Axial length,vitreoretinal pathology,and anterior chamber depth can predict postoperative refractive outcomes in phacovitrectomy/silicone oil removal

AIM:To evaluate the postoperative refractive prediction error(PE)and determine the factors that af fect the refractive outcomes of combined pars plana vitrectomy(PPV)or silicone oil removal(SOR)with cataract surgery.METHODS:The study is a retrospective,case-series study.Totally 301 eyes of 301 patients undergoing combined PPV/SOR with cataract surgery were enrolled.Eligible individuals were separated into four groups according to their preoperative diagnoses:silicone oil-filled eyes after PPV(group 1),epiretinal membrane(group 2),macular hole(group 3),and primary retinal detachment(RD;group 4).The variables af fecting postoperative refractive outcomes were analyzed,including age,gender,preoperative best-corrected visual acuity(BCVA),axial length(AL),keratometry average,anterior chamber depth(ACD),intraocular tamponade,and vitreoretinal pathology.The outcome measurements include the mean refractive PE and the proportions of eyes with a PE within±0.50 diopter(D)and±1.00 D.RESULTS:For all patients,the mean PE was-0.04±1.17 D,and 50.17%of patients(eyes)had a PE within±0.50 D.There was a significant difference in refractive outcomes among the four groups(P=0.028),with RD(group 4)showing the least favorable refractive outcome.In multivariate regression analysis,only AL,vitreoretinal pathology,and ACD were strongly associated with PE(all P<0.01).Univariate analysis revealed that longer eyes(AL>26 mm)and a deeper ACD were correlated with hyperopic PE,and shorter eyes(AL<26 mm)and a shallower ACD were correlated with myopic PE.CONCLUSION:RD patients have the least favorable refractive outcome.AL,vitreoretinal pathology,and ACD are strongly associated with PE in the combined surgery.These three factors affect refractive outcomes and thus can be used to predict a better postoperative refractive outcome in clinical practice.

Anterior Chamber Depth Changes in Narrow Iridocorneal Angles after Phacoemulsification

Background: The burden of cataract and glaucoma has been increasing. Primary angle closure occurs as a result of crowded anterior segment anatomy causing appositional contact between peripheral iris and trabecular meshwork. Lens extraction has been proposed as a method of deepening anterior chamber and managing intraocular pressure. Purpose: To assess changes in anterior chamber depth after phacoemulsification with intraocular lens implantation in narrow angle eyes. Design: Prospective controlled trial (before-after) study. Method: The study was conducted from March 2015 to August 2017 among the patients of department of Ophthalmology of BSMMU who were diagnosed as cataract with narrow angles. Anterior chamber angle grading of 2 or less (Shaffer grading) in 3 or more quadrants was considered narrow angle (NA). The purposive type sampling technique was applied to collect sample from the study population, as per inclusion and exclusion criteria. Complete clinical evaluation including history, physical examination, relevant ocular examinations and systemic examinations were performed. In this prospective study, subjects underwent phacoemulsification with foldable lens implantation. A scan ultrasonography was performed preoperatively and 10th and 30th postoperative days of surgery. Results: Thirty eyes of 29 patients included in the study, male: female ratio was 1:1, with an overall mean age of 62.03 ± 8.95 years. The mean preoperative central ACD was 2.95 ± 0.35 mm. At 10th and 30th POD mean central ACD were 3.94 ± 0.32, and 3.92 ± 0.28 mm respectively. Mean of increase in central ACD at final follow-up was 0.96 mm (p Conclusion: Phacoemulsification with posterior chamber in bag lens implantation can deepen the anterior chamber depth in patients with narrow angles. Based on these findings, it is concluded that phacoemulsification with foldable intraocular lens implantation is an effective tool in deepening the anterior chamber.

Axial length and anterior chamber indices in elderly population: Tehran Geriatric Eye Study

AIM:To determine the normative distribution of axial length(AL),anterior chamber depth(ACD),anterior chamber volume(ACV),anterior chamber angle(ACA),and some of their associated factors in subjects aged 60 and over.METHODS:In this cross-sectional study,160 clusters were sampled using multi-stage cluster sampling in Tehran,Iran.After a preliminary interview,the participants underwent optometric examinations including visual acuity and refraction measurement followed by slit lamp biomicroscopy.Finally,ocular imaging was done using the Pentacam AXL to measure AL,ACD,ACV,and ACA.RESULTS:A total of 4519 eyes of 2436 participants were evaluated,of whom 58.0%(n=1412)were female.The mean age of the subjects was 67.32±6.05y(range:60-95y).The mean AL,ACD,ACV,and ACA was 23.22 mm(23.18-23.27 mm),2.61 mm(2.59-2.62 mm),126.56 mm3(125.08-128.04 mm3),and 30.61°(30.3°-30.92°),respectively.In the multivariable model,after adjusting for the effect of both eyes,the longest and shortest AL was seen in myopic and hyperopic subjects,respectively.AL,ACD,ACV and ACA were significantly larger in men compared to women(P<0.001).Except ACA,other evaluated parameters showed an inverse correlation with age(P<0.001),however,this correlation was insignificant for AL(P=0.623).CONCLUSION:Normative value of AL,and other biometric parameters are specific for each ethnicity,age and sex group.Any alteration in these parameters and their effect on refraction should be considered in this age group,especially in case of cataract surgery.

Device interchangeability on anterior chamber depth and white-to-white measurements: a thorough literature review

We have reviewed a set of recently published studies that compared the anterior chamber depth（ACD） and/or white-to-white（WTW） distance obtained by means of different measuring devices.Since some of those studies reached contradictory conclusions regarding device interchangeability,this review was carried out in attempting to clarify which clinical devices can or cannot be considered as interchangeable in clinical practice to measure ACD and/or WTW distance,among these devices：A-scan,ultrasound biomicroscopy,Orbscan and Orbscan Ⅱ（Bausch＆Lomb Surgical Inc.,San Dimas,California,USA）,Pentacam and Pentacam HR（Oculus,Wetzlar,Germany）,Galilei（Ziemer,Switzerland）,Visante optical coherence tomography（Visante OCT,Carl Zeiss Meditec Inc.,Dublin,California,USA）,lOLMaster（Carl Zeiss Meditec,Jena,Germany）,and Lenstar LS 900/Biograph（Haag-Streit AG,Koeniz,Switzerland/Alcon Laboratories Inc.,Ft Worth,Texas,USA）.

Effect of low dose laser cycloplasty on deepening anterior chamber in chronic angle-closure glaucoma

AIM:To describe the outcome of using low-dose laser cycloplasty(LCP)in chronic angle-closure glaucoma(CACG).METHODS:A retrospective case series.Medical charts of CACG patients who underwent LCP in the Eye Hospital of Wenzhou Medical University were reviewed.The main outcomes included intraocular pressure(IOP),the number of glaucoma medication,anterior segment parameters and surgery-related complications.RESULTS:A total of 7 eyes of 7 CACG patients(age 38.9±11.0y)underwent LCP with a mean follow-up of 27.1±13.7mo(range 16-48mo).Following LCP,mean IOP and glaucoma medications decreased from 26.1±6.1 mm Hg with 3.1±1.1 glaucoma medications pre-treatment to 14.9±3.1 mm Hg(P=0.027)with 0.4±1.1 glaucoma medications(P=0.001)at final follow-up.The anterior chamber depth(ACD),angle opening distance500 and trabecular-iris angle increased from 1.65±0.33 mm,0.05 mm(range 0-0.30 mm)and 5.1°(range,0-31.97°)at baseline to 1.98±0.43 mm(P=0.073),0.53 mm(range 0.42-0.91 mm,P=0.015),45.9°(range,40.2°-59.4°),(P=0.015)in the long-term follow-up,respectively.The deepening of ACD and reopening of anterior chamber angle(ACA)was observed in 6 eyes(85.7%).CONCLUSION:LCP is a promising treatment option for patients with CACG via reducing IOP and glaucoma medication without serious complications.In addition,LCP can bring a significant deepening in ACD and reopening of ACA.

Effect of axial length and anterior chamber depth on the peripheral refraction profile

AIM:To evaluate the effect of axial length(AL)and anterior chamber depth(ACD)on peripheral refractive profile in myopic patients compared to emmetropic participants.METHODS:This cross-sectional study was conducted in right eyes of 58 participants of whom 38 were emmetropic and 20 were myopic.Central and peripheral refraction were measured at 10°,20°,and 30°eccentricities in nasal and temporal fields using an open-field autorefractor.The Lenstar LS900 was used to measure ACD and AL.The participants were divided into three groups of short(<22.5 mm),normal(22.5-24.5 mm),and long eye(>24.5 mm)according to AL and three groups of low ACD(<3.00 mm),normal ACD(3.00-3.60 mm),and high ACD(>3.60 mm)according to ACD.RESULTS:The mean age of the participants was 22.26±3.09 y(range 18-30 y).The peripheral mean spherical refractive error showed a hypermetropic shift in myopic and emmetropic groups although this shift was more pronounced in the myopic group.The results showed significant changes in the spherical equivalent,J0,and J45 astigmatism in all gazes with an increase in eccentricity(P<0.001).The pattern of refractive error changes was more noticeable in long and short eyes versus normal AL eyes.Moreover,the pattern of peripheral refractive changes was much more prominent in the high ACD group versus the normal ACD group and in the normal ACD group versus the low ACD group.CONCLUSION:Peripheral refraction changes are greater in participants with AL values outside the normal range and deeper ACD values compared to participants with normal AL and ACD.

Measurement of the depths at different regions of the anterior chamber in healthy Chinese adults

AIM: To measure the depths of different regions of the anterior chamber(AC) in healthy Chinese adults, and to explore possible correlations with age or gender.METHODS: The AC was imaged by swept-source optical coherence tomography in healthy Chinese adults. The horizontal scan of the right eye was used to measure the anterior chamber depth(ACD) at 199 points.RESULTS: A total of 309 images from 309 subjects were analyzed. The ACD values at nearly all locations were negatively correlated with age(all P<0.05), except for ACD1, 2, 198, and 199(correspond to the iris roots). The mean annual decrease 0.013±0.005 mm/y for all ACDs combined, 0.008±0.004 mm/y for the peripheral region, 0.017±0.003 mm/y for the middle peripheral region, and 0.014±0.001 mm/y for the central region. The mean annual decrease was significantly different among these three regions(P<0.001). The ACD was greater in males than in females(P<0.05). The mean difference in ACD between males and females was 0.081±0.025 mm.CONCLUSION: This study showed that optical coherence tomography can be used to measure the ACD of different regions of the AC. We found reductions in ACD with age, although the reduction varied among different points, in healthy Chinese adults.

Distribution of Axial Length, Anterior Chamber Depth and Lens Thickness of Pre-Operative Cataract Patients in Indonesian Population

Purpose: Biometry measurement of pre-operative cataract patients plays a major role in calculating intraocular lens power. This study aimed to review and determine the distribution of biometry components, such as axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) of pre-operative cataract patient in Indonesian population. Methods: A cross-sectional study data were obtained from 2015-2018 cataract surgery at Prima Husada Citra Hospital, Surabaya, East Java, Indonesia. A total of 1295 eyes with cataract was included in the study based on their medical record. We analyzed the data using descriptive analysis and correlated each variable using the Spearman’s Rho analysis. Results: Mean AL, LT and ACD was 23.81 ± 1.46 mm, 4.49 ± 0.55 mm, 3.25 ± 0.70 mm respectively. Male has longer AL and deeper ACD with (p < 0.001), while LT was found thicker in female (p = 0.005). The increase of AL was accompanied by ACD (r = 0.457;p < 0.001) and a thinner LT (r = -0.101;p < 0.001). Conclusions: LT is increased with age while AL and ACD are shortened with age. There was a positive correlation between AL and ACD, but an inverse correlation between AL and LT.

The Effects of Anterior Chamber Depth to Endothelial Cell Loss Using Tranversal Phacoemulsification

Background: Phacoemulsification surgery is the most frequent cataract surgery performed in developed countries because of its effectiveness and safety. However, some degree of endothelial loss is inevitable in any type of cataract surgery, including phacoemulsification. Anterior chamber depth (ACD) could be considered as one of important anatomical parameters for preserving endothelial loss from the mechanical and thermal damage that can occur during the procedure. Purpose: To evaluate the effects of ACD on endothelial cell density, hexagonality, coefficient variation (CV) and central corneal thickness (CCT) at one and four weeks after phacoemulsification using transversal ultrasound. Method: This was a prospective study conducted at Cicendo National Eye Hospital Indonesia from April to August 2018, where we performed phacoemulsification in 148 patients with ACD < 3 mm group, ACD ≥ 3 mm group. Specular microscopy examination was performed prior to phacoemulsification and repeated at one and four weeks after surgery. The changes in endothelial density, percentage of hexagonality, CV and CCT between two groups were evaluated and compared. Result: Mean (SD) endothelial density in ACD < 3 mm group and ACD ≥ 3 mm group at 1-week evaluation was 1761.9 (503.3) and 1966.1 (530.6) cells/mm2 respectively, with p value 0.030. At 4-week evaluation, endothelial cell density in ACD < 3 mm group and ACD ≥ 3 mm group was 1537.8 (504.9) and 1798.7 (554.0) cells/mm2 respectively, with p value 0.010. There was no statistical difference regarding hexagonality, CV and CCT between both groups at 1-week and 4-week evaluation. Endothelial density changes percentage also higher in ACD < 3 mm group at 1-week and 4-week evaluation. Conclusion: Endothelial cell density in ACD < 3 mm group was significantly lower compared to ACD ≥ 3 mm group at 1-week and 4-week evaluation after phacoemulsification.

Relationship between the Alignment of a Non-Mydriatic Fundus Camera,Anterior Chamber Depth and Axial Length

Purpose:To evaluate the relationship between the position of the focal adjustment knob of a fundus camera and refractive error and biometric data as measured in the same eye.Methods:Normal eyes of patients presenting to clinics at the Beijing Tongren Hospital were examined with a non-mydriatic fundus camera.The position on the focal scale of a knob adjusting the distance between the camera lens and film plane,used to adjust focus the image of the patients fundus relative to the refractive power of the eye,was recorded in degrees.Ocular biometry and refractometry were performed on the same eyes.Results:The study included 136 subjects with a mean age of 36.5 ±19.6 years and a mean refractive error of-1.31 ±2.77 diopters.In univariate analysis,the position of the adjustment knob was significantly associated with refractive error.(P < 0.001;correlation coefficient r=-0.77),axial length.(P<0.001;r=0.65) and anterior chamber depth (P<0.001;r=0.48).After adjustment for age,anterior chamber depth decreased by 0.01 mm(95% confidence interval:0.003,0.017) for change per degree in the position of the adjustment knob.Conclusion:A fundus camera can be used to estimate anterior chamber depth,axial length and refractive error.In a screening setting,a fundus camera operated by a technician may be helpful to detect a shallow anterior chamber and evaluate a potential risk factor for primary angle closure.

超高度近视合并白内障患者术后ACD和晶状体悬韧带的变化及相关影响因素

目的:探讨超高度近视合并白内障患者超声乳化白内障摘除联合人工晶状体植入术后前房深度(ACD)和晶状体悬韧带变化及相关影响因素。方法:选取2016-10/2022-12我院超高度近视合并白内障患者45例60眼,均接受超声乳化白内障摘除联合人工晶状体植入术。随机数字表法分为植入组和未植组,植入组术中联合囊袋张力环(CTR)植入,未植组术中未植入CTR。比较所有患者手术前后ACD和晶状体悬韧带长度变化,并行相关性分析。观察两组手术前后ACD和晶状体悬韧带长度变化的差异。结果:超高度近视合并白内障患者术后1、3mo ACD均高于术前(均P<0.05)。超高度近视合并白内障患者白内障术后1、3mo 3∶00位、6∶00位、9∶00位、12∶00位及平均晶状体悬韧带长度均低于术前(均P<0.05);术后3mo 3∶00位、6∶00位、9∶00位、12∶00位及平均晶状体悬韧带长度与术后1mo比较无差异(均P>0.05)。超高度近视合并白内障术前平均晶状体悬韧带长度与眼轴和术前ACD均呈正相关关系(均P<0.05)。植入组和未植组术前,术后1、3mo ACD组间比较均无差异(P>0.05)。植入组和未植组术前,术后1mo 6∶00晶状体悬韧带长度组间比较均无差异(P>0.05),术后3mo 6∶00晶状体悬韧带长度组间比较有差异(P<0.05)。植入组和未植组术前,术后1、3mo 3∶00位、9∶00位、12∶00位和平均晶状体悬韧带长度组间比较均无差异(P>0.05)。结论:超高度近视合并白内障患者超声乳化白内障摘除术后前房加深,晶状体悬韧带缩短;联用CTR会影响晶状体悬韧带长度的变化。

ICL植入术治疗高度近视术后早期眼前节形态的变化分析

目的探讨有晶体状眼后房型人工晶状体(ICL)植入术治疗高度近视术后早期眼前节形态的变化情况。方法选取60例(113眼)高度近视患者,均接受ICL植入术治疗。对比患者治疗前后裸眼视力、最佳矫正视力变化情况,眼前节形态变化情况[角膜厚度(CCT)、角膜曲率(K值)、中央前房深度(ACD)],角膜像差变化情况[角膜高阶像差(CHOA)、角膜低阶像差(CLOA)、角膜总像差(CTA)]。结果治疗后30 d、90 d、半年的裸眼视力、最佳矫正视力均优于治疗前(P<0.05)。治疗前及治疗后30 d、90 d、半年,角膜厚度分别为(532.50±25.40)、(532.54±23.17)、(534.64±22.55)、(532.97±24.10)μm,角膜曲率分别为(43.80±0.89)、(43.55±0.92)、(43.55±0.97)、(43.43±1.03)D,中央前房深度分别为(3.22±0.14)、(3.06±0.17)、(3.06±0.14)、(3.09±0.11)mm。与治疗前对比,治疗后30 d、90 d、半年的角膜曲率、中央前房深度均有所减小(P<0.05);治疗前后各个阶段,角膜厚度对比均无明显差异(P>0.05)。治疗后30 d、90 d、半年的CHOA均大于治疗前(P<0.05);治疗后30 d、90 d、半年的CLOA、CTA与治疗前对比均无明显差异(P>0.05)。结论高度近视患者应用ICL植入术治疗,患者的最佳矫正视力、裸眼视力均有所改善,角膜曲率变小、中央前房深度变浅、前房角变窄,患者术后早期眼前节形态良好,且较小影响角膜,安全性较高,可促进患者术后早日康复。

中心性浆液性脉络膜视网膜病变眼部特征的研究进展

中心性浆液性脉络膜视网膜病变(CSC)是一种以特发性浆液性视网膜脱离(SRD)为特征的脉络膜视网膜疾病,伴有一处或多处视网膜色素上皮脱离(PED)或病变,具有特征性的眼球结构改变。CSC被归类为厚脉络膜相关疾病(PSD),近年来进一步发现主要为Haller层增厚。最近的研究重点关注了CSC患者的厚巩膜特征,阐述了其与脉络膜循环的密切关系,并提出CSC可能与葡萄膜渗漏综合征(UES)具有相似的发病机制。此外,CSC还具有短眼轴、远视性屈光不正、浅前房等特征,表明CSC不仅是眼球后极部的病变,而且累及全眼球。本文对CSC眼部特征的最新进展进行了综述,为进一步探究CSC发病机制提供新思路。

藏族年龄相关性白内障患者眼球生物学参数特征分析

目的:比较藏族与汉族年龄相关性白内障患者眼球生物学参数的差异,分析藏族患者眼球生物学参数的分布特征。方法:回顾性队列研究。收集2019-01/2020-12就诊于我院的年龄相关性白内障患者661例1 030眼,其中藏族患者483例739眼,汉族患者178例291眼。术前所有患者均采用IOL Master 500测量眼轴长度、前房深度、角膜曲率、散光及散光轴向。结果:藏族年龄相关性白内障患者眼轴长度为23.33(22.81,23.86)mm,前房深度为3.04(2.79,3.30)mm,散光度为0.73(0.47,1.07)D,平均角膜曲率为43.89±1.35 D,较汉族患者眼轴短,角膜曲率小(均P<0.05)。藏族患者的年龄与眼轴长度和前房深度均呈负相关,而与平均角膜曲率呈正相关(均P<0.05)。藏族患者中男性患者较女性患者眼轴更长、前房更深、角膜更平坦(均P<0.05)。结论:藏族与汉族年龄相关性白内障患者的眼球生物学参数存在差异,不同年龄和性别藏族患者眼球生物学参数的分布有所变化。

两种术式联合治疗白内障合并青光眼的疗效分析

目的探究白内障合并青光眼运用两种术式的有效性。方法选取聊城市第三人民医院于2021年2月—2023年2月收治的100例白内障合并青光眼患者为研究对象,利用随机数表法分为参照组(50例,白内障超声乳化人工晶体植入手术治疗)和研究组(50例,改良小切口非超声乳化白内障摘除人工晶状体植入与小梁切除术联合治疗),比较两组患者的眼压、视力水平及前房深度。结果术后,研究组的眼压小于参照组,视力水平优于参照组,前房深度大于参照组,差异有统计学意义(P均<0.05)。研究组术后并发症总发生率(4.00%)低于参照组(16.00%),差异有统计学意义(χ^(2)=4.000,P=0.045)。结论白内障合并青光眼运用改良小切口非超声乳化白内障摘除人工晶状体植入与小梁切除术联合治疗的效果突出,可以更好地降低术后的眼压,提高视力水平和前房深度,降低并发症发生率。

Comparison of anterior section parameters using anterior segment optical coherence tomography and ultrasound biomicroscopy in myopic patients after ICL implantation

AIM：To compare the agreement of anterior chamber depth（ACD）and central vault measurements obtained by anterior segment optical coherence tomography（AS-OCT）and ultrasound biomicroscopy（UBM）of post surgical high myopic eyes with posterior chamber phakic intraocular lens（Visian ICL;STAAR Surgical）implantation.·METHODS：Fifty-two phakic eyes of 28 high myopic patients who underwent implantable Collamer lens（ICL）surgery for the correction of high myopia were studied.The postoperative ACD,the distance between the corneal endothelium and the anterior surface of ICL（cornea-ICL）and the central vault were measured with the AS-OCT system and the UBM system.Intraclass correlation coefficient（ICC）and the Bland-Altman plot were used to evaluate the repeatability and agreement of two devices.·R ESULTS：The mean ACD,cornea-ICL and central vault in the 52 phakic eyes after ICL surgery was 3.19±0.28 mm,2.47±0.28 mm,0.50±0.19 mm by AS-OCT and3.13±0.25 mm,2.49±0.25 mm,0.44±0.19 mm by UBM,respectively.Pairwise comparison of ACD and central vault measurements showed significant differences between AS-OCT and UBM（〈0.05）.However,no statistically significant difference was found between these imaging techniques in cornea-ICL（〉0.05）.The Pearson correlation coefficient（）between AS-OCT and UBM measurements for ACD,cornea-ICL and vault was0.88,0.80 and 0.89,respectively（〈0.001）.The ICC was0.89-0.94 for the measurements of AS-OCT and UBM.Bland-Altman analysis showed the 95%limits of agreement of ACD,cornea-ICL,central vault measurements between these two devices were-0.20 to 0.32 mm,-0.36to 0.32 mm and-0.12 to 0.24 mm,respectively.58·CONCLUSION：Central ACD and vault measurements using AS-OCT demonstrated a slight significantly higher value than using UBM in phakic eyes after ICL surgery.These two devices should not be used interchangeably for measurements of central ACD and vault in patients after phakic intraocular lens implantation.

Comparison of postoperative anterior segment changes associated with pars plana vitrectomy with and without vitreous base shaving

AIM:To compare changes in anterior segment topography and axial length(AL)evaluated with Pentacam and IOL Master after pars plana vitrectomy(PPV)performed with and without vitreous base shaving.METHODS:This prospective study included patients who underwent PPV or phacoemulsification+PPV(Phaco+PPV)for various indications.Patients who underwent total posterior hyaloid detachment and excessive vitreous base shaving with scleral indentation were referred to as complete PPV(c-PPV).The patients whom posterior hyaloid was separated as far as the posterior arcades and vitreous base shaving with scleral depression was not performed were classified as the partial PPV(p-PPV)group.All patients underwent detailed ophthalmologic examinations preoperatively and lwk,I,and 3mo postoperatively.Changes in the anterior chamber depth(ACD),anterior chamber volume(ACV),iridocorneal angle(ICA)f central corneal thickness(Cd),and keratometric measurements(K1 and K2)were evaluated with Pentacam HR.Changes in the AL measurements were analyzed with IOL Master.RESULTS:A significant increase in ACD was observed in c-PPV cases(P=0.02),but this increase was not significant in the p-PPV group(P=0.053).In contrast,ICA increased significantly in the c-PPV group(P=0.02)but decreased in the p-PPV group(P=0.09).BCVA was significantly improved in the c-PPV group from week 1(P<0.001)while the increase in the p-PPV group reached significance at 3mo(P=0.035).Cd increased in the first week and later returned to baseline in both groups.No significant differences in the other parameters were observed between the groups,and there were no significant changes in intraocular pressure,ACV,AL,K1 or K2 values(P>0.05 for all).CONCLUSION:Incomplete posterior hyaloid excision and not removing the vitreous base in PPV surgeries may create a more stable anterior chamber,thus preventing the downward movement of the lens-iris diaphragm,and may cause ciliary body retraction,thereby reducing ICA.Awareness of these effects can provide some amount of guidance to physicians in selecting the appropriate PPV procedure and preempting surgical complications.

Measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients

AIM:To evaluate the measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients.·METHODS:A hundred and one eyes of 55 keratoconus patients were enrolled in this study.The mean age was26.2 ±8.9 years.The inclusion criteria were keratoconus stage I to III according to the Amsler-Krumeich keratoconus classification.All the measurements were done by the same operator,under the mesopic light condition and repeated with three different optical methods;Visante,Orbscan and Pentacam.The evaluated anterior segment parameters were anterior chamber depth(ACD),central and thinnest corneal thickness(CCT and TCT) and pupil diameter(PD).·RESULTS:The mean CCT measured by Visante,Orbscan and Pentacam were as follows:462.0 ±48.1μm,463.9±60.9μm,476.5±45.3μm,respectively(P =0.873).The mean ACD values were 3.34±0.33mm,3.26±0.33mm,3.49±0.40mm,respectively(P=0.118).The mean PD measurements were 5.11 ±1.14mm,4.80 ±0.85mm,3.80 ±1.38mm,respectively(P 【0.001).The mean TCT measurements of Visante,Orbscan and Pentacam were 437.9 ±48.2μm,447.6±60.6μm and 459.9±44.0μm,respectively(P =0.214).The Visante and Orbscan measured CCT similarly,while Pentacam measured CCT thicker than the other two.The Visante measured TCT thinner than the other two devices.In ACD measurements,Orbscan was the one giving the lowest values.PD was measured differently by the devices.·CONCLUSION:Although TCT,CCT and ACD measurements acquired by Visante,Orbscan and Pentacam in keratoconus patients are similar,PDmeasurements show large differences among the devices.

Comparison of anterior segment measurements using rotating Scheimpflug imaging and partial coherence interferometry

AIM:To compare central corneal thickness(CCT) and anterior chamber depth(ACD) measurements using rotating Scheimpflug imaging and partial coherence interferometry.·METHODS:As part of the first phase of Shahroud Eye Cohort Study with 5 190 subjects of 40 to 64 years of age,CCT and ACD were measured using Scheimpflug imaging with the Pentacam(Oculus,Inc.,Lynnwood,WA,USA) and partial coherence interferometry with the Allegro BioGraph(Wavelight,Erlangen,Germany).·RESULTS:After applying exclusion criteria,we had data of 4 387 subjects with a mean age of 50.7±6.2 years.Mean CCT with Pentacam and BioGraph were 528.6 ±33.2μm and 525.6 ±32μm respectively;the difference was statistically significant(P 【0.001),but the correlation was high(R=0.920).Mean ACD measurements using Pentacam and BioGraph were 2.68 ±0.35mm and 2.62 ±0.33mm respectively;the inter-device difference was significant(P 【0.001) with high correlation(R=0.944).The 95% limits of agreements between devices were-22.65μm to28.61μm and-0.16mm to 0.29mm for CCT and ACD measurements,respectively.·CONCLUSION:For both CCT and ACD,the BioGraph gave significantly lower values than the Pentacam(P 【0.05).Despite the high inter-device correlation,the 95%limits of agreements were wide,and this may limit their interchangeability in measuring the CCT and ACD.

波前像差引导FS-LASIK矫正中高度近视患者术后1年眼前节变化

目的探讨波前像差引导FS-LASIK矫正中高度近视患者术后1年对眼前节结构的影响。方法收集2020年7月至2021年3月在徐州市第一人民医院就诊符合手术适应证且接受波前像差引导FS-LASIK患者共40例78眼的临床资料,分为中度近视组和高度近视组;分别于术前、术后1个月、术后1年行Pentacam AXL眼前节分析仪测量眼前节,包括角膜后表面Q值,全角膜像差,后表面高阶像差、球差、彗差,角膜后表面曲率、顶点高度及最薄点高度,前房深度(ACD)、前房容积(ACV)和前房角(ACA),并对比分析。结果中度近视组患眼角膜后表面曲率和角膜后表面Q值术前与术后1个月、术后1年相比差异均有统计学意义(均为P<0.05),高度近视组患眼角膜后表面最薄点高度和角膜后表面Q值术前与术后1年相比差异均有统计学意义(均为P<0.05)。中度近视组患眼角膜后表面垂直彗差术前与术后1个月、术后1年相比差异均有统计学意义(均为P<0.05),高度近视组患眼全角膜像差、角膜后表面球差和垂直彗差术前与术后1个月、术后1年相比差异均有统计学意义(均为P<0.05)。中度近视组及高度近视组患眼ACD、ACV术前与术后1个月、术后1年相比差异均有统计学意义(均为P<0.05),ACA术前术后相比差异均无统计学意义(均为P>0.05)。术后1年和术前球差变化值与术前等效球镜度(SE)相关性分析发现,高度近视组患眼球差变化值与术前SE呈中度相关(r=-0.349,P=0.025),而中度近视组患眼球差变化值与术前SE无明显相关性(r=-0.052,P=0.758)。结论波前像差引导FS-LASIK虽然对患者高阶像差有一定改善,但对角膜后表面和前房结构仍然有一定影响,主要集中在中央区,对周边影响相对较小,术后1年眼前节结构相对稳定。