Seidel and India ink tests assessment of different clear cornea side-port incision configurations.

BACKGROUND: Post-cataract endophthalmitis has increased after introduction of clear cornea incisions (CCI). Laboratory models suggested that these incisions might not be competent at certain changes in intraocular pressure (IOP). Considering that side-port incisions (SPI) might behave similarly, the purpose of the present study was to determine the most stable side-port incision configuration. METHODS: Using four cadaveric human eyes, four different side-port incisions (SPI) were created in each cornea: 1.5 mm and 2.5 mm squared tunnel, 1.5 mm and 2.5 mm stab tunnel. Fluorescein was placed on the eye, and the IOP varied from 10 to 80 mmHg. IOP at which each SPI started leaking was recorded. In the second part of the study, India ink was applied to the corneal surface at normal IOP, and then rinsed with balanced salt solution (BSS). The ink influx was recorded by planimetry. IOP was elevated to 80 mmHg, ink was reapplied, and IOP was dropped to 0 mmHg. Ink influx was measured again. Histological examination was used to visualize ink inflow into each incision. RESULTS: There was no statistically significant difference in the IOP levels at which the different incisions leaked (p = 0.52). A significant increase in the length of India ink ingress in all incision types was measured after IOP variation (p < 0.05). The 2.5 mm squared incision showed the least increase in ink inflow in this test. CONCLUSION: All incision types of SPIs tested exhibited similar resistance to leakage after IOP variation. Good resistance to wound leakage may not predict adequate resistance to the inflow of bacterial-sized particles into the wound.

Efficacy of three different methods for side port incision wound sealing

PURPOSE: To evaluate wound leakage and bacteria-sized particle influx in differently corneal sealed side port incisions. METHODS: Four 1.5mm tunnel squared incisions were created in each of four cadaveric human eyes. In each cornea, one incision was left unsealed, whereas the other three incisions were sealed using a 10-0 nylon suture, cyanoacrylate glue, or stromal hydration, respectively. A Seidel and an India ink test were performed on each eye. During each Seidel test, flourescein was applied, the IOP increased from 15 to 80mmHg, and the IOP at which each incision started to leak recorded. During each India ink test, ink was placed on the eye and rinsed out with balanced salt solution (BSS). Ink penetration was then measured by planimetry at physiologic conditions and after an IOP plunge from 80mmHg to 0mmHg. RESULTS: Regardless of IOP variations, no leakage or ink inflow was observed through the glued incisions. In contrast, leakage did occur in the other three sealing methods, albeit at significantly different IOP levels in each one (p=0.013). Ink inflow occurred in these sealing methods at physiologic IOP and, to a significantly greater extent, after the IOP challenge (p<0.05). At both of these IOP conditions, the differences in ink influx among these three incision-sealing methods were deemed statistically insignificant. CONCLUSION: This study showed that glue was more effective at preventing wound leakage and bacteria-sized particle influx than other commonly used methods especially hydrosealing.

OBJETIVO: Avaliar o sinal de Seidel positivo e a penetração de tinta da Índia em incisões corneanas acessórias seladas por diferentes métodos. MÉTODOS: Quatro incisões de 1,5 x 1,5mm foram criadas em cada um dos quatro olhos provindos do banco de olhos. Em cada córnea, uma incisão foi mantida sem manipulação, enquanto que as outras três incisões foram seladas respectivamente com Nylon 10-0, cola de cianoacrilato e hidratação estromal. Foram realizados dois testes: Sinal de Seidel positivo e penetração da tinta da Índia. No primeiro, foi aplicado fluoresceína gotas e a pressão intraocular (PIO) elevada de 15 para 80mmHg. No segundo, a tinta da Índia foi aplicada sobre o olho estudado em duas situações: sob PIO fisiológica e sob variação súbita da pressão, de 80 para 0mmHg. RESULTADOS: Na incisão selada com cola, apesar da variação da PIO, não houve vazamento e nem penetração de partículas de tinta. Por outro lado, o sinal de Seidel foi positivo nas outras três incisões em diferentes níveis de PIO (p=0,013). A penetração da tinta da Índia ocorreu nestas três incisões sob pressão fisiológica e com maior extensão após a variação da PIO (p<0,05). Esta diferença, no entanto não foi considerada estatisticamente significante quando comparadas as incisões entre si. CONCLUSÃO: No presente estudo, a cola foi mais eficaz em prevenir Seidel e entrada de partículas do que outro método comumente usado especialmente, hidratação estromal.