Dear Editor,

The application of three-dimensional (3D) printing techniques in ophthalmology enables cost-effective design and production of custom medical instruments

.Complications of cataract surgery, such as a dropped nucleus, cortex, or intraocular lens, may require vitreoretinal surgery

. Although there is a vitrectomy port in most phacoemulsification machines, endoillumination is not available

. There are some external light source devices such as Photon (Synergetics), Xenotron III (Geuder) and Bright Star (DORC), but they are expensive and may not be available in all hospitals. This study was approved by the Institutional Review Board of Joint Shantou International Eye Center.

We developed a 3D printed adaptor that connects a LED flashlight to an Alcon 23-gauge fiber (Figure 1A and Video 1,online supplementary). The adaptor was designed using the 3D Builder software (version 18.0.1931.0, Microsoft Corp.)which is a free Windows app. The adaptor is fashioned using two hollow cylinders on top of each other with the same external diameter but different internal diameter. The external diameter of the adaptor is consistent with the internal diameter of the flashlight, so that the adaptor fits well in the flashlight.The upper hollow cylinder with a smaller internal diameter matched with the external diameter of the fiber. The inferior hollow cylinder with a larger internal diameter serves as a light channel (Figure 1B). The diameter can be modified according to the model of the flashlight and the fiber. The adaptor was printed using a Fused Deposition Modelin 3D printer, da Vinci nano (XYZ Printing, Suzhou, China; Figure 1C). The cost of 3D printing material was less than 1 USD, and the time spent was less than 2h. The cost of the 3D printer is 150 USD. It can also be printed using an online service. A 50 W LED flashlight was purchased from an online shopping website, Taobao(https://item.taobao.com/item.htm?spm=a1z0d.6639537.19971 96601.4.76ed74846RJdsb&id=625303655848), with a price of 78 CNY (12 USD). The cost of the entire device is affordable,even in rural regions where this device is most in need.

對(duì)實(shí)驗(yàn)過(guò)程中聲發(fā)射信號(hào)進(jìn)行分析發(fā)現(xiàn)，無(wú)論是聲發(fā)射信號(hào)能量或是信號(hào)幅值，寬頻傳感器接收的聲發(fā)射信號(hào)強(qiáng)度均小于窄頻傳感器。除了信號(hào)強(qiáng)度，信號(hào)數(shù)量也是體現(xiàn)傳感器靈敏度的一項(xiàng)特征。表1為兩類(lèi)傳感器接收的聲發(fā)射數(shù)據(jù)量統(tǒng)計(jì)表，可以看出寬頻傳感器在實(shí)驗(yàn)過(guò)程中接收的聲發(fā)射信號(hào)數(shù)量遠(yuǎn)小于窄頻傳感器，平均數(shù)據(jù)量只占窄頻傳感器的51%。說(shuō)明窄頻傳感器信號(hào)響應(yīng)程度高于寬頻傳感器，對(duì)信號(hào)的靈敏度較高。

We measured the brightness of the 23-gauge fiber connected with our 3D-printed adaptor/flashlight and the xenon lamp on the Alcon Constellation machine using a spectrometer(Hopoocolar OHSP-350, China). The tip of the 23-gauge fiber was positioned at 10 mm above the spectrometer in a dark room. The luminance of our adaptor/flashlight was 7468 lx. It was higher than 20% illuminator setting of the Alcon Constellation (7059 lx), which is the typical setting in our routine operations (Figure 1D). We also used this device in real surgery. The view was bright and clear during vitreoretinal operations (Figure 1E).

The irradiance of the adaptor and the Constellation was also measured using the spectrometer (Table 1). The irradiance of the adaptor at 305-400 nm was between 10%-20% luminosity of Constellation. While the irradiance of the adaptor at 305-700 nm was at between 20%-30% luminosity of Constellation.Based on these data, the irradiance safety of our adaptor/flashlight is comparable with the common setting on Constellation illuminator.

Authors’ contributions: Liao XL and Lin PM conducted the study; Chen HY designed the study and the adaptor.

We encourage the use of this device as an emergency tool when a traditional light source is not working during vitrectomy. Moreover, some cataract surgeons are not welltrained vitreoretinal ones and it is better to close the eye and refer more than try to do something without the specific skills.Overall, our 3D printed adaptor with a LED flashlight provides a simple, low-cost, efficiency and safe light source for endoillumination of intraocular surgery.

“Canterbury”英格蘭肯特郡的一個(gè)城市，有許多古舊精美的建筑，包括英國(guó)國(guó)教會(huì)的著名的中心大教堂。1170年托馬斯·貝克特在這里遇害后，此地成為基督徒朝圣地?，F(xiàn)在是重要的旅游勝地。1988年坎特伯雷大教堂入選世界遺產(chǎn)名錄（克勞瑟，2007）。[13]譯者采用音譯的方法，保留了源語(yǔ)言文化，但是由于兒童讀者在身心發(fā)展兩方面都還沒(méi)有發(fā)育完全，太多的異質(zhì)語(yǔ)言會(huì)超過(guò)他們的知識(shí)范圍和理解能力。添加注釋?zhuān)瑫?huì)更易于兒童讀者接受。

ACKNOWLEDGEMENTS

The applications of this device is not only for the management of complications of cataract surgery but also other vitreoretinal surgeries performed using the cataract machine

. It can also be used in some cases where the xenon lamp of the vitrectomy machine is broken. Besides the cost, our device also has the advantage of small size compared to the current commercially available external light sources (Figure 1F).

Supported by Shantou Science and Technology Program (No.200629165261641); 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(No.2020LKSFG14B).

CIVE(Color Index of Vegetation Extraction)值：CIVE = 0.441R - 0.811G + 0.385B + 18.787 45。

Conflicts of Interest: Liao XL, None; Lin PM, None; Chen HY, None.

1 Sommer AC, Blumenthal EZ. Implementations of 3D printing in ophthalmology.

2019;257(9):1815-1822.

2 Canabrava S, Diniz-Filho A, Schor P, Fagundes DF, Lopes A,Batista WD. Production of an intraocular device using 3D printing:an innovative technology for ophthalmology.

2015;78(6):393-394.

3 Scupola A, Abed E, Sammarco MG, Grimaldi G, Sasso P, Parrilla R, Traina S, Blasi MA. 25-gauge pars plana vitrectomy for retained lens fragments in complicated cataract surgery.

2015;234(2):101-108.

4 Spandau U, Heimann H. Practical handbook for small-gauge vitrectomy.

-

2018:116-119.