Juliana Mantovani Bottós

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.

Higher-order aberrations of age-related cataract

PURPOSE: To analyze higher‐order aberrations induced by different types of lenticular opacities. SETTING: Federal University of São Paulo, São Paulo, Brazil. METHODS: One hundred thirty‐eyes of 65 patients with bilateral cataract, classified according to the Lens Opacities Classification System III (LOCS III), had complete ophthalmic examinations, corneal topography (EyeSys Technologies), and wavefront analysis (LADARWave, Alcon Laboratories). Patients with cataracts that could not be measured by a Hartmann‐Shack sensor or those with coexisting ocular disease were excluded. Higher‐order aberrations were compared between the nuclear, cortical, and posterior subcapsular groups for statistical significance. RESULTS: One hundred five eyes of 65 patients were assessed. Twenty‐eight eyes (23.33%) had predominantly nuclear opacification (NO1‐NO6 and C1‐2), and 13 (10.83%) had mainly cortical opacification (C1‐4). Sixty‐four eyes (65.83%) had a mixed pattern of LOCS III classification, which hindered the establishment of a correlation between the aberrometry and cataract type. Eighteen eyes that presented with dense posterior subcapsular cataract (P4‐5) and 7 eyes with cortical C5 LOCS III classification were excluded. In eyes with nuclear opacification, the mean spherical aberration with a 6.0 mm pupil was 0.45 μm ± 0.17 (SD) and the mean coma was 0.29 ± 0.13 μm. In eyes with predominantly cortical cataract, the mean spherical aberration was 0.12 ± 0.10 μm and the mean coma was 0.49 ± 0.23 μm. The cortical cataract group had statistically significantly higher coma than the other groups (P<.001). The nuclear cataract group had statistically significantly higher spherical aberrations than the other groups (P<.001). CONCLUSIONS: Different types of early lenticular opacities induced different wavefront aberration profiles. Coma predominated in the cortical cataract group, and spherical aberration predominated in the nuclear cataract group.

Current concepts in vitreomacular traction syndrome.

Purpose of review As Reese first described the vitreomacular traction (VMT) syndrome in 1970, the knowledge base about the disease has been changing over time due to the advent of the high-definition optical coherence tomography (HD-OCT). The aim of this article was to present the current information on the pathophysiology, anatomic macular abnormality associations, treatments, and new concepts in VMT syndrome. Recent findings HD-OCT has provided unprecedented visualization of the vitreomacular interface, which has led to better comprehension of the VMT syndrome. The technologic advances also emphasized the need to review the basis of the VMT syndrome and define as yet unsettled and often confusing concepts. Summary The recognition of the role of VMT in a variety of macular conditions is imperative for proper diagnosis and appropriate management of these diseases.

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.

Impaired glucose tolerance plus hyperlipidaemia induced by diet promotes retina microaneurysms in New Zealand rabbits

With the increasing prevalence of diabetes mellitus and metabolic syndrome worldwide, experimental models are required to better understand the pathophysiology and therapeutic approaches to preserve pancreatic beta cells, attenuate atherosclerosis and protect target organs. The aims of this study were to develop an experimental model of impaired glucose tolerance combined with hypercholesterolaemia induced by diet and assess metabolic alterations and target organ lesions. New Zealand male rabbits were fed high‐fat/high‐sucrose (10/40%) and cholesterol‐enriched diet for 24 weeks, when they were sacrificed. Biochemistry, fundus photographs with fluorescein angiography and pathological analyses were performed. Cholesterol‐fed and normal animals of same age were compared. Results: The animals with diet‐induced impaired glucose tolerance combined with hypercholesterolaemia gained weight, increased blood glucose, total cholesterol, LDL‐C and triglycerides and decreased HDL‐C (P < 0.05 vs. baseline). Fructosamine levels and the homeostasis model assessment of insulin resistance (HOMA‐IR) index were increased, while there was a reduction in the HOMA‐β (P < 0.05 for all vs. baseline). Histomorphologic findings of this model were aortic atherosclerosis, hepatic steatofibrosis and glomerular macrophage infiltration. Early clinical features of diabetic retinopathy with hyperfluorescent dots consistent with presence of retina microaneurysms were seen since week 12, progressing up to the end of the experiment (P < 0.0005 vs. baseline and 12 weeks). Our model reproduced several metabolic characteristics of human diabetes mellitus and promoted early signs of retinopathy. This non‐expensive model is suitable for studying mechanistic pathways and allowing novel strategic approaches.

Impending central retinal vein occlusion associated with cilioretinal artery obstruction

We report a case of a patient with an impending central retinal vein occlusion (CRVO) with cilioretinal artery obstruction, which may help to understand the nature of the retinal hemodynamic changes associated with CRVO which shows direct evidence of arterial vasospasm, suggesting an increased contractility of retinal arteries. The clinical course, with initial retinal whitening along a cilioretinal artery followed by signs of venous stasis, seems to confirm the pathogenesis hypothesis concerning a primary arterial affection due to arterial vasospasm.

Wavefront-guided refractive surgery results of training-surgeons

PURPOSE To assess clinical outcomes and changes on higher-order aberrations (HOA) after wavefront-guided laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correction of myopia and myopic astigmatism performed by training-surgeons. METHODS One hundred and seventy patients had customized LASIK (207 eyes) and PRK (103 eyes) performed by surgeons in-training using the LADARVision 4000 (Alcon, Fort Worth, TX). Preoperative and 1, 3, 6 and 12 months postoperative data of spherical equivalent (SE), best spectacle-corrected visual acuity (BSCVA) and uncorrected visual acuity (UCVA) were analysed. Wavefront changes were determined using the LADARWave Hartmann-Shack wavefront aberrometer and the pupil size was scaled for 6.5 mm. RESULTS The mean SE in the LASIK group was -3.04 ±1.07 D and in the PRK group was -1.60 ± 0.59 D. At 1-year follow-up, (80.6%) (LASIK) and (66.7%) (PRK) were within ± 0.50 D of the intended refraction. The UCVA was 20/20 or better in (58.1%) (LASIK) and (66.7%) (PRK) of the operated eyes. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups: LASIK (r=0.975, P<0.0005) and PRK (r=0.943, P<0.005). The higher-order aberrations (HO) RMS and coma did not changed significantly in the PRK group between preoperative and 1-year follow-up. In the LASIK group the HO RMS and coma changed between preoperative and 1-month postoperative but remained statistically unchanged during 1-year follow-up. The spherical aberration showed statistically significant changes in both groups. CONCLUSIONS Wavefront-guided LASIK and photorefractive keratectomy performed by training-surgeons were found to be similarly effective, predictable and stable.

Vitreomacular traction syndrome: postoperative functional and anatomic outcomes.

BACKGROUND AND OBJECTIVE To analyze a variety of vitreomacular traction (VMT) morphologies to establish a major classification that better reflects the preoperative predictive factors of postoperative visual and anatomic outcomes. PATIENTS AND METHODS Thirty-six eyes submitted to vitrectomy surgery were categorized with a VMT pattern (V- or J-shaped) and diameter (focal < 1,500 µm or broad > 1,500 µm) based on optical coherence tomography. RESULTS The researchers compared different classifications of VMT. Despite similar postoperative best corrected visual acuity (BCVA) values (P = .393), cases with focal VMT had greater visual improvement (P = .027) because the preoperative BCVA was significantly lower in the focal group (P = .007). However, the BCVA improvements did not differ between the groups regarding the classic VMT morphologic patterns (P = .235). CONCLUSION Postoperative outcomes and macular disorders are closely related to VMT size. The adhesion diameter (focal or broad VMT) and not the classic VMT morphologic pattern (V- or J-shaped) may better predict the postoperative anatomic and functional outcomes.

Long-term results of photorefractive keratectomy for myopia and myopic astigmatism

PURPOSE To assess the long-term refractive outcomes of photorefractive keratectomy in myopia and myopic astigmatism. METHODS A retrospective study of 120 photorefractive keratectomy operated eyes with at least four-year follow-up (maximum of 96 months, mean follow-up 55 months). We divided patients into group 1 (G1) spherical equivalent (SE) up to -4.00 diopters (D) and group 2 (G2) SE >-4.00 D. The Summit Apex Plus excimer laser was used for ablation. All eyes were analyzed in terms of uncorrected and best spectacle corrected visual acuity (UCVA/BSCVA) and cycloplegic refraction. Data were analyzed using the Refractive Surgery Consultant Elite database software. RESULTS G1 with 85 eyes (49 patients) presented mean SE -2.42 D and G2 with 35 eyes (22 patients) and mean SE of -4.45 D. Ninety-four percent of eyes in G1 and 82.9% of G2 were within +/-1.00 D of emmetropia at 4 years. The UCVA was 20/30 or better in 82.0% of G1 eyes and 77.0% of G2 in the last postoperative follow-up. No patient lost more than one line in G2 compared to 13.0% in G1. Eyes that gained one or more lines after 4-year follow-up were 11.9% G1 and 2.9% in G2, respectively. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups (r=0.925, p<0.0005). CONCLUSIONS Photorefractive keratectomy was a safe and stable surgical procedure to correct myopic refractive errors, with no significant change in mean postoperative spherical equivalent refraction in the long-term follow-up.

Macular hole: 10 and 20-MHz ultrasound and spectral-domain optical coherence tomography

PURPOSE Optical coherence tomography (OCT) is valuable for macula evaluation. However, as this technique relies on light energy it cannot be performed in the presence of opaque media. In such cases, the ultrasound (US) may predict some macular features. The aim of this study was to characterize images obtained by ultrasound with 10 and 20-MHz transducers comparing to OCT, as well as to analyze the relationship between the vitreous and retina in eyes with macular hole (MH). METHODS 29 eyes of 22 patients with biomicroscopic evidence of MH at different stages were included. All patients were evaluated using ultrasonography with 10 and 20-MHz transducers and OCT. RESULTS OCT identified signs of MH in 25 of 29 eyes. The remaining 4 cases not identified by US were pseudoholes caused by epiretinal membranes. In MH stages I (2 eyes) and II (1 eye), both transducers were not useful to analyze the macular thickening, but suggestive findings as macular irregularity, operculum or partial posterior vitreous detachment (PVD) were highlighted. In stages III (14 eyes) and IV (5 eyes), both transducers identified the double hump irregularity and thickening. US could measure the macular thickness and other suggestive findings for MH: operculum, vitreomacular traction and partial or complete PVD. In cases of pseudoholes, US identified irregularities macular contour and a discrete depression. CONCLUSION 10-MHz US was useful for an overall assessment of the vitreous body as well as its relationship to the retina. The 20-MHz transducer allowed valuable information on the vitreomacular interface and macular contour. OCT provides superior quality for fine morphological study of macular area, except in cases of opaque media. In these cases, and even if OCT is not available, the combined US study is able to provide a valid evaluation of the macular area improving therapeutic approach.