An experimental and clinical study on the initial experiences of Brazilian vitreoretinal surgeons with heads-up surgery.

PURPOSE: To evaluate the initial experiences of several vitreoretinal surgeons in Brazil, both experienced and beginners, with a three-dimensional (3D) system, and to report the advantages and disadvantages of this technology. We also report surgical manipulations performed using the heads-up method in porcine eyes. For full-thickness idiopathic macular holes (MHs), we analyzed the times required for pars plana vitrectomy (PPV) and internal limiting membrane (ILM) rhexis by using traditional microscopy and 3D system, and to evaluate anatomical surgical results. METHODS: During experimental vitreoretinal surgery on porcine eyes, two retinal surgeons applied the heads-up method. In clinical surgery, 14 retinal surgeons performed almost all types of vitreoretinal surgeries in association with facectomy, Ahmed glaucoma valve implant, or minimally invasive glaucoma surgery using an iStent®. The Ngenuity® 3D Visualization System was digitally integrated with intraoperative optical coherence tomography, the Verion™ Image-Guided System, and an endoscope (with a modified GoPro® camera). To compare the 3D system with traditional microscopy, ergonomics, educational value, image sharpness, depth perception, field of view, advantages and disadvantages, and technical feasibility were assessed using a questionnaire. One year later, the 14 surgeons answered the same questionnaire again, in order to assess whether they became more comfortable or not with 3D. For treating MHs, four surgeons (surgeon 1, fellows 1, 2, 3) performed the total of 40 surgeries. Each one performed 10 surgeries (5 with traditional microscopy and 5 with 3D visualization). The completion time for PPV and ILM rhexis were determined by using both methods. RESULTS: In porcine eyes, disabling the color channels allowed better visualization of the ILM, either with Brilliant Blue G (BBG), indocyanine green chorioangiography (ICG), or açai dye; transillumination through the sclera was also better without a color channel, but visualization of the peripheral vitreous was better with a blue channel. Regarding clinical experience, the questionnaire responses showed that the respondents generally favored the heads-up method compared with traditional microscopy (p < 0.05); however, despite a slightly higher average score, the 3D system was not statistically significantly preferred in terms of technical feasibility (p = 0.1814). Answering again the same questionnaire 1 year later, the 14 surgeons felt more comfortable with 3D (p < 0.05). The type of surgery benefitting most from the 3D system was peeling of the ILM or epiretinal membrane (p < 0.001), and that receiving the least benefit was anterior segment surgery (p < 0.001). In addition, surgeons did not report benefits of color channels, preferring to disable it (p < 0.001). Comparisons between the average time for full PPV and ILM rhexis by using the two methods were non-significant, neither in each individual case of 3D surgery for each surgeon. Surgeon 1 had always been faster than his fellows. Thirty-six (90%) full-thickness MHs were successfully closed with one surgery. CONCLUSIONS: The 3D system was preferred to traditional microscopy. The 3D system was especially helpful for certain specific types of surgeries and served as an educational tool, having reduced illumination and allowing precise focusing. Concerning MH surgery, heads-up method was similar to traditional microscopy regarding length of time and anatomical surgical results. As a digital platform, it will be amenable to constant upgrades and may ultimately become the new standard for ophthalmic surgery.

Intraocular pressure fluctuation in healthy and glaucomatous eyes: a comparative analysis between diurnal curves in supine and sitting positions and the water drinking test.

Purpose: To compare intraocular pressure (IOP) using the simplified daily tensional curve (SDTC) between supine and sitting positions in terms of peak levels and amount of fluctuation in both, glaucomatous and healthy subjects. The secondary endpoint was the comparison of these measures with those derived from the water drinking test (WDT). Methods: Thirty patients with primary open-angle glaucoma (POAG) that were undergoing medical therapy and 30 healthy subjects were enrolled in this study. Each patient underwent a diurnal curve between 8 am and 4 pm. After lying down for 5 minutes, the IOP was measured with the Perkins tonometer. Patients were instructed to sit in the upright position for 5 minutes and the tonometry was repeated. At 4:15 pm, the WDT test was performed. Fluctuation was defined as the difference between the highest and the lowest IOP readings (range). The Student's t test was used to assess differences and a P value <0.05 was considered to be statistically significant. Results: The diurnal curve in the supine position demonstrated higher IOP average values (on average 3-4 mmHg higher) compared to the sitting position (p<0.0001) for both groups. IOP peaks were higher in the supine position; however, the IOP range was essentially the same between the three methods. Treated glaucomatous patients had higher IOP levels in all measurements, but the fluctuation for all tests performed appeared to be similar to that of healthy patients. Conclusion: The data suggested that WDT can be used to estimate the diurnal IOP peak and fluctuation observed in the SDTC of the supine position for treated glaucomatous patients. Further studies can compare the possible correlation between the WDT results and those obtained from nocturnal supine measurements.

State of the art in chromovitrectomy / Estado da arte da cromovitrectomia

Vitrectomy is a surgery that involves complex and delicate techniques that treat diseases such as macular hole, epiretinal membrane and diabetic macular edema. Chromovitrectomy is one of these techniques and includes the use of coloring agents such as vital dyes or crystals to enhanced visibility of transparent structures during vitrectomy. The aim of this study was to present a modern approach, based on scientific evidence, about the application and indication of vital coloring agents during vitrectomy. The use of such agents has made this surgery more predictable and has increased its post-operative prognosis. Although research on chromovitrectomy is currently expanding there is still not an established gold standard dyeing agent.

A cirurgia vitreorretiniana é uma cirurgia que envolve técnicas complexas e delicadas que tratam doenças como buraco macular, membrana epirretiniana e o edema macular diabético. A cromovitrectomia é uma dessas técnicas que incluem o uso de corantes compostos de pigmentos vitais ou cristais para melhorar a visibilização de estruturas transparentes durante a cirurgia de vitrectomia. O objetivo desse artigo foi apresentar uma abordagem atual, baseada em evidências, sobre a aplicação e indicação de corantes vitais durante a cirurgia vitreorretiniana. O emprego desses corantes possibilitou uma maior previsibilidade para a cirurgia, melhorando assim seu prognóstico pós-operatório. Apesar do campo da cromovitrectomia está em plena expansão de pesquisas, um corante gold standard para cromovitrectomia ainda não está estabelecido.

Intraocular pressure fluctuation in healthy and glaucomatous eyes: a comparative analysis between diurnal curves in supine and sitting positions and the water drinking test / Flutuação da pressão intraocular em olhos saudáveis e olhos glaucomatosos: análise comparativa entre a curva tensional diária simplificada nas posições sentada, supina e o teste de sobrecarga hídrica

Purpose: To compare intraocular pressure (IOP) using the simplified daily tensional curve (SDTC) between supine and sitting positions in terms of peak levels and amount of fluctuation in both, glaucomatous and healthy subjects. The secondary endpoint was the comparison of these measures with those derived from the water drinking test (WDT). Methods: Thirty patients with primary open-angle glaucoma (POAG) that were undergoing medical therapy and 30 healthy subjects were enrolled in this study. Each patient underwent a diurnal curve between 8 am and 4 pm. After lying down for 5 minutes, the IOP was measured with the Perkins tonometer. Patients were instructed to sit in the upright position for 5 minutes and the tonometry was repeated. At 4:15 pm, the WDT test was performed. Fluctuation was defined as the difference between the highest and the lowest IOP readings (range). The Student's t test was used to assess differences and a P value <0.05 was considered to be statistically significant. Results: The diurnal curve in the supine position demonstrated higher IOP average values (on average 3-4 mmHg higher) compared to the sitting position (p<0.0001) for both groups. IOP peaks were higher in the supine position; however, the IOP range was essentially the same between the three methods. Treated glaucomatous patients had higher IOP levels in all measurements, but the fluctuation for all tests performed appeared to be similar to that of healthy patients. Conclusion: The data suggested that WDT can be used to estimate the diurnal IOP peak and fluctuation observed in the SDTC of the supine position for treated glaucomatous patients. Further studies can compare the possible correlation between the WDT results and those obtained from nocturnal supine measurements. .

Objetivo: Comparar a flutuação da pressão intraocular (PIO) nas posições sentada e supina, através da curva tensional diária simplificada (CTDS), durante o horário de consultório em pacientes saudáveis e com glaucoma primário de ângulo aberto (GPAA). O objetivo secundário foi comparar estas medidas com a flutuação da PIO verificada através do teste de sobrecarga hídrica (TSH) desses dois grupos. Métodos: A amostra foi constituída por 60 indivíduos, divididos em dois grupos, 30 saudáveis e 30 glaucomatosos. Nenhum dos pacientes saudáveis usava medicação anti-glaucomatosa. Entre os portadores de glaucoma, todos estavam medicados. Foi realizada a CTDS (medidas realizadas entre 8:00 h e às 16:00 h) na posição sentada e supina utilizando o mesmo tonômetro de Perkins. Imediatamente após a última medida (às 16:15 h), foi realizado o TSH. Flutuação foi definida como a diferença entre a maior e a menor medida de PIO. O teste t-Student foi usado para analisar as diferenças e o valor de p<0,05 foi considerado estatisticamente significante. Resultados: Os picos de PIO foram sempre maiores na CTDS quando medidos na posição supina (em média 4 mmHg maior) em pacientes saudáveis e pacientes glaucomatosos em tratamento, comparado a posição sentada (p<0.0001). Pacientes glaucomatosos em tratamento apresentaram PIO mais alta em todas as medidas, porém a flutuação em todos os testes realizados foi semelhante comparada aos pacientes saudáveis. A flutuação da PIO não apresentou diferença estatística entre os 3 métodos. Conclusão: Dados sugerem que o TSH pode ser usado para estimar o pico e a flutuação diurna da PIO na posição supina na CTDS em pacientes glaucomatosos em ...