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.

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.

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 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.

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.

Correlation between Lens Thickness and Central Anterior Chamber Depth

Purpose:.To investigate gender differences in lens thickness (LT) and central anterior chamber depth (ACD) in normal subjects,.and to assess age associated changes in these measures. Methods:.The anterior chamber depth (ACD), and lens thickness (LT), of 150 normal subjects (150 eyes) was measured by anterior segment optical coherence tomography (AS- OCT)..Gender differences were assessed by independent t-test,.and correlation analysis was used to examine the effect of age. Results:.The mean values of ACD and LT were 2.69±0.32 mm and 4.85±0.43 mm, respectively. Women had a significantly lower Mean ACD as compared to men (2.56±0.33 mm vs 2.85±0.29 mm; P﹤0.05). No statistically significant difference was found in LT between male and female subjects (P>0.05)..Correlation analysis findings suggest that LT increases with age (r=0.83,P﹤0.05), and that ACD decreases with age (r=-0.57,P﹤0.05). After controlling for LT, no significant correlation was observed between age and ACD (P>0.05). Conclusion:.The ACD of female subjects was,.on average, shallower than that of their male counterparts..Aging was associated with increasing LT,.and the observed narrowing of ACD with age,.might be partially mediated by the increasing LT.

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.

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.

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.

Assessment of anterior chamber angle changes after phacoemulsification with swept-source OCT

AIM:To assess the changes of anterior chamber angle in patients with shallow anterior chamber after phacoemulsification combined with intraocular lens(IOL)implantation,based on anterior segment swept-source optical coherence tomography(AS-SS-OCT)measurements.METHODS:This was a prospective case control study;sixty eyes of sixty case were scheduled for cataract surgery with normal intraocular pressure(IOP).Based on anterior chamber depth(ACD)and gonioscopy findings,the eyes were divided into two groups:group of shallow anterior chamber and narrow angle(SAC group,30 eyes);and group of normal anterior chamber group with wide angle(NAC group,30 eyes).Measurements of ACD,anterior chamber volume(ACV),iris volume(IV),lens vault(LV),angle opening distance(AOD),angle recess area(ARA),trabecular iris space area(TISA),and trabecular iris angle(TIA)were conducted in each group before and 3mo after surgery.RESULTS:There was no significant difference in age,axial length(AL),corneal curvature,corneal diameter,intraocular pressure,and IV between two groups before surgery,except for the LV(P=0.000).ACD and ACV were prominently larger in the NAC group than the SAC group 3mo after operation(3.69±0.38 vs 3.85±0.39 mm,P=0.025;161.37±19.47 vs 178.26±20.30 mm3,P=0.002).AOD750,ARA750 in nasal and inferior quadrants,TISA750 in all quadrants except temporal,and TIA750 in all quadrants in SAC group were significantly smaller than those in NAC group after operation(all P<0.05).CONCLUSION:Cataract surgery can deepen anterior chamber and increase the width of anterior chamber angle in Chinese subjects,but the angle related parameters including AOD750,ARA750,TISA750,TIA,TISA750,and ACV in patients with shallow anterior chamber and narrow angle do not reach the normal level.

Changes in anterior chamber depth following vitrectomy

Background Anterior segment morphometry is crucial for ophthalmologists to understand the visual outcomes of cataract surgery,keratorefractive surgery,as well as some other anterior segment disorders.Previous reports in literature have shown that anterior chamber depth （ACD） may shift slightly after vitrectomy.This study aimed to characterize the shortterm changes in ACD in eyes after vitrectomy by means of A-scan ultrasound.Methods A prospective case series study was carried out on 29 eyes of 29 patients who underwent vitrectomy as the sole procedure.ACD was measured using A-scan ultrasound biometry shortly before vitrectomy and 1 week,1 month,and 3 months after the surgery.Postoperative ACDs were compared with baseline.Results Twenty-nine patients （16 males and 13 females） were enrolled in the study,with mean age of （50±11） （25-65） years.Twenty-three eyes of 23 patients were vitrectomized for vitreous hemorrhage （VH） and the other six were operated for idiopathic epiretinal membrane （ERM）.The mean preoperative ACD of the VH eyes was （2.98±0.38） mm.No significant difference was found between the ACD of the VH eyes and their fellow eyes （P=0.058）.The average preoperative ACD in the ERM eyes was （2.94±0.31） mm,which was statistically deeper than that of their fellow eyes （（2.85±0.28） mm,P=0.008）.No statistical difference was found in the postoperative average ACD of the VH eyes compared with baseline.In the ERM group,the postoperative ACD in the surgical eyes was still statistically deeper than the fellow eyes 1 week after surgery （P=0.034）.However,such statistical difference disappeared at 1 or 3 months postoperative （P=0.186 and 0.682）.Conclusions ERM may induce deepening of the ACD,which can be recovered by uneventful vitrectomy.VH does not cause shift of ACD,neither does vitrectomy.

Risk factors for flat anterior chamber after glaucoma filtration surgery

AIM： To investigate the incidence rate and risk factors for grade Ⅲ flat anterior chamber（FAC） after glaucoma filtration surgery based on 5-year data.METHODS： Patients who underwent glaucoma filtration surgery in Daping hospital from January 2009 to December 2013 were enrolled in this retrospective study. The incidence of grade Ⅲ FAC following glaucoma filtration surgery was determined. Regression analysis was performed to investigate the influence of glaucoma type, surgical approach, age, and preoperative intraocular pressure（IOP） on the risk of postoperative FAC.RESULTS： A total of 2179 eyes receiving anti-glaucoma surgery were included. Ninety-one eyes suffered from postoperative FAC, with an overall incidence rate of 4.18%. Of 471 eyes with primary open angle glaucoma（POAG）, grade Ⅲ FAC occurred in only 3 eyes（0.64%）. Primary angleclosure glaucoma（PACG） was diagnosed in 1076 eyes, 39（3.62%） of which developed grade Ⅲ FAC, including 12 eyes（12/300, 4%） with acute PACG（aP ACG） and 27 eyes（27/776, 3.48%） with chronic PACG（c PACG）. Six of 259 eyes（2.32%） with secondary glaucoma, 28 of 186 eyes（15.05%） with neovasular glaucoma, 1 of 66 eyes（1.52%） with congenital glaucoma, and 14 of 115 eyes（12.17%） with remnant glaucoma suffered from grade Ⅲ FAC. Of 6 eyes with mixed glaucoma, none developed grade Ⅲ FAC after surgery. When stratified by surgical approach, 24 of 766 eyes（3.13%） undergoing trabeculectomy, 21 of 924 eyes（2.27%） treated by trabeculectomy plus mitomycin C（MMC）, 18 of 109 eyes（16.51%） undergoing Ahmed glaucoma valve implantation, 23 of 201 eyes（11.44%） managed by Ahmed implantation plus MMC, and 5 of 133 eyes（3.76%） treated by Ahmed implantation plus lens extraction or vitrectomy developed grade Ⅲ FAC. Logistic regression analysis revealed that factors including neovasular glaucoma, remnant glaucoma, glaucoma valve implantation, glaucoma valve implantation＋MMC, glaucoma valve implantation＋vitrectomy, age〉60 y, and IOP at admission 〉50 mm Hg were significantly associated with an increased risk for grade Ⅲ FAC.CONCLUSION： The overall incidence of grade Ⅲ FAC after glaucoma filtration surgery is 4.18%. Patients with neovasular glaucoma and remnant glaucoma are at a higher risk of developing FAC. Ahmed glaucoma valve implantation is associated with a higher risk for grade Ⅲ FAC compared with trabeculectomy. No significant correlation was observed between the use of MMC in glaucoma filtration surgery and the risk of postoperative FAC. Higher IOP at admission（〉50 mm Hg） and old age（〉60 y） are risk factors for grade Ⅲ FAC.

Comparison of measurements of anterior chamber angle via anterior segment optical coherence tomography and ultrasound biomicroscopy

BACKGROUND Glaucoma is an irreversible optic neuropathy with the loss of visual field and decrease of vision.The variable clinical manifestations may result in differential diagnostic difficulties.The early screening and diagnosis of glaucoma are currently experiencing a demand for anterior segment analysis tools that can gather more information with one short measurement.Therefore,we analyzed the agreement,difference,and correlation of chamber angle parameters such as angel opening distance at 500μm(AOD500)and trabeculo-iris space area at 500μm^2(TISA500)measured by anterior segment optical coherence tomography(ASOCT)and ultrasound biomicroscopy(UBM).AIM To compare the differences,correlation,and agreement in measuring AOD500 and TISA500 by AS-OCT and UBM.METHODS Both AS-OCT and UBM were performed to measure AOD500 and TISA500 in 45 subjects(72 eyes).All subjects without glaucoma were collected from October 2015 to August 2016 at the Ophthalmology Department of the Fourth Affiliated Hospital of China Medical University.Data of the two groups(AOD500 and TISA500)were compared by nonparametric tests.Pearson correlative analysis and Bland-Altman analysis were used to compare the correlation and agreement.RESULTS There were no significant differences between AS-OCT and UBM in measuring AOD500(P1=0.110,P2=0.633,P3=0.078,and P4=0.474)and TISA500(P1=0.584,P2=0.889,P3=0.297,and P4=0.550)of the four quadrants of the anterior chamber angle.There was a high correlation in measuring AOD500(r1=0.562,r2=0.671,r3=0.635,and r4=0.720;P<0.001)and TISA500(r1=0.584,r2=0.889,r3=0.297,and r4=0.550;P<0.001).There was a good agreement in measuring AOD500 and TISA500 by the two modalities.CONCLUSION There is a high correlation and agreement between AOD500 and TISA500 measurements by AS-OCT and UBM.They are interchangeable under some circumstances.AS-OCT proves to be a better early screening tool for glaucoma.

Incidence and predisposing factors of anterior chamber gas bubbles during femtosecond laser flap creation

AIM:To investigate the incidence and the predisposing factors of anterior chamber(AC)gas bubbles during femtosecond laser(FS)flap creation for laser in situ keratomileusis(LASIK).METHODS:All patients who underwent FS-LASIK surgery at CMU LASIK Center between January 2013 and May 2016 were retrospective reviewed.Preoperative and intraoperative data including keratometry,white-towhite(WTW)corneal diameter,flap parameters(diameter,thickness,hinge position,and tunnel length)and pulse energy were reviewed and compared between incident group and control group.To determine the risk factors,univariate and multivariate conditional logistic regression were used;the eye was unit of analysis.RESULTS:The incidence of AC gas bubbles was 1.6%(22 out of 1378 eyes).The median WTW in the AC bubbles group was 11.5 mm(range 11.1-12.1),which was significantly different from the control group(11.7 mm,range 10.5-12.8,P=0.021).The result of the median WTW minus the flap diameter in the AC bubbles group was 2.5 mm(range 2.1-3.2),which was statistically different to the control group(2.7 mm,range 1.5-3.8,P=0.008).The logistic regression analysis showed that the result of the WTW minus the flap diameter in the AC bubbles group had an adjusted odds ratio of 0.204(95%CI;0.056-0.747,P=0.016).CONCLUSION:Development of AC gas bubbles during FS flap creation is not an uncommon event in Asian eyes which typically have a small WTW.The flap diameter when adjusted relatively to the WTW is a predisposing factor to the possibility of AC gas bubbles occurrence.

Comparison between Ophthalmologists and Community Health Workers in Screening of Shallow Anterior Chamber with Oblique Flashlight Test

Objective To study the agreement between ophthalmologists and community health workers in detecting shallow anterior chamber with oblique flashlight test. Methods Totally 425 subjects were given an eye examination in a community health center. The anterior chamber depth of each subject was examined by one ophthalmologist and two trained community health workers (one nurse and one non-professional health worker) using oblique flashlight test. Inter-observer agreement was determined using the weighted kappa statistic. Results Among the enrolled subjects,148 (35%) were male and 277 (65%) were female. Good agreement was noted in all the three observers. The comparison between the ophthalmologist and the nurse showed a kappa statistic of 0.42 for both eyes (P<0.001). The kappa statistic was 0.54 and 0.52 for right and left eyes respectively between the ophthalmologist and the non-professional health worker (P<0.001). As for agreement between the nurse and the non-professional health worker,the kappa statistic was 0.49 and 0.38 for right and left eyes,respectively (P<0.001). Conclusion The oblique flashlight test may be used as an applicable tool by trained community health workers for screening of shallow anterior chamber and play a role in blindness prevention in community.

Unilateral spontaneous lens absorption and dislocation of the empty capsular bag into the anterior chamber

Cases involving spontaneous aphakic change in the visual axis are rare in Outpatient Clinics. However, we can often ascertain the past events affecting the patient＇s eye by examining its current status. The placement of the dislocated internal material of the lens, the remnant lens capsular bag status, lens and zonular status of the contralateral eve.

Lymphocyte infiltration and activation in iris-ciliary body and anterior chamber of mice in corneal allograft rejection

AIM: To investigate the infiltration and activation of lymphocyte in iris-ciliary body and anterior chamber after allogenic penetrating keratoplasty (PK), for further revealing the role of iris-ciliary body in corneal allograft immune rejection. METHODS: In the mice models of PK, BALB/C mice received orthotopic isografts (n =35) or C57BL/6 donor allografts (n=25). Grafts were examined daily for 3 weeks by slit-lamp microscopy and scored for opacity. The infiltration of CD4(+) T lymphocyte in iris-ciliary body and anterior chamber was examined by immunohistology and the mRNA of CD80 and CD86 in both cornea graft and iris-ciliary body by RT-PCR was analyzed in allograft recipient at days 3, 6, 10 and the day when graft rejection occurred. Isograft recipients were examined as control at the corresponding time points. Transmission electron microscope was used to study the ultrastructure, especially cell infiltration, of iris-cilary body and corneal graft at day 3, 7 and the day when rejection occurred after allogenic PK. RESULTS: Rejection was observed in all the allograft recipients followed more than 10 days, at a median time of 15 days (range 12-18 days), but not in any of isografts. CD4(+) T cells were first detected at day 6 after transplantation in limbus and Ciliary body, and then in the stroma of recipient, iris, anterior chamber and corneal allograft with an increased number until graft rejection occurred. CD80 and CD86 mRNA were detected under RT-PCR examination in both graft and iris-ciliary body of allograft recipient, but not in any of isograft recipient. Three days after operation, lymphocytes and monocytes macrophages were visible in iris blood vessels and the anterior chamber, and vascular endothelial cell proliferation and activation were significant under transmission electron microscopy examination. At day 7, corneal endothelial cells became thinner. Lymphocytes and mononuclear macrophages were found with great number in the anterior chamber and adhered to the corneal endothelium. Blood vessels in iris increased and were filled with lymphocytes. And lymphocytes were detected to migrate through endothelial cell gap out of vessels. When allograft rejection occurred, macrophages attached to endothelial cells with large number of lymphocytes and macrophages infiltrating in iris. CONCLUSION: Lymphocyte infiltration and activation occurred in iris-ciliary body after allogenic PK, and the lymphocytes could migrate from iris blood vessel to the anterior chamber, which might play an important role in corneal allograft immune rejection.

Management of hypotony and flat anterior chamber associated with glaucoma filtration surgery

AIMTo determine the effectiveness of pharmacological and interventional treatment of hypotony and flat anterior chamber (FAC) resulting from glaucoma filtration surgery.METHODSWe retrospectively examined the medical records of fifty-two trabeculectomy patients (52 eyes) who developed postoperative hypotony and FAC. The management and associated complications of hypotony, changing intraocular pressure (IOP) and best corrected visual acuity (BCVA) were evaluated.RESULTOf the 52 patients with hypotony, 29 (56%) had a grade 1 FAC, 21 (40%) had a grade 2 FAC, and only 2 had a grade 3 FAC. There was no significant difference between the mean preoperative IOP and the mean IOP at three and six months after surgery. Thirteen eyes (25%) required antiglaucomatous medication three months after surgery. The mean BCVA at 6mo after surgery was significantly reduced as compared with the mean preoperative BCVA.CONCLUSIONHypotonia and FAC following trabeculectomy are associated with troublesome complications that require pharmacological and/or surgical treatment. Thus, close follow-up is essential for affected patients.