Morphological and functional changes of the macula after vitrectomy and creation of posterior vitreous detachment in eyes with diabetic macular edema

Yamamoto, Shuichi; Yamamoto, Tohru; Ogata, K.; Hoshino, Akiko; Sato, Eiju; Mizunoya, Satoshi

doi:10.1007/s10633-004-8056-4

Cited by 24 publications

(20 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have examined the macular function by using multifocal electroretinography (mfERG), and found that the electrical responses obtained from the macular area were also significantly correlated with the foveal thickness. 11,12 The results indicated that the mfERGs may provide an objective method to evaluate and assess DME.…”

Section: Discussionmentioning

confidence: 95%

Correlation of retinal sensitivity measured with fundus-related microperimetry to visual acuity and retinal thickness in eyes with diabetic macular edema

Okada

Yamamoto

Mizunoya

et al. 2005

Eye

108

View full text Add to dashboard Cite

Aim To determine whether significant correlations exist between retinal sensitivity measured by fundus-related microperimetry and the visual acuity and the foveal thickness measured by optical coherence tomography (OCT) in eyes with diabetic macular edema (DME). Methods A retrospective chart review of 32 eyes with DME and 17 normal healthy eyes that had undergone fundus-related microperimetry and OCT. The macular sensitivity was measured using the recently introduced fundus-related microperimeter, Micro Perimeter 1. The mean retinal sensitivities within the central 21 and 101 were correlated with the best-corrected visual acuity and OCT-measured foveal retinal thickness. Results The mean sensitivities in the central 21 and 101 were significantly lower in patients with DME than in normal subjects (Po0.0001). The mean retinal sensitivities in the central 21 and 101 were inversely correlated with visual acuity (r 2 ¼ 0.623, Po0.0001; r 2 ¼ 0.581, Po0.0001) and foveal thickness (r 2 ¼ 0.581, Po0.0001; r 2 ¼ 0.551, Po0.0001). Conclusions The mean retinal sensitivities measured with fundus-related microperimetry were significantly lower in eyes with DME than in normal eyes. Because a significant correlation of the microperimeter-determined retinal sensitivity to visual acuity and foveal thickness was observed, the retinal sensitivities obtained by fundus-related microperimetry may be another measure that can be used to assess the effects of DME.

show abstract

Section: Discussionmentioning

confidence: 95%

Correlation of retinal sensitivity measured with fundus-related microperimetry to visual acuity and retinal thickness in eyes with diabetic macular edema

Okada

Yamamoto

Mizunoya

et al. 2005

Eye

108

View full text Add to dashboard Cite

show abstract

“…Terasaki et al (66) found improved vision and electroretinographic activity and thinning of retina following vitrectomy in patients with diabetic macular edema. Yamamoto et al (67) proposed that the creation of a posterior vitreous detachment is critical in order to influence diabetic macular edema through vitreous surgery. In all reports there is structural improvement of macular edema following vitrectomy, but visual improvement is variable and in some cases either minimal or transient (60,68,69).…”

Section: Diabetic Macular Edemamentioning

confidence: 99%

Physiology of vitreous surgery

Stefánsson

2008

Graefes Arch Clin Exp Ophthalmol

256

198

View full text Add to dashboard Cite

Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Silicone oil is the exception that proves the rule: it is more viscous than vitreous humour, re-establishes the transport barrier to oxygen and VEGF, and reduces the risk for iris neovascularization in the vitrectomized-lentectomized eye. Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids. Starling's law explains vasogenic edema, which is controlled by osmotic and hydrostatic gradients between vessel and tissue. It explains the effect of VEGF-induced vascular permeability changes on plasma protein leakage and the osmotic gradient between vessel and tissue. At the same time, it takes into account hemodynamic changes that affect the hydrostatic gradient. This includes the influence of arterial blood pressure, and the effect oxygen (laser treatment) has in constricting retinal arterioles, increasing their resistance, and thus reducing the hydrostatic pressure in the microcirculation. Reduced capillary hydrostatic pressure and increased osmotic gradient reduce water fluxes from vessel to tissue and reduce edema. Finally, Newton's third law explains that vitreoretinal traction decreases hydrostatic tissue pressure in the retina, increases the pressure gradient between vessel and tissue, and stimulates water fluxes from vessel into tissue, leading to edema.

show abstract

“…Similar findings were observed in two other studies on DMO patients who had undergone vitrectomy with the creation of a posterior vitreous detachment. 11,12 We assessed the macular function by multifocal electroretinography (mfERG) and found that the electrical responses obtained from the macular area were also significantly correlated with the FT. 11 In that electrophysiological study, we examined the macular mfERG from the central 10 degrees along with the VA and OCT-determined FT. Although the VA improved significantly and the FT was reduced significantly at 6 months postoperatively, the amplitude of the mfERGs did not show any significant change, and only the peak latency of the macular response decreased significantly.…”

mentioning

confidence: 99%

“…Although the VA improved significantly and the FT was reduced significantly at 6 months postoperatively, the amplitude of the mfERGs did not show any significant change, and only the peak latency of the macular response decreased significantly. 12 It was concluded that the recovery of the macular electrical response might be limited to the shortening of the implicit time because of the severely depressed macular function due to the chronic oedema.…”

mentioning

confidence: 99%

Functional and morphological changes of macula after subthreshold micropulse diode laser photocoagulation for diabetic macular oedema

Nakamura

Mitamura

Ogata

et al. 2009

Eye

View full text Add to dashboard Cite

Purpose To examine the early changes of retinal sensitivity by fundus-related microperimetry after subthreshold micropulse diode laser photocoagulation (SMDLP) for diabetic macular oedema (DMO). Methods Twenty-eight eyes of 28 patients with diffuse DMO were treated with SMDLP. The mean retinal sensitivity within the central 10 degrees measured with a fundus-related microperimeter, MP1, best corrected visual acuity (BCVA) in logarithm of minimum angle of resolution units, and optical coherence tomography-determined foveal thickness (FT) were examined before and 3 months after SMDLP. The pretreatment values of the retinal sensitivity, FT, BCVA, and funduscopic findings were compared with the corresponding values at 3 months after SMDLP. Results At 3 months, the BCVA was significantly improved (P ¼ 0.03), and the FT was significantly reduced (P ¼ 0.0043). The mean retinal sensitivity within the central 10 degree, however, did not change significantly (P ¼ 0.70). The correlation between the changes in the retinal sensitivities and the decrease in the FT was not significant. The correlation between the changes in the retinal sensitivities and the BCVA was also not significant. Conclusions Significant improvements in retinal sensitivities within the central 10 degrees were not observed even though the decrease in FT and the improvement of BCVA were significant. On account of this difference of changes in retinal sensitivity and BCVA, the combination of retinal sensitivity by MP1 and BCVA may be beneficial in assessing the visual function from various angles after SMDLP for eyes with DMO.

show abstract

Morphological and functional changes of the macula after vitrectomy and creation of posterior vitreous detachment in eyes with diabetic macular edema

Cited by 24 publications

References 9 publications

Correlation of retinal sensitivity measured with fundus-related microperimetry to visual acuity and retinal thickness in eyes with diabetic macular edema

Correlation of retinal sensitivity measured with fundus-related microperimetry to visual acuity and retinal thickness in eyes with diabetic macular edema

Physiology of vitreous surgery

Functional and morphological changes of macula after subthreshold micropulse diode laser photocoagulation for diabetic macular oedema

Contact Info

Product

Resources

About