Teiko Yamamoto

Vitrectomy for Diabetic Macular Edema: The Role of Posterior Vitreous Detachment and Epimacular Membrane

PURPOSEnTo evaluate the surgical efficacy of pars plana vitrectomy on eyes with diabetic macular edema in the presence or absence of a complete posterior vitreous detachment and with or without an epimacular membrane.nnnMETHODSnPars plana vitrectomy was performed on 30 eyes of 29 cases with diabetic macular edema. Visual acuity was measured, and retinal thickness was determined by optical coherence tomography before and after vitrectomy. To evaluate the relationship between the effects of vitrectomy and the presence or absence of posterior vitreous detachment and/or epimacular membrane, all eyes were placed into one of four groups: group A, eyes with posterior vitreous detachment and epimacular membrane; B, eyes with posterior vitreous detachment and without epimacular membrane; C, eyes without posterior vitreous detachment and with epimacular membrane; and D, eyes without posterior vitreous detachment and without epimacular membrane. The expression of vascular endothelial growth factor and interleukin-6 was investigated immunohistochemically in epimacular membrane specimens obtained from seven eyes with diffuse diabetic macular edema.nnnRESULTSnThe postoperative mean visual acuity (0.653 +/- 0.350: mean +/- SD logarithm of minimal angle of resolution [logMAR]) was significantly better than the mean preoperative visual acuity (0.891 +/- 0.319 logMAR; Wilcoxon signed-rank test, P =.0007). The postoperative foveal thickness (264.5 +/- 118.6 microm) was significantly thinner than the preoperative foveal thickness (477.8 +/- 147.7 microm; Wilcoxon signed-rank test, P <.0001). There were no significant differences in the improvement of visual acuity and decrease of foveal thickness between the four groups (Kruskal-Wallis test, P =.13, P =.65, respectively). All of the epimacular membranes obtained at surgery expressed vascular endothelial growth factor and interleukin-6.nnnCONCLUSIONSnThese results demonstrated that vitrectomy with removal of epimacular membrane is generally an effective procedure in reducing diabetic macular edema, and the outcome does not depend on the presence absence of posterior vitreous detachment and epimacular membrane.

Early postoperative retinal thickness changes and complications after vitrectomy for diabetic macular edema

PURPOSEnTo determine the early postoperative changes in retinal thickness and complications after pars plana vitrectomy for diabetic macular edema.nnnDESIGNnConsecutive interventional case series.nnnMETHODSnStudied retrospectively, pars plana vitrectomy was performed on 65 consecutive eyes of 63 patients with diabetic macular edema. The follow-up interval ranged from 6 to 36 months (12.6 +/- 7.4 months [mean +/- standard deviation (SD)]). The indications of pars plana vitrectomy in this study were (1) diffuse diabetic macular edema, (2) preoperative visual acuity less than 20/40, and (3) noneffective macular photocoagulation therapy. Preoperative and postoperative examinations by stereoscopic biomicroscopy, color fundus photography of the macula and optical coherence tomography (OCT) were performed on all eyes. Preoperatively, direct photocoagulation to microaneurysms in the macula had been performed in 48 eyes, and focal/grid photocoagulation had been performed in five eyes. Preoperative examination showed that epiretinal membranes were observed in 20 eyes, cystoid macular edema in 40 eyes, and 23 eyes had a complete posterior vitreous detachment (PVD). Epimacular membranes, removed during surgery, were examined histopathologically.nnnRESULTSnThe postoperative mean best-corrected visual acuity (logarithm of the minimum angle of resolution [logMAR] = 0.696 +/- 0.491 [mean +/- SD]) was significantly better than the preoperative mean best-corrected visual acuity (0.827 +/- 0.361; P <.0001; Wilcoxon signed-rank test). The final visual acuity improved by 2 or more lines in 32 of 65 eyes (45%), remained unchanged in 32 of 65 eyes (49%), and exacerbated after the surgery in 4 of 65 eyes (6%) due to neovascular glaucoma (2 eyes) and residual cystoid macular edema (2 eyes). The postoperative foveal retinal thickness (224.9 +/- 116.9 microm) at the last visit was significantly thinner than the preoperative foveal retinal thickness (463.7 +/- 177.3 microm; P <.0001; Wilcoxon signed-rank test). The foveal retinal thickness did not decrease linearly but fluctuated: The mean postoperative retinal thickness had decreased significantly 7 days after surgery, then remained unchanged for approximately 1 month, and thereafter gradually decreased until 4 months. The intraoperative and postoperative complications included peripheral retinal tear in 3 of 65 (4.6%) eyes, postoperative rhegmatogenous retinal detachment in 1 of 65 (1.5%) eyes, neovascular glaucoma in 3 of 65 (5%) eyes, recurrent vitreous hemorrhage in 1 of 65 (1.5%) eyes, hard exudates in the center of the macula in 3 of 56 (4.6%) eyes, postoperative epiretinal membrane formation in 9 of 65 (13.8%) eyes, and a lamellar macular hole in 1 of 65 (1.5%) eyes.nnnCONCLUSIONSnVitrectomy for diabetic macular edema is an effective procedure for reducing the edema and improving visual acuity. Because the postoperative reduction in retinal thickness is not complete until 4 months, the assessment of vitrectomy on foveal thickness should not be made until this time. In addition, there are severe complications from vitrectomy for diabetic macular edema, and careful preoperative and postoperative examinations and surgical methods are required.

Morphological and functional analyses of diabetic macular edema by optical coherence tomography and multifocal electroretinograms

Abstract.Purpose: To determine the correlation between the tomographic features and the visual functions of eyes with diabetic macular edema. Methods: Optical coherence tomographic (OCT) images and multifocal electroretinograms were obtained from 45 eyes of 25 patients with diabetic macular edema and from 21 eyes of 21 normal subjects. Results: The OCT images showed cystoid macular edema in 18 eyes and diffuse retinal swelling without cystoid edema in the other 27 eyes. The fovea was significantly thicker in eyes with cystoid macular edema and in those with diffuse retinal swelling than in normal eyes. The fovea of eyes with cystoid edema was significantly thicker than the fovea of eyes with diffuse swelling. The best-corrected visual acuity and the electrical response density from the macular area were significantly reduced in eyes with diabetic macular edema, particularly in those with cystoid edema. The best-corrected visual acuity and macular response density of the multifocal ERGs were inversely correlated, and the implicit times were directly correlated with foveal thickness. Conclusion: The visual acuity was correlated significantly with morphological changes revealed by OCT and with multifocal ERGs. The combination of OCT and multifocal ERGs may provide objective criteria for the evaluation and assessment of diabetic macular edema.

Macular configuration determined by optical coherence tomography after idiopathic macular hole surgery with or without internal limiting membrane peeling.

Aims: To evaluate the effect of pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling on the closure and configuration of idiopathic macular holes (IMH). Methods: PPV was performed for IMH on 44 eyes with ILM peeling (ILM peeled group) and on 42 eyes without ILM removal (ILM preserved group). Optical coherence tomography (OCT) was performed on 34 ILM peeled eyes and 14 ILM preserved eyes after successful surgery. The repaired macular holes were classified by the OCT images as being of “good shape” (nearly normal foveal contour) or “poor shape” (abnormal foveal contour with flat fovea and steep edge, or with a thick retina without a foveal pit). Results: The anatomical closure rate was significantly higher in the ILM peeled group (93.2%) than in the ILM preserved group (76.2%) (p = 0.028). In the ILM peeled group, 31 eyes had a fovea of good shape and three eyes had a fovea with a poor shape, while in the ILM preserved group, six eyes had a fovea of good shape and eight eyes had a fovea of poor shape. The percentage of eyes with good macular configuration in the ILM peeled group was significantly higher than in the ILM preserved group (p = 0.0003). No significant difference was found in the postoperative visual acuity and the increase of visual acuity between the ILM peeled group and the ILM preserved group (p = 0.26, and p = 0.91 respectively). There was also no significant difference in the postoperative visual acuity and improvement in visual acuity between eyes with a fovea of good shape and those with fovea of poor shape fovea (p = 0.99 and p = 0.66, respectively). Conclusions: ILM peeling may provide better anatomical success and recovery of the macular shape, but the postoperative visual acuity and improvement of visual acuity were not related to the morphological results.

Surgical Outcomes in Juvenile Retinal Detachment

PURPOSEnTo evaluate retrospectively clinical features and surgical outcomes of rhegmatogenous retinal detachment in juvenile patients.nnnMETHODSnBetween 1991 and 1996, 28 patients younger than 15 years of age with rhegmatogenous retinal detachment (32 eyes) underwent the first surgical procedure, scleral buckling and/or pars plana vitrectomy, at our hospital.nnnRESULTSnThe major types of juvenile detachment, in order of frequency, were idiopathic, familial exudative vitreoretinopathy, trauma, and high myopia. Proliferative vitreoretinopathy (PVR) of grade C or D was involved in 12 cases (37.5%). Among the 12 eyes with PVR, 7 attained retinal reattachment after the first surgery with scleral buckling. The overall reattachment rate was 28/32 (87.5%) after the first operation and 30/32 (93.8%) after the second operation.nnnCONCLUSIONnThese findings indicate that the reattachment rate and visual prognosis can be as good in juvenile retinal detachment as in adult cases, when appropriate surgical procedures are used.

Monocyte chemotactic protein-1 levels in the Vitreous of patients with proliferative vitreoretinopathy

PURPOSEnTo assess the potential role of monocyte chemotactic protein-1 (MCP-1) in the pathogenesis of proliferative vitreoretinopathy (PVR) and to investigate its possible interaction with the macrophage migration inhibitory factor (MIF).nnnMETHODSnWe assayed MCP-1 and MIF levels in the vitreous samples of 85 consecutive patients with PVR (29 eyes), rhegmatogenous retinal detachment (RRD; 22 eyes), and macular hole or idiopathic epimacular membrane (controls; 34 eyes), by enzyme-linked immunosorbent assay.nnnRESULTSnVitreous levels of MCP-1 were 1760.7 +/- 471.3 pg/mL (mean +/- SD) in PVR patients, 1200.4 +/- 579.8 pg/mL in RRD patients, and 436.3 +/- 286.1 pg/mL in the controls. Vitreous MCP-1 levels in PVR patients were significantly higher than those in RRD patients and in the controls (P <.0001, respectively). MCP-1 levels in grade C of PVR (1883.7 +/- 479.5 pg/mL) were significantly greater than those in grade D (1437.8 +/- 258.8 pg/mL) (P =.0112). Vitreous concentrations of MCP-1 had no correlation with those of MIF.nnnCONCLUSIONSnThe results indicate the possibility that MCP-1 may have a role mainly in the early stage of PVR and that the role of MCP-1 in PVR may differ from that of MIF.

Screening and follow-up of diabetic retinopathy using a new mosaic 9-field fundus photography system

AIMnTo evaluate the clinical usefulness of a newly developed fundus photographing system and assess its applicability to telemedicine.nnnMETHODSnNine overlapping 45 degrees fundus photographs were taken by a new camera equipped with nine internal fixation targets to provide standardized 9-field photographs. The digitally stored images were either edited in 3x3 form or reconstructed as collage (9F) and compared to the ophthalmological examination (OP) and single-field non-mydriatic photography (SC). In telemedicine, 9-field images derived from 61 adolescent diabetics were sent to ophthalmologists over an analog phone line.nnnRESULTSnThe sensitivities of the examinations by 9F without and with mydriasis (78 and 82%) were equivalent to OP (84%) and superior to SC (64%). The diagnosis of severity by 9F was also comparable to those by OP, whereas SC tended to underestimate the severity. An average of 1 min 19 s was required to send one edited 9-field photography (average size 259+/-30 KB) over the Internet. Twelve of these eyes were diagnosed as diabetic retinopathy on a desktop monitor whereas SC gave only seven.nnnCONCLUSIONnThis new 9-field fundus photography system can be appropriate for the screening and follow-up of diabetic retinopathy in adult and adolescent diabetic subjects, especially when applied to telemedicine over the Internet.

Expression and Possible Roles of Activin A in Proliferative Vitreoretinal Diseases

PURPOSEnTo examine the expression of activin A in eyes and to determine the possible functions of activin A in proliferative vitreoretinal diseases.nnnMETHODSnThe activin A concentration in vitreous specimens obtained from eyes with or without retinal ischemia was measured by a bioassay using erythroid differentiation factor effects of activin A. The expression of activin A and activin receptors in the preretinal membranes was observed by immunohistochemical analysis.nnnRESULTSnThe mean concentration of activin A in the eyes with proliferative diabetic retinopathy was 1. 50 +/- 1.27 ng/mL (mean +/- SD; n = 10), and that in the nondiabetic eyes without retinal ischemia (macular hole and epiretinal membrane) was 0.90 +/- 0.55 ng/mL (n = 5). Neither difference was significant. Activin A and its receptors were detected in the vascular endothelial cells, fibroblast-like cells and round-shaped macrophage-like cells in preretinal proliferative membranes by immunohistochemical analysis.nnnCONCLUSIONSnActivin A is involved in the proliferative membrane formation in both ischemic and nonischemic vitreoretinal proliferative diseases. Activin A, a member of TGF-beta superfamily, regulates angiogenesis and tissue fibrosis in the wound healing process.

S-cone electroretinograms in multiple evanescent white dot syndrome

Cone electroretinograms (ERGs), elicited by different color flashes under Ganzfeld conditions, were recorded from 6 patients with multiple evanescent white dot syndrome (MEWDS). All of the patients had normal color vision as determined by the Farnsworth Panel D-15 except for one who showed non-specific errors. The b-waves elicited from short wavelength sensitive (S-) cones were reduced more than the mixed long (L-) and middle (M-) wavelength sensitive cones in the affected eyes. The ratio of the S-cone b-wave amplitude of the affected eyes to that of the normal fellow eyes was significantly lower than the comparable ratio for the L- and M-cone ERG b-waves (p= 0.012). The S-cone ERGs recorded from 2 patients recovered to normal levels after their symptoms abated. These ERG results indicate that the S-cone system is more impaired than the L- and M-cone systems in the acute stage of MEWDS, and the changes in the S-cones may be reversible.

Selective reduction of S-cone response and on-response in the cone electroretinograms of patients with X-linked retinoschisis.

AbstractPurpose. To examine the electroretinograms (ERGs) of the short-wavelength-sensitive (S-) and the mixed long- and middle-wavelength-sensitive (L,M-) cones, and the ON- and OFF-responses of the cone ERGs in three patients with X-linked juvenile retinoschisis (XLRS).n Methods. Cone ERGs elicited by different color flashes and those elicited by long duration stimuli under Ganzfeld conditions were recorded from three patients with XLRS.n Results. The S-cone b-waves were undetectable to short-wavelength stimuli in all three XLRS patients, while the L,M-cone ERG b-waves were within the normal range. To long-duration white stimuli, the ON-response (b-wave) was reduced and delayed in all patients compared with that of the normal subjects, while the d-wave or OFF-response appeared normal in amplitude and implicit time.n Conclusions. These results support the hypothesis that the normal S-cone ERG arises primarily from the ON-pathway of the cone ERGs and the hypothesis that ON-bipolar cells are predominant in the S-cone system.