Clinical application of a shape-preserving rapid corneal donor dehydrater

INTRODUCTION

Corneal blindness has been reported as the second only to cataract in the leading causes of blindness, 10 million of the patients having bilateral corneal blindness

. Keratoplasty is the main method for the treatment of corneal blindness

.At present, corneal materials from donors are in short supply worldwide with the exception of a few countries, such as the United States and European countries. An estimated 12.7 million patients are placed on a long waiting list and the number is still growing

. Due to the paucity of trained keratoplasty surgeons and the shortage of cornea donors in some areas, cornea donations obtained cannot be used in reasonable time and efficiently

.

慢性胸、肺疾病會(huì)引起呼吸功能障礙,隨著病情的發(fā)展會(huì)加重,最終引起呼吸衰竭,近年臨床各醫(yī)院對(duì)慢性呼吸衰竭報(bào)道逐漸增多。患者多表現(xiàn)為高碳酸血癥、低氧血癥等,嚴(yán)重的會(huì)出現(xiàn)全身系統(tǒng)紊亂[1-2]。適當(dāng)?shù)淖o(hù)理干預(yù),可預(yù)防并發(fā)癥出現(xiàn),改善治療效果。筆者為分析循證護(hù)理價(jià)值,報(bào)道如下:

甲洛洛嘴上的條條皺紋擠在一起，后背冒出汗，他翻了個(gè)身，整個(gè)身子縮成一團(tuán)，再度沉入思慮：我雖然只是一個(gè)守倉庫的，但在營(yíng)業(yè)部里我的年歲最大，人緣也不錯(cuò)，不管別人當(dāng)面怎么說也好，背面怎么說也好，管我叫甲洛洛（漢人坨子）也行，但我還是笑臉相迎，從沒得罪過任何人啊。就算所有人管我叫甲洛洛，可部里無論遇到打架斗毆的，還是小偷小摸的，都是我去息事寧人，大家雖然表面不說，可暗地里還是對(duì)我有幾許佩服的，更別說小瞧了我。

To solve the problem of shrinkage and deformation of corneas during dehydrating, the second innovation we proposed involves dehydrating donor corneas on 304 stainless steel beads that are the same diameter. Positioning holes are located in the dehydrating box that hold stainless steel beads of different diameters. When dehydrating, the donor cornea is laid flat on the stainless-steel bead with the endothelium facing downward. Given that the cornea and the bead have the same diameters, the cornea completely fits the circumference of the steel ball, thus maintaining the normal shape of the donor cornea.

SUBJECTS AND METHODS

This study was adhered to the tenets of the Declaration of Helsinki and approved by the Institutional Review Board of Shandong Eye Hospital, Jinan, China.ID:201904. All patients signed an informed consent approved by the Institutional Review Board.

由此可知，實(shí)驗(yàn)組巨大兒、新生兒高膽紅素血癥等并發(fā)癥發(fā)生率低于對(duì)照組，差異有統(tǒng)計(jì)學(xué)意義（P<0.05）。實(shí)驗(yàn)組新生兒低血糖、低胎齡兒、呼吸窘迫綜合征等并發(fā)癥發(fā)生率與對(duì)照組相比，差異無統(tǒng)計(jì)學(xué)意義（P＞0.05）。

The corneal dehydrater that can be assembled quickly is made of high transparent plastic material. The box body is a vertical rectangular structure. The external size is 530×390×320 mm

, and the specification is 45 liters. The system is composed of ultraviolet lamp tube,powerful silent circulating fan, color-changing silica gel,dustproof filter net, dehydrating box, and 304 steel balls(Figures 1 and 2).

The rated voltage of the power supply is 220 V, and the rated frequency is 50 Hz. There are two ultraviolet lamp tubes that are 4 W and 6 W, separately. The lamps are used to sterilize the inner space of the dehydrater and keep the air sterile.Rapid dehydrating of donor corneas is primarily achieved using color-changing silica gel and a strong silent circulating fan. A rechargeable hygroscopic card monitors air humidity and ensures the use of dehydrated air in the dehydrater. The specification of the strong silent circulating fan is 100 mm, the input power is 25 W, and the rated speed is 2800 r/min. The fan is used to circulate the air inside the dehydrater forcibly and then transmit the dry air to the dehydrating box through the circulating pipe (110 PVC pipe, after reducing diameter to 50). In addition, to ensure that the circulating air is free of impurities, the fan side of the circulation fan and the circulation pipe are equipped with a 3-mm thick dustproof screen.

The dehydrating box is a semienclosed space that is 170×110×9 mm

in size. The dehydrating box is provided with 8 positioning holes to hold stainless steel beads of different diameters (10-20 mm in diameter). During dehydrating, the corneal donor is placed on 304 steel balls of the same diameter as the cornea to maintain the normal shape of the cornea and solve the problem of corneal tissue shrinkage and deformation during dehydrating.

The process of rapid shaping and dehydrating of the corneal donor: The indoor temperature and humidity were adjusted to 22℃-23℃ and 48%-50%, respectively. First, the inner wall of the dehydrater was wiped with 75% alcohol, and then the ultraviolet lamp is turned on for 30min for disinfection. An agar plate was placed in the dehydrater for air detection. After the system was validated, the corneal donor was dehydrated.The corneal donor was removed using surgical forceps, and the endothelium was placed downward on 304 stainless steel beads that were the same diameter as the cornea. The cornea was leveled using surgical forceps. The strong silent circulation fan was turned on for dehydrating, and the dehydrating time is approximately 103±11min. After the completion of dehydrating, the cornea was transferred to a storage container and stored in a refrigerator at 4℃ after vacuum pumping(Figure 3).

For the dehydrated corneal materials, the average dehydrating time was 103±11.2min. After the completion of dehydrating,all the donor corneas maintained a normal shape without any shrinkage or distortion, and the average intraoperative rehydration time was 43.3±12.1s during operation.

實(shí)驗(yàn)界面由4部分組成,對(duì)應(yīng)簡(jiǎn)化模型的4個(gè)功能區(qū),如圖4所示,功能區(qū)(左上)模擬雷達(dá)目標(biāo)搜索界面,功能區(qū)(右上)模擬表格顯示界面,功能區(qū)(左下)模擬圖標(biāo)搜索點(diǎn)擊界面,功能區(qū)(右下)模擬菜單狀態(tài)顯示界面.所有界面元素(文字、圖標(biāo)、圖形符號(hào))不針對(duì)任何現(xiàn)存顯示界面,均為實(shí)驗(yàn)需求模擬制作.

Donor corneas cannot be preserved in Optisol corneal storage medium for more than two weeks

. To properly preserve donor corneas and avoid waste, dehydration treatment is often required for lamellar keratoplasty. At present, the main preservation methods of inactive corneal materials include glycerol preservation and dehydration preservation

. The most common disadvantage of glycerol preservation is that the glycerol molecules cannot be completely removed from the corneal donor after rehydration, thereby generating high water content and poor transparency of the corneal button

.

The dehydrater group was followed for an average of 8.5±2.0mo, whereas the control group was followed for an average of 8.3±1.7mo. The age, sex,and preoperative BCVA of the two groups of patients were comparable, and intergroup comparisons showed no significant differences.

The standard of postoperative corneal button transparency: 0:The corneal buttons is transparent; 1: Small superficial noninterstitial opacity, and the pupillary margin and iris vessels are visible through the corneal buttons; 2: Small, deep interstitial opacity with visible pupillary margin and iris vessels; 3:Moderate interstitial opacity, visible only at pupillary margin;4: Large interstitial opacity with only part of the pupillary margin visible; 5: Very large interstitial opacity with no anterior chamber visible.

Statistical analyses were performed using SPSS 21.0 (SPSS,Chicago, Illinois, USA). The demographics between the two groups were compared with independent samples

-test and Chi-square analysis. The BCVA, transparency of corneal buttons, thickness of the corneal buttons and the time of epithelium completely healed were compared between the two groups using independent samples

-test. A

value of ＜0.05 was considered statistically significant.

在運(yùn)營(yíng)管理方面，建立現(xiàn)代化的綠色礦業(yè)集團(tuán)，構(gòu)建“互聯(lián)網(wǎng)+礦業(yè)”模式，建設(shè)礦山生產(chǎn)自動(dòng)化系統(tǒng)，打造智慧礦山。

RESULTS

All patients were observed daily during the first week after surgery, weekly during the next 2mo, and monthly thereafter. The best corrected visual acuity (BCVA)and the thickness of the corneal buttons were evaluated at 1wk,1, and 6mo after surgery. The transparency of corneal buttons were evaluated at 1d, 1wk, and 1mo.

The age, sex, and mean preoperative BCVA of the two groups of patients were comparable, and intergroup comparisons showed no significant differences (

＞0.05; Table 1).

A consecutive series of 83 eyes (83 patients)underwent deep anterior lamellar keratoplasty (DALK)using corneal donor tissue preserved with corneal dehydrater(dehydrater group) for fungal keratitis at the Shandong Eye Hospital from January 1, 2019 to October 1, 2020. To compare the postoperative outcomes, 60 patients (60 eyes) who received DALK using corneal donor tissue preserved with glycerol for fungal keratitis by the same surgeon were included in the control group (glycerol group).

All of the 143 corneal materials were used in DALK surgery

,and all surgeries were performed by a single surgeon (Gao H).

The mean BCVA was 0.30±0.18 at 1wk and 0.32±0.16 at 1mo in the dehydrater group; these values were significantly better than those in the glycerol group, which were 0.14±0.09 and 0.23±0.09,respectively (

＜0.001). However, no statistically significant difference was obtained at 6mo between the two groups in BCVA (Table 2).

The score of transparency of corneal buttons in dehydrater group was lower than that of the control group at 1d (1.3±0.8

2.8±0.7) and 1wk (0.4±0.5

2.0±0.4), which means postoperative corneal button transparency rate was higher in the dehydrater group, with statistical difference (

＜0.001,Table 2). The epithelium completely healed at 3.3±0.6d after surgery (negative for fluorescein sodium staining; Figure 4).

After the surgery, the thickness of corneal buttons was 588±18 μm at 1wk and 544±41 μm at 1mo in the dehydrater group; these values were significantly better than those in the glycerol group, which were 654±30 and 585±49 μm, respectively(

＜0.001). But no statistically significant difference wasobtained at 6mo between the two groups (

＞0.05). These values indicate that the corneal buttons were stable and reached the normal level after 6mo (Table 2).

全面預(yù)算管理要以公司組織結(jié)構(gòu)為基礎(chǔ)，合理確定預(yù)算控制主體。遵循“誰使用、誰承擔(dān)、誰管理、誰控制”的原則，充分發(fā)揮歸口管理部門在預(yù)算控制中的作用。同時(shí)制定一套科學(xué)完善、嚴(yán)謹(jǐn)規(guī)范的組織制度為全面預(yù)算管理的有效實(shí)施提供保障。在制度建立的過程中，要對(duì)相關(guān)部門的權(quán)責(zé)進(jìn)行明確，同時(shí)闡明預(yù)算目標(biāo)，并對(duì)預(yù)算編制、審批、執(zhí)行、考核等一系列程序進(jìn)行合理的制定。在制度構(gòu)建完成后，要將制度的落實(shí)和企業(yè)文化建設(shè)有機(jī)的結(jié)合起來，使其逐漸成為一種文化，滲透到廣大員工的行為習(xí)慣中。

The surgery was smooth and lacked implant bed microperforations, posterior elastic layer ruptures and other complications.

DISCUSSION

Keratoplasty is the main method used to restore vision in patients with corneal blindness

. At present, many developing countries, including China, lack corneal donors due to traditional, cultural, and religious reasons

. In addition to the shortage of corneal donors, there are some practical problems in clinic, such as patients waiting for donors and donors waiting for corneas

. The utilization rate of donor corneas cannot reach the ideal level, and some freshly corneal donors may not be immediately used in patients. This phenomenon aggravates the shortage of donors

. If a freshly corneal donor is discarded towards the end of the preservation period, donor resources will be wasted. If the cornea is dehydrated, it can be used for lamellar keratoplasty in the future. Therefore, a high-quality, long-term dehydrating and preservation method is helpful to make full use of the limited corneal donor resources.

Some problems are associated with traditional glycerol preservation and anhydrous calcium chloride dehydrating preservation, such as incomplete dehydration and donor shape changes after dehydration. These limitations prevent the clinical application of these methods. Compared with the traditional dehydrating and preservation methods, the dehydrater described in this study has two advantages: fast dehydrating and maintaining the original shape of the cornea.The rapid dehydrating of corneal donors is mainly dependent on the hydroscopicity of discolored silica gel and a strong silent circulation fan. Discoloration silica gel is a fine porous silica gel with high active adsorption capacity that is combined with cobalt chloride on the internal pore surface of silica gel using specific technological steps. The gel has a strong adsorption effect on water vapor in the medium and is nontoxic and harmless, odorless, and highly safe for clinical application.We placed the discolored silica gel at the bottom of the dehydrating box to directly absorb the volatile water from the donor corneas. In addition, the strong silent circulation fan continuously circulates the air in the dehydrating box,thus ensuring that the corneal donor dries quickly within 2h,avoiding donor pollution, autolysis and other problems caused by long-term separation.

In addition, postoperative complications, such as interlamellar effusion and double anterior chamber, easily occur. The traditional dehydrating preservation uses anhydrous calcium chloride, which exhibits strong water absorption and releases a considerably amount of heat in the process, which damages and deforms the cornea, thus limiting its clinical application.This paper introduces a new type of corneal dehydrater that can be used to quickly dehydrate and still maintain the shape of the cornea. Using this system, the cornea dries fast without wrinkling and deforming. This system solves the problem of high-quality preservation of corneal donor tissue and is a new method worthy of clinical application.

All patients met the following inclusion criteria for surgery

:1) clinically diagnosed as fungal keratitis confirmed by the presence of fungus in potassium hydroxide preparations,confocal microscopic images, or positive culture results; 2)antifungal medication as reported in our previous studies was given for at least 2wk but was ineffective; 3) slit-lamp examination and RTVue optical coherence tomography(Optovue; Fremont, CA, USA) scans displaying stromal layer pathological changes with fusion and diffuse opacity reaching more than 3/5 of the depth of the stroma but without reaching Descemet’s membrane (DM)

; 4) a complete follow-up of at least 6mo.

Based on the results, the dehydrater can efficiently dehydrate the corneal material and maintain the original shape. Cases of shrinkage and deformation were not observed. A significant improvement in the BCVA was noted with an average increase of more than two lines. In terms of the transparency of corneal buttons, the corneal buttons exhibited mild edema on the first day after DALK. The edema generally disappeared one week after operation. The epithelium healed quickly after the operation. In terms of the thickness of corneal buttons, the central thickness of corneal buttons was 588±18 μm 1wk after operation and 544±41 μm 1mo after operation. These results indicate that the corneal buttons were stable and reached the normal level.

In summary, the cornea dehydrater with rapid dehydrating and shaping quickly dehydrates the corneal donor, and significantly reduces early complications, such as interlamellar effusion and double anterior chamber after operation. It can also maintain the original shape of the cornea during the process of dehydrating. This dehydrater solves the problem of long term and high-quality preservation of corneal materials, and this new method is worthy of clinical application.

The authors would like to thank Ms. Tong Liu for her editorial assistance.

本文通過Eviews 6.0軟件，采用普通最小二乘法基于截面數(shù)據(jù)進(jìn)行多元線性回歸分析.首先，對(duì)浙江省對(duì)外直接投資的出口效應(yīng)進(jìn)行檢驗(yàn)，回歸結(jié)果如下：

④繼續(xù)使用的水工建筑物、廠房及水工金屬結(jié)構(gòu)等，這些固定資產(chǎn)設(shè)施已使用30多年，應(yīng)只考慮剩余價(jià)值的效益貢獻(xiàn)。

Sun Y, Qi XL and Gao H was responsible for its design. Sun Y wrote the first draft of the manuscript. Lin X and Zhang XY participated in its design of manuscript. Zhang XY and Gao L helped revise of manuscript.Sun Y and Lin X was involved in data collection and statistical analysis. All authors have read and approved the final manuscript.

Supported by National Natural Science Foundation of China (No.81870639; No.82070923;No.81900907); Taishan Scholar Program (No.tspd20150215;No.tsqn201812150); the Academic Promotion Program of Shandong First Medical University (No.2019RC009).

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