Relation of diabetic macular edema to cytokines and posterior vitreous detachment

PURPOSE: To investigate whether angiotensin II (AII) or vascular endothelial growth factor (VEGF) is related to diabetic macular edema (DME) in patients with and without posterior vitreous detachment (PVD). DESIGN: A case-control study. METHODS: Vitreous fluid samples were obtained at vitreoretinal surgery from 28 eyes of 28 DME patients without PVD, 8 eyes of 8 DME patients with PVD, 14 eyes of 14 nondiabetic patients, and 8 eyes of diabetic patients without retinopathy. The VEGF levels in vitreous fluid and plasma were determined by enzyme-linked immunosorbent assay, while AII levels were measured by radioimmunoassay.RESULTS: The vitreous levels of AII and VEGF were significantly higher in DME patients with or without PVD than in nondiabetic patients or diabetic patients without retinopathy (without PVD: P < .0061, P < .0001, P = .0261, and P < .0001; with PVD: P < .0012, P < .0001, P = .0473, and P < .0001, respectively). There was no significant difference in the vitreous levels of AII or VEGF between patients with or without PVD (P = .4948 and P = .6642, respectively). The vitreous level of AII significantly correlated with that of VEGF in DME patients without PVD (P = .576) or with PVD (P = .488). AII and VEGF levels in vitreous fluid were significantly higher than the respective plasma levels. CONCLUSIONS: We found that the vitreous levels of AII and VEGF were elevated in DME patients irrespective of the status of PVD. Angiotensin II and VEGF may be induced in the eyes and be related to the pathogenesis of DME.     

Vitrectomy for diabetic cystoid macular edema

PURPOSE: We evaluated the visual outcome of vitrectomy for diabetic cystoid macular edema. METHODS: Visual outcome and factors which may influence final visual acuity were assessed and documented retrospectively in 45 eyes of 40 patients, all of whom were followed for at least 6 months postoperatively. RESULTS: Final postoperative visual acuity was two or more lines better than preoperative visual acuity in 58%, within one line in 40%, and had decreased by two lines or more in 2%. A final postoperative visual acuity of 0.5 or better was achieved in 38%. Preoperative visual acuity and the extent of the cystoid space on fluorescein angiography were significantly related to final visual acuity. A final postoperative visual acuity of 0.5 or better was noted in 8% of eyes with a preoperative visual acuity below 0.1, in 50% of eyes with preoperative visual acuity of 0.1 or better, in 71% of eyes with a cystoid space smaller than 5 disc areas, and in 20% of eyes with a cystoid space of 5 disc areas or more. The posterior vitreous membrane condition did not influence final visual acuity. There were no complications which decreased visual acuity. CONCLUSION: Based on the above results, we conclude that diabetic cystoid macular edema is a good indication for vitrectomy regardless of the posterior vitreous membrane condition. A preoperative visual acuity of 0.1 or better and/or a cystoid space smaller than 5 disc areas may be indications for surgery aimed at achieving a final postoperative visual acuity of 0.5 or better.     

Vitrectomy for refractory diabetic macular edema

Diabetic macular edema may occur or worsen as a consequence of vitreomacular traction in some eyes. The precise role of the posterior hyaloid in the pathogenesis of diabetic maculopathy remains unclear. The determination of which eyes might benefit from vitrectomy is the most challenging aspect in the treatment of this condition. Fluorescein angiography, B-scan untrasonography, and optical coherence tomography may be helpful in this regard. Most often, vitreous surgery is performed when diabetic macular edema persists despite multiple laser treatments. All reports published to date regarding vitrectomy for diabetic macular edema are uncontrolled and nonrandomized patient series. Visual improvement after vitrectomy is related to the duration of edema, as well as the extent of intraretinal lipid and vascular nonperfusion.     

Vitrectomy for diabetic cystoid macular edema

PURPOSE: We evaluated visual outcomes following vitrectomy for diabetic cystoid macular edema. METHODS: Visual outcomes and factors possibly influencing final visual acuity were assessed and documented retrospectively in 45 eyes of 40 patients, all of whom were followed up for at least 6 months postoperatively. RESULTS: Compared with the preoperative logarithm of the minimum angle of resolution (logMAR) visual acuity, final logMAR visual acuity improved 0.2 or more in 51% of the eyes, was unchanged in 47%, and decreased 0.2 or more in 2%. A final postoperative visual acuity of 0.5 or better was achieved in 38%. Preoperative visual acuity and the extent of the cystoid space on fluorescein angiography were significantly related to final visual acuity. A final postoperative visual acuity of 0.5 or better was noted in 8% of eyes with a preoperative visual acuity below 0.1, in 50% of eyes with a preoperative visual acuity of 0.1 or better, in 71% of eyes with a cystoid space smaller than 5 disc areas, and in 20% of eyes with a cystoid space of 5 disc areas or more. The state of the posterior vitreous membrane did not influence final visual acuity. There were no complications that decreased visual acuity. CONCLUSIONS: We conclude that diabetic cystoid macular edema is a good indication for vitrectomy, regardless of the state of the posterior vitreous membrane. A preoperative visual acuity of 0.1 or better and/or a cystoid space smaller than 5 disc areas may be indications for surgery aimed at achieving a final postoperative visual acuity of 0.5 or better.     

The influence of spontaneous posterior vitreous detachment in resolution of diabetic macular edema in NIDDM

PURPOSE: To establish the influence of posterior vitreous detachment on development and resolution of diabetic macular edema in NIDDM. To asses the posterior vitreous detachment role in argon laser treatment of diabetic macular edema. MATERIAL AND METHODS: Retrospective study. RESULTS: 68 eyes of 36 patients were involved into the study, 52 eyes (76.5%) with macular edema and 16 eyes (23.5%) without macular edema. Posterior vitreous detachment (PVD) was present in 62.5% of cases without macular edema, and only 30.77% of cases had macular edema. Laser treatment applied in accordance to general standards cased resolution of macular edema in all cases with posterior vitreous detachment. In group with no spontaneous posterior vitreous detachment, macular edema resolved only in 19.23% of cases. CONCLUSIONS: Diabetic macular edema is less common in eyes with spontaneous posterior vitreous detachment. This observation shows, that not only vascular factor but also vitreo-macular tractions are responsible for macular pathology in diabetic macular edema. The efficacy of standard argon laser treatment depends also on vitreo-macular relation--presence of PVD, and is more sufficient in eyes with posterior vitreous detachment.     

Vitrectomy in diabetic macular edema

Macular edema remains one of the important therapeutic issues. Vitero-macular tractions are said, to be the cause of persistent, non responding to laser treatment diabetic macular edema. Surgical removal of these tractions is used in treatment of non resolving macular edema. However, vitrectomy in treatment of diabetic macular edema remains the experimental, method requiring further studying.     

The role of the vitreous in diabetic macular edema

The authors assessed retrospectively clinical records of 76 patients (125 eyes) 60 years of age or older with diabetic retinopathy who had undergone a vitreous examination. The groups consisted of 105 eyes (63 patients) with macular edema and 20 eyes (13 patients) without macular edema. Vitreous studies were done using the El Bayadi-Kajiura lens to determine whether or not the posterior vitreous was attached to the retina in the macula. Twenty-one of 105 eyes (20.0%) in the edema group and 11 of 20 eyes (55.0%) in the no-edema group had a detached posterior vitreous. This difference was found to be statistically significant, indicating that diabetic cases without macular edema have a significantly higher rate of posterior vitreous detachment than those with macular edema. This study demonstrates that the vitreous may play a role in diabetic macular edema.     

Vitrectomy for diabetic macular edema associated with a taut premacular posterior hyaloid

Diabetic macular edema represents an important cause of visual loss in patients with diabetes. Although the pathophysiology of diabetic macular edema is unknown, various demographic, metabolic, and systemic factors have been implicated. More recently, the role of the posterior vitreomacular relationship has been evaluated, and studies suggest that posterior vitreous separation confers a protective effect on the development of diabetic macular edema. Furthermore, vitreomacular separation occurring in eyes with diabetic macular edema may facilitate spontaneous resolution of the edema and improvement in visual acuity. In a subset of patients, diffuse diabetic macular edema can result from a taut and condensed posterior hyaloid and often responds poorly to focal or grid-pattern laser photocoagulation. Previous studies have reported favorable results following vitrectomy and peeling of the posterior hyaloid in such cases.     

Vitrectomy for diabetic macular edema with and without internal limiting membrane removal

PURPOSE: To compare the efficacy of surgically removing or not removing the internal limiting membrane (ILM) during pars plana vitrectomy on the visual acuity and retinal thickness in eyes with diabetic macular edema. METHODS: A prospective, case-control study was carried out on 30 eyes of 29 patients undergoing pars plana vitrectomy for diabetic macular edema. Fifteen eyes underwent pars plana vitrectomy with ILM removal and 15 eyes without ILM removal. RESULTS: In 7 of 15 eyes (47%) in the ILM-removed group, the visual acuity improved by 0.2 or more log of the minimum angle of resolution (log MAR) units and remained unchanged in 8 eyes (53%). In the ILM-preserved group, the final visual acuity improved in 9 of 15 eyes (60%) and remained unchanged in 6 eyes (40%). The difference in visual acuity between the two groups after 11 months the surgery was not significant (Fisher's exact test, p=0.4938). In the ILM-removed group, the final retinal thickness decreased by more than 20% of the preoperative retinal thickness in 12 of 15 eyes (80%), remained unchanged in 2 of 15 eyes (13%), and increased in 1 of 15 eyes (7%). In the ILM-preserved group, the final retinal thickness decreased in 13 of 15 eyes (87%) and remained unchanged in 2 of 15 eyes (23%). The differences in the changes in the retinal thickness between the two groups were not statistically significant (Fisher's exact test, p=0.5945). CONCLUSION: Vitrectomy in eyes with diabetic macular edema without ILM removal was as effective in reducing the retinal thickness and improving the visual acuity as eyes with ILM removal. We conclude that ILM need not be removed to treat eyes with diabetic macular edema.     

Vitrectomy for diabetic macular traction and edema associated with posterior hyaloidal traction.

Pars plana vitrectomy with separation of the posterior hyaloid was performed in 10 eyes with diabetic macular edema and traction associated with a thickened and taut premacular posterior hyaloid. Nine of the 10 eyes had previous macular photocoagulation. Preoperative fluorescein angiography showed a deep and diffuse pattern of leakage in the macula. Intraoperatively, the attached and thickened posterior hyaloid was lifted and separated from the retina. Postoperatively, vision improved in nine eyes. The macular traction and edema resolved in eight eyes and decreased in two. Complications included a vitreous hemorrhage, a rhegmatogenous retinal detachment, cataract formation, and a mild epimacular membrane, each occurring in one eye. Vitreous surgery can improve the visual prognosis of some eyes with diabetic macular traction and edema associated with a thickened and taut posterior hyaloid.     

玻璃体切除术治疗糖尿病黄斑水肿

目的　探讨玻璃体切除术治疗糖尿病黄斑水肿的效果。方法　对 70例 (10 9只眼 )糖尿病黄斑水肿进行了回顾性地分析 ,所有病例均接受了玻璃体切除术 ,其中 32例 (48只眼 )同时接受了眼内光凝治疗 ,对术前、术后平均视力变化情况进行了比较。结果　玻璃体切除术后 6 4.2 2 %病例视力得到提高 ,术后平均视力较术前显著提高(P <0 .0 0 1)。结论　玻璃体切除术是治疗糖尿病黄斑水肿的有效方法。     

Vitrectomy for traction macular detachment in diabetic retinopathy

Background: A small number of eyes with proliferative diabetic retinopathy develop massive central fibrovascular membranes characterized by vitreoretinal tractions along the arcades and optic disk and retinal traction lines extending through the macula. The aim of our study was first to present the results of vitrectomy for removal of these central membranes and second to determine the correlation between preoperative parameters and postoperative visual outcome. Subjects and methods: We treated 28 eyes with severe central fibrovascular diabetic membranes by a modified bimanual en bloc excision technique during vitrectomy. Preoperative examination included general status, visual acuity, slit-lamp investigation, binocular funduscopy, ultrasound investigation and visual evoked potentials (VEP). Further, we analyzed intraoperative complications and postoperative anatomic and functional outcomes. Results: The retinas of 27 eyes with central traction retinal detachments were reattached by surgery. With a minimum of 6 months' follow-up, the macula remained attached in 24 eyes, while the retinas were completely attached in 22 eyes. Preoperative visual acuity was defective light perception to 0.1; an increase in visual acuity to maximal 0.1 was seen in 50% of the patients postoperatively. Preoperative visual acuity of light perception was associated with no functional improvement. Preoperative ultrasound investigation gave information about the real anatomic situation of the retina, especially if funduscopy was not possible. The other preoperative parameters could not predict correctly the functional outcome of vitrectomy in diabetics with severe central fibrovascular membranes because of the damage of the optic nerve and the retina. Conclusions: The high rate of anatomical rettachment after vitrectomy in diabetic eyes with severe central fibrovascular membranes is associated with a slight improvement of function; only preoperative visual acuity of hand motions or better was associated with an improvement of function.     

Internal limiting membrane peeling in vitreous surgery for diabetic macular edema

PURPOSE: To evaluate the effect of internal limiting membrane (ILM) peeling in vitreous surgery for diabetic macular edema. METHODS: This study was done on 135 eyes of 103 patients who all underwent diabetic macular edema surgery under the same surgeon. The subjects were 74 eyes of 55 males and 61 eyes of 48 females, aged 35-81 years, with an average of 62 years. The postoperative follow-up period ranged from 12 to 39 months, with an average of 20 months. The ILM peeling was performed in 74 eyes. The subjects were divided in two types of macular edema from the presence (type II, 81 eyes) or absence (type I, 54 eyes) of hard exudates in the macular region. We evaluated the effects of the ILM peeling on the absorption rate of macular edema, the period required for absorption of macular edema, and the postoperative visual acuity. RESULTS: The absorption rate of macular edema was more than 90% with or without the ILM peeling. The period required for absorption of macular edema in eyes with ILM peeling was shorter in type II. There was no difference in the postoperative visual acuity with or without ILM peeling. ILM peeling was not an important factor for the postoperative visual acuity. RESULTS: ILM peeling accelerates the absorption of edema in more severe diabetic macular edema, but we could not find any improvement of visual acuity.     

Visualization of the posterior vitreous membrane in diabetic macular edema patients using three-dimensional optical coherence tomography

PURPOSE: To study the visualization of the vitreoretinal interface in diabetic macular edema patients using three-dimensional optical coherence tomography (3 D-OCT) and to compare it to surgical findings. METHODS: We prospectively examined the medical records of 25 patients (30 eyes) with diabetic macular edema measured by 3 D-OCT (optic disc and macular lesions) who received vitrectomy between August 2006 and February 2007. We compared the findings of 3 D-OCT to the findings during surgery using triamcinolone acetonide. RESULTS: Posterior vitreous membrane was found in 18 eyes using 3 D-OCT. The findings in all cases corresponded to operative findings. Six cases were characterized by posterior vitreous membrane attached to the optic disc and macular area. Twelve cases were characterized by posterior vitreous membrane diffusely attached to the posterior pole. CONCLUSIONS: Vitreoretinal interfaces were visualized using 3D-OCT and confirmed by operative findings. 3 D-OCT is an effective tool to determine the pathogenesis of diabetic macular edema.