A comparison of surgical efficacy between a 1.8-mm microincision and 3.2-mm and 5.5-mm incisions for phacoemulsification

Phacoemulsification is a commonly used surgical method in cataract surgery. This paper observes and compares the surgical efficacy of three incisions of different length for phacoemulsification to identify the optimal method for cataract surgery. Ninety patients were enrolled in the present study and divided into three groups. The 1.8-mm group received Bausch & Lomb MI60 foldable intraocular lens (IOL) implantation (n=30), 3.2-mm group received Bausch & Lomb Akreos AO foldable lens implantation (n=30), and 5.5-mm group received Alcon TYPE 05 rigid IOL implantation (n=30). Visual acuity, Oculyzer-based anterior segment analysis, and corneal endothelial cell count before surgery, and 3, 7, 30, and 90d after surgery were recorded and compared. Pseudophakic accommodation three days, one week, one month, and three months after surgery was determined. Intraoperative ultrasound time and ultrasonic energy were recorded. It was finally concluded that for phacoemulsification with the same phaco tip, a 1.8-mm microincision can lead to quicker recovery of visual acuity, more stable astigmatism, and higher pseudophakic accommodation than conventional incision.     

【In Press】 A comparison of surgical efficacy between a 1.8-mm microincision and 3.2-mm and 5.5-mm incisions for phacoemulsification

Phacoemulsification is a commonly used surgical method in cataract surgery. This paper observes and compares the surgical efficacy of three incisions of different lengths for phacoemulsification to identify the optimal method for cataract surgery. Ninety patients were enrolled in the present study and divided into three groups. 1.8-mm group received Bausch & Lomb MI60 foldable IOL implantation (n=30), 3.2-mm group received Bausch & Lomb Akreos AO foldable lens implantation (n=30), and 5.5-mm group received Alcon TYPE 05 rigid IOL implantation (n=30). Visual acuity, Oculyzer-based anterior segment analysis, and corneal endothelial cell count before surgery, and 3, 7, 30, and 90d after surgery were recorded and compared. Pseudophakic accommodation three days, one week, one month, and three months after surgery was determined. Intraoperative ultrasound time and ultrasonic energy were recorded. It was finally concluded that for phacoemulsification with the same phaco tip, a 1.8-mm microincision can lead to quicker recovery of visual acuity, more stable astigmatism, and higher pseudophakic accommodation than conventional incisions.     

Long-term observation of aqueous flare following penetrating keratoplasty

PURPOSE: To understand the influence of preoperative corneal conditions, combined implant surgeries, and subsequent rejection on the aqueous flare value following penetrating keratoplasty (PK). METHODS: A total of 86 eyes of 86 patients were included. PK alone was performed on eyes with keratoconus (n = 7), corneal scar (from previous trauma or nonherpetic infection; n = 19), pseudophakic bullous keratopathy (PBK) (n = 16), and for regraft (n = 14). Combined ECCE and PC-IOL implantation (triple procedure) was performed on 17 eyes with corneal scar, and combined AC-IOL exchange was performed on 13 eyes with PBK. Aqueous flare was measured with a laser flare-cell meter at 1 week and 1, 3, 6, 12, and 24 months postoperatively. The mean follow-up was 24.7 (range 7-76) months. RESULTS: There were 11 cases (12.8%) of endothelial rejection (two in PK for corneal scar group, two in triple procedure group, two in PK for PBK group, three in PK and AC-IOL exchange group, and two in regraft group). Two corneas in PK for corneal scar group, one in PK and AC-IOL exchange group, and one in regraft group cleared up later; the remaining seven cases failed subsequently. Another 10 grafts (11.6%) failed from other causes. Eventually, 69 grafts (80.2%) remained clear at last follow-up. There was a significant difference in aqueous flare values among eyes undergoing PK only for keratoconus, corneal scar, PBK, and regraft from 1 week to 3 months postoperatively. In the corneal scar group, aqueous flare value was significantly higher from 1 week to 3 months when combined with cataract surgery. In the PBK group, the value was significantly higher from 1 week to 1 month and 6 months again when combined with AC-IOL exchange. Notably, significantly higher flare values were measured from 1 week to 6 months in eyes with later rejection. CONCLUSIONS: Preoperative diagnoses and additional implant surgeries influenced the aqueous flare counts at the early postoperative period. Persistently elevated flare value may be associated with later rejection.     

The Effects of Oversize Donor Buttons on Postoperative intraocular Pressure and Corneal Curvature in Aphakic Penetrating Keratoplasty

Forty-one consecutive aphakic corneal transplants performed by the same surgeon were stuided in order to determine the effects on intraocular pressure and corneal curvature of using 8.0-mm donor buttons in 7.5-mm recipient openings. One half of the grafts had oversize donor buttons, and all were followed for 13 months. The intraocular pressure in the oversize donor group was statistically significantly less during the first five days after keratoplasty, but not subsequently. Eliminating eyes with preoperative glaucoma, more transplants in the same size donor group (P = 0.08) needed glaucoma therapy 13 months after operation. The anterior corneal curvature (mean keratometry reading) was statistically significantly greater in the oversize donor group throughout the postoperative period. Concurrently, the oversize donor group was less hyperopic after all sutures were removed. There was no difference in keratometric astigmatism or corneal thickness between the two groups. Thus, the use of 0.5-mm oversize donor tissue in aphakic corneal transplants reduced the intraocular pressure and increased the central corneal curvature after keratoplasty.     

Comparison of corneal storage in K-Sol and chondroitin sulfate corneal storage medium in human corneal transplantation

Fifty-one pairs of corneas, stored in either K-Sol or CSM (chondroitin sulfate corneal storage medium) from 8 to 97 hours (mean +/- standard deviation, 58 +/- 21 and 57 +/- 21 hours, respectively), were transplanted in a prospective, randomized manner into 99 patients (n = 102 eyes), paired by diagnostic group and procedure. Ninety-six percent of K-Sol grafts (n = 51) and 94% of the CSM grafts (n = 51) were clear at 6 months; 92% of both the K-Sol (n = 38) and CSM (n = 35) grafts were clear at 12 months. One primary donor failure occurred, a K-Sol cornea stored for 76 hours. The CSM group experienced a greater number of persistent epithelial defects beyond 2 weeks (7 versus 4 defects) and graft reaction episodes (7 versus 3 episodes) than the K-Sol group; however, an equal number of late graft failures (3) occurred in both groups. No significant differences by paired t test analyses were found in endothelial cell density, area, coefficient of variation, or figure coefficient at 3 (n = 37 pairs), 6 (n = 36 pairs), and 12 (n = 26 pairs) months between the two groups. Mean endothelial cell density significantly decreased by 11% +/- 22 by 3 months in the K-Sol group, whereas the 7% +/- 24 decrease in the CSM group was insignificant. By 12 months, both groups experienced a significant decrease: K-Sol, 27% +/- 22; CSM, 17% +/- 26. A significant decrease in the mean coefficient of variation (polymegathism) was noted after 3 months in the K-Sol group which returned to the preoperative mean by 1 year, whereas this parameter remained unchanged in the CSM group. Both chondroitin sulfate-based media result in successful corneal transplantation with storage up to 4 days; however, endothelial survival with both media are comparable with previous studies with McCarey-Kaufman (M-K) medium.     

Effects of 1alpha,25-dihydroxyvitamin D3 on Langerhans cell migration and corneal neovascularization in mice

PURPOSE: To examine the effects of 1alpha,25-dihydroxyvitamin D3 (1alpha,25[OH]2D3), a hormone that has immunosuppressive properties, on Langerhans cell (LC) migration and corneal neovascularization in mouse corneas. METHODS: Two 10-0 nylon interrupted sutures were placed in the center of 50 BALB/c mouse corneas to induce LC migration and corneal neovascularization. The mice were then randomly assigned to one of five groups. Three groups (n = 11, n = 11, n = 6) received topical 1alpha,25(OH)2D3 (at concentrations of 10(-7) M, 10(-)8 M, 10(-9) M), one group (n = 11) received vehicle only, and one group (n = 11) received no eye drops. Instillation (three times a day) began on the first day after suturing. Corneal neovascularization was assessed by slit lamp microscopy and scored according to the length of newly formed corneal vessels. Fourteen days after suturing, the number of LCs that had migrated into the central corneal epithelium was counted by an immunofluorescence assay using an anti-Ia antibody. RESULTS: The number of LCs in the central cornea was 21.9 +/- 2.8 cells/mm2 in the nontreated group and 17.8 +/- 3.9 cells/mm2 in the vehicle-only group. Significantly fewer LCs were detected in all groups that had received 1alpha,25(OH)2D3 compared with the vehicle only and nontreated groups (10(-7) M: 7.4 +/- 1.2 cells/mm2, 10(-8) M: 7.2 +/- 2.0 cells/mm2, 10(-9) M: 6.2 +/- 0.7 cells/mm2). Moderate inhibition of corneal vascularization was observed in the 10(-7) M 1alpha,25(OH)2D3 group, but not the other groups. CONCLUSIONS: Topical administration of 1alpha,25(OH)2D3 can be effective in suppressing ocular surface inflammation by inhibiting LC migration into mouse corneas.     

Intraocular dexamethasone delivery system for corneal transplantation in an animal model

PURPOSE: To assess the efficacy of a new intraocular biodegradable polymer dexamethasone drug delivery system (DEX DDS) in a high-risk corneal transplantation model. METHODS: Lewis rats that received orthotopic corneal transplants (Balb/c mice donors) were divided into three groups (six rats in each); group 1 received no treatment and served as controls, group 2 was treated with 0.1% betamethasone eyedrops three times daily for 6 weeks, and group 3 received DEX DDS in the anterior chamber at the time of transplantation. RESULTS: All grafts in the untreated control group were rejected within 8 days. In the betamethasone eyedrop group, five eyes (83%) were rejected during the 8-week study period. None of the grafts in the DEX DDS group was rejected. The administration of DEX DDS significantly prolonged the survival rate of the corneal grafts (p < 0.001, log-rank test). CONCLUSION: DEX DDS is effective in suppressing graft rejection in high-risk corneal transplantation.     

生物工程角膜移植治疗感染性角膜炎

目的：观察生物工程角膜移植治疗感染性角膜炎的疗效,评价其临床应用价值和意义。

方法：对我院35例35眼需要进行手术治疗的感染性角膜炎患者分为3组：观察组15例,使用生物工程角膜施行板层角膜移植手术。对照组有两组：对照1组10例,使用保存人角膜施行板层角膜移植手术; 对照2组10例,实施自体结膜瓣遮盖手术。随访3～20mo,观察视力、感染控制情况以及角膜透明度。

结果：观察组15眼术后感染控制,视力不同程度提高,除1眼在随访中发生植片混浊外,其余14眼植片均维持基本透明。对照1组,除1眼病毒性角膜炎因病毒复发导致角膜混浊外,其余9眼角膜植片维持透明。对照2组,除1眼真菌性角膜溃疡感染加重,行眼内容物剜除术,其余角膜溃疡瘢痕修复。

结论：生物工程角膜是一种新型的人角膜替代材料,为解决逐年增长的角膜病患者与短缺的角膜供体之间的矛盾发挥了作用。     

人羊膜作为载体体外培养兔角膜上皮细胞移植治疗碱烧伤动物的实验研究

目的观察培养生长于人羊膜的兔角膜上皮细胞使其扩增并移植治疗角膜碱烧伤的效果。为培养角膜上皮细胞移植技术及应用于临床实践提供最佳的理论和实验依据。方法新西兰白兔30只（30眼）,随机分为3组（n=10）,右眼制成碱烧伤模型。A组：角膜上皮细胞羊膜移植组;B组单纯羊膜移植组;C组为对照组（碱烧伤后不作任何移植）。术后观察角膜透明度、角膜新生血管及上皮修复情况,裂隙灯显微镜照相记录。3组均于术后1周、2周、1个月及3个月时各取1眼角膜标本行病理组织检查。结果A组除1眼移植片在第7天脱落外,所有移植片在术后3d水肿消退,角膜逐渐透明。B组移植片持续水肿,眼前段炎性反应稍重,但较碱烧伤对照组轻。C组角结膜高度水肿浑浊,烧伤后观察3个月未发现角膜恢复透明现象。病理组织检查显示：A组角膜及周边上皮细胞为多层结构,角膜新生血管消失,基质的炎性细胞浸润减退;B组覆盖上皮细胞表现为完整上皮细胞型,C组角膜浑浊,新生血管及肉芽组织形成。结论人羊膜作载体体外培养兔角膜上皮细胞移植重建角膜基底膜和角膜上皮结构治疗兔碱烧伤后的角结膜损伤是一种合理有效的方法。     

CD4和CD8基因敲除鼠行穿透性角膜移植术后免疫排斥特征的研究

目的　探讨CD4和CD8基因敲除小鼠行穿透性角膜移植术后免疫排斥反应发生的机制。方法　CD4、CD8基因敲除小鼠及C57BL/6小鼠各20只,分成3组,右眼接受穿透性角膜移植术,供体为BALB/c小鼠,术后裂隙灯显微镜评价角膜移植片情况,并详细记录免疫排斥的发生时间,在术后1、2、4周各取2只鼠术眼行免疫组织化学检查,观察眼前段CD+4 、CD+8 T细胞的变化。在术后2周, 3组小鼠各选其中10只接受皮肤移植,供体为BALB/c小鼠,监测皮肤移植后皮肤植片免疫排斥反应的时间和在皮肤发生排斥反应时角膜移植片的情况。结果　3组小鼠角膜移植术后免疫排斥发生时间明显不同,CD4基因敲除鼠角膜移植片保持透明,至少观察了90d未见免疫排斥反应发生;CD8基因敲除小鼠在(28±3)d时发生免疫排斥反应;C57BL/6小鼠发生免疫排斥反应的时间为(14±2)d(F=2034, P<0. 01)。移植皮肤后发生免疫排斥反应时间为:CD4基因敲除鼠(14±2)d,CD8基因敲除鼠(12±1)d,C57BL/6小鼠(10±1)d(F=42. 54, P<0. 01)。结论　小鼠行穿透性角膜移植术后免疫排斥反应可能是以T淋巴细胞,主要为CD+4 T细胞介导的免疫排斥反应,CD+8 T细胞参与了排斥反应过程。