Retinal Recovery Research Articles

Duration of rhegmatogenous retinal detachment predicts recovery of retinal sensitivity

The decision to treat a disease is often based on the presence or absence of symptoms, one prototype case being rhegmatogenous retinal detachment. Detachment of the neural retina from the pigment epithelium is a major cause of anatomical and functional dysfunction of the retina, where retinal recovery is inversely related to duration of detachment. The purpose of retinal reattachment is to effect recovery of the photoreceptors and pigment epithelium from degeneration. The aim of this study was to determine the critical duration of rhegmatogenous retinal detachment resulting in optimal retinal recovery after reattachment. A prospective study was conducted at a private hospital in Yogyakarta. Thirty five eyes were involved in this study. Three months after reattachment, central retinal recovery was measured by means of a Goldmann manual kinetic perimeter. The results showed that retinal recovery developed three months after surgery if the onset of rhegmatogenous retinal detachment was less than 28 days before surgery. The results were not significant if the onset of rhegmatogenous retinal detachment was more than 35 days. Although the Goldmann manual kinetic perimeter can efficiently detect central retinal sensitivity, it should be supported by more sensitive tools to evaluate the anatomy and function of the retina.

Microstructural Retinal Findings by Spectral-Domain Optical Coherence Tomography After Vitrectomy Repair of Rhegmatogenous Retinal Detachments

To evaluate macular microstructural changes after macula-involving rhegmatogenous retinal detachment repair and correlate with visual recovery. A prospective, observational study was performed of select patients presenting with macula-involving rhegmatogenous retinal detachments (RRD). Spectral-domain optical coherence tomography (SD-OCT) imaging was performed at postoperative visits over the course of the first year after operative repair of the RRD. The maculas of seven patients were evaluated. Postoperative best corrected visual acuity (BCVA) at the final follow-up ranged from 20/20 to 20/70 for all patients. Eyes with final BCVA greater than 20/40 had intact external limiting membrane and outer photoreceptor structures, while those with BCVA of less than 20/70 had poorer definition to those structures. Serial images showed resolution of irregularities in both the external limiting membrane and outer photoreceptor structures. Macular structure and function can progressively improve in the first year after successful RRD repair, including in the external limiting membrane, damage to which has previously been thought to be irreversible. SD-OCT serves as a useful tool to monitor postoperative retinal recovery.

Mouse retinal adaptive response to proton irradiation: Correlation with DNA repair and photoreceptor cell death

Emerging body of data indicate protecting effect of low level of stress (preconditioning) on retina. Our previous study revealed non-linear dose-response relationship for cytotoxicity of both ionizing radiation and N-methyl-N-nitrosourea (MNU) on mouse retina. Moreover, non cytotoxic dose of MNU increased tolerance of retina to following challenge dose of MNU. This result displays protection of retina through mechanism of recovery. In present study we used the mouse model for MNU-induced retinal degeneration to evaluate adaptive response of retina to proton irradiation and implication in it of glial Muller cells. The data showed that the recovery of retina after genotoxic agents has been associated with increased efficacy of DNA damage repair and lowered death of retinal photoreceptor cells.

Topography of retinal recovery processes in humans.

BackgroundThe purpose of this study was to examine retinal recovery processes to pographically by the application of three flash sequences with specific interstimulus intervals.MethodsTwelve healthy subjects underwent multifocal electroretinography with a light-emitting diode stimulator. Every flash sequence consisted of three flashes with 25 msec between the first and the second flash and 35 msec between the second and the third flash. The interval between the third and the first flash of the next step was 85 msec. The interstimulus interval-dependent amplitude reductions of the multifocal electroretinographic response for these three intervals yielded three data points that were used to determine the complete curve of the recovery kinetics.ResultsAmplitude reductions were higher with shorter interstimulus intervals. The mean half-life periods of the recovery kinetics for the different concentric rings and all subjects were: ring 1, 29.3±5.9 msec; ring 2, 24.2±6.4 msec; ring 3, 23±4.1 msec; ring 4, 23.1±4.6 msec; and ring 5, 22.3±4.4 msec. The differences between the first and all other rings were statistically significant (P<0.05).ConclusionThe kinetics of the amplitude recovery after short interstimulus intervals showed a spatial distribution, with faster recovery toward the macular periphery.

Cone implicit time as a predictor of visual outcome in macular hole surgery.

To investigate whether preoperative retinal function measured by full-field ERG and multifocal ERG is correlated to postoperative visual acuity after macular hole surgery. Standard pars plana vitrectomy with removal of the internal limiting membrane (ILM) was performed on 19 consecutive patients undergoing macular hole surgery. Intraocular gas tamponade with a C2F6 gas-air mixture was employed, followed by a face-down position for at least 5 days. The patients were examined with the ETDRS chart, full-field ERG (Espion), multifocal ERG (Veris 6), and optical coherence tomography (OCT) preoperatively, and 6 weeks, 6 months, and 18 months after surgery. The cone 30-Hz flicker implicit time in the full-field ERG reflecting retinal function was prolonged (p = 0.016) before surgery compared to aged-matched controls. After macula hole surgery, longstanding alteration of cone function reflected by mfERG and full-field ERG was verified 18 months after surgery. The prolonged cone 30-Hz flicker implicit time in the full-field ERG before surgery was significantly correlated to the ETDRS visual acuity 6 months postoperatively (p = 0.03). Preoperative evaluation of retinal function with multifocal ERG and full-field ERG improves the understanding of the retinal recovery process after macular hole surgery. The cone implicit time in full-field 30-Hz flicker ERG could be a valid predictor of long-term visual outcome, which may be useful for selecting patients suitable for surgery.

Effect of Coadministration of Neuronal Growth Factors on Neuroglial Differentiation of Bone Marrow–Derived Stem Cells in the Ischemic Retina

Brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) have limited and transient supportive effects on retinal recovery from ischemia. The aim of this study was to investigate their effect on engrafted adult bone marrow-derived stem cells in a rodent model of anterior ischemic optic neuropathy (rAION). Small cells were isolated from the bone marrow of green fluorescent protein expressing mice by counterflow centrifugal elutriation, depleted of cells expressing lineage markers, and grafted in conjunction with growth factors into the vitreous body of mice with unilateral rAION. Progenitors were mobilized with granulocyte macrophage colony-stimulating factor (GM-CSF) or stem cell factor (SCF). The contralateral eye served as a control. At 4 weeks, the quantitative incorporation of donor cells in the injured retina was increased by BDNF (P < 0.01 versus control) and decreased by CNTF (P < 0.01 versus control), with no notable difference at 24 weeks. Both growth factors improved the short-term and long-term qualitative engraftment of cells adopting neural phenotypes in the retinal ganglion cell (RGC) layer and astrocyte phenotypes in the anterior vasculature. The RGC-engrafted cells formed extensions toward the inner nuclear layer. In the presence of growth factors, donor cells migrated to the optic nerve and contributed to repair by gliosis. Mobilization with GM-CSF restricted cell fate to microglia, whereas SCF was associated with limited neuroglial differentiation. Both BDNF and CNTF enhance engraftment and neuroglial differentiation of adult bone marrow stem cells in injured retina, with BDNF having an early quantitative and qualitative advantage over CNTF. Mobilization with differentiation factors restricts cell fate in the injured retina.

Correlation with OCT and histology of photocoagulation lesions in patients and rabbits

To examine spectral domain optical coherence tomographic (OCT) and histological images from comparable retinal photocoagulation lesions in rabbits, and to correlate these images with comparable OCT images from patients. 508 rabbit lesions were examined by HE-stained paraffin histology. 1019 rabbit lesions versus 236 patient lesions were examined by OCT, all at the time-points 1 hr, 1 week and 4 weeks after photocoagulation. We analysed 100 μm lesions (in humans) and 133 μm lesions (in rabbits) of 200 ms exposures at powers titrated from the histological threshold up to intense damage. Lesions were matched according to morphological criteria. Dome-shaped layer alterations, retinal infiltration by round, pigmented cells, outer nuclear layer interruption, and eventually full thickness retinal coagulation are detectable in histology and OCT. Horizontal damage extensions are found 1½ times larger in OCT. More intense irradiation was necessary to induce comparable layer affection in rabbit OCT as in histology. Restoration of the inner retinal layers is only shown in the OCT images. Comparable primary lesions caused more pronounced OCT changes in patients than in rabbits during healing. Optical coherence tomographic images indicate different tissue changes than histologic images. After photocoagulation, they show wider horizontal damage diameters, but underestimate axial damage particularly during healing. Conclusions on retinal restoration should not be drawn from OCT findings alone. Retinal recovery after comparable initial lesions appears to be more complete in rabbit than in patient OCTs.

Senescent changes in retinal recovery after light stimulation using the mfERG

Senescent changes in retinal recovery after light stimulation using the mfERG

Human RNA Integrity After Postmortem Retinal Tissue Recovery

Purpose: To assess the parameters for postmortem retinal tissue recovery and processing that affect the quality of RNA extracted from the retina/retinal pigment epithelium (RPE) complex.Methods: RNA was extracted from retina/RPE samples. The RNA quality was determined based on qualitative/quantitative measurements made with a Bioanalyzer (Agilent) and on the expression of a long retinal gene (RPE65). After a pilot analysis on rats, ocular RNA was extracted from human donor eyeballs (group A) explanted according to conventional procedures for cornea transplantation. In a second experiment, another group of human donor eyeballs (group B) were processed in a much shorter time. The postmortem interval (T) comprised two periods: T1, the time between a donor’s death and enucleation, and T2, the time between eyeball explantation and immersion of the excised retina/RPE sample in preservative solution (T = T1 + T2).Results: A short T2 was correlated with good quality of RNA extracted from the retina/RPE complex (p = 0.043) and successful expression of a tissue-specific gene (p = 0.007). No other parameter appeared to influence RNA quality.Conclusions: The time between eyeball explantation and immersion of the retina/RPE sample in preservative solution was the chief parameter affecting the quality of RNA extracted from the retina/RPE complex.

Hydrogen-rich saline protects retina against glutamate-induced excitotoxic injury in guinea pig

Molecular hydrogen (H 2) is an efficient antioxidant that can selectively reduce hydroxyl radicals and inhibit oxidative stress-induced injuries. We investigated the protective effects and mechanism of hydrogen-rich saline in a glutamate-induced retinal injury model. Retinal excitotoxicity was induced in healthy guinea pigs by injecting glutamate into the vitreous cavity. After 30 min, hydrogen-rich saline was injected into the vitreous cavity, the peritoneal cavity or both. Seven days later, the retinal stress response was evaluated by examining the stress biomarkers, inducible nitric-oxide synthase (iNOS) and glucose-regulated protein 78 (GRP78). The impaired glutamate uptake was assessed by the expression of the excitatory amino acid transporter 1(EAAT-1). The retinal histopathological changes were investigated, focusing on the thicknesses of the entire retina and its inner layer, the number of cells in the retinal ganglion cell layer (GCL) and the ultrastructure of the retinal ganglion cells (RGCs) and glial cells. Compared with the glutamate-induced injury group, the hydrogen-rich saline treatment reduced the loss of cells in the GCL and thinning of the retina and attenuated cellular morphological damage. These improvements were greatest in animals that received H 2 injections into both the vitreous and the peritoneal cavities. The hydrogen-rich saline also inhibited the expression of glial fibrillary acidic protein (GFAP) in Müller cells, CD11b in microglia, and iNOS and GRP78 in glial cells. Moreover, the hydrogen-rich saline increased the expression of EAAT-1. In conclusion, the administration of hydrogen-rich saline through the intravitreal or/and intraperitoneal routes could reduce the retinal excitotoxic injury and promote retinal recovery. This result likely occurs by inhibiting the activation of glial cells, decreasing the production of the iNOS and GRP78 and promoting glutamate clearance.

Stem Cells are Mobilized from the Bone Marrow into the Peripheral Circulation in Response to Retinal Pigment Epithelium Damage—A Pathophysiological Attempt to Induce Endogenous Regeneration

Purpose: Stem cell regeneration of damaged tissue has recently been reported in many different organs. Here, we investigated the mobilization of different stem/progenitor cell (SPC) populations into the peripheral blood (PB), their subsequent homing to the injured retina (IR) and contribution to its regeneration in a retinal pigment epithelium (RPE) damage model induced by sodium iodate (NaIO3).Methods: Mobilization of SPCs was evaluated by flow cytometry. SPCs distribution in IR was assessed using bone marrow (BM)-derived GFP+Lin− cells transplanted intravenously into NaIO3-treated C57Bl/6 mice. The quantity of the chemokine SDF-1 in PB and IR was measured by ELISA and qRT-PCR, respectively. Apoptosis (TUNEL assay), cell proliferation (PCNA analysis) as well as functional retinal activity (electroretinogram) were examined at several time points after NaIO3 administration.Results: Mobilization of SPCs along with the highest cell proliferation and massive apoptosis within IR were observed on the third day after NaIO3 administration. Similarly, donor GFP+Lin− cells were detected in the retina as soon as day 4 after NaIO3 injection. Plasma levels of SDF-1 did not differ significantly in mice exposed to NaIO3 compared to healthy controls, however mRNA for SDF-1 was overexpressed locally in IR. Functional retinal recovery was not achieved.Conclusion: Our study provides evidence that BM SPCs egress into PB and home to the injured retina, but are not capable of restoring its function. These results indicate that if the range of retinal destruction is profound, endogenous regeneration is ineffective and may ultimately require adjuvant therapeutic transplantation of specific SPCs subpopulations.

Diagnosing and Treating Vitreomacular Adhesion

Perifoveal vitreous detachment with residual vitreofoveal adhesion is considered as the first stage of posterior vitreous detachment. A key point is the transition from an innocuous vitreomacular adhesion (VMA) to a pathological vitreomacular traction (VMT). By using optical coherence tomography (OCT), VMA is defined as adhesion of the posterior hyaloid cortex involving the centre of the foveal region with or without a hyper-reflective signal on the inner surface of the retina. VMT is diagnosed when the inner macular surface slopes steeply, or sharp angulation and localised deformation of the retinal profile is detected at the VMA site. Otherwise, VMA is simply considered to be persistent adherence of the cortical vitreous. The tractional effects of perifoveal vitreous detachment cause a variety of macular pathologies determined by the size and the strength of the residual vitreoretinal adhesion. Vitreomacular adhesion plays a major role in the development of diseases such as vitreomacular traction syndrome (VMTS), macular hole, epiretinal membrane, tractional macular oedema and myopic macular retinoschisis. In addition, clinical evidence supports the theory that the course of diabetic retinopathy and age-related macular degeneration may be strongly influenced by an incomplete posterior vitreous separation. The current standard of care of vitreomacular interface pathologies is vitrectomy and membrane peeling – a procedure that is thought to relieve epiretinal traction – followed by regeneration of the retinal architecture and recovery of visual function. Over the last few years, with the introduction of 25-gauge (0.50mm) and 23-gauge (0.72mm) instruments, there has been another major shift toward transconjunctival microincisional vitrectomy surgery (MIVS). Pharmacological induction of posterior vitreous detachment (PVD) can become a further step toward a real ‘minimally invasive vitreous surgery’ for VMTS.

Neural plasticity and accidental human laser macular injury

Purpose: To evaluate mechanisms of long term recovery of visual function based on three human laser accident cases and the remarkable recovery these cases demonstrated in the presence of macular damage. Methods: Visual acuity, contrast sensitivity, eye movement fixation pattern, the FM 100 hue color discrimination test and anomaloscope matches were used in analysis of visual function. CSLO Ophthalmoscopy and Optical Coherence Tomography (OCT) characterized the presence of retinal traction, scar, thickness and hole formation. Ophthalmoscopy was used to evaluate preferred retinal location (PRL) in focal contrast sensitivity tests. Results: Visual acuity, contrast sensitivity and color vision recovered within 3 months (cases 1 and 2). In case 1, a thinner than normal foveal thickness was measured with OCT. Foveal OCT measurements (case 2) showed a break in foveal thickness. Foveal PRL measurements indicated functionality for case 1 and non foveal functionality for case 2 which developed a new PRL superior temporal to the fovea. Color vision metrics (case 3) recovered completely within 12 months post. Visual acuity and contrast sensitivity were near full recovery at two years post. OCT imaging revealed a macular hole at 3 months post and ophthalmoscopy revealed the presence of traction about the hole. At 12–24 months considerable “filling” of the hole appeared with the absence of traction. Ocular motility involved foveal and parafoveal retina. Conclusion: These cases suggest that morphological changes in retinal recovery may induce higher order visual brain centers to accept weaker retinal afferent signals from damaged retinal sites. More severe scar and traction limit retinal and cortical neural plasticity.

Effect of VEGF-B on neuroprotection in mouse retinal ganglion cells

To investigate the expression of vascular endothelial growth factor-B (VEGF-B) in retina and its effect on neuroprotection in mouse retinal ganglion cells (RGCs). It was a experimental study. 35 of C57BL/6 mice (adult male) were used. Optic nerve crush injury was made in 28 mice, 7 as control. Expression of VEGF-B in retina was detected by hybridization in situ in each group of 2 at 6 hours, 1 day, 1 and 2 weeks after optic nerve crush. A quantitative analysis of VEGF-B mRNA was determined by real time reverse transcription polymerase chain reaction (RT-PCR) in each group of 5 at 6 hours, 1 day, 1 and 2 weeks after optic nerve crush. Additional 36 mice were divided into 4 groups: control (8), optic nerve crush (9), optic nerve crash plus PBS intravitreal injection (7), and optic nerve crash plus VEGF-B (450 mg/L) intravitreal injection (12). RGCs were counted by retrograde tracing of Fluorogold to evaluate the effect of VEGF-B on neuroprotection by microscope. Compared with control group, the expression of VEGF-B was significantly increased in the retina of mice and peaked at one week after the optic nerve crush. The number of RGCs was 1.7 fold higher in optic nerve crush alone and 1.9 fold higher in optic nerve crush combined with intravitreal injection of VEGF-B, which reached statistically significance (t = 0.001, P < 0.01 and t = 0.001, P < 0.01, respectively). Our results indicate that VEGF-B is involved in the retinal recovery processes and plays a potent role of neuroprotection in RGCs after the optic nerve crush.

Immunohistochemical Findings in Epiretinal Membrane after Long-Term Silicone Oil Tamponade: Case report

To report pre- and post-operative macular optical coherence tomography (OCT) and immunohistochemical findings in a case of long-lasting silicone oil tamponade followed by silicone oil removal and epimacular membrane peeling. A 69-year-old man with long-standing silicone oil tamponade and an epiretinal membrane at the posterior pole in his right eye (RE) underwent silicone oil/BSS exchange with epiretinal membrane peeling. Preoperatively, RE best-corrected visual acuity was 20/200 and macular OCT examination revealed a small increase in foveal thickness (250 microm) with the appearance of a linear hyper-reflective signal at the foveal vitreoretinal interface and a thicker (440 microm) hyperreflective finding causing posterior shadowing at the vitreoretinal interface inferiorly to the fovea. Histopathologic and immunohistochemical study of the specimen including the epiretinal membrane was performed. Light microscopy revealed extensive rounded empty spaces interpreted as silicone oil bubbles in the preretinal membrane. Macrophages marker (CD68) positive staining cells were found surrounding the empty spaces within the preretinal membrane and several empty spaces were observed intracellularly within macrophage cytoplasm. Thirty days after surgery best-corrected visual acuity was 20/60 and OCT examination showed an evident decrease in foveal thickness (220 microm) with the disappearance of any hyper-reflective signal at the vitreoretinal interface referable to an epiretinal membrane. The immunohistochemical study showed both silicone oil droplets and macrophagic cells embedded in the epiretinal membrane. Postoperative OCT demonstrated retinal recovery after silicone oil removal and epiretinal membrane peeling, thus justifying an unexpected visual acuity recovery despite the very long term tamponade.

Central Retinal Vein Occlusion Caused by Human Herpesvirus 6

We describe a 1-year-old girl with central retinal vein occlusion caused by human herpesvirus 6. She received systemic corticosteroid therapy. Although there was retinal recovery after the therapy, the visual acuity in her left eye still could not be measured.

Long-term anatomical and visual outcome of vitreous surgery for retinal detachment with choroidal coloboma

Vitreous surgery has been advocated as an alternative treatment of selected retinal detachments with choroidal colobomas. To study the long term anatomical and visual outcome of choroidal coloboma with retinal detachment managed by pars plana vitrectomy with silicone oil tamponade. Retrospective study conducted in a tertiary eye care hospital. Fourty two eyes of 40 patients with retinal detachments related to coloboma of the choroid without any peripheral breaks were analyzed. All eyes underwent pars plana vitrectomy with internal tamponade using silicone oil. Endolaser was performed along the coloboma border. Silicone oil was removed in 50% of patients. The main outcome measures were retinal reattachment and visual recovery. SPSS (Statistical Package for the Social Science), version 10.0 was used for analysis. The retina in all cases (100%) undergoing vitrectomy were completely reattached intra-operatively. After a mean follow-up of 14 months, 37 (88.1%) eyes had attached retina. The best corrected visual acuity was 10/200 or better in 33 (78.4%) eyes. The best corrected visual acuity improved from a preoperative median of counting fingers (range 20/40 to perception of light) to median best corrected visual acuity of 20/200 (range 20/40 to perception of light) at the end of 6 months. Of the 50% (21) cases that underwent silicone oil removal, two eyes had re-detachment of retina. Pars plana vitrectomy along with silicone oil tamponade for retinal detachment related to choroidal coloboma improves the long-term anatomical and visual outcome.

Evaluation of retinal function using the Dynamic Focal Cone ERG

The development of effective means of assessing visual function in retinal disease holds the key to improved understanding of pathogenesis, and better monitoring of treatment outcomes. In diseases such as age-related macular degeneration, in which the primary locus of dysfunction is the outer retina, tests which provide a direct measure of the functional integrity of the photoreceptor/retinal pigment epithelium (RPE) complex are of great importance. Recovery of retinal function following adaptation to a bright light requires the healthy function of photoreceptors, RPE, Bruch's membrane and choroidal circulation, making an assessment of this recovery a potentially useful clinical tool. However, current techniques are either subjective in nature, or are influenced by post-retinal processing of visual information. This report describes a novel technique, the 'Dynamic Focal Cone Electro-retinogram (ERG)', which allows direct, objective assessment of the recovery of macular function following photopigment bleach. A series of 41 Hz ERGs was recorded, and ERG amplitude was plotted as a function of time following cessation of the bleach. Normative data was collected from 10 healthy subjects. For all subjects, there was no measurable ERG immediately after the bleach, but the amplitude had returned to a pre-bleach level within 4 min. The amplitude recovery data were adequately described both by an exponential recovery function and by a model based on a rate-limited recovery process. We conclude that this technique provides a clinically applicable, objective measure of outer retinal recovery.

Glutamate transporter localization does not correspond to the temporary functional recovery and late degeneration after acute ocular ischemia in rats

Purpose To determine whether the localization of retinal glutamate transporters is affected by retinal ischaemia and whether their ability to transport glutamate decreases with the progression of ischemic retinal and optic nerve degeneration. Methods Retinal ischemia was induced in rats by acutely increasing the intraocular pressure (IOP, 110 mmHg/60 min). Reperfusion was permitted for periods up to 60 days post-ischemia. Functional evaluation was performed by monitoring the pupil light reflexes (PLRs) and electroretinograms (flash, flicker ERG and oscillatory potentials). Glutamate transporter localization and d-aspartate (glutamate analogue) uptake were assessed by immunohistochemistry. Results Intense immunoreactivity for the retinal glutamate transporters (GLAST, GLT1, EAAC1 and EAAT5) was observed at all time points after the insult, despite severe retinal degeneration. d-aspartate was also normally accumulated in the ischemic retinas. Ten days post-operatively the PLR ratio (ratio=indirect/direct PLR=34±7·5%) was significantly less than the pre-operative value (pre-op=76·7±2·6%, p<0·05). However, 25 and 35 days post-operatively PLR ratios did not differ significantly from pre-operative values (44·4±6·9 and 53·8±9·6%, p>0·05). Forty-five and 60 days post-operatively the PLR ratio declined again and was significantly lower than the pre-operative value (33·8+8·7 and 26·2+8·9%, p<0·05). Statistical analysis revealed that all tested ERG components had significantly higher values at 32, but not at 42 and 58 days post-operatively when compared to the first time point recorded post-operatively (10 days). Conclusions While retinal glutamate transport is compromised during an acute ischemic insult, consequent retinal recovery and degeneration are not due to a change in the excitatory amino acid transporter localization or d-aspartate (glutamate analogue) uptake. Rat retina and optic nerve are capable of spontaneous, but temporary, functional recovery after an acute ischemic insult.

Reversed visual field constrictions in children after vigabatrin withdrawal—true retinal recovery or improved test performance only?

While vigabatrin-associated visual field constrictions have been generally considered irreversible, some case reports have raised the hope of partial improvement after drug withdrawal in occasional patients . Here we describe seven children with epilepsy, whose visual field constrictions, as demonstrated by the kinetic perimetry (Goldmann), attenuated or recovered after discontinuation of vigabatrin therapy. While this improvement may be largely due to better performance in later test sessions, we want to raise the possibility that some visual field recovery may be possible at least in young patients .