136 resultados para Investigative Reporters and Eidtors
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Purpose:To determine the surgical outcomes of patients undergoing repeat deep sclerectomies with collagen implant (DSCI) at a tertiary referral centre. Methods:The medical notes of 208 patients undergoing multiple DSCI were reviewed. Those undergoing repeat DSCI were identified and post operative data for each DSCI were analysed. Group A: the first DSCI; group B: second DSCI; group C: third DSCI. Results:Mean age was 66.8 ±13.0 years. At 12 months, percentage of mean IOP reduction in groups were 18%, 24% and 17% respectively. Mean interval to starting glaucoma medications, re-operation, mitomycin injection and goniopuncture all decreased as the number of operations increased. There was a significant reduction in complete success rates between groups A and B and groups B and C. Few minor complications were observed in all 3 groups. Conclusions:Despite the possibility of bleb independent outflow pathways in patients undergoing non-penetrating surgery, there are significantly reduced success rates in eyes undergoing repeat DSCI. This has important implications for the choice of subsequent operations in patients who have failed non-penetrating filtration surgery.
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Purpose:To functionally and morphologically characterize the retina and optic nerve after transplantation of Brain-derived neurotrophic factor (BDNF) and Glial-derived neurotrophic factor (GDNF) secreting mesenchymal stem cells (MSCs) into glaucomatous rat eyes. Methods:Chronic ocular hypertension (COH) was induced in Brown Norway rats. Lentiviral constructs were used to transduce rat MSCs to produce BDNF, GDNF, or green fluorescent protein (GFP). The fellow eyes served as internal controls. Two days following COH induction, eyes received intravitreal injections of transduced MSCs. Electroretinography was performed to assess retinal function. Tonometry was performed throughout the experiment to monitor IOP. 42 days after MSC transplantation, rats were euthanized and the eyes and optic nerves were prepared for analysis. Results:Increased expression and secretion of BDNF and GDNF from lentiviral-transduced MSCs was verified using ELISA, and a bioactivity assay. Ratio metric analysis (COH eye/ Internal control eye response) of the Max combined response A-Wave showed animals with BDNF-MSCs (23.35 ± 5.15%, p=0.021) and GDNF-MSCs (28.73 ± 3.61%, p=0.025) preserved significantly more visual function than GFP-MSC treated eyes MSCs (18.05 ± 5.51%). Animals receiving BDNF-MSCs also had significantly better B-wave (33.80 ± 7.19%) and flicker ERG responses (28.52 ± 10.43%) than GFP-MSC treated animals (14.06 ± 12.67%; 3.52 ± 0.07%, respectively). Animals receiving GDNF-MSC transplants tended to have better function than animals with GFP-MSC transplants, but were not statistically significant (p=0.057 and p=0.0639). Conclusions:Mesenchymal stem cells are an excellent source of cells for autologous transplantation for the treatment of neurodegenerative diseases. We have demonstrated that lentiviral- transduced MSCs can survive following transplantation and preserve visual function in glaucomatous eyes. These results suggest that MSCs may be an ideal cellular vehicle for delivery of specific neurotrophic factors to the retina.
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Introduction: In normal mice, lentiviral vector (LV) shows a great efficiency to infect the RPE cells, but transduces retinal neurons more efficiently during development. Here, we investigated the tropism of LV in the degenerating retina of mice, knowing that the retina structure changes during degeneration. We postulated that the viral transduction would be increased by the alteration of the interphotoreceptor matrix (IPM). We tested two different LV-pseudotypes using the VSVG and the Mokola envelopes. Methods: Subretinal injections were performed in wild-type (C57/Bl6) and rhodopsin knockout (Rho-/-) mice. We injected LV-VSVG-EFS-GFPII into 3.3-4.9 month old mice and LV-VSVG-Rho-GFP into 1-1.4 month old mice to target the photoreceptors (PR). LV-MOK-CMV-GFP was injected into 2.4-3.3 months old mice. We sacrificed the animals one week post injection, used immunohistochemistry to identify the transduced cells, and investigated the OLM integrity. Results: Using LV-VSVG-EFS-GFPII into 3.3-4.9 months mice, we observed significant retinal and RPE transduction in Rho-/- mice. However, the retinas showed transduction mainly at the injection's site. We mostly observed GFP+ cells having a Müller cell morphology. Using LV-MOK-CMV-GFP into 2.4-3.3 months mice, we evidenced the same pattern of viral infection, but with more Müller cells targeted by the virus. Using LV-VSVG-Rho-GFP into 1-1.4 month old mice, we don't note any difference between Rho-/- and wild-type mice for transduced cells. The IPM stained with ZO1 appears irregular into the 4.9 months old Rho-/- mice; for the youngest mice (Rho-/- and C57/Bl6), there is no modification of the IPM. Conclusion: The degeneration improves retinal cells transduction due to the alteration of the IPM in old Rho-/- mice. Müller cells seem (by morphological evidences) to be the principal cells expressing the transgene. The LV with Mokola envelope can transduce Müller cells in a degenerating retina with an intact IPM. In 1 month old mice, the degeneration doesn't enhance the transduction in rod PR probably because the IPM is not yet altered. The possibility to target photoreceptors at a later stage of the degeneration is under investigation.
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Purpose:We analyzed the transcriptional activity of disease-causing NR2E3 mutant proteins in a heterologous system. NR2E3 belongs to the nuclear receptor superfamily of transcription factors, characterized by evolutionary-conserved DNA-binding (DBD) and ligand-binding (LBD) domains. NR2E3 acts in concert with the transcription factors CRX and NRL to repress cone-specific genes and activate rod-specific genes in rod photoreceptors. During development, NR2E3 is also required to suppress cone cell generation from retinal progenitor cells. In humans, mutations in NR2E3 have been associated with the recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS), the Goldman-Favre syndrome, and, more recently, with autosomal dominant retinitis pigmentosa (adRP). Methods:The different NR2E3 mutants were generated by QuickChangeR mutagenesis and analyzed by transfection in heterologous HEK293T cells. Results:In transactivation assays in HEK293T cells, the adRP-linked p.G56R mutant protein exhibited a more severe effect both in activation of a rhodopsin promoter reporter construct and in repression of M-opsin promoter reporter construct, than the ESCS-linked R76Q, R76W, G88V, R97H, R104Q, R104W mutants of the DBD. In contrast, the ESCS-linked p.R311Q mutant of the LBD behaved like the NR2E3 wild-type protein in these assays. By co-expressing the corepressors atrophin-1 and -2, a differential repression of the M-opsin promoter was observed in presence of the p.R311Q, p.R385P and p.M407K. Interestingly, corepressor expression also affected the activity of CRX, but not NRL, in both rhodopsin and M-opsin transactivation assays. Conclusions:Taken together, these in vitro results suggest a distinct disease mechanism for the adRP-linked mutation, but open the possibility of different mechanisms for the development of ESCS that is clinically characterized by important phenotypic variations.
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PURPOSE: The objective of this study was to evaluate the long-term safety and pharmacokinetic profile of a dexamethasone-loaded poly-epsilon-caprolactone (PCL) intravitreous implant. METHODS: The PCL devices were prepared by compression and were inserted into the vitreous of pigmented rabbits. At different time points, vitreous samples were retrieved, and dexamethasone concentration was analyzed by high-performance liquid chromatography. The biodegradation of the implants was evaluated by scanning electron microscopy, and the dexamethasone remaining was evaluated at the end of follow-up. Clinical and histologic examinations were performed to evaluate the implant's tolerance. RESULTS: The PCL implant allows for a controlled and prolonged delivery of dexamethasone in rabbits eyes since it released the drug within the therapeutic range for at least 55 weeks. At 55 weeks approximately 79% of the drug was still present in the implant. Biodegradation study showed that PCL implants degradation is very slow. Clinical and histologic observations showed that the devices were very well tolerated in the rabbit eye. CONCLUSIONS: This study demonstrates the feasibility and tolerance of intravitreous PCL drug delivery systems, which can offer a wide range of applications for intraocular drug delivery because of their controlled and prolonged release over months or even years.
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Purpose: We report an unusual appearance of fundus autofluorescence (FAF) associated with NR2E3-p.G56R-linked autosomal dominant retinitis pigmentosa (ADRP).Methods: Patients were enrolled among three generations in a Swiss family. Molecular diagnosis identified a c.166G>A (p.G56R) mutation. Ophthalmic examination included fundus photography, FAF, near-infrared autofluorescence (NIA), optical coherence tomography (OCT) and visual fields (VF).Results: Fundus examination revealed a wide range of features from unremarkable to attenuated arterial caliber, clumped and spicular pigment deposits in the mid-periphery and optic nerve pallor. FAF showed a double concentric hyperautofluorescent ring: an inner perimacular ring which tended to be smaller in older patients, and an outer ring located along the vascular arcades, which appeared to extend over time towards the periphery and eventually became hypoautofluorescent. The inner and outer hyperautofluorescent rings were seen both on NIA and FAF at a similar localization. There was also a spatial correspondence between the loss of photoreceptor inner segment and outer segment junction on OCT and the area delimited by both double FAF and NIA rings. VF showed either midperipheral annular scotoma or constricted visual field loss in advanced cases, correlating with dystrophic non-functional retinal regions demarcated by the hyperautofluorescent annuli. A double ring of hyperautofluorescence was observed in all but one patient of two additional families, but not in patients harboring mutations in other ADRP genes, including PRPF3, RHO, RP1, PRPH2, PROM1 and CTRP5.Conclusions: The presence of a double concentric hyperautofluorescent ring of FAF may represent a highly penetrant early phenotypic marker of NR2E3-p.G56R-linked ADRP.
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PURPOSE: To test the ability of two preparations of FGF2-saporin, either FGF2 chemically conjugated to saporin (FGF2-SAP) or genetically engineered FGF2-saporin (rFGF2-SAP) to inhibit the growth of bovine epithelial lens (BEL) cells in vitro when in solution and when immobilized on heparin surface-modified (HSM) polymethylmethacrylate (PMMA) intraocular lenses (IOLs). METHOD: Bovine epithelial lens cells were incubated with various concentrations FGF2-saporin for as long as 4 days. The number of surviving cells was determined by counting the number of nuclei. Because FGF2 binds to heparin, FGF2-saporin was incubated with HSM PMMA IOLs; excess toxin was washed off, and the BEL cells were grown on the FGF2-saporin-treated IOLs (HSM and non-HSM) for 4 days. Cell density was determined by image analysis. RESULTS: Both FGF2-SAP and rFGF2-SAP were highly cytotoxic (nM range), with rFGF2-SAP 10 times less active than FGF2-SAP. FGF2-saporin bound to the surface of HSM IOLs and eluted by 2M NaCl retained its activity. Toxin bound to HSM IOLs killed more than 90% of the BEL cells placed on the IOL surface within 4 days. The ability of FGF2-saporin to prevent the growth of cells on the IOL surface was strictly dependent on the presence of heparin on the IOL. CONCLUSIONS: FGF2-saporin is bound to HSM PMMA IOLs and prevents the growth of epithelial cells on the surface of the lens.
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Purpose. To investigate the role of the myocyte enhancer factor 2 (Mef2) transcription factor family in retinal diseases, Mef2c expression was assessed during retinal degeneration in the Rpe65(-/-) mouse model of Leber's congenital amaurosis (LCA). Mef2c-dependent expression of photoreceptor-specific genes was further addressed. Methods. Expression of Mef2 members was analyzed by oligonucleotide microarray, quantitative PCR (qPCR) and in situ hybridization. Mef2c-dependent transcriptional activity was assayed by luciferase assay in HEK293T cells. Results. Mef2c was the only Mef2 member markedly downregulated during retinal degeneration in Rpe65(-/-) mice. Mef2c mRNA level was decreased by more than 2 fold at 2 and 4 months and by 3.5 fold at 6 months in retinas of Rpe65(-/-) mice. Downregulation of Mef2c at the protein level was confirmed in Rpe65(-/-) retinas. The decrease in Mef2c mRNA levels in the developing Rpe65(-/-) retinas, from post-natal day (P)13 onward, was concomitant with the decreased expression of the rod-specific transcription factors Nrl and Nr2e3. Nrl was further shown to drive Mef2c transcriptional activity, supporting a physiological role for Mef2c in the retina. In addition, Mef2c appeared to act as a transcriptional repressor of its own expression, as well as those of the retina-specific retinal G-protein coupled receptor (Rgr), rhodopsin and M-opsin genes. Conclusions. These findings highlight the early altered regulation of the rod-specific transcriptional network in Rpe65-related disease. They further indicate that Mef2c may act as a novel transcription factor involved in the development and the maintenance of photoreceptor cells.
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PURPOSE: To evaluate the effect of XG-102 (formerly D-JNKI1), a TAT-coupled dextrogyre peptide that selectively inhibits the c-Jun N-terminal kinase, in the treatment of endotoxin-induced uveitis (EIU). METHODS: EIU was induced in Lewis rats by LPS injection. XG-102 was administered at the time of LPS challenge. The ocular biodistribution of XG-102 was evaluated using immunodetection at 24 hours after either 20 microg/kg IV (IV) or 0.2 microg/injection intravitreous (IVT) administrations in healthy or uveitic eyes. The effect of XG-102 on EIU was evaluated using clinical scoring, infiltration cell quantification, inducible nitric oxide synthase (iNOS) expression and immunohistochemistry, and cytokines and chemokines kinetics at 6, 24, and 48 hours using multiplex analysis on ocular media. Control EIU eyes received vehicle injection IV or IVT. The effect of XG-102 on c-Jun phosphorylation in EIU was evaluated by Western blot in eye tissues. RESULTS: After IVT injection, XG-102 was internalized in epithelial cells from iris/ciliary body and retina and in glial and microglial cells in both healthy and uveitic eyes. After IV injection, XG-102 was concentrated primarily in inflammatory cells of uveitic eyes. Using both routes of administration, XG-102 significantly inhibited clinical signs of EIU, intraocular cell infiltration, and iNOS expression together with reduced phosphorylation of c-Jun. The anti-inflammatory effect of XG-102 was mediated by iNOS, IFN-gamma, IL-2, and IL-13. CONCLUSIONS: This is the first evidence that interfering with the JNK pathway can reduce intraocular inflammation. Local administration of XG-102, a clinically evaluated peptide, may have potential for treating uveitis.
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PURPOSE: The antiangiogenic effect of an antisense oligodeoxynucleotide (ODN) targeting insulin receptor substrate (IRS)-1 was evaluated on rat corneal neovascularization. METHODS: Eyes with neovessels were treated with subconjunctival injections of IRS-1 antisense oligonucleotide (ASODN), IRS-1 sense ODN (SODN), or PBS. At 8 and 24 hours after the first subconjunctival injection, the expression of IRS-1, VEGF, and IL-1beta mRNA was evaluated. IRS-1 protein levels were also measured at 8 hours by Western blot analysis (n = 4/group). On day 10, corneal neovascularization was quantified in flatmount corneas of rats treated daily from days 4 to 9. RESULTS: On day 10, new vessels covered 95.5% +/- 4% of the corneal area in PBS-treated eyes, 92% +/- 7% in SODN-treated eyes and 59% +/- 20% in ASODN-treated eyes (P < 0.001). In the ASODN-treated group, the expression and synthesis of IRS-1 were significantly downregulated when compared with the control groups. ASODN did not significantly affect the expression of VEGF but significantly decreased the expression of IL-1beta at 24 hours (P = 0.04). CONCLUSIONS: Subconjunctival injections of IRS-1 antisense ODN significantly inhibit rat corneal neovascularization. This effect may be mediated by a downregulation of IL-1beta. IRS-1 proteins may be interesting targets for the regulation of angiogenesis mediated by insulin, hypoxia, or inflammation.
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Purpose:Given the advances of gene therapy studies to cure RPE65-derived Leber Congenital Amaurosis (LCA) (clinical trials phase I) and the heterogeneity of the targeted patients both genetically and phenotypically, it is of prime importance to examine the rescue efficiency of gene transfer in different mutant contexts. Indeed, half of these mutations are missense mutations, leading to potential residual RPE65 activity. Consequently, we wanted to evaluate the effect on retinal activity and cone survival of lentivirus-mediated gene therapy in the R91W knock-in mouse model expressing the mutant Rpe65R91W gene (Samardzija et al. 2008), a mutation found in LCA patients. Notably we investigated whether if the therapeutic window is prolonged in comparison to null mutations. Methods:An HIV-1-derived lentiviral vector (LV) expressing either the GFP or the mouse Rpe65 cDNA under the control of a 0.8 kb fragment of the human Rpe65 promoter (R0.8) was produced by transient transfection of 293T cells. LV-R0.8-RPE65 or GFP was injected into 5-days-old (P5) or 1 month-old R91W mice. Functional rescue was assessed by ERG (1 and 4 months post-injection) and pupillary light response (PLR) recordings and cone survival by histological analysis. Results:Increased light sensitivity was detected by scotopic ERG in animals injected with LV-R0.8-RPE65 at both P5 and 1 month compared to GFP-treated animals or untreated mice. PLR was also improved in some eyes and histological analysis of cone markers showed that the density of cones reached the wild type level in the region of wt RPE65 delivery after treatment at P5. However, the rescue effect of the injection at 1 month was limited and attained 60% of the wild type level, but still more cones were observed in the treated area than in 1 month-old untreated Rpe65R91W mice. Conclusions:We were able to show that lentivirus-mediated Rpe65 gene transfer not only increases retinal activity of the Rpe65R91W mouse and survival of cones after treatment at P5 but also after treatment at 1 month. However even if the treatment at 1 month is more limited (60% of the wild type level) than treatment at P5, the amount of cone markers is increased compared to the proportion found at 1 month of age in untreated animals. This results contrast with the lack of cone rescue by treatment at 1 month of age in Rpe65-/- (Bemelmans et al, 2006). Thus patient suffering from R91W mutation might benefit from a prolonged therapeutic window.
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PURPOSE: To investigate the effect of intraocular straylight (IOS) induced by white opacity filters (WOF) on threshold measurements for stimuli employed in three perimeters: standard automated perimetry (SAP), pulsar perimetry (PP) and the Moorfields motion displacement test (MDT).¦METHODS: Four healthy young (24-28 years old) observers were tested six times with each perimeter, each time with one of five different WOFs and once without, inducing various levels of IOS (from 10% to 200%). An increase in IOS was measured with a straylight meter. The change in sensitivity from baseline was normalized, allowing comparison of standardized (z) scores (change divided by the SD of normative values) for each instrument.¦RESULTS: SAP and PP thresholds were significantly affected (P < 0.001) by moderate to large increases in IOS (50%-200%). The drop in motion displacement (MD) from baseline with WOF 5, was approximately 5 dB, in both SAP and PP which represents a clinically significant loss; in contrast the change in MD with MDT was on average 1 minute of arc, which is not likely to indicate a clinically significant loss.¦CONCLUSIONS: The Moorfields MDT is more robust to the effects of additional straylight in comparison with SAP or PP.
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PURPOSE: Diabetic retinopathy (DR) is a leading cause of blindness, yet pertinent animal models are uncommon. The sand rat (Psammomys obesus), exhibiting diet-induced metabolic syndrome, might constitute a relevant model. METHODS: Adult P. obesus (n = 39) were maintained in captivity for 4 to 7 months and fed either vegetation-based diets (n = 13) or standard rat chow (n = 26). Although plant-fed animals exhibited uniform body weight and blood glucose levels over time, nearly 60% of rat chow-raised animals developed diabetes-like symptoms (test group). Animals were killed, and their eyes and vitreous were processed for immunochemistry. RESULTS: Compared with plant-fed animals, diabetic animals showed many abnormal vascular features, including vasodilation, tortuosity, and pericyte loss within the blood vessels, hyperproteinemia and elevated ratios of proangiogenic and antiangiogenic growth factors in the vitreous, and blood-retinal barrier breakdown. Furthermore, there were statistically significant decreases in retinal cell layer thicknesses and densities, accompanied by profound alterations in glia (downregulation of glutamine synthetase, glutamate-aspartate transporter, upregulation of glial fibrillar acidic protein) and many neurons (reduced expression of protein kinase Cα and Cξ in bipolar cells, axonal degeneration in ganglion cells). Cone photoreceptors were particularly affected, with reduced expression of short- and mid-/long-wavelength opsins. Hypercaloric diet nondiabetic animals showed intermediate values. CONCLUSIONS: Simple dietary modulation of P. obesus induces a rapid and severe phenotype closely resembling human type 2 DR. This species presents a valuable novel experimental model for probing the neural (especially cone photoreceptor) pathogenic modifications that are difficult to study in humans and for screening therapeutic strategies.
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Purpose: Cystoid macular oedema (CMO) is a very rare condition following cataract surgery in paediatric population. Nevertheless, we report a case series of patients with radiation induced cataract after retinoblastoma (Rb) treatment that underwent cataract surgery and developed subsequently late onset CMO. Methods: Between January 1984 and December 2009, 25 consecutive eyes (25 patients) with Rb presented with radiation induced cataract surgery at the Jules Gonin Eye Hospital. Sixteen eyes (16 patients) had prior radiation induced retinopathy and maculopathy (IRM). Out of these, 3 eyes (3 patients) developed CMO after cataract surgery. Results: One eye had Rb stage B, and 2 eyes had stage D International classification. All of them developed IRM following brachytherapy and/or external beam irradiation. Patients underwent phako-aspiration and in bag intraocular lens implantation after IRM had resolved. Mean age at cataract surgery was 10.7 ± 2.8 (SEM) (range 5-14) years old. Mean time between resolution of IRM and cataract surgery was 76.0 ± 27.2 (SEM) (range 24-116) months. Mean time of onset CMO after cataract surgery was 81.0 ± 34.4 (SEM) (range 13-124) months. There was no other underlying vascular or tractional factor for CMO development. All of them were treated with a combination of oral carbonic anhydrase inhibitor, topical steroid and topical non-steroid. Mean macular thickness pre-, during-, and post CMO were 134.0 ± 10.3, 298.0 ± 37.1, and 154.0 ± 4.0 (SEM) µm, respectively. Mean best corrected visual acuity pre-, during-, and post CMO were 0.31 ± 0.19, 0.46 ± 0.12, and 0.34 ± 0.18 (SEM) LogMAR, respectively. Mean time for CMO reabsorption was 17.0 ± 9.8 (SEM) months. Conclusions: To the best of our knowledge, CMO following paediatric cataract surgery is a very uncommon condition. Moreover, late onset CMO after phako-aspiration for radiation induced cataract in Rb patients has never been described. It is a rare complication but can be treated successfully.
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Purpose: to describe a case of probable bilateral diffuse uveal melanocytic proliferation (BDUMP) with scleral involvement, free from systemic malignancies and cataract. Methods: fifty months of follow up with recurrent complete ophthalmological examinations, including fundus photography, fluorescein/indocyanine green angiography (FA) and optical coherence tomography (OCT). Investigations also included an electroretinography (ERG) and histological examination of scleral biopsy. Extraocular malignancies were repeatedly searched. Results: the patient was a 61 year-old Italian man with chronic hepatitis type C. At first visit his best corrected visual acuity (BCVA) was 20/32 in OS and 20/25 in OD. Funduscopy showed multiple patch-shaped pigmented alterations involving macular region and mid retinal periphery. FA showed corresponding areas of late-phase hyperfluorescent pinpoints (figure 1a, OS) and intemediate-phase hypocyanescence (figure 1b, OS), with subtle serous neurosensory retinal detachment confirmed by OCT. Photopic and scotopic ERG tested normal. Systemic prednisone was administered for one month without any improvement. After ten months round pigmentary lesions appeared also in superior scleral surface of both eyes. Biopsy allowed to disclose slightly pigmented spindle cells. BCVA worsened for further 10 months, with enlargement of FA alteration areas but lenses still clear. After 30 months spontaneous coalescence and atrophy of retinal lesions started, paralleled by progressive visual recovery. At the end of our follow up BCVA was 20/25 in OU while scleral pigmentary lesions remained unchanged. Conclusions: we report the case of a patient with main features of BDUMP and some unusual findings. Although not all classical diagnostic criteria were fulfilled, the presence of scleral pigmented lesions and spontaneous visual recovery may enlarge clinical spectrum of the disease.