Verônica Castro Lima

The Use of Vital Dyes in Ocular Surgery

Vital dyes have advanced diagnosis and surgical technique in various specialties, including oncology, gastroenterology, and ophthalmology. In ocular surgery vital dyes are widely used in cataract and vitreoretinal surgery. Worldwide, intra-operative use of trypan blue during cataract surgery has enhanced visualization of the anterior capsule during capsulorrhexis, and patent blue has been recently licensed in Europe for cataract surgery. For chromovitrectomy, the vital dyes indocyanine green, infracyanine green, and brilliant blue stain the internal limiting membrane, and trypan blue and triamcinolone acetonide help visualize epiretinal membranes and vitreous, respectively. Intra-operative vital dyes are finding uses in corneal, glaucoma, orbit, strabismus, and conjunctival surgery. We provide a summary of current knowledge of the use of vital dyes in ocular surgery. We review the properties of dyes, techniques of application, indications, and complications in ocular surgery. Vital dyes represent an expanding area of research, and novel dyes deserve further investigation.

Spectral-domain optical coherence tomography for early glaucoma assessment: analysis of macular ganglion cell complex versus peripapillary retinal nerve fiber layer

OBJECTIVEnWe sought to compare the glaucoma discrimination ability of macular inner retinal layer (MIRL) thickness with that of conventional peripapillary retinal nerve fiber layer (pRNFL) thickness as measured by spectral-domain optical coherence tomography (SD-OCT) in patients with early glaucoma.nnnDESIGNnCross-sectional study.nnnPARTICIPANTSnWe studied 67 patients with early glaucoma (visual field mean deviation index ≥-6 dB), and 56 healthy subjects were prospectively enrolled.nnnMETHODSnAll patients underwent MIRL thickness measurement (ganglion cell complex [GCC] scan) and pRNFL thickness measurement (3.45 mm scan) by SD-OCT. Whenever both eyes were eligible, one was randomly selected. Receiver operating characteristic curves and sensitivities at fixed specificities were generated for different parameters. The areas under the receiver operating characteristic curves (AUCs) of each parameter were compared.nnnRESULTSnThe average mean deviation for the glaucomatous eyes was -2.5 ± 1.6 dB. The AUCs for average (0.815); superior (0.807); and inferior (0.788) MIRL thicknesses were not significantly different (p ≥ 0.18). The AUCs for average (0.735); superior (0.728); and inferior (0.697) pRNFL thicknesses were also similar (p ≥ 0.15). Average MIRL thickness had a significantly larger AUC compared to average pRNFL thickness analysis (0.815 vs 0.735; p = 0.03). Sensitivities at 80% specificity for average MIRL and pRNFL thicknesses were 66.7% (cutoff, 89.9 μm) and 62.9% (cutoff, 111.8 μm), respectively.nnnCONCLUSIONSnThe GCC scan showed a similar or even a slightly better ability to discriminate between healthy and early glaucomatous eyes compared to the pRNFL scan. Different from previous analyses considering total macular thickness, the GCC macular scan seems to be a useful tool for identification of early structural damage in patients with glaucoma.

Association between corneal biomechanical properties and optic nerve head morphology in newly diagnosed glaucoma patients

Background:u2002 To investigate the association between corneal biomechanics and optic nerve head morphology in newly diagnosed primary open‐angle glaucoma patients.

Macular pigment optical density measured by dual-wavelength autofluorescence imaging in diabetic and nondiabetic patients: a comparative study.

PURPOSEnTo compare macular pigment optical density (MPOD) in type 2 diabetic and nondiabetic patients by using dual-wavelength autofluorescence imaging and to investigate the correlation of MPOD with glycosylated hemoglobin (HbA1C) and serum lipid levels.nnnMETHODSnForty-three patients were divided into groups 1 (controls, n = 14), 2 (diabetic without retinopathy, n = 17), and 3 (diabetic with mild nonproliferative retinopathy, n = 12). MPOD was measured with a modified confocal scanning laser ophthalmoscope and compared among groups (analysis of variance). The correlation of HbA1C and serum lipid (HDL, LDL, total cholesterol, and triglycerides) levels with MPOD was determined for each group (linear regression analysis).nnnRESULTSnMean ± SD ages in groups 1 (56.2 ± 11.7 years), 2 (58.6 ± 11.5 years), and 3 (62.8 ± 9.8 years) were similar (P = 0.324). Mean MPOD averaged in a 2°-diameter circle around the fovea was significantly different between the three groups: 1, (0.29 ± 0.07 density units [DU]), 2 (0.22 ± 0.09 DU), and 3 (0.14 ± 0.05 DU) (P < 0.001). There was a significant difference in mean MPOD levels at 0.5° between groups 1 (0.51 ± 0.12 DU) and 2 (0.24 ± 0.11 DU; P < 0.001), but not between groups 2 and 3 (0.33 ± 0.15 DU; P > 0.05). A significant inverse correlation was observed between HbA1C levels and mean MPOD, averaged at 2° around the fovea in all patients (r = -0.63, P < 0.001). No significant correlations were found between MPOD and serum lipid levels or age.nnnCONCLUSIONSnType 2 diabetic patients, with or without retinopathy, had reduced MPOD when compared with that in nondiabetic patients. In addition, a significant inverse correlation between MPOD and HbA1C levels was observed.

Current Concepts of Trypan Blue in Chromovitrectomy

Trypan blue (TB) is a blue vital dye with fine color properties to stain the anterior lens capsule and thereby may facilitate capsulorrhexis during cataract surgery. In addition, the blue stain may assist in the visualization of various preretinal membranes and tissues during vitreoretinal surgery in a procedure also called chromovitrectomy. TB has demonstrated great binding affinity for the glial epiretinal membranes, although it remains yet to be determined in which circumstances the dye may color the vitreous and internal limiting membrane. Most studies suggest that 0.06% TB does not pose harm to the retina, but at higher concentrations further investigation is necessary. In this paper, various aspects of the application of TB for chromovitrectomy are discussed including laboratory investigations, surgical technique and clinical outcomes.

Factors associated with topographic changes of the optic nerve head induced by acute intraocular pressure reduction in glaucoma patients.

PurposeTo investigate factors associated with changes in optic nerve head (ONH) topography after acute intraocular pressure (IOP) reduction in patients with primary open-angle glaucoma (POAG).MethodsUntreated POAG patients (IOP >21u2009mmu2009Hg) were prospectively enrolled. Systemic and ocular information were collected, including central corneal thickness (CCT) and corneal hysteresis (CH). All patients underwent confocal scanning laser ophthalmoscopy and tonometry (Goldmann) before and 1u2009h after pharmacological IOP reduction. The mean of three measurements was considered for analysis. Changes in each ONH topographic parameter were assessed (one eye was randomly selected), and those that changed significantly were correlated with patients systemic and ocular characteristics.ResultsA total of 42 patients were included (mean age, 66.7±11.8 years). After a mean IOP reduction of 47.3±11.9%, significant changes were observed in cup area and volume, and in rim area and volume (P<0.01), but not in mean cup depth (P=0.80). Multiple regression analysis (controlling for baseline IOP and magnitude of IOP reduction) showed that CH (r2=0.17, P<0.01) and diabetes diagnosis (r2⩾0.21, P<0.01) were negatively correlated with the magnitude of changes in ONH parameters, whereas the cup-to-disc ratio was positively correlated (r2=0.30, P<0.01). Age, race, disc area, and CCT were not significant (P⩾0.12). Including all significant factors in a multivariable model, only the presence of diabetes remained significantly associated with all ONH parameters evaluated (P<0.01).ConclusionsDifferent systemic and ocular factors, such as diabetes, CH, and the relative size of the cup, seem to be associated with the magnitude of changes in ONH topography after acute IOP reduction in POAG patients. These associations partially explain the ONH changes observed in these patients and suggest that other factors are possibly implicated in an individual susceptibility to IOP.

Retinal vascular occlusions occur more frequently in the more affected eye in exfoliation syndrome

PurposeTo evaluate the relationship between retinal vascular occlusions (RVOs) and exfoliation syndrome (XFS) in a cohort of patients with the two conditions.MethodsWe reviewed the records of patients with XFS with or without glaucoma and any type of RVO between 1983 and 2007. Patients with prior incisional surgery or a history of uveitis were excluded. Data collected included demographics, systemic comorbidities, type of RVO, and intraocular pressure (IOP) before the RVO. Slit-lamp biomicroscopy regarding the presence of exfoliation material on the lens capsule and pupillary margin before the vascular event was used to evaluate the laterality and degree of XFS.ResultsWe identified 36 patients (mean age 78.4±8.3 years, 19 women). Most patients were of European descent (34/36) and 20 (56%) had no prior glaucoma diagnosis. The most common retinal vascular events were central retinal vein occlusion (18/36) and BRVO (10/36). Mean IOP between eyes with (19.5±6.5u2009mmu2009Hg) and without (17.9±4.8u2009mmu2009Hg) RVO was similar (P=0.12). RVOs occurred more commonly in the eye with more pronounced XFS in 92% (33/36) of the cases. A similar agreement was found when considering patients with and without glaucoma separately (94% (15/16) vs90% (18/20); P=0.83). In addition, no difference in the agreement percentage was observed when comparing patients with unilateral XFS (87% (13/15)) with all study patients (P=0.87).ConclusionsRetinal vascular occlusion in patients with XFS occurs most often in the affected or more severely affected eye. As vascular occlusions happened in patients with and without glaucoma in similar proportions, the presence of XFS seems to play an important role in these findings.

Macular pigment in retinal health and disease

Lutein and zeaxanthin, two carotenoid pigments of the xanthophyll subclass, are present in high concentrations in the retina, especially in the macula. They work as a filter protecting the macula from blue light and also as a resident antioxidant and free radical scavenger to reduce oxidative stress-induced damage. Many observational and interventional studies have suggested that lutein and zeaxanthin may reduce the risk of various eye diseases, especially late forms of AMD. In vitro and in vivo studies indicate that they could protect various ocular cells against oxidative damage. Recent research has shown that in addition to traditional mechanisms, lutein and zeaxanthin can influence the viability and function of cells through various signal pathways or transcription factors: for instance, they can affect immune responses and inflammation, and have anti-angiogenic and anti-tumor properties. This review covers the basic aspects and results of recent studies regarding the effects of lutein, zeaxanthin and other carotenoids, such as meso-zeaxanthin, on the eye in different clinical and experimental models and the management of various ocular diseases using these molecules.

Factors affecting the variability of the Heidelberg Retina Tomograph III measurements in newly diagnosed glaucoma patients

PURPOSEnTo determine factors associated with the test-retest variability of optic nerve head (ONH) topography measurements with confocal scanning laser ophthalmoscopy (CSLO) in newly diagnosed glaucomatous patients.nnnMETHODSnConsecutive patients with newly diagnosed primary open-angle glaucoma were prospectively enrolled. Patients presenting with any ocular disease other than glaucoma were excluded. All patients underwent CSLO using the Heidelberg Retina Tomograph III (HRT-III) in one randomly selected eye (three consecutive scans; performed by the same examiner). For each Heidelberg Retina Tomograph III parameter, repeatability was assessed using within subject standard deviation (Sw) and coefficient of variation (CVw), repeatability coefficient (RC) and intraclass correlation coefficient (ICC). Scatter plots and regression lines were constructed to identify which factors influenced test-retest measurement variability.nnnRESULTSnA total of 32 patients were included (mean age, 65.4 ± 13.8 years). Most patients were female (65%) and white (50%). Among all Heidelberg Retina Tomograph III parameters evaluated, rim area and mean cup depth had the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined by optic disc stereophotograph examination) was significantly associated (R²=0.21, p<0.01) with test-retest measurement variability. Eyes with larger CDR showed less variable measurements. Other factors, including age, disc area, central corneal thickness and intraocular pressure were not significant (p>0.14).nnnCONCLUSIONnHeidelberg Retina Tomograph III showed good test-retest repeatability for all ONH topographic measurements, mainly for rim area and mean cup depth. Test-retest repeatability seemed to improve with increasing CDR. These findings suggest that HRT-III topographic measurements should be cautiously interpreted when evaluating longitudinally glaucoma patients with early structural damage (small CDR).

Avaliação estrutural do polo posterior em pacientes com doença de Behçet

OBJETIVO: Avaliar achados demograficos, de exame ocular, alteracoes vasculares e estruturais por meio de angiografias com fluoresceina e indocianina verde e de tomografia de coerencia optica em retina e coroide em pacientes com doenca de Behcet com controle clinico. METODO: Revisao de prontuarios de 16 pacientes com doenca de Behcet em fase inativa da doenca. Foram submetidos a exame oftalmologico, angiografias com fluoresceina e indocianina e tomografia de coerencia optica e divididos em dois grupos de acordo com o tempo de doenca. RESULTADOS: Avaliou-se 13 pacientes do sexo feminino e 3 do sexo masculino. Os principais achados de exame ocular foram estreitamento vascular, catarata, atrofia do disco optico e membrana epirretiniana macular. Sessenta e dois e meio por cento dos pacientes estavam com acuidade visual igual ou melhor que 0,1. Os principais achados na angiografia com fluoresceina foram vazamento capilar e impregnacao da parede vascular, na angiografia com indocianina verde foram lesoes hipofluorescentes bem definidas e na tomografia de coerencia optica foram membrana epirretiniana e atrofia retiniana. Analisando a acuidade visual, nao se encontrou diferenca estatistica entre os parâmetros de sexo, tempo de doenca, presenca de edema retiniano na tomografia de coerencia optica ou na angiografia com fluoresceina. O aumento da espessura macular nao se correlacionou positivamente com a idade, tempo de doenca ou com a acuidade visual. O encontro de afinamento vascular na angiografia com fluoresceina correlacionou-se com maior duracao da doenca (p=0,033). Os demais achados dos exames nao se correlacionaram com o tempo de doenca. CONCLUSAO: Os exames de angiografias com fluoresceina e indocianina verde e tomografia de coerencia optica fornecem dados importantes do acometimento do polo posterior na doenca de Behcet. Apesar do aparente controle clinico, esses exames podem evidenciar atividade inflamatoria persistente, a qual ocasiona progressao da perda visual e significante numero de pacientes com cegueira legal.