observaram-se correlações significativas para as zonas centrais de 3 mm e 5 mm, entre retroespalhamento luminoso corneano e idade (r=0,604 p=0,025 e r=0,614 p=0,022, respectivamente) e espessura central corneana (r=0,641 p=0,017; r=0,671 p=0,012, respectivamente), o que não foi encontrado no grupo IDDM (p>0,05). O teste de Kruskall-Wallis indicou que a presença de diabete tem um efeito significativo sobre a retroespalhamento central da córnea (p<0,001). Conclusões: Pacientes diabéticos apresentaram valores mais elevados de retroespalhamento luminoso corneano do que indivíduos saudáveis. A análise da densidade óptica corneana pode ser uma ferramenta útil para monitorar e avaliar as alterações oculares causadas pela diabete.

Intrastromal corneal ring segment implantation for ectasia after refractive surgery / Implante de segmento de anel intraestromal de córnea para ectasia pós-cirurgia refrativa

ABSTRACTPurpose:To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS) implantation to correct ectasia in eyes with prior refractive surgery.Methods:Forty-one eyes of 25 patients (13 men, 12 women; mean age, 28.66 years) with ectasia after refractive surgery [photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK)] were included in a nonrandomized, retrospective, observational case series. Corneal tunnels were created by mechanical dissection in all eyes. Main outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), refraction, keratometry, and computerized analysis of corneal topography. Patients were divided into two groups by the type of refractive surgery (Group A: PRK, Group B: LASIK).Results:The mean preoperative manifest astigmatism decreased from -1.88 to -0.84 D in Group A (p=0.096) and -3.18 to -1.77 D in Group B (p=0.000). The mean keratometric astigmatism decreased from -2.58 to -1.66 D in Group A (p=0.010) and -4.80 to -2.78 D in Group B (p=0.000). The mean spherical equivalent decreased from -2.97 to -2.05 D in Group A (p=0.065) and -3.31 to -2.42 D in Group B (p=0.014). No significant between-group differences were noted on the comparison of preoperative and postoperative results. No intraoperative or postoperative complications were observed.Conclusion:ICRS implantation is a useful treatment option for ectasia following refractive surgery, and it has significantly reduced the refractive cylinder and increased best spectacle-corrected visual acuity.

RESUMOObjetivo:Avaliar os resultados do implante de anel intraestromal de córnea para correção de ectasia pós-cirurgia refrativa.Métodos:Quarenta e um olhos de 25 pacientes, 13 homens e 12 mulheres, com ectasia pós-cirurgia refrativa (PRK ou LASIK) foram incluídos em um estudo não randomizado, retrospectivo e observacional. A média de idade no momento do implante do anel é de 28,66 anos. Em todos os olhos, o túnel corneano foi criado através da dissecção mecânica da córnea. Os resultados avaliaram acuidade visual sem correção (AVSC) e acuidade visual com correção (AVCC), refração, ceratometria e topografia corneana computadorizada. Os pacientes foram divididos em dois grupos de acordo com a cirurgia refrativa. Grupo A: PRK, Grupo B: LASIK.Resultados:A média do astigmatismo pré-operatório foi reduzida de -1,88 D para -0,84 D no grupo A (P=0,096) e de -3,18 D para -1,77 D no grupo B (P=0,000). A média do astigmatismo ceratométrico foi reduzida de -2,58 D para -1,66 D no grupo A (P=0,010) e de -4,80 para -2,78 D no grupo B (P=0,000). A média do componente esférico foi reduzida de -2,97 D para -2,05 D no grupo A (P=0,065) e de -3,31 D para -2,42 D no grupo B (P=0,014). Nenhuma diferença estatisticamente significativa foi observada entre os grupos, quando se comparou os resultados do pré e pós-operatório. Não ocorreram complicações intra ou pós-operatórias.Conclusão:O implante de anel intraestromal de córnea é uma boa opção para o tratamento de ectasia pós-cirurgia refrativa, tendo resultado na redução significativa do astigmatismo refracional e melhora da acuidade visual com correção.

Outcome of optical penetrating keratoplasties at a tertiary care eye institute in Western India.

Aim: To study the indications, risk factors, postoperative course, and long-term survival of corneal transplants done for optical purposes. Design: Retrospective case series. Materials and Methods: Data were obtained by reviewing the records of 181 patients operated at our institute (H.V. Desai Eye Hospital) between October 2005 and October 2007 for optical penetrating keratoplasty. Patients with less than one year of follow up, pediatric cases, therapeutic, tectonic, and lamellar keratoplasties were excluded. Kaplan Meier survival analysis was used to calculate median survival time of grafts and to see correlation between nine variables viz. age, gender, corneal vascularization, previous failed grafts, previous Herpes Simplex keratitis, post-perforation corneal scars, donor tissue quality, graft size, type of surgery and follow-up. These variables were also used for univariate and multivariate analysis using Cox Proportional Hazard Regression Modeling. Results: Median survival of the cohort was 27 months (95% confidence interval: 20.47-33.52). One- and two-year survival rates were 65% and 52.5%, respectively. Median survival was significantly lower in poor prognosis cases (14 months) than good prognosis cases (27 months, P = 0.0405). Graft survival was lower in vascularized corneas (18.55 months, P = 0.030) and in post-perforation corneal scars (17.96 months, P = 0.09, borderline significance). Multivariate analysis showed that the same factors were predictive of graft failure. Conclusion: Long-term survival of grafts at our center is different from centers in western world. More high-risk cases, paucity of excellent quality donor corneas, and differences in patient profile could be the contributory factors.

Descemet stripping and endothelial keratoplasty in endothelial dysfunctions: three-month results in 75 eyes.

PURPOSE: To analyze the results of Descemet stripping and endothelial keratoplasty (DSEK) in the first consecutive 75 cases. MATERIALS AND METHODS: Prospective, non-randomized, non-comparative interventional case series. Seventy-five eyes of 75 patients with endothelial dysfunctions of different etiology, scheduled for DSEK, were included in this study. Healthy donor cornea with a cell count of> 2000 cells/sq mm was considered for transplantation in each case. Indications, operative problems and postoperative complications were noted. Best corrected visual acuity (BCVA), refractive and keratometric astigmatism, central corneal thickness (CCT) and endothelial cell density (ECD) were analyzed for each patient after a minimum follow-up of three months. RESULTS: Main indication was pseudophakic corneal edema and bullous keratopathy in 53 (70.7%) eyes. Seventeen (22.7%) cases had moderate to severe Fuchs' dystrophy with various grades of cataract; and DSEK was combined with manual small-incision cataract surgery (MSICS) with posterior chamber intraocular lens (PCIOL) in those cases. After three months, BCVA was 20/60 or better in 62 (82.7%) cases. Mean refractive and keratometric astigmatism were 1.10 +/- 0.55 diopter cylinder (DCyl) and 1.24 +/- 0.92 DCyl. The CCT and ECD were 670.8 +/- 0.32 microm and 1485.6 +/- 168.6/sq mm respectively. The mean endothelial cell loss after three months was 26.8 +/- 4.24% (range: 13.3-38.4%). Dislocation of donor lenticule occurred in six (8.0%) eyes. Graft failure occurred in one case. CONCLUSIONS: Descemet stripping and endothelial keratoplasty is a safe and effective procedure in patients with endothelial dysfunctions with encouraging surgical and visual outcomes. It can be safely combined with MSICS with PCIOL in patients with moderate to severe Fuchs' dystrophy with cataract.

Un enfoque holístico de las enfermedades de la superficie ocular / A holistic approach for ocular surface diseases

La transparencia comeal es producto de un complejo sistema de interacciones. El conocimiento de estas es muy importante para establecer una terapia adecuada para patologías tan diversas como son la disfunción lagrimal, el haze comeal post PRK, y el rechazo comeal. La conjuntiva y el epitelio comeal indemnes son imprescindibles para mantener la función del sistema ocular. A su vez la integridad de estas estructuras depende de la integridad de párpados y lágrimas. Actualmente sabemos que la interacción entre estos cuatro componentes permite mantener en equilibrio la homeostasis de la superficie ocular. Asegurando la indemnidad de las células progenitoras límbicas. La alteración en cualquiera de estos factores produce ojo rojo, infecciones, mayor predisposición a úlceras, y alteraciones de la epitelización. Desequilibrios en el funcionamiento de este sistema se engloban hoy como enfermedades de la superficie ocular, y están dando origen a una nueva subespecialidad. Ya que los avances en el conocimiento de la fisiopatología de la lagrima y de su interacción con la come a, han permitido el desarrollo de una mirada más racional de la patología de este segmento creemos interesante revisar este conjunto de desordenes y proponer una aproximación terapéutica.

Comeal transparency is own to a complex system of interactions. Settle the right therapeutic approach in quite different pathologies as comeal haze, comeal rejection and tears disfunction, is related with the knowledge ofthese relationships. Comeal and conjunctival epithelium integrity is essential in ocular system function, as lids and tears . Nowadays we know that reciprocal relations between this items are essential in ocular surface homeostasis. Any disruption means the rise of redness, infections, ulcers predisposition, and disruptions in epithelization. Today all this malfunctions are known as Ocular Surface Pathologies rising a new subspeciality. Since new advances in tears physiology allows a rational approach to diagnosis and treatment ,we find useful to list out this disorders and proposing a therapeutic schedule.

Queratotoxon o anillos cornéales / Corneal rings

Los anillos cornéales habitualmente no son completos, pueden representar desde cambios fisiológicos (anillo limbar ) hasta enfermedades que, si no son diagnosticadas y tratadas oportunamente, pueden terminar con la visión, el ojo e, incluso, con la vida del paciente (anillo limbar, embriotoxon anterior, embriotoxon posterior), de la segunda a cuarta década de la vida (arco juvenil, anillo de Fleisher, anillo de Kayser-Fleisher, queratoconjutivitis alérgica, distrofia corneal anular, desgeneración marginal de Terrien) y seniles (gerotoxon). La distrofia corneal de Schnyder puede presentarse tan precozmente como al año y medio de edad. El anillo por anestésico local, lo hemos visto desde la adolescencia en adelante. Los anillos cornéales intraestromales se implantan, en general, a partir de la tercera o cuarta década de la vida. El anillo de Wessely, el anillo por queratoplastía y el anillo blanco de Cotas pueden presentarse en cualquier etapa de la vida. Respecto a su ubicación pueden ser paracentrales, paralimbares y perilesionales.

Correlation of neuropathy with corneal sensitivity and lacrimal gland secretion in type 2 diabetes mellitus patient.

AIM: To evaluate correlation between blood glucose control, corneal sensitivity and lacrimal secretion in type 2 DM with peripheral neuropathy. METHODS: A cross sectional study has been conducted in 20 type DM with peripheral neuropathy and 20 without peripheral neuropathy at the Department of Internal Medicine and Ophthalmology, Ciptomangunkusumo Hospital, Faculty of Medicine University of Indonesia, from August through November 2002. All subject underwent a comprehensive medical examination, including esthesiometer Semmes-Weinstein 10 g, HbA1c, Schirmer test, and corneal sensitivity measurements. RESULTS: The mean corneal sensitivity was significantly lower in diabetic patients with neuropathy (p=0.000). HbA1(c) was related to corneal sensitivity (p=0.016). CONCLUSION: In type 2 DM with peripheral neuropathy, corneal sensitivity was demonstrated to be significantly decrease, all of which seems to be due to the status of blood glucose control.

Alteraçöes corneanas pós-tracoma näo associadas a entrópio ou triquíase / Corneal findings not related to entropion or trichiasis after trachoma

Descrever alteraçöes corneanas pós-tracoma näo associadasa deformidades palpebrais. Métodos: Foi realizada avaliaçäo oftalmológica completa em 7 pacientes do ambulatório de Córnea e Doenças Externas da Escola Paulista de Medicina da Universidade Federal de Säo Paulo. Para o nosso estudo selecionamos pacientes com diagnóstico prévio de tracoma sem deformidades palpebrais, história pregressa de correçäo de entrópio ou epilaçäo, mas com opacidades corneanas. Resultados: Dentre os achados oftalmológicos observados neste estudo destacaram-se: opacidade corneana bilateral em 100 por cento dos casos, afinamento corneano em 85,7 por cento dos casos, pannus superior bilateral em 71,4 por cento dos casos e fibrose da conjuntivatarsalsuperior bilateral em 85,7 por cento dos casos. Conclusäo: As alteraçöes corneanas pós-tracomatosas podem se manifestar sob diversas formas clínicas, incluindo opacidades, afinamentos, ceratites secundáriasa infecçäo, vascularizaçäo, ectasias, alteraçäo da sensibilidadee xerose. Na ausência de entrópio ou triquíase estas alteraçöes podem resultar na inflamaçäo tracomatosa, ceratite intersticialou formas de tratamento utilizadas no passado, no entanto a sua fisiopatologia ainda é controversa.

Amniotic membrane transplantation for ocular surface reconstruction.

OBJECTIVE: To study the efficacy of amniotic membrane transplantation in various indications for ocular surface reconstruction. METHOD: Amniotic membrane transplantations were performed in 140 eyes (130 patients) for ocular surface reconstruction. The indications for the corneal group were limbal stem cell deficiency, bullous keratopathy, persistent epithelial defect, band keratopathy, prosthesis, corneal ulcer and acute chemical burn. The indications for the conjunctival group were grafts for pterygium, conjunctival tumors, symblepharon, and covering the scleral graft. RESULTS: Success was noted in 75.7 per cent (106/140) eyes, partial success in 17.9 per cent (25/140) eyes, and failure in 6.4 per cent (9/140) eyes for a mean follow-up of 6.6 months (1-19 months). The success and partial success rate were 80.6 per cent (54/67), 14.9 per cent (10/67) in the corneal group and 71.2 per cent (52/73), 20.6 per cent (15/73) in the conjunctival group. CONCLUSION: Amniotic membrane transplantation can solve some difficult ocular surface problems, and can be used to promote epithelial healing, reduce inflammation and scarring.

Cornea stress test--evaluation of corneal endothelial function in vivo by contact lens induced stress.

Reliable and valid assessment of corneal endothelial function is a critical input for diagnosing, prognosticating and monitoring progression of disorders affecting corneal endothelium. In 123 eyes, corneal endothelial function was assessed employing data from the corneal hydration recovery dynamics. Serial pachometric readings were recorded on Haag-Striet pachometer with Mishima-Hedbys modification before and after two hours of thick soft contact lens wear. Percentage Recovery Per Hour (PRPH) was derived from raw data as an index of endothelial function. Assessed PRPH in pseudophakic corneal oedema and Fuchs' endothelial dystrophy eyes (35.9 +/- 9.8%) was significantly lower than normal controls (61.9 +/- 10.5%). On employing receiver operation characteristics curve analysis the tested results demonstrated high sensitivity (87%) and specificity (92%) for detection of low endothelial function at PRPH cut off of 47.5%. Using this PRPH cut off, 80% of Fuchs' endothelial dystrophy and 93.3% of pseudophakic corneal oedema eyes could be demonstrated to have low endothelial function. A total of 66.7% of diabetic eyes also demonstrated PRPH of lower than 47.5%. Clear corneal grafts demonstrated PRPH values of 24.6% to 73.0%. Of 6 corneal grafts that demonstrated initial PRPH of lower than 47.5%, 4 failed within 4 to 6 months. Our data demonstrated high sensitivity and specificity of this corneal stress test. PRPH index was useful in quantifying endothelial function in clinical disorders including diabetes mellitus. The index PRPH was demonstrated to be useful in monitoring and prognosticating outcome of corneal grafts.

Perfuraçäo em degeneraçöes ectásicas da córnea / Perforation in ectatic corneal degenerations

A degeneraçäo marginal de Terrien, a degeneraçäo marginal pelúcida e o ceratoglobo säo patologias ectásicas da córnea. Essas degeneraçöes produzem áreas de afinamento periférico que causam ectasia, astigmatismo irregular e maior suscetibilidade a perfuraçöes corneanas. Säo apresentados 4 casos de degeneraçöes ectásicas com perfuraçäo corneana (1 casos de ceratoglobo, 2 casos de degeneraçäo marginal de Terrien, e 1 caso de degeneraçäo marginal pelúcida). O tratamento cirúrgico dessas degeneraçöes é controverso. As técnicas descritas säo pouco estudadas devido ao pequeno número de casos. Geralmente requerem grande habilidade do cirurgiäo. As perfuraçöes säo complicaçöes graves e de difícil manejo. Assim, justificam-se medidas preventivas

Healing of a graft in vascularized and non-vascularized corneal lesions.

The healing of graft and visual results were compared in 21 vascularized and 29 non-vascularized corneal lesion. The healing and visual results were better in those cornea which were non-vascularized.