External Limiting Membrane, Photoreceptor Ellipsoid Zone Disruption, and Retinal Pigment Epithelium Alterations in Diabetic Retinopathy

Objective?Diabetic retinopathy (DR), a microvascular complication of diabetes, is a leading cause of preventable blindness. Spectral domain optical coherence tomography (SD-OCT) provides cross-sectional and topographical imaging of the retina. SD-OCT resolves outer retinal layers into three hyperreflective bands—external limiting membrane (ELM), ellipsoid zone (EZ), and retinal pigment epithelium (RPE). In this article, we have studied the role of these outer retinal layers in structural and molecular changes taking place in DR. Materials and Methods?Articles with clinical features, pathogenesis, diagnosis, and treatment of DR were thoroughly studied. Articles were searched on PubMed, MEDLINE, and Cochrane Library from 2000 to 2020. Studies focusing on the role of ELM, EZ, and RPE in pathogenesis of DR based on SD-OCT were included. Results?The long-standing hyperglycemia leads to protein glycosylation resulting in formation of advanced glycation end products (AGEs). AGEs have an impact through their effect on retinal microvasculature, vascular endothelial growth factor (VEGF), intercellular adhesion molecule-1, nitrosative and oxidative stress, and vitamin D and calcium metabolism. All these factors have been linked with disruption of outer retinal layers. AGEs lead to vascular endothelial dysfunction and release of proangiogenic factors by increasing the expression of VEGF in retinal pericytes and RPE cells. This leads to leakage and fluid accumulation resulting in diabetic macular edema (DME). In DME, there is sequential disruption of ELM and EZ and decrease in visual acuity (VA). The RPE alterations have been reported to be associated with the severity of DR and decrease in VA. Anti-VEGF therapy, most common treatment of DME, leads to restoration of barrier effect of ELM, it was found to be restored first followed by EZ restoration. Newer anti-AGEs agents and their receptor blockers are being developed which have a positive effect on maintaining the health of RPE. Conclusion?A complex molecular association exists between the structural changes in ELM, EZ, and RPE in DR. SD-OCT is an indispensable tool to study these changes as integrity of these outer layers of retina is essential for maintaining visual function of retina in DR.

Effects of internal limiting membrane peeling on post-vitrectomy epiretinal membrane and visual prognosis of rhegmatogenous retinal detachment / 中华实验眼科杂志

Objective:To analyze the effect of vitrectomy combined with internal limiting membrane (ILM) peeling on the prevention of post-vitrectomy epiretinal membrane (ERM) in macular-off rhegmatogenous retinal detachment (RRD) and its influence on visual outcomes.Methods:A cohort study was conducted.Seventy-four patients (74 eyes) with macular-off RRD, who realized retinal reattachment after vitrectomy and silicone oil tamponade from January 2015 to January 2018 in Baoding NO.1 Central Hospital, were enrolled.The patients were divided into the non-ILM peeling group (36 cases, 36 eyes) and ILM peeling group (38 cases, 38 eyes) according to whether they received ILM peeling or not.The patients underwent silicone oil removal within 3 to 5 months after the surgery.Best corrected visual acuity (BCVA), slit-lamp microscopy, indirect ophthalmoscopy, fundus photography and optical coherence tomography (OCT) were examined before and at 1, 6 and 12 months after the surgery.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Baoding NO.1 Central Hospital (No.[2019]042). Written informed consent was obtained from each patient.Results:There was no ERM found in the two groups at 1 month after the operation.There were 3 eyes (8.33%) with ERM in the non-ILM peeling group and 2 eyes (5.26%) in the ILM peeling group at 6 months after the operation, with no statistically significant difference between them ( P=0.067). There were 9 eyes (25.00%) with ERM in the non-ILM peeling group and 4 eyes (10.53%) in the ILM peeling group at 12 months postoperatively, with no statistically significant difference between them ( χ2=2.674, P=0.102). There was a significant difference in BCVA between before and after the operation in the two groups ( Ftime=31.692, P<0.001). Postoperative 1-, 6-and 12-month BCVA were all significantly better than the preoperative BCVA in the two groups (all at P<0.05). There was no significant difference in BCVA between the two groups ( Fgroup=0.117, P=0.773). OCT images showed that there were 25 eyes (77.78%) and 30 eyes (78.95%) with the intact ellipsoid zone in the non-ILM peeling group and ILM peeling group at 12 months after the operation, respectively, with no statistically significant difference between them ( χ2=0.875, P=0.350). Conclusions:Compared with vitrectomy alone, the vitrectomy combined with ILM peeling does not show better efficacy in the prevention of ERM occurrence in macula-off RRD patients and has no obvious influence on postoperative visual acuity.

Validation of 2d ultrasound and volume estimation formulae for volume assessment of kidneys and spleens: an in-vitro study / alidación de la fórmula de estimación de volumen y ultrasonido 2D para la evaluación del volumen de los riñones y el bazo: un estudio in vitro

The accuracy of internal organ volume estimation done with ultrasound (US) was found to be multifactorial. Hence, we aimed to describe and validate the volume assessment of ultrasound and standard volume estimation formulae for different shaped intra-abdominal organs using spleens and kidneys.Dissected cadaveric kidneys (n=25) and spleens (n=29) were scanned to obtain linear measurements and ultrasound auto-generated volumes (USV). Linear measurements were used to calculate the volumes manually with ellipsoid, prolate, and Lambert volume estimating formulae. The actual volumes (AV) of organs were obtained by the water displacement method. Volume assessment accuracy of USV and different formulae were compared by comparing bias, precision and Bland-Altman plot analysis. The US linear and volume measurement procedure was reliable with high inter and intra-observer agreements (linear: Chronbach's α=0.983 to 0.934; volumes: Chronbach's α=0.989). USV estimates were accurate with a high correlation to AV and low estimation bias (-5.9%). Also, prolate (bias=-0.75%) and ellipsoid formulae (bias=-3.75%) were reliable with a negligible bias in estimated volumes. Contrary, the Lambert formula was unreliable due to a high bias (41.6%). For all evaluated methods, the estimation error found to be related to the organ size (T=3.483; p=0.001), mainly when the assessed organ is larger than 50 ml. Also, the shape related estimation error found to be related to the volume estimation formula used.This study has validated the USV for kidney and splenic volume assessments while describing volume-calculating formula employed, organ size and shape as significant contributors for volume estimation accuracy.

Se encontró que la precisión de la estimación del volumen de órganos internos realizada con ultrasonido (US) es multifactorial. El objetivo fue describir y validar la evaluación de volumen mediante ecografía y las fórmulas estándar de estimación de volumen para órganos intraabdominales de diferentes formas utilizando bazos y riñones.Se evaluaron riñones cadavéricos disecados (n = 25) y bazos (n = 29) para obtener medidas lineales y volúmenes autogenerados por ultrasonido (USV). Se utilizaron medidas lineales para calcular los volúmenes manualmente con fórmulas de estimación de volumen elipsoide, prolate y Lambert. Los volúmenes reales (AV) de los órganos se obtuvieron mediante el método de desplazamiento de agua. Se comparó la precisión de la evaluación del volumen de USV y diferentes fórmulas comparando el sesgo, la precisión y el análisis de la gráfica de Bland-Altman. El procedimiento de medición lineal y de volumen mediante US fue confiable con alta concordancia inter e intraobservadores (lineal: α de Chronbach = 0,983 a 0,934; volúmenes: α de Chronbach = 0,989). Las estimaciones de USV fueron precisas con una alta correlación con AV y un bajo sesgo de estimación (-5,9%). Además, las fórmulas prolate (sesgo= -0,75%) y elipsoide (sesgo = -3,75%) fueron confiables con un sesgo insignificante en los volúmenes estimados. Por el contrario, la fórmula de Lambert no fue confiable debido a un alto sesgo (41,6%). Para todos los métodos evaluados, se encontró que el error de estimación estaba relacionado con el tamaño del órgano (T = 3.483; p = 0.001), principalmente cuando el órgano evaluado es mayor de 50 ml. Además, se encontró que el error de estimación de forma está relacionado con la fórmula de estimación de volumen utilizada.Este estudio ha validado el USV para evaluaciones de volumen renal y esplénico al mismo tiempo que describe la fórmula de cálculo de volumen empleada, el tamaño y la forma de los órganos como contribuyentes significativos de la precisión de la estimación de volumen.

PPV combined with internal limiting membrane tamponade and rat nerve growth factor injection in the treatment of large diameter IMH / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To observe the effect of pars plana vitrectomy(PPV)internal limiting membrane(ILM)insertion and nerve growth factor(NGF)injection in the treatment of large idiopathic macular hole(IMH). <p>METHODS: This was a retrospective clinical study which included 16 patients(16 eyes)with large IMH diagnosed in the Affiliated Eye Hospital of Nanjing Medical University from May 2018 to May 2020. All patients were treated with PPV combined with ILM insertion and NGF injection and the follow-up period was at least 6mo. Macular hole closure rates, best-corrected visual acuity(BCVA)(LogMAR), and optical coherence tomography(OCT)findings including ellipsoid zone(EZ)and external limiting membrane(ELM)were analyzed, the complications were also observed postoperatively.<p>RESULTS: The BCVA was 1.15±0.21 before operation, and the follow-up of BCVA was 1.02±0.19 and 0.87±0.24 respectively at 3 and 6mo after operation(<i>F</i>=34.966, <i>P</i><0.01); The BCVA was improved 3 and 6mo after operation(<i>P</i><0.01), and the BCVA at 6mo after operation was better than that at 3mo(<i>P</i><0.01). The closure rate of the MH was 100% and 11 eyes showed U-shaped closure in OCT(69%), 3 eyes were V-shaped closure(19%)and 2 eyes were irregular closure(13%). The BCVA of U-shaped closure group, V-shaped closure group and irregular closure group were 0.75±0.18, 1.1±0.19, and 1.20±0.00 respectively(<i>F</i>=6.937, <i>P</i><0.01). The recovery of BCVA in U-shaped closure group was significantly better than that in V-shaped closure group and irregular closure group(<i>P</i>=0.027, 0.007). Six months after operation, 10 eyes(91%)of ELM and 7 eyes(64%)of ellipsoid zone resumed continuity in U-shaped closure group, 2 eyes(67%)of ELM and 1 eye(33%)of resumed continuity in V-shaped closure group. ELM and ellipsoidal zone were not recovered continuously in irregular closure group(<i>P</i><0.05). During the follow-up period, we found no ocular or systemic complications.<p>CONCLUSION: PPV combined with ILM insertion and NGF injection is safe and effective in treating large IMH. The synergetic effect of NGF and ILM can obviously promote the closure of IMH, which is beneficial to the recovery of photoreceptor layer integrity and the improvement of visual function after operation.

Analysis of factors of metamorphopsia after vitrectomy for rhegmatogenous retinal detachment / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To identify factors associated with metamorphopsia in patients with rhegmatogenous retinal detachment(RRD)who underwent primary vitrectomy(PPV). <p>METHODS:This retrospective study included 94 patients(94 eyes)who underwent 23G PPV for repair of RRD between January, 2017 and January, 2019. Each patient were examined both eyes preoperatively and postoperatively(at 1, 6, 12mo and last visits). At each time-point, patients received a complete ophthalmological examination, including best corrected visual acuity(BCVA), intraocular pressure, slit-lamp biomicroscopy, optical coherence tomography(OCT), and M-chart examination.<p>RESULTS: One month after surgery, metamorphopsia occurred in 53%(<i>n</i>=50), the mean M value was 0.68±0.28. The metamorphopsia rate differed significantly between macula-off and macula-on RRD(<i>P</i><0.01). There was significant difference in M-chart among the different time(<i>F</i>=26.442, <i>P</i><0.01). Univariate analysis demonstrated that the macula status, location of retinal breaks, and disrupted EZ was a risk factor that was significantly associated with metamorphopsia. In multivariate analysis, macula-involving retinal detachment(<i>OR</i>=9.020, 95% <i>CI</i>:1.808-45.011, <i>P</i>=0.007)and disrupted EZ(<i>OR</i>=10.570, 95% <i>CI</i>:2.909-38.400, <i>P</i><0.01)was a significant predictors of metamorphopsia.<p>CONCLUSION: The metamorphopsia was improved after anatomically successful RRD surgery. Macular involvement retinal detachment and disrupted EZ were more likely to develop metamorphopsia.

Humeral Head And Glenoid Dimensions In The Indian Population: A Cadaveric Study

Background: Shoulder prosthesis should accurately mimic the proximal shoulder and glenoid anatomy to recreatethe shoulder biomechanics. There may be a mismatch in the sizes of the Indian native bone and the currentlyavailable western shoulder prosthesis, since the bony morphology of Indians may be different from that of thewestern counterpart.Purpose: To measure the average humeral head diameter and glenoid length and width, so that a proper implantselection may be done based on the knowledge of average Indian bony morphology.Methods: Twenty shoulders in ten fresh cadavers were dissected to expose the humeral head and glenoidarticular surface. The humeral head diameter was measured with the help of a digital vernier caliper in twoplanes: Supero-inferior diameter (D1) and antero-posterior diameter (D2). The glenoid length (l) and width (w)were measured with the help of a vernier caliper.Results: The average humeral head diameter (D1) ± S.D. in the Supero-inferior plane was 45±3.4 mm (range 40-50.6mm) and antero-posterior (D2) plane was 42.7±2.2 mm (range 40-46mm) with a mean difference of 2.2 mm.The average length of the glenoid (l) was 35.4±1.3 mm (range 32-37mm) and width of the glenoid (w) was 25.3±2.1mm (range 21-28mm). The shape of the humeral head was more ellipsoidal at diameters above 45 mm.Conclusion. We can conclude that the humeral head diameters and glenoid length and width in Indian populationare smaller than the western counterparts. The ellipsoidal shape of the humeral heads becomes more marked atdiameters above 45mm.

SD-OCT morphological changes in wet age-related macular degeneration patients after bevacizumab treatment / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the changes in spectral domain optical coherence tomography(SD-OCT)quantitative and qualitative parameters in a group of patients with age-related macular degeneration(AMD)that underwent bevacizumab intravitreal injections(IV). We assessed if one or more of these parameters can be used as prognostic factors of the post treatment visual acuity(VA).<p>METHODS:Totally 66 eyes of 61 patients, with treatment naive AMD, that were treated with at least 3 monthly bevacizumab IV, were retrospectively studied. SD-OCT quantitative \〖central foveal thickness(CFT), external limiting membrane(ELM)and ellipsoid zone(EZ)lengths\〗 and qualitative parameters were studied and compared before and after IV. We also tried to establish correlation between these parameters and before/after treatment VA.<p>RESULTS:Mean VA(logMAR), CFT(μm), ELM length(μm)and EZ length(μm)changed from pre-IV values of 0.62±0.41, 419.3±110.0, 378.2±377.2 and 156.4±253.7 to post-IV values of 0.53±0.44, 325.8±117.9, 547.1±421.5 and 173.1±207.1. There was correlation between pre-IV VA and pre-IV CFT(<i>rs</i>=0.27), ELM length(<i>rs</i>=-0.30)and ELM disruption(<i>rs</i>=0.43). There was also correlation between post-IV VA and post-IV ELM length(<i>rs</i>=-0.40). Post-IV VA showed correlation with pre-IV VA(<i>rs</i>=0.66), ELM length(<i>rs</i>=-0.35)and ELM disruption(<i>rs</i>=0.46). <p>CONCLUSION: In our study group pre-IV VA, ELM length and ELM disruption can be used as post-IV VA prognostic factors.

Effect on macular structure and visual acuity after scleral buckling and pars plana vitrectomy for macula-off rhegmatogenous retinal detachment / 中华实验眼科杂志

Background The patients who have undergone successful surgery for retinal detachment (RD) cannot recover their vision quickly,and the reason is not very clearly now.Objective This study was to compare the ellipsoid zone integrity in macula and frequency and duration of subretinal fluid after scleral buckling and pars plana vitrectomy (PPV) in primary macula-off rhegmatogenous RD,and to discuss the sequent influence of subretinal fluid on postoperative visual acuity.Methods A retrospective analysis was carried out on 66 cases of rhegmatogenous RD in Peking University People's Hospital from January 2010 to January 2013.All the cases were divided into 2 groups:scleral buckling group and PPV group.The courses of disease,refractive status,best corrected visual acuity (BCVA) and complications were recorded.The duration of subretinal fluid and ellipsoid zone integrity in macula were observed and the occurrence rates of subretinal fluid were calculated 1 month after surgery.Results There were no statistic differences on age,gender,courses of disease,refractive status and LogMAR visual acuity (all at P＞0.05).The average duration of subretinal fluid was (96 ±60) days in scleral buckling group,and (21 ±6) days in PPV group,with a statistically significant difference between the two groups (t =7.966,P =0.000).The occurrence rate of subretinal fluid at 1 month after surgery was 78.6％ in the scleral buckling group and 12.5％ in the PPV group,with a statistically significant difference between the two groups (x2=26.891,P =0.000).The LogMAR visual acuity was significantly different between the patients with and without subretinal fluid at 1 month after scleral buckling surgery (t=3.185,P=0.003).The LogMAR visual acuity was not significantly different between the scleral buckling group and PPV group 6 months after scleral surgery (t =1.876,P =0.065).The LogMAR visual acuity was not significantly different between the patients with and without subretinal fluid at 6 month after scleral buckling surgery (t =1.755,P=0.087).After the subretinal fluid was reabsorbed,the LogMARs visual acuity were significantly different between the patients with intact ellipsoid zone and with disrupt ellipsoid zone in both groups (scleral buckling group:t=2.555,P=0.015;PPV group:t=4.005,P=0.001).Conclusions The disruption extent of the ellipsoid zone is related to the duration of RD,and the integrity affects the postoperative visual acuity distinctly.The subretinal fluid is removed more rapidly after PPV when compared with scleral buckling in macula-off rhegmatogenous RD.The subretinal fluid delays visual recovery postoperatively but the operation method does not influence final visual acuity seriously.

Association between Microperimetric Parameters and Optical Coherent Tomographic Findings in Various Macular Diseases

PURPOSE: To analyze the correlation between microperimetric parameters and optical coherent tomographic findings in the eyes of patients with macular diseases. METHODS: A total of 64 eyes were included in this retrospective cross-sectional study. Differences in the macular integrity index and microperimetric parameters were analyzed according to types of outer retinal band defects. Correlations between average threshold values and retinal thickness in the corresponding areas were analyzed. Finally, microperimetric parameters were compared between inner and outer retinal lesions. RESULTS: Measures of best-corrected visual acuity, macular integrity index, and average threshold values were significantly worse in eyes with defects in the ellipsoid portion of the photoreceptor inner segment (ISe), the cone outer segment tip (COST), and the external limiting membrane (ELM) than in eyes without ISe, COST, and ELM defects. Also, visual functionality is more significantly impacted by ELM defects than by other hyper-reflective band defects. There was a significant negative correlation between retinal thickness and the average threshold of the corresponding area in the Early Treatment Diabetic Retinopathy Study grid. Microperimetric parameters in the eyes of patients with inner retinal lesions were better than in the eyes of patients with outer retinal lesions. CONCLUSIONS: The macular integrity index may be a useful factor for reflecting the functional aspects of macular diseases. Specifically, ELM, ISe, and COST defects are significantly associated with poor retinal sensitivity and macular integrity index values that suggest abnormalities. Among eyes with these particular defects, the visual functionality of patients is most sensitively impacted by ELM defects. This finding suggests that microperimetric parameters are sensitive and useful for evaluating functional abnormalities in the eyes of patients with macular disease, particularly in patients with outer retinal pathology.

Fine structure and circulation of spleen ellipsoid in Pelodiseus sinensis / 解剖学报

Objective To examin and analyze the structure, ultrastructure and the circulation of the spleen ellipsoid in the soft-shelled turtle, Pelodiseus sinensis. Methods Twelve turtles were used and observed by light- and electron-microscopy and injection of ink suspension in this study. Results The spleen white pulp was consisted of the periarteriolar lymphatic sheath (PALS) and periellipsoidial lymphatic sheath (PELS). There was no lymphoid nodule in the spleen. Red pulp included splenic cords and splenic sinusoids. The marginal zone was not found in the turtle spleen. When the central arteriole left out of the PALS, it divided into several ellipsoid capillaries which were surround by the PELS. The end of the ellipsoid capillary opened directly to the splenic cord and the blood cells then entered into the splenic sinusoid through the gap between the endothelial cells. The ellipsoid capillary was consisted of simple cuboidal epithelium with an uncompleted basement membrane. The ellipsoid wall was consisted of supporting cells,ellipsoid-associated cells and reticular fibres. Lymphocytes and red cells were always found on the ellipsoid wall. After 40min of the injection of ink suspesion, much carbon particles of ink were restricted on the wall. Conclusion The ellipsoid capillary in the soft-shelled turtle, just like the high endothelial venule, was the important passage of the lymphocytes and blood cells going out and into the lymph tissue. The splenic circulation in the turtle belongs to the opening model.

Effect of three-cell latrine and methane tank for eliminating eggs of Schistosoma japonicum / 中国血吸虫病防治杂志

Objective To understand the effect of the three-cell latrine and B-type tilted ellipsoid methane tank for eliminating eggs of schistosome in different seasons and temperatures in order to evaluate their values for popularization and application in schistosomiasis endemic areas.Methods The eggs of schistosome collected from infected rabbits were put into the three-cell latrines and methane tanks in different seasons.The miracidia were observed and counted after collecting the eggs for hatching experiments on the 5th,10th,15th,20th,25th,30th,40th,50th,and 60th day,respectively.Results In the three-cell latrine,the time of eliminating eggs completely in the fecal residue in winter,spring(autumn),and summer was 50,30,15 days,respectively,and the time of completely eliminating 100 eggs of schistosome was 40,20,10 days,respectively.Correspondingly,in the methane tank,the time of eliminating eggs completely in the fecal residue in winter,spring(autumn),and summer was 30,15,10 days,respectively,and the time of completely eliminating 100 eggs of schistosome was 20,15,5 days,respectively.Conclusions The three-cell latrine and B-type tilted ellipsoid methane tank could effectively eliminate schistosome eggs in human and animal excreta and achieve the national hygienic standard on night soil in the endemic areas of Jiangxi Province.