Visicare Eye Centre, Tarn Taran, Punjab, India.
Department of Ophthalmology, Kalpana Chawla Government Medical College and Hospital, Karnal Haryana, India.
Indian J Ophthalmol. 2021 Feb;69(2):376-383. doi: 10.4103/ijo.IJO_2204_20.
The aim of this study was to describe a poly-vinyl chloride air condition (PVC AC) curtain shield placed at the intervening space between the chin rest and the illuminating and optical arm of the slit lamp microscope (distal barrier) instead of the present position at the oculars (proximal barrier) to guard against severe acute respiratory syndrome Coronavirus 2. This experimental study was done to validate and compare the protection offered by the conventional breath shields and the one described by us in a simulated environment.
In this experimental study, 12 puffs of fine mist were sprayed over a period of 1 minute using "magenta-colored dye" and "cyan-colored dye" for analyzing proximal barrier and distal barrier respectively. To access the amount of contamination of the slit lamp, caused by sprayed "magenta" and "cyan" colored dye, we covered the entire slit lamp with appropriately sized white-colored cotton sheet. The stained sheets were individually photographed and then the images were first cropped, then color threshold adjusted and then converted to binary and finally fraction of surface area stained was calculated using the ImageJ software. (P Surface Area (%) during analysis of "proximal barrier" and P Surface Area (%) during the analysis of "distal barrier", where P refers to various parts of slit lamp.
The entire surface area of the cloth covering the slit lamp was 9912.45 cm. The surface area of the cloth which was stained when using the "proximal barrier" was 567.50 cm whereas when using the "distal barrier" was 222.93 cm. When using proximal barrier, 97.71% of the staining was present on the slit lamp base, viewing arm, illumination arm and the pivot of the slit lamp. While using the distal breath shield no parts of the viewing arm, illumination arm, the pivot or the mechanical base with joystick were stained.
The novel PVC AC curtain shield provides better barrier against the simulated contaminated stream of patient's breath directed towards the working parts of the slit lamp as compared to conventional slit lamp oculars mounted breath shields.
本研究旨在描述一种聚氯乙烯（PVC）空调（AC）窗帘屏风，放置在下巴托与裂隙灯显微镜的照明和光学臂之间的间隔处（远端屏障），而不是目前位于目镜（近端屏障）的位置，以防止严重急性呼吸综合征冠状病毒 2. 本实验研究旨在验证和比较传统的呼吸屏障和我们在模拟环境中描述的呼吸屏障所提供的保护。
在这项实验研究中，使用“洋红色染料”和“青色染料”，在 1 分钟内连续喷雾 12 次，分别对近端屏障和远端屏障进行分析。为了评估被喷雾的“洋红色”和“青色”染料对裂隙灯的污染程度，我们用大小合适的白色棉质床单覆盖整个裂隙灯。对被染色的床单进行单独拍照，然后对图像进行裁剪，再调整颜色阈值，然后转换为二进制图像，最后使用 ImageJ 软件计算染色面积的比例。（P 表面面积（%）在分析“近端屏障”时和 P 表面面积（%）在分析“远端屏障”时，其中 P 指的是裂隙灯的各个部分。
覆盖裂隙灯的床单总面积为 9912.45 平方厘米。使用“近端屏障”时，染色的床单面积为 567.50 平方厘米，而使用“远端屏障”时，染色的床单面积为 222.93 平方厘米。使用近端屏障时，97.71%的染色位于裂隙灯底座、观察臂、照明臂和裂隙灯的枢轴上。而使用远端呼吸屏障时，观察臂、照明臂、枢轴或带有操纵杆的机械底座都没有被染色。
与传统的裂隙灯目镜安装的呼吸屏障相比，新型的 PVC AC 窗帘屏风在模拟的来自患者的受污染气流直接指向裂隙灯的工作部件时提供了更好的屏障。
