INTRODUCTION

Over the past decade through, anterior lamellar keratoplasty(ALK) has become an alternative surgical procedure to penetrating keratoplasty (PKP) in the treatment of a variety corneal diseases which does not involve the Descemet’s membrane and endothelium[1-3]. Otherwise, the shortage of donor grafts is a major limitation for the development of corneal transplantation in China, and this situation will worsen with an aging population and the increased use of cornea laser surgery[4]. Fresh donors were not required for ALK, which is an advantage of ALK compared with PKP. The aim of this study is to analyze the indications and the reasons of graft failure after ALK from June 1, 2009 to May 31, 2016 in Qingdao Eye Hospital, Shandong Eye Institute, and provide reference for future ALK operation.

SUBJECTS AND METHODS

Medical records of 434 patients (462 eyes) underwent ALK at the Qingdao Eye Hospital, Shandong Eye Institute, China from June 1, 2009 to May 31, 2016 were retrospectively reviewed. This study was approved by the Ethics Committee of Shandong Eye Institute and conformed to Declaration of Helsinki guidelines.Data of gender, age, preoperative diagnosis, rate of surgery success, and causes of graft failure were retrieved. The indications for ALK were divided into 8 categories: infectious keratitis, keratoconus, corneal dystrophy and degeneration,Mooren’s ulcer, corneal neoplasm, viral keratitis, primary graft failure and others (such as ocular trauma, burn, keratoglobus,corneal ectasia after laser assisted in situ keratomilensis).Additionally, infectious keratitis was further classified into fungal, bacterial and Acanthamoeba keratitis according to the different pathogens. For cases with graft failure after ALK,reasons of graft failure and the primary diagnosis before ALK were reviewed.

In order to study the changes of ALK surgical indications with time and indications during this period, this study divided the case data into two groups, according to time, each group includes 3.5y of case data (June 1, 2009 to November 30, 2012 and December 1, 2012 to May 31, 2016).

RESULTS

Demographics, Culture Results, and Clinical Features During the seven-year period, a total of 462 ALK performed for 434 patients were included in this study. The ages ranged from 5.5mo to 85y, with a mean age of 39.1±19.7y. There were 165 females (38.1%) and 269 males (61.9%). The majority of patients were in the age range of 41-60y (38.3%), 21-40y(26.2%), and 0-20y (22.3%).

Table 1 Annual indications distribution for ALK n (%)

ALK: Anterior lamellar keratoplasty.

Indications June 2009-May 2010 June 2010-May 2011 June 2011-May 2012 June 2012-May 2013 June 2013-May 2014 June 2014-May 2015 June 2015-May 2016 Total Infectious keratitis 41 (46.6) 26 (43.3) 21 (42.9) 13 (34.3) 18 (17.3) 12 (21.4) 23 (34.4) 154 (33.3)Keratoconus 20 (22.8) 12 (20.0) 13 (26.5) 4 (10.5) 36 (34.6) 14 (25.0) 10 (14.9) 109 (23.6)Corneal dystrophy and degeneration 9 (10.2) 3 (5.0) 4 (8.2) 7 (18.5) 6 (5.8) 9 (16.1) 7 (10.4) 45 (9.8)Mooren’s ulcer 6 (6.8) 5 (8.3) 5 (10.2) 1 (2.6) 9 (8.7) 6 (10.8) 7 (10.4) 39 (8.4)Corneal neoplasm 5 (5.7) 5 (8.3) 2 (4.1) 4 (10.5) 9 (8.7) 5 (8.9) 6 (9.0) 36 (7.8)Viral keratitis 3 (3.4) 2 (3.4) 2 (4.1) 1 (2.6) 10 (9.5) 5 (8.9) 7 (10.4) 30 (6.5)Regrafting 1 (1.1) 3 (5.0) 1 (2.0) 4 (10.5) 7 (6.7) 0 (0) 1 (1.5) 17 (3.7)Others 3 (3.4) 4 (6.7) 1 (2.0) 4 (10.5) 9 (8.7) 5 (8.9) 6 (9.0) 32 (6.9)Total 88 (100) 60 (100) 49 (100) 38 (100) 104 (100) 56 (100) 67 (100) 462 (100)

Table 2 Infectious keratitis for ALK n (%)

ALK: Anterior lamellar keratoplasty.

Indications June 2009-May 2010 June 2010-May 2011 June 2011-May 2012 June 2012-May 2013 June 2013-May 2014 June 2014-May 2015 June 2015-May 2016 Total Fungal keratitis 32 (78.0) 24 (92.4) 18 (85.7) 12 (92.3) 12 (66.7) 8 (66.7) 7 (30.4) 113 (73.4)Bacterial keratitis 3 (7.3) 1 (3.8) 1 (4.8) 0 (0) 4 (22.2) 1 (8.3) 3 (13.1) 13 (8.4)Acanthamoebic keratitis 1 (2.5) 0 (0) 0 (0) 1 (7.7) 0 (0) 2 (16.7) 5 (21.7) 9 (5.8)Others 5 (12.2) 1 (3.8) 2 (9.5) 0 (0) 2 (11.1) 1 (8.3) 8 (34.8) 19 (12.4)Total 41 (100) 26 (100) 21 (100) 13 (100) 18 (100) 12 (100) 23 (100) 154 (100)

Indications for Anterior Lamellar Keratoplasty In the 462 eyes, the leading indications for ALK was infectious keratitis(33.3%), followed by keratoconus (23.6%), corneal dystrophy and degeneration (9.8%), Mooren’s ulcer (8.4%) and corneal neoplasm (7.8%; Table 1). The most common pathogen of infectious keratitis was fungi, which accounted for 73.4%(113/154) in infectious cases (Table 2).

Fungal keratitis is one of the most severe eye diseases worldwide that may lead to blindness, for uncontrollable or further aggravated infection, surgical interventions are suggested.In this study, fungal infections accounted for 81.8% of the infectious keratitis cases failed ALK surgery. Growth patterns of fungal pathogens may be an important factor for fungal recurrence after ALK. In cases of horizontal hyphal growth,the lesions are generally superficial at the early stage of the disease and can be excised thoroughly by ALK. However, the perpendicular growth of fungal filaments such as Aspergillus species made the infection penetrate deep into the corneal layers in a short time such that the tissue could not be excised thoroughly with ALK, and the rudimentary fungi in the deep stroma may cause fungal recurrence postoperatively[23].DALK using the big bubble technique may be effective in the treatment of deep fungal keratitis, which can not only remove the mycetes in the deep corneal stroma, but also provide a clear interface between the recipient and the graft,achieving satisfactory visual acuities[24]. In this study, we used manual deep lamellar keratoplasty for fungal corneal ulcers involving deep corneal stroma. The recurrence rate for these patients treated with steroids or immunosuppressants before surgery was significantly higher than not. Hypopyon,corneal infection expanding to limbus and lens infection are major risk factors for recurrence of fungal keratitis after corneal transplantation[25]. The first two weeks after ALK is the critical period for the success or failure, and antifungal drugs should continue to be applied[10]. Sometimes it is not easy to distinguish treatment failure from local inflammation after ALK for fungal keratitis, some ophthalmologists thought cases of treatment failure usually show the following characteristics:patients report increasing irritation and decreasing vision of the operated eyes; exudation in the anterior chamber aggravates,and hypopyon develops in some cases; the focus of infection demonstrates gray infiltration and expands rapidly in the transplanted cornea; antifungal medications are ineffective.Appropriate treatment methods were chosen according to the different sites of recurrence.

In the 36 eyes of reoperation, 17 eyes (47.2%) were performed with PKP, 13 eyes (36.1%) were performed second lamellar keratoplasty, 5 eyes (13.9%) were operated with lamellar keratoplasty and amniotic membrane transplantation and the other 1 eye (2.7%) was operated with corneal debridement and conjunctival flap cover.

Figure 1 Indications for ALK between June 2009 and May 2016.

Figure 2 Primary disease of reoperation after ALK between June 2009 and May 2016 Infectious keratitis and keratoconus were the leading indications for ALK, and fungal infections were the major cause of corneal infections. Primary disease recurrence was the main reason of failure for ALK. The leading initial diagnoses associated with failure were Mooren’s ulcer and fungal keratitis.

Table 3 Indications for ALK between 2009 and 2016 n (%)

ALK: Anterior lamellar keratoplasty.

Etiology June 2009-November 2012 December 2012-May 2016 Total Infectious keratitis 92 (43.8) 62 (24.6) 154 (33.3)Keratoconus 47 (22.4) 62 (24.6) 109 (23.6)Corneal dystrophy and degeneration 18 (8.6) 27 (10.7) 45 (9.8)Mooren’s ulcer 17 (8.1) 22 (8.8) 39 (8.4)Corneal neoplasm 13 (6.2) 23 (9.1) 36 (7.8)Viral keratitis 7 (3.3) 23 (9.1) 30 (6.5)Regrafting 7 (3.3) 10 (4.0) 17 (3.7)Others 9 (4.3) 23 (9.1) 32 (6.9)Total 210 (100) 252 (100) 462 (100)

Reasons of Graft Failure for Anterior Lamellar Keratoplasty In this study, ALKs were failed in 36 patients and were performed again. The causes of reoperation was recurrence of primary disease (63.9%), graft infection (16.7%), corneal graft melting (8.3%) and others (11.1%). The leading primary diseases associated with reoperation were Mooren’s ulcer(36.1%) and infectious keratitis (30.6%; Figure 2), and fungal infections accounted for 81.8% in the infectious keratitis cases reoperated.

DISCUSSION

第二，考虑未来是一件很悲伤的事。除“走一步算一步”的想法外，还有照料者认为：“既然考虑未来是一件令人悲伤的事，现在能开心生活就想些开心的事情，不要去想不开心的事！”这些不开心的事很大程度上指的是残障成员的未来安置问题。虽然担心他们的未来，但囿于相关支持和信息缺位、可供选择的方案缺乏等因素，照料者考虑未来只会因无法预见的未来而加剧失望和焦虑。无奈之下，他们只能推迟对未来的规划。需要指出的是，考虑未来虽然会遇到很多挑战和不安，但因为悲伤和担忧而消极回避，无疑是不明智的选择。

2.2.1 术前检查 根据医嘱检查3大常规，肝肾功能、生化、出凝血时间、B超、心电图、X线和TCT检查，了解患者心肺功能有无异常。术前1 d视情况备血。

Keratoconus, corneal dystrophy and degeneration, Mooren’s ulcer and corneal neoplasm were the four most common indications after infectious keratitis in our study. Over the past seven years, the infectious keratitis for ALK in our hospital have been declining, this trend may be attributable to improved management of corneal diseases with new drugs and diagnostic tools. Besides, because of the increasing awareness of the patients and the increasing number of patients who treated in time, the opportunity for ALK surgery has been increased. Meanwhile, keratoconus increased dramatically as an indication for ALK, further in 2013-2014 and 2014-2015,keratoconus became the most common indication for ALK,which is consistent with the reports of Western countries. In United States during the period of 2005-2014, the top four indications for ALK were corneal degeneration, ulcerative keratitis or perforation, keratoconus, and unspecified anterior stromal scarring[11], while keratoconus, keratitis and non-Fuch’s corneal dystrophies (NFCD) were the main clinical indications for ALK in the West of Scotland[12]. Zhang et al[13]reported that ALK accounted for approximately 30% of keratoplasty procedures for keratoconus in Ontario, Canada in 2012. In Western Scotland, ALK surpassed PKP as the more popular keratoplasty procedure for keratoconus after 2004[12].Many groups advocate the use of ALK over PKP on the basis of reports that similar postoperative visual acuity and longer graft survival based largely on the reported outcomes of single centers were found[14-16]. Further, femtosecond laser-assisted ALK facilitates the preparation of donor and recipient tissue[17],and achieve less interface irregularity and haze, which may result in faster and better visual rehabilitation[18]. Since 2013,most of the ALK for keratoconus have been done using femtosecond laser-assisted DALK at Qingdao Eye Hospital.

In our study, primary disease recurrence was the major cause of failure for ALK, and Mooren’s ulcer and infectious keratitis were the leading initial diagnoses. Mooren’s ulcer is an idiopathic peripheral ulcerative keratitis that is characterized by painful and progressive ulceration of the peripheral cornea in the absence of scleritis and systemic rheumatologic diseases, and is commonly seen in China[19]. It is generally thought that Mooren’s ulcer is an autoimmune disease that targets the cornea, but its exact pathogenesis is not clear[20],so despite many therapies recommended in previous reports,the recurrence of Mooren’s ulcer is frequently encountered.The rate of recurrence was reported to be 25.6% in a series of 550 Chinese patients suffering Mooren’s ulcer[21], and the author thought ALK surgery is the most effective treatment of Mooren’s ulcer, because ALK could removes antigenic targets of the cornea, prevents immunological reactions, reconstructs the anatomical structure, prevents it from perforating, and improves vision, besides, primary lamellar keratoplasty combined with topical cyclosporine. A achieve good results, the final cure rate was 95.6%, and the postoperative preservation rate of the eye globe was 99.7%. In our study, medication was given aggressively for patients with Mooren’s ulcers before surgery, including 1% cyclosporine A or 0.1% tacrolimus eye drops, 0.1% dexamethasone, and antibacterial eye drops 4 times daily, along with tobramycin and dexamethasone ointment at night. Systemic use of corticosteroids and cyclophosphamide was implemented if the ulcer was not relieved by those first approaches. When the signs and symptoms of the disease showed no improvement despite the above interventions, surgical treatment was considered. When the ulcer invading the cornea had more than one half of the corneal thickness and occurred extensively along the limbus or toward the center, lamellar keratoplasty was performed, including crescent lamellar keratoplasty,donut-shaped lamellar keratoplasty, and lamellar keratoplasty with a large corneoscleral graft, depending on the morphology of the ulcer and the in filtration depth in the cornea. For eyes with corneal perforation, lamellar keratoplasty was also considered if the perforation was small, was located in the periphery, or was obstructed by prolapsed iris. Intraoperatively,a small perforation was repaired with Tenon’s capsule before the corneal graft was placed on the recipient bed. The main treatment principle for recurrent ulcers was the same as that for the primary disease. Immunosuppressants were given for a longer period according to the severity of the disease[22]. In this study, the recurrence rate of Mooren’s ulcer after ALK was 33.3%, higher than previous report. A recent research found the use of corticosteroids and immunosuppressants guided by in vivo confocal microscopy may reduce the disease recurrence after corneal transplantation[20].

The shortage of donor grafts is a major limitation for the development of corneal transplantation in China. In 2015,the first bioengineered cornea (Acornea, China Regenerative Medicine International Limited, CRMI) was approved by China Food and Drug Administration (CFDA) to be applied clinically as a substitute for human cornea in lamellar keratoplasty[7], so suf fi cient donors could be supplied for ALK and a bright future of ALK development could be expected in China.

说明性的文章自有其独特之处，不仅体现在表现手法上，也表现在语言特点上。一般集中体现在语言的生动和准确上。本文花开四种形态生动传神，耐人寻味。细细体会，消化吸收，对学生言语发展大有裨益。

Infectious keratitis is the most common indication for ALK in this study, and the predominating pathogen of infectious keratitis is fungi. Fungal keratitis is one of the most severe infectious eye diseases leading to blindness, especially in the developing countries with temperate climates, such as China[8]and India[9]. It had been reported that fungal keratitis accounted for 61.9% in the infectious corneal diseases in China[8].With the advancement of surgical techniques, fewer surgical complications and more easily obtained donor corneas than PKP, ALK has become an important and effective method for fungal keratitis uncontrollable with medical treatment[10].

As a extraocular surgery, ALK could avoid intraocular tissue damage and complications of PKP, such as eye content prolapse, secondary glaucoma, endothelial rejection. ALK retains the host endothelium, so no endothelial rejection will occur. The incidence of corneal graft rejection after ALK(1%)[5-6] is significantly lower than that after penetrating keratoplasty (8.2%)[1]. So ALK has become an alternative surgical procedure to PKP in the treatment of variety corneal diseases[1-3].

A significant increase in the number of ALK was noted during the 7y in the study, from 210 ALK in the first time period to 252 ALK in the second time period. In the first group, 43.8%of ALK were performed for infectious keratitis, while the second group of infectious keratitis accounted for only 24.6%(Table 3). The percentage of ALK performed for infectious keratitis decreased each year (Figure 1), further in 2013-2014 and 2014-2015, infectious keratitis was not the most common indication for ALK (Table 1). Conversely, there was a remarkable increase in ALK procedures used to treat keratoconus, corneal dystrophy and degeneration, Mooren’s ulcer, corneal neoplasm and viral keratitis (Table 3).

In summary, infectious keratitis and keratoconus are the main indications for ALK, of which fungal keratitis was the major cause of corneal infections. Recurrence of primary disease was the main reason of graft failure after ALK, in which the the main primary diseases with graft failure are Mooren’s ulcer and fungal keratitis.

ACKNOWLEDGEMENTS

Foundations: Supported by the National Natural Science Foundation of China (No.81500703); the Natural Science Foundation of Shandong Province (No.ZR2015YL027).

Conflicts of Interest: Wang Z, None; Tan XJ, None; Zhai HL, None; Cheng J, None; Gao Y, None; Xie LX, None.

尖尾风药材的HPLC指纹图谱建立及聚类分析和主成分分析 ……………………………………………… 高 微等（16）：2215

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