Macular epiretinal membranes

Epiretinal membranes (ERM) are a common finding in older patients. Although they may be associated with numerous clinical conditions, most epiretinal membranes occur in the absence of ocular pathology. Patients symptoms range from asymptotic to complaints of severe vision loss and metamorphopsia. Epiretinal membranes are commonly classified according to their density, to the severity of retinal distortion and to associated biomicroscopic changes. Pars plana vitrectomy has been found to be effective in removing ERM from the macula, improving the visual acuity and decreasing metamorphopsia. Both idiopathic and secondary ERMs do well after surgery, although secondary ERMs showed a greater amount of improvement than idiopathic ones. Complications are frequent including accelerated postoperative nuclear sclerosis, retinal breaks and RD, macular edema, RPE and, occasionally, macular hole and hypotony. However only RD involving the macula have a worsening prognosis on final outcome.     

Plasminogen activation in epiretinal membranes

Background: Formation of epiretinal membranes occurs in proliferative vitreoretinopathy, macular pucker and after penetrating trauma. Epiretinal membrane formation includes cell migration and proliferation, extracellular matrix formation and tissue contraction. Generally in scar tissue formation, the production of new extracellular matrix occurs concomitantly with its proteolytic degradation, resulting in continuous tissue remodelling. The plasminogen activator-mediated proteolytic cascade is an important mechanism for pericellular degradation of the extracellular matrix. Therefore we wanted to study the presence of the plasminogen activator-mediated proteolytic cascade in epiretinal membranes. Methods: Specimens of 18 epiretinal and 3 subretinal membranes were obtained during vitreous surgery for retinal detachment with proliferative vitreoretinopathy or macular pucker. Plasminogen activators and plasmin were characterized in frozen sections of epiretinal membranes by in situ zymography and in membrane lysates by zymography. Indirect immunofluorescence staining was performed to localize urokinase in epiretinal membranes. Results: Urokinase was present in 17/21 and tissue-type plasminogen activator in 12/21 of the membranes studied. Active plasmin was not detected in the frozen sections of epiretinal membranes. Immunofluorescence staining localized urokinase predominantly in the areas invaded by macrophages and cells of retinal pigment epithelial origin. Conclusion: Our results demonstrate the presence of proteolytic activity in periretinal scar tissue. Urokinase was more consistently present, but smaller amounts of tissue-type plasminogen activator were also found in the specimens. These results indicate that continuous tissue remodelling with simultaneous extracellular matrix production and breakdown regulates the growth of epiretinal membranes.     

视网膜表面膜的超微结构特征

目的 探讨视网膜收缩膜细胞与胶原作用的超微结构特征及细胞外间质的作用。方法 对１６例孔源多膜脱离伴增殖性玻璃体视网膜病变（ｐｒｏｌｉｆｅｒａｔｉｖｅ ｖｉｔｒｅｏｒｅｔｉｎｏｐａｔｈｙ,ＰＶＲ）患者行玻璃体切除术,并应用免疫胶体金标记技术对术中获得的视网膜表面膜进行细胞外间质（ｅｘｔｒａｃｅｌｌｕｌａｒ ｍａｔｒｉｘ,ＥＣＭ）－－Ⅰ和Ⅲ型胶原及纤维粘连蛋白（ｆｉｂｒｏｎｅｃｔｉｏｎ,ＦＮ）的免疫电     

Surgical removal of epiretinal membranes

In this paper we present the results of fiftheen consecutive patients who underwent vitrectomy surgery for epiretinal membranes in the posterior pole of the eye, resulting in a visual improvement in 75% of the cases. Complaints of metamorphopia disappeared or decreased considerably in nearly all cases.     

Aniseikonia associated with epiretinal membranes

AIMS: To determine whether the computerised version of the new aniseikonia test (NAT) is a valid, reliable method to measure aniseikonia and establish whether aniseikonia occurs in patients with epiretinal membranes (ERM) with preserved good visual acuity. METHODS: With a computerised version of the NAT, horizontal and vertical aniseikonia was measured in 16 individuals (mean 47 (SD 16.46) years) with no ocular history and 14 patients (mean 67.7 (14.36) years) with ERM. Test validity was evaluated by inducing aniseikonia with size lenses. Test reliability was assessed by the test-retest method. RESULTS: In normal individuals, the mean percentage (SD) aniseikonia was -0.24% (0.71) horizontal and 0% (0.59) vertical. Validity studies revealed mean (SD) 0.990 (0.005) horizontal and 0.991 (0.004) vertical correlation coefficients, 0.985 (0.111) horizontal and 0.989 (0.102) vertical slope. Repeatability coefficients were 1.04 horizontal and 0.88 vertical. Aniseikonia in patients with ERM ranged from 4% to 14%. Eight patients showed 2% or more size difference between horizontal and vertical meridians. CONCLUSIONS: The aniseikonia test used in this study can be considered a simple, fast, valid and reliable method to measure the difference in image size perceived by each eye. Aniseikonia does occur in symptomatic patients with ERM. The effect of ERM on image size is heterogeneous across the retinal area affected.     

玻璃体手术后黄斑视网膜前膜形成的临床分析

探讨玻璃体手术后黄斑视网膜前膜MacularEpiretinalMembranes (MEM )的形成时期、原因及对视功能的影响。方法 :回顾性分析了我院视网膜脱离患者 2 49例 ( 2 49眼 )行玻璃体视网膜复位手术后形成MEM的 5 1例 ( 5 1眼 )的临床资料 ,观察术后视力恢复及MEM形成情况 ,平均随访时间 4 82月。结果 :术后视力提高 34眼占 6 6 7% ,视力不变 10眼占 19 6 % ,视力下降 7眼占 13 7% ,视力于 12周后趋于稳定。MEM最早于术后 2周出现 ,随病程延长而明显增殖 ,于 8～ 12周达到高峰 ,12周后基本稳定。视网膜最终复位 48眼占 94 1%。结论 :玻璃体手术后MEM的形成是多种因素共同作用的结果 ,术前仔细检查玻璃体后脱离 (PosteriorVitreousDetachment ,PVD)状态 ,术中避免对视网膜过度损伤是防止术后MEM形成的关键 ;无论有无PVD ,部分病例均可发生MEM ,两者的病理机制及膜的超微结构有待于进一步观察。     

Complications of surgery for epiretinal membranes

· Purpose: Surgery has been successful in removing epiretinal membranes (ERM) from the macula, allowing some improvement in vision in 80–90% of patients; however, complications are relatively frequent. We conducted a retrospective study to evaluate the rate of peri- and postoperative complications and their influence on functional outcome of eyes having been operated on for ERM. · Material and methods: Preoperative findings, intraoperative and postoperative complications as final results of 70 consecutive cases of idiopathic or secondary ERM operated on by the same retina surgeon were analyzed. · Results: In all cases the ERMs were succesfully removed from the fovea. The mean visual acuity (VA) increased from 0.34±0.2 to 0.54±0.31 (P<0.05) postoperatively. Idiopathic and secondary ERM both showed significant improvement after surgery. Complications included intraoperative hemorrhage and retinal tears and postoperative progressive nuclear sclerosis, retinal tears causing detachments, macular edema and retinal pigmentary epitheliopathy. Final VA was not significantly different from the mean after complications, apart from when retinal detachments involved the macular area. · Conclusions: Performing surgery for ERM is worthwhile in eyes with major decreased VA and in eyes with metamorphopsia but only moderately reduced vision. Postoperative complications are frequent but can usually be managed successfully. Of them, only retinal detachment has a negative effect on the final functional outcome. Received: 8 July 1997 Accepted: 20 November 1997     

Clinicopathologic correlation of pigmented epiretinal membranes

We performed clinicopathologic correlation on ten surgically removed pigmented epiretinal membranes causing macular pucker. All cases occurred in eyes with existing retinal holes or tears, including eight cases of macular pucker after previous retinal detachment. These cases probably represented a limited form of proliferative vitreoretinopathy. All membranes contained pigment epithelial cells with polarity, basement membrane, and melanosomes. Cytoplasmic melanin granules accounted for the clinical feature of pigmentation in these eyes.     

Surgical management of idiopathic epiretinal membranes

The authors reviewed 33 consecutive cases of idiopathic epiretinal membranes removed by vitreous surgical techniques. Visual acuity improved in 79% of surgically treated eyes. In uncomplicated cases, a 47% gain in visual acuity was achieved. Of those eyes that had improved visual acuity post-operatively, 82.5% of the final visual acuity returned by four to eight weeks post-operatively. Eyes with opaque membranes had visual acuity results no worse than those with translucent membranes. Eyes with no pre-operative cystoid edema had better visual acuity results than eyes with cystoid macular edema (CME), although no statistically significant difference was shown. Surgical removal of membranes decreased fluorescein dye leakage in 30% of eyes; while no change in post-operative leakage was noted in 60%, one eye had increased CME post-operatively. Complications included development of nuclear sclerotic cataract, retinal breaks, retinal detachment, and one case of pigment epithelial/retinal burn from the endoilluminator, residual and recurrent membrane formation, and anterior ischemic optic neuropathy.     

Perifoveal microcirculation in eyes with epiretinal membranes

BACKGROUND/AIMS: Eyes with epiretinal membranes (ERMs) often have alterations of retinal vessels. The authors studied perifoveal microcirculation in eyes with epiretinal membranes (ERMs) using scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured as an index of perifoveal microcirculation by SLO fluorescein angiography in 26 eyes with ERMs (19 eyes with idiopathic epiretinal membranes, seven eyes with epiretinal membranes after retinal detachment surgery) before and 6 months after vitreous surgery, and in 23 healthy control subjects. RESULTS: The mean CFV was significantly reduced in eyes with ERMs compared with healthy controls (p=0.012), and the postoperative mean CFV was significantly increased compared with the preoperative mean CFV (p=0.041). CONCLUSION: Significant changes of capillary blood flow velocity in the perifoveal areas were observed between normal subjects and eyes with epiretinal membranes. This indicates that eyes with ERMs show abnormal haemodynamics in the perifoveal capillaries.     

Osteopontin in vitreous and idiopathic epiretinal membranes

Graefe's Archive for Clinical and Experimental Ophthalmology - To investigate osteopontin (OPN) expression in vitreous and in related idiopathic epiretinal membranes (ERMs), with respect to...     

Quantification of metamorphopsia in patients with epiretinal membranes

PURPOSE: To quantify the degree of metamorphopsia in patients with idiopathic epiretinal membranes (ERMs), by use of a new metamorphopsia chart (M-CHARTS) developed by the authors. METHODS: These M-CHARTS had 19 dotted lines with dot intervals of between 0.2 degrees (fine) and 2.0 degrees (coarse) visual angles. As the dot intervals were changed from fine to coarse, a decrease in the severity of metamorphopsia was noted. In this study, the minimum visual angle of the dotted lines needed to cause the metamorphopsia to disappear was measured in 51 eyes of 51 patients with ERM. The metamorphopsia scores were compared with the stages of ERM classified by scanning laser ophthalmoscope (SLO) images. RESULTS: In patients with ERM, the metamorphopsia score increased depending on the severity of membrane proliferation classified by SLO images. The scores obtained from the horizontal dotted lines were larger than those of the vertical lines in advanced stages of ERM. CONCLUSIONS: M-CHARTS provide a very simple and useful method for evaluating the severity of metamorphopsia in patients with ERM.     

Secondary complications in surgery of epiretinal membranes]

MATERIAL AND METHODS: Preoperative findings, intraoperative and postoperative complications as final results of 70 consecutive cases of idiopathic or secondary ERM operated by the same retina surgeon were analyzed. RESULTS: In all cases the ERMs were successfully removed from the fovea. The mean v.a. increased from 0.34 +/- 0.2. to 0.54 +/- 0.31, (p < 0.05) postoperatively. Idiopathic and secondary ERMs both showed significant improvement after surgery. Complications included intraoperative hemorrhage and retinal tears. Postoperative progressive nuclear sclerosis, retinal tears causing detachments, macular edema and retinal pigmentary epitheliopathy. CONCLUSIONS: Performing surgery for ERMs is worthwhile on eyes with major decreased v.a. and on eyes with metamorphopsia but only moderately reduced vision. Postoperative complications are frequent but can usually be managed successfully. Of them only retinal detachment is of some worse prognosis on the final functional outcome.     

Vitreoretinal juncture —Simple epiretinal membranes

Summary Simple epiretinal membranes are delicate cellular membranes occurring at the vitreoretinal juncture. They produce no symptoms or macroscopically detectable change, but are a common microscopic finding in enucleated eyes. The ultrastructural features of these membranes were studies in eight eyes surgically enucleated for unrelated ocular conditions or for orbital lesions. Simple epiretinal membranes are composed exclusively of glial cells. Evidence is presented that these cells derive from accessory glia of the superficial retina which react to a variety of stimuli and migrate through breaks in the retinal surface (which may later heal). This pathogenic sequence is discussed in light of present knowledge of retinal accessory glia and their role in retinal disease. This investigation was supported in part by Public Health Service research grants EY 00331 and EY 00725 from the National Eye Institute, National Institutes of Health.