A comparative study on endothelial cell loss in nanophthalmic eyes undergoing cataract surgery by phacoemulsification

Purpose:The purpose of this study is to compare the endothelial cell loss (ECL) in nanophthalmic eyes and age-matched controls undergoing cataract surgery by phacoemulsification and also to identify the risk factors influencing the endothelial cell density (ECD). This was a prospective comparative interventional case series.Methods:We enrolled 19 nanophthalmic eyes (study group) and 42 age-matched cataract controls (control group) undergoing phacoemulsification after meeting the inclusion criteria. Ocular parameters like best-corrected visual acuity, intraocular pressure, pachymetry, specular microscopy, and slit lamp findings were noted preoperatively and at month 1 and 3 postsurgery. All nanophthalmic eyes underwent cataract surgery with concomitant prophylactic posterior sclerostomy.Results:The median percentage endothelial loss in nanophthalmic eyes was 4.0 (IQR 0–23.5), 7.4 (IQR 1.0–-22.4) at 1 and 3 months postoperatively compared to 6.3 (IQR 1.7–14.1) and 6.4 (IQR 2.6–-12.1) in age controlled normal eyes (P = 0.94, P = 0.46, respectively). Linear regression analysis showed increasing age as the only variable influencing the percentage decrease in corneal ECD in the study group (P = 0.001). Nanophthalmic eyes with ACD <2.5 mm had a significantly greater reduction in ECD at 3 months postcataract surgery compared to baseline (P = 0.039). Visual outcomes and IOP reduction in the study group with ACD >2.5 mm were significantly better postcataract surgery (P = 0.02 and P = 0.002, respectively).Conclusion:The percentage of ECL in nanophthalmic eyes undergoing phacoemulsification is equivalent to normal eyes. However, in the nanophthamic eyes with AC depth <2.5 mm, the percentage cell loss was significantly higher warranting the need for extensive intraoperative care. Increasing age was found to be the only significant risk factor influencing the ECD in short eyes.     

Long-term follow-up of changes in corneal endothelium after primary and secondary intraocular lens implantations in children

Background

To evaluate long-term changes in corneal endothelial cell count and morphology after congenital cataract extraction and intraocular lens implantation.

Methods

Cataract extraction and posterior chamber intraocular lens (IOL) implantation was performed on 54 congenital cataract patients (83 eyes). The corneal endothelial cell density (ECD), coefficient of variation (CV), hexagonality, and central corneal thickness (CCT) were measured for a retrospective analysis of long-term changes in corneal endothelial characteristics.

Results

The mean age at the time of IOL implantation was 5.00 (3.62) years [mean (SD)], and the mean follow-up period was 8.83 (1.49) years. In a comparison of the treated and normal eyes of patients who underwent unilateral surgery, the treated eyes showed a significantly greater CCT (p?<?0.05), and there was no significant difference in ECD, CV, and hexagonality (p?>?0.05). In addition, there was no statistically significant difference in the ECD and CCT between the primary and secondary IOL implantation groups.

Conclusions

Our results did not show any significant corneal endothelial cell loss in congenital cataract patients; however, their CCTs were increased.     

Oxidative Stress Levels in Aqueous Humor from High Myopic Patients

PurposeTo compare oxidative stress status in the aqueous humor of highly myopic eyes and control eyes.MethodsAqueous humor samples were collected from 15 highly myopic eyes (high myopia group) and 23 cataractous eyes (control group) during cataract surgery. Central corneal thickness, corneal endothelial cell density, hexagonality of corneal endothelial cells, and cell area of corneal endothelial cells were measured using specular microscopy. Axial length was measured using ultrasound biometry. 8-Hydroxydeoxyguanosine (8-OHdG) and malondialdehyde levels were measured using enzyme-linked immunosorbent assay.Results8-OHdG level was lower in the aqueous humor of myopic patients than in that of control group (p = 0.014) and was positively correlated with central corneal thickness and negatively correlated with axial length (r = 0.511, p = 0.02; r = -0.382, p < 0.001). There was no correlation between 8-OHdG level and corneal endothelial cell density, hexagonality, or cell area. Malondialdehyde level did not show any correlation with any parameters evaluated.Conclusions8-OHdG might be a sensitive biomarker for evaluating oxidative stress status in the eye. Oxidative stress level was lower in the aqueous humor of highly myopic eyes compared to that in control eyes, which indicates lower metabolic activity in these eyes.     

Long-term (≥10 years) results of corneal endothelial cell loss after cataract surgery

ObjectiveTo investigate the extent of long-term corneal endothelial loss after uneventful cataract surgery and the factors associated with decreases in corneal endothelial cell density (ECD).DesignRetrospective case series.ParticipantsPatients who had undergone uncomplicated cataract surgery.MethodsThis study comprised 81 eyes of 48 patients who had undergone cataract surgery >10 years previously by a single surgeon with the same intraocular lens and visited the outpatient clinic between January 2014 and February 2017. Long-term (≥10 years) changes in visual outcome and ECD after uncomplicated cataract surgery were evaluated. To analyze factors correlated with endothelial cell loss, preoperative biometric variables, including cataract grade, anterior chamber depth, axial length, and postoperative corneal edema, were evaluated.ResultsThe mean ± SD preoperative and long-term postoperative ECD was 2793 ± 351.09 and 2148 ± 478.38 cells/mm², respectively. The mean follow-up period was 11.08 ± 1.06 years and 10-year ECD loss rate was 20.62 ± 13.63%. Preoperative nuclear firmness was most statistically correlated with 10-year ECD loss (β-coefficient 0.394 [95% CI 3.402–9.448]; p < 0.001). The degree of postoperative corneal edema was also a significant predictive factor of 10-year ECD loss after cataract surgery (β-coefficient 0.378 [95% CI 2.854–8.358]; p = 0.002).ConclusionPreoperative nuclear firmness and postoperative corneal edema were predictors of long-term (≥10 years) endothelial cell loss and severe endothelial cell loss after cataract surgery. It is important to remember that eyes with increased nuclear firmness have a significantly higher risk of long-term enhanced ECL.     

Cambios morfométricos de las células del endotelio corneal en el síndrome pseudoexfoliativo y glaucoma pseudoexfoliativo

ObjetiveTo evaluate the corneal endothelial morphometry and central corneal thickness (CCT) in pseudoexfoliative (PEX) eyes with and without glaucoma and to compare with normal eyes and eyes with primary open-angle glaucoma (POAG).MethodA total of 166 patients were included in this study: 36 eyes with pseudoexfoliation syndrome (PXS), 30 eyes with pseudoexfoliation glaucoma (PXG), 40 eyes with POAG, and 60 normal eyes. Corneal endothelial cell density (ECD), coefficient of variation (CV) in cell size, and percentage of hexagonal cells, were measured using a non-contact specular microscope, whereas CCT was measured with an ultrasonic pachymeter.ResultsECD and percentage of hexagonal cells were lower in PEX groups and in the POAG group compared with normal eyes, while the CV in cell size was greater. There was a tendency for greater cell loss and morphological abnormalities of the corneal endothelial cells in PXG eyes compared to PXS eyes, when all pseudoexfoliative eyes were analyzed together. Changes in endothelial cells increased with age. There were no significant differences in mean CCT between the four groups.ConclusionEndothelial cell density is significantly decreased, and pleomorphism and polymegathism of cells are increased in PEX eyes, particularly when intraocular pressure is high.     

重组牛碱性成纤维细胞生长因子对角膜内皮细胞密度低下患者白内障术后角膜内皮的保护作用

目的　研究角膜内皮细胞密度（ECD）低下患者行超声乳化白内障吸除术后应用重组牛碱性成纤维细胞生长因子（re-bFGF）对角膜内皮的保护作用。方法　前瞻性队列研究。选取2019年9月至2022年4月在北京大学第三医院眼科就诊、拟行超声乳化白内障吸除且合并ECD低下的患者80例 (90眼)为研究对象,随机分为两组,试验组41例(45眼),对照组39例(45眼)。术后除常规抗炎治疗外,试验组患眼应用re-bFGF滴眼液每日4次滴眼,对照组患眼应用1 g·L^-1玻璃酸钠滴眼液每日4次滴眼,均使用至术后6个月。对比分析两组患眼术前和术后1个月、3个月、6个月的ECD和中央角膜厚度（CCT）等。结果　术后1个月、3个月、6个月,试验组患眼的ECD和CCT均较术前变化不明显（均为P>0.05）,而对照组患眼的ECD均较术前下降,CCT均较术前增加（均为P<0.05）。术前,试验组和对照组患眼ECD分别为（1120.6±306.1）个·mm^-2、（1040.5±317.3）个·mm^-2 ,CCT分别为（543.1±51.6）μm、（546.8±35.6）μm,两组相比差异均无统计学意义（均为P>0.05）;术后6个月,试验组和对照组患眼ECD分别为（1271.3±288.6）个·mm^-2、（746.5±193.5）个·mm^-2 ,CCT分别为（542.0±55.3）μm、（583.5±45.3）μm,两组相比差异均有统计学意义（均为P<0.05）。术后2眼发生了角膜内皮失代偿,且均发生在对照组。结论　re-bFGF对ECD低下患者行超声乳化白内障吸除术后的角膜内皮有保护作用,可减轻超声乳化手术造成的ECD下降,减少角膜水肿及术后短期角膜内皮失代偿的严重并发症的发生率。     

抗青术后白内障行Phaco后角膜内皮和形态学参数的变化

目的:比较抗青光眼术后白内障眼和正常白内障眼行超声乳化手术后角膜内皮和角膜形态学参数的变化。方法:前瞻性系列病例研究。 我院2010-01/12行白内障超声乳化患者160例200眼,其中包括抗青光眼术后白内障和正常眼白内障各100眼。以抗青光眼术后白内障作为实验组,正常眼白内障作为对照组。用非接触角膜内皮显微镜（SP-2000P）分别于术前,术后1, 3mo测量角膜内皮密度（endothelial cell density,ECD）;用Pentacam分析仪分别于术前,术后1,3mo测量角膜形态学参数,包括角膜中央厚度（central corneal thinkness,CCT）和角膜体积（corneal volume,CV）。结果:术前实验组平均的ECD（1203±245个/mm²）比对照组（2648±167个/mm²）小（P＜0.01）,而实验组的平均CCT（543±32μm）值较对照组（525±36μm）大（P＜0.01）,实验组的平均CV(59.14±2.79mm³)值较对照组（57.26±3.24mm³）大（P＜0.05）,有统计学意义。术后1,3mo实验组平均的ECD较对照组明显减少（P＜0.01）,而CCT值较对照组明显增加（P＜0.01）,CV值较对照组也明显增加（P₁＜0.01,P₂＜0.05）,有统计学意义。术后1,3mo角膜内皮细胞丢失百分率（％）在实验组比对照组大（P₁=01145,P₂=0.2018),但无统计学意义。CCT值增加百分率（％）实验组比对照组在1mo时要显著增加（P=0.0142）,有统计学意义,而在3mo时两者无明显差异（P=0.3562）。CV值增加百分率（％）实验组比对照组在1mo时要显著增加（P=0.0134）,有统计学意义,而在3mo时两者无明显差异（P=0.4538）。结论:抗青光眼术后白内障眼术前ECD较正常眼低,行白内障超声乳化手术术后的角膜内皮细胞丢失率比正常眼要大,术后短期角膜水肿较正常眼严重,所以抗青光眼术后白内障眼只有更精密的规划手术和更精细的手术操作,才能在术中尽量减少对内皮细胞的损害,缩短角膜水肿恢复的时间,降低术后角膜内皮失代偿的风险。     

Corneal endothelial cells and central corneal thickness in patients with neurofibromatosis type 1

Purpose:The aim of this study was to evaluate the morphological properties of corneal endothelial cells and central corneal thickness (CCT) in patients with neurofibromatosis type 1 (NF1) and to compare them with age-matched healthy controls.Methods:Nineteen NF1 patients and 38 healthy individuals were recruited. All participants underwent complete ophthalmological examination as well as noncontact specular microscopy to measure endothelial cell density (ECD), average cell area (AVG), coefficient of variation of cell area (CV), the percentage of hexagonal cells, and CCT. Eyes with previous ocular trauma, inflammation or surgery, and preexisting corneal and ocular surface diseases were excluded.Results:NF1 patients had higher ECD compared to healthy controls of the same age (2764.2 ± 270.4 versus 2570.4 ± 449.2 cells/mm, respectively), although at a borderline level (P = 0.051). Patients with NF1 presented significantly lower CV and AVG when compared to controls (32.9 ± 4.6 versus 37.8 ± 9.5%, P = 0.011 and 364.9 ± 34.4 versus 406.0 ± 107.4 µm, P = 0.038, respectively). The NF1 group had significantly higher hexagonality in comparison with controls (55.7 ± 6.5 versus 50.5 ± 9.9%, P = 0.025). CCT was similar between the two groups (P = 0.955).Conclusion:Our results show that corneal endothelium has more favorable morphological characteristics in NF1 patients compared to healthy individuals of the same age.     

Effect of torsional mode phacoemulsification on cornea in eyes with/without pseudoexfoliation

AIM: To evaluate the effect of torsional mode phacoemulsification on central corneal thickness, corneal endothelial cell density, and morphology in eyes with/without pseudoexfoliation (PEX) syndrome. METHODS: Fourty-two consecutive patients with and 42 patients without PEX as a control group scheduled for cataract surgery was studied. Phacoemulsification, using OZiL IP system, was performed with quick chop technique. Using noncontact specular microscopy, the central endothelial cell density (ECD), coefficient of variation, percentage of hexagonal cells, and the central corneal thickness (CCT) were evaluated preoperatively and postoperatively at 1, 7 and 30d. RESULTS: The ECD in PEX syndrome was statistically significantly lower than that in the control group preoperatively and postoperatively (P≤0.001). Percentage change in ECD was statistically significantly higher in PEX than that in control group after surgery follow up (P≤0.04). There was no statistically significant difference between both groups comparing percentage of hexagonal cells and coefficient of variation in the cell size before and after the surgery. At 1 and 7d after surgery, percentage change in CCT was statistically significantly higher in PEX group than that in the control group (P≤0.041). CONCLUSION: Although torsional mode phacoemulsification and intraocular lens (IOL) implantation provided a safe and favorable surgical outcome in patients with/without PEX, torsional phacoemulsification led to significantly higher ECD loss in the PEX group than that in the control group during the whole follow up period. In addition, more corneal swelling in the PEX group than that in the control group during the early postoperative period has indicated that the corneal endothelium, in presence of PEX endotheliopathy, seems to be more susceptible to the effects of phacoemulsification surgery in eyes with PEX. The increased risk of anterior chamber manipulations in patients with PEX should be taken into account for an increased risk of bullous keratopathy.     

角膜内皮移植联合超声乳化白内障吸除及人工晶状体置换手术的疗效评价

目的 探讨角膜后弹力层剥除自动角膜刀取材内皮移植术(DSAEK)联合超声乳化白内障吸除及人工晶状体置换手术治疗角膜内皮失代偿并有白内障或人工晶状体异常患者的疗效和并发症情况.方法 回顾性临床自身对照研究.对2007年12月至2008年12月在北京大学第三医院就诊的各种原因引起的角膜内皮失代偿合并有晶状体异常的患者18例(20只眼)分别行DSAEK联合超声乳化白内障吸除人工晶状体植入手术5例(7只眼)、DSAEK联合前房型人工晶状体取出与前段玻璃体切除及后房型人工晶状体悬吊术7例(7只眼)或DSAEK联合前段玻璃体切除及后房型人工晶状体悬吊术6例(6只眼).术后观察视力、角膜透明性的恢复、植片厚度、角膜内皮细胞丢失、植片的脱位率及排斥反应发生情况.采用治疗前后均数比较t检验.结果 术后18例患者眼部刺激症状均消除,角膜水肿全部消退,术前和术后的角膜厚度分别为859μm、553 μm,差异有统计学意义(t=5.303,P＜0.01);术前供体角膜内皮细胞密度为2987个/mm2,术后3个月角膜内皮细胞密度为1803个/mm2,内皮细胞丢失率为41%.术后除去患有眼底病变的患者9只眼,其余患者视力均有大幅度的提高,视力恢复到0.8以上的有6只眼,在眼底正常的患者中占55%(6/11).术后前房人工晶状体眼炎症反应最重,其余患者反应轻微;术后有6只眼植片脱位(30%,6/20)、术后5例出现眼压升高、1例发生植片排斥反应,均为前房人工晶状体眼的患者.结论 DSAEK联合超声乳化白内障吸除及人工晶状体置换手术对于治疗角膜内皮失代偿并有晶状体或人工晶状体异常患者是一种较安全、有效的手术方法.前房人工晶状体眼行DSAEK术后并发症较多,对虬膜、房角结构异常的患者行角膜内皮移植手术应谨慎.

Abstract：

Objective To evaluate the effect and explore the complications of Descemet-stripping automated endothelial keratoplasty (DSAEK) combined with phacoemulcification cataract surgery or lens exchange in corneal endothelial dysftnction eyes with lens disorders. Methods Retrospective case series.Eighteen consecutive cases (20 eyes) were performed DSAEK combined with lens surgery from December 2007 to December 2008 in Department of Ophthalmology, Peking University Third Hospital. Five cases (7 eyes) were performed DSAEK combined with phacoemulcification and intraocular lens (IOL) insertion.Seven cases were combined with anterior chamber IOL extraction, anterior vitrectomy and posterior chamber IOL insertion. Six aphakia cases were performed with DSAEK combined with anterior vitrectomy and sclera fixation posterior chamber IOL insertion. Postoperatively, the visual acuity, corneal transparency, central corneal thickness (CCT), endothelial cell density (ECD) and complications were observed during the follow-up. Results The irritation was disappeared in all of patients. All of the corneas became transparent.The preoperative and postoperative mean CCT of the recipient beds was 859 μm and 553 μm respectively. T value was 5.303 ( t = 5.303, P ＜ 0.01 ). It was extremely significant difference. The mean ECD of the donors was 2987 cells/mm2. The ECD was 1803 cells/mm2 in three months postoperatively. The rate of endothelial cells loss was 41%. The visual acuity improved significantly except 9 eyes which had fundus disorders. Six eyes were better than 0.8. It was 55% in normal retinal function patients (6/11). The inflammatory reaction of the anterior chamber IOL eyes was most serious. Six eyes underwent graft dislocation. Five cases underwent high intraocular pressure. One case occurred graft rejection.These complications occurred in anterior chamber IOL eyes. Conclusions DSAEK combined with phacoemulcification cataract surgery or lens exchange is a safe and effective surgical treatment for corneal endothelial dysfunction with lens disorders. More complications occur in anterior chamber IOL eyes. DSAEK should be cautiously chosen in abnormal iris and chamber angle structural eyes.     

Cataract surgery in eyes with associated coloboma: Predictors of outcome and safety of different surgical techniques

Purpose:The aim of this study was to report the outcome of cataract surgery with different surgical techniques in eyes with coexisting coloboma and to define factors of prognostic importance.Methods:Retrospective case sheet review of patients presenting between January 2016 and December 2018, who underwent cataract surgery in eyes with coexisting coloboma.Results:Of the 3,30,231 cases operated during the study period, 280 eyes of 276 patients had associated colobomatous malformation. The prevalence of coloboma in eyes undergoing cataract surgery was 0.085%. The mean age of the patients was 46.4 years (range 19 - 88 years). Phacoemulsification (PE) was performed in 130 eyes (46.4%), manual small incision cataract surgery (M-SICS) was done in 115 eyes (41.1%), and 35 eyes (12.5%) underwent intra capsular cataract extraction. Intra-operative complications were noted in 26 (9%) eyes. Incidence of intra-operative and post-operative complications was comparable between PE and M-SICS groups (p = 0.94). The mean corrected distance visual acuity (CDVA) improved from logMAR 1.71 ± 0.62 to 0.87 ± 0.61 (p = 0.00009). On multivariate analysis, microcornea (p = 0.002), type 1 and 2 coloboma (p < 0.001), and intraoperative complications (p = 0.001) were associated with poor visual outcome.Conclusion:Favorable functional outcomes can be achieved with phacoemulsification in eyes with softer cataract and corneal diameter >8 mm and with M-SICS in eyes with hard cataracts and corneal diameter of 6–8 mm. PE should be considered as the primary choice whenever permissible by the corneal diameter and severity of nuclear sclerosis. Poor functional outcomes were seen in eyes with smaller corneal diameter, extensive chorioretinal coloboma, and intraoperative complications.     

Effect of bimatoprost on intraocular pressure after cataract surgery

Background: An increase in intraocular pressure (IOP) frequently occurs after otherwise uneventful phacoemulsification cataract surgery. This study was conducted to determine the efficacy of bimatoprost 0.03% drops given preoperatively in preventing IOP rise following phacoemulsification cataract surgery.Methods: In this prospective, randomized, double-masked, placebo-controlled study, 91 eyes of 85 patients scheduled to have clear corneal phacoemulsification cataract surgery were randomly divided into 2 groups. One hour before surgery, 1 group (48 eyes) received 1 drop of bimatoprost 0.03%, and the other group (43 eyes) received 1 drop of a balanced saline solution (placebo). A masked observer measured IOP preoperatively, and 3 and 24 hours postoperatively. Anterior chamber cellular reaction was measured on the first day after surgery. Preoperative and postoperative central corneal thickness (CCT) was assessed.Results: The mean IOP changes from baseline were not statistically different between the 2 groups at 3 hours (p = 0.618). At 24 hours, there was a statistically significant difference between the mean IOP changes of the groups (p = 0.001). The incidence of IOP elevation greater than 5 or 10 mm Hg at 24 hours was significantly higher in the control group (9 of 43 eyes) than the bimatoprost group (3 of 48 eyes) (p = 0.039). Anterior chamber reaction was not increased by bimatoprost. Mean CCT change was not different between the groups at 24 hours (p = 0.615).Interpretation: When compared with placebo, prophylactic use of 1 drop of bimatoprost before phacoemulsification cataract surgery failed to produce a significantly different effect on IOP levels from placebo at 3 hours postoperatively, but it caused a significant IOP reduction at 24 hours.     

Age-related variation in corneal biomechanical parameters in healthy Indians

Purpose:To report age-related variations in corneal biomechanical parameters in healthy Indians.Methods:A retrospective study where healthy Indian individuals aged between 5 and 70 years having undergone corneal biomechanics assessment using Corvis ST between January 2017 and December 2018 and having best corrected visual acuity of 20/20 were enrolled. Subjects with central corneal thickness <500 microns, intra-ocular pressure (IOP) ≥ 22 mmHg, refractive error ≥ 6.00D, history of any systemic and ocular disease, previous ocular surgery, poor scans quality, and subjects with any missing data were also excluded. Corneal biomechanical parameters were noted and compared across different age groups.Results:Total of 3125 eyes had undergone the Corvis ST analysis. After applying exclusion criteria, 718 right eyes of 718 patients were included for the analysis and were further divided into different age groups as per each decade (sample size), such as 5-10 (37), 11-20 (113), 21-30 (396), 31-40 (116), 41-50 (39), 50 and above (17). All the subjects were matched for IOP and central corneal thickness (p > 0.05). A total of 19 out of 26 corneal biomechanical parameters were significantly different across age groups (p < 0.05). Vinciguerra screening parameters, such as deformation amplitude ratio max, biomechanically corrected IOP, and stiffness parameter A1 were significantly different across different age groups (p < 0.05).Conclusion:Corneal biomechanical parameters are affected by age as cornea becomes progressively stiffer. The information reported here would serve as a reference for future corneal biomechanical researches and would help in differentiating the abnormal eyes from normal healthy eyes.     

Structural Analysis of Different Incision Sizes and Stromal Hydration in Cataract Surgery Using Anterior Segment Optical Coherence Tomography

Purpose

To analyze healing changes of corneal wounds of different corneal incision sizes with or without stromal hydration in cataract surgery using anterior segment optical coherence tomography.

Methods

Cataract surgeries were performed by a single surgeon and 2.2- and 2.8-mm corneal incisions were made using a diamond blade (ME-759; Meyco, Biel-Bienne, Swiss). Patients were divided into four groups according to incision size (2.2 and 2.8 mm), and with/without stromal hydration. Fifteen eyes were assigned to each group and incision wounds were measured using anterior segment optical coherence tomography at 2 hours, 1 day, 1 week, 1 month, and 3 months postoperatively. Corneal thickness, incision length and incision angle were measured and existence of epithelial, endothelial gaping and Descemet''s membrane detachment was evaluated.

Results

Incision thickness was greater in the group with stromal hydration than in the group without on operation day (p < 0.05). Stromal hydration exerted greater influence in the 2.2-mm incision group than in the 2.8-mm incision group. Corneal thickness decreased more rapidly in the stromal hydration group than in the group with no hydration (p = 0.022). Endothelial gaping was greater in the 2.2-mm incision group than in the 2.8-mm incision group 1 day, 1 month, and 3 months after surgery (p = 0.035, p = 0.009, and p = 0.008, respectively). No other statistical significance was observed between the two groups (2.2 and 2.8 mm) during follow-up regarding corneal thickness, epithelial gaping and Descemet''s membrane detachment.

Conclusions

Corneal wounds with a smaller incision could be more vulnerable to external stimuli such as stromal hydration and are less stable than those with a larger incision.     

飞秒激光辅助的超声乳化手术对小梁切除术后并发性白内障患者角膜的影响

目的　比较飞秒激光辅助的超声乳化手术和常规超声乳化手术对小梁切除术后并发性白内障患者角膜的影响。方法　前瞻性研究。选取我院2017年1月至12月收治的小梁切除术后并发性白内障患者100例100眼,利用随机数字表法将患眼分为两组,分别为行飞秒激光辅助的超声乳化手术的试验组和行常规超声乳化手术的对照组,每组各50例50眼。记录两组患者术前最佳矫正视力(best corrected visual acuity,BCVA)及术后裸眼视力(uncorrected visual acuity,UCVA)。用非接触角膜内皮显微镜（SP-2000P）分别于术前及术后 1个月、3个月测量角膜内皮细胞密度（endothelial cell density,ECD）;用 Pentacam分析仪分别于术前及术后1 d、1个月、3个月测量中央角膜厚度（central corneal thickness,CCT）和角膜体积（corneal volume,CV）。对比两组术中各项超声参数及术后各指标间的差异。结果　两组患者核硬度分级、手术时间、灌注液量相比,差异均无统计学意义（均为P＞0.05）。两组间超声时间、超声能量、超声累积释放能量之间,差异均有统计学意义（均为P＜0.05）。两组术后1 d UCVA相比差异有统计学意义(P=0.025),术前BCVA和术后1个月UCVA两组相比差异均无统计学意义(均为P＞0.05)。术前两组患者的 ECD、CCT、CV相比,差异均无统计学意义（均为P＞0.05）。术后1个月、3个月两组间ECD相比差异均有统计学意义（均为P＜0.05）,但ECD减少率相比差异均无统计学意义（均为P＞0.05）。术后1 d、1个月两组间CCT、CV相比差异均有统计学意义（均为P＜0.05）,而术后3个月两组间的 CCT、CV相比差异均无统计学意义（均为P＞0.05）。术后 1 d、1 个月,两组间 CCT、CV增加率相比差异均有统计学意义（均为P＜0.05）。术后 3 个月,两组患者的 CCT、CV 增加率相比差异均无统计学意义（均为P＞0.05）。结论　飞秒激光辅助的超声乳化手术能够减轻手术对角膜内皮细胞的损害,缩短角膜水肿恢复时间,降低术后角膜内皮失代偿的风险,提高小梁切除术后并发性白内障手术的安全性。     

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: a four-year comparative study

Purpose:

To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus.

Materials and Methods:

Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter.

Results:

Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years.

Conclusions:

As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.     

Comparative evaluation of modified crater (endonucleation) chop and conventional crater chop techniques during phacoemulsification of hard nuclear cataracts: A randomized study

Purpose:To compare the clinical outcomes of endonucleation chop (EC) versus conventional crater (CC) chop techniques in phacoemulsification of hard nuclear cataracts.Methods:In this Prospective, longitudinal, randomized controlled study with double-blinding. Hundred consecutive eyes with uncomplicated cataracts (nucleus grades 3 and 4) were equally divided into Group A (EC) and Group B (CC). Intraoperative effective phacoemulsification time (EPT) and balanced salt solution (BSS) volume used was noted. Postoperative central corneal thickness (CCT), endothelial cell density (ECD), uncorrected Visual Acuity (UCVA), best-corrected visual acuity (BCVA), and IOP were recorded at days 1, 7, 30, and 90 postoperatively. The Chi-square test (categorical data), Mann–Whitney U test, and t-tests for other parameters were done.Results:The mean EPT in Groups A and B were 6.6 and 14.25 s, respectively (P < 0.001). The BSS volume used was 105.9 and 221.7 mL, respectively (P < 0.001). At 3 months, the ECD loss was 4.35 and 8.6%, respectively (P = 0.025). The-first day CCT was significantly increased in Group B but was the same in both groups at 3 months. A significant improvement in BCVA was noted in both groups. This new technique significantly reduces EPT, the BSS used, and ECD loss.Conclusion:Compared with the CC chop technique, the EC technique for phacoemulsification of hard nuclear cataracts conserved phacoemulsification energy and minimized exposure to the intraocular irrigating solution, provided a significant reduction in corneal endothelial damage, and led to faster visual rehabilitation.     

Two-year clinical outcome after Descemet membrane endothelial keratoplasty using a standardized protocol

Purpose:The purpose of this study is to evaluate 2-year clinical outcome after Descemet membrane endothelial keratoplasty (DMEK) in a variety of endothelial dysfunctions using a standardized protocol.Methods:From a group of 230 eyes which underwent DMEK for Fuchs'' endothelial corneal dystrophy (FECD), aphakic and pseudophakic bullous keratopathy, failed full thickness corneal transplants, ICE syndrome, failed DSEK, and TASS the clinical outcomes [best spectacle-corrected visual acuity (BSCVA), central endothelial cell density (ECD)] were evaluated before, and at 6, 12, and 24 months and the success rate, failure rate and postoperative complications were also analyzed.Results:Out of 230 eyes, 144 eyes (70%) had BSCVA 6/9 or better 2 years postoperatively. Mean donor ECD was 2692.23 (range, 2300–3436) cells/mm² preoperatively, which was reduced to 1433.64 (range, 619.0–2272.0) cells/mm² 2 years after DMEK surgery, indicating a mean reduction of 1258 cells/mm² (46%) in ECD.Conclusion:DMEK is a highly successful surgical procedure when following a standard protocol for treating diseases of the corneal endothelium providing a near perfect anatomic restoration and a high degree of visual rehabilitation.     

Cataract surgery in patients older than 90 years of age

ObjectiveThe aim of this study was to examine whether differences exist after cataract surgery is performed in patients over and under 90 years of age.Study DesignRetrospective, nonrandomized study.ParticipantsCataract surgery was performed in 21 patients (31 eyes) who were older than 90 years of age and in 45 patients (70 eyes) who were younger than 90 years of age.MethodsThe medical records of all patients who underwent cataract surgery between January 2005 and September 2010 at Dokkyo Medical University Koshigaya Hospital were reviewed. Factors evaluated included systemic disease, changes in systemic condition, surgical time, preoperative and postoperative visual acuity, corneal endothelial cell density, and intraoperative complications.ResultsThe group of patients older than 90 years of age experienced greater occurrences of systemic disease (p < 0.05; χ² test) and intraoperative changes in systemic conditions (p < 0.001; χ² test). These patients also had significantly lower preoperative visual acuity (p < 0.001; Student t test). No differences were noted between the 2 age groups in surgical time, postoperative visual acuity, preoperative corneal endothelial cell density, or intraoperative complications.ConclusionsPoorer cataract surgery outcome results were noted in patients older than 90 years due to systemic disease and intraoperative changes in systemic condition. Factors that need to be taken into consideration prior to performing cataract surgery in older patients include age, systemic disease, and the likelihood of intraoperative changes in systemic condition.     

Effect of Head Position and Tube Entry on Corneal Endothelial Cells in Patients with Glaucoma Drainage Implants: A Cross-sectional Study

PurposeTo investigate the effect of head tilt on the tube position of the Ahmed glaucoma valve (AGV) implanted in patients with glaucoma and to assess how the head tilt-induced alterations of tube parameters and the level of tube entry influence corneal endothelial cell density (ECD).MethodsA total of 29 eyes of 26 patients with AGV implantation were included. Tube-cornea distance, tube-cornea angle, and intracameral tube length were measured using anterior segment optical coherence tomography in three different head positions (neutral, 30° temporalward tilt, and 30° nasalward tilt). The tube entry was assessed using static gonioscopy. ECD was measured using specular microscopy before and after surgery.ResultsThe mean tube-cornea distance, tube-cornea angle, and intracameral tube length (neutral: 0.87 ± 0.39 mm, 30.56 ± 5.89˚, and 3.10 ± 0.82 mm, respectively) decreased with head tilts (temporalward: 0.82 ± 0.39 mm, 29.27 ± 5.82˚, and 3.04 ± 0.82 mm, respectively; nasalward: 0.83 ± 0.40 mm, 29.61 ± 6.04˚, and 3.05 ± 0.81 mm, respectively; all p < 0.01). The multivariate analyses found age and the tube insertion level to be associated with postoperative changes in the central ECD (p = 0.039 and 0.013, respectively), and the postoperative follow-up period and tube insertion level to be associated with the difference between the inferonasal and superotemporal ECDs (p = 0.034 and 0.007, respectively).ConclusionsMild alterations of head positions induced changes in the intracameral tube positions of AGV implants; nevertheless, it did not significantly affect ECD loss. However, the eyes with tubes inserted anteriorly to Schwalbe’s line may be more susceptible to corneal ECD loss.