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Review Advances in the development of visual prostheses. 2003
Lakhanpal RR, Yanai D, Weiland JD, Fujii GY, Caffey S, Greenberg RJ, de Juan E, Humayun MS. · Intraocular Retinal Prosthesis (IRP) Group, Doheny Retina Institute, Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA. · Curr Opin Ophthalmol. · Pubmed #12777929 No free full text.
Abstract: Visual prostheses are based on neuronal electrical stimulation at different locations along the visual pathway (ie, cortical, optic nerve, epiretinal, subretinal). In terms of retinal prostheses, advances in microtechnology have allowed for the development of sophisticated, high-density integrated circuit devices that may be implanted either in the subretinal or epiretinal space. Analogous to the cochlear implants for some forms of deafness, these devices could restore useful vision by converting visual information into patterns of electrical stimulation that would excite the remaining spared inner retinal neurons in patients with diseases such as retinitis pigmentosa and age-related macular degeneration. The different types of implants and recent results are discussed, but special emphasis is given to retinal implants.
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Review Limited macular translocation: current concepts. 2002
Fujii GY, Au Eong KG, Humayun MS, de Juan E. · Retina Institute, Doheny Eye Institute, Keck School of Medicine, University of Southern California, DEI-3600, 1450 San Pablo Street, Los Angeles, CA 90033, USA. · Ophthalmol Clin North Am. · Pubmed #12515074 No free full text.
Abstract: Macular translocation is a promising treatment modality that offers patients a chance to improve their vision, potentially to a level that may allow reading and driving. Proper patient selection avoids surgery in eyes with permanently damaged central retina and identifies eyes with the greatest potential for good visual outcomes. Functionally, those patients with recent-onset subfoveal CNV without permanent foveal neurosensory retina damage have the greatest likelihood of good visual outcome. Use of fixation evaluation by means of the SLO appears to greatly optimize patient selection. Anatomically, the best candidates have small minimum desired translocations and healthy RPE-Bruch membrane-choriocapillaris complex beyond the borders of the lesion. The exact role of limited macular translocation for the management of subfoveal CNV in this era of photodynamic therapy remains to be evaluated, and a pilot multicenter, randomized, clinical trial is under way to compare the efficacy of limited macular translocation with photodynamic therapy in eyes with subfoveal CNV secondary to AMD.
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Review Retinal prosthesis for the blind. 2002
Margalit E, Maia M, Weiland JD, Greenberg RJ, Fujii GY, Torres G, Piyathaisere DV, O'Hearn TM, Liu W, Lazzi G, Dagnelie G, Scribner DA, de Juan E, Humayun MS. · Intraocular Prosthesis Group, Wilmer Eye Institute, Johns Hopkins, Baltimore, MD 21287-9277, USA. · Surv Ophthalmol. · Pubmed #12161210 No free full text.
Abstract: Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective.
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Review Limited macular translocation. 2001
de Juan E, Fujii GY. · The Wilmer Ophthalmological Institute, Johns Hopkins Hospital, The Johns Hopkins University, Baltimore, Maryland 21287-9277, USA. · Eye. · Pubmed #11450767 No free full text.
This publication has no abstract.
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Clinical Conference Initial experience of inferior limited macular translocation for subfoveal choroidal neovascularization resulting from causes other than age-related macular degeneration. 2001
Fujii GY, Humayun MS, Pieramici DJ, Schachat AP, Au Eong KG, de Juan E. · Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine., Baltimore, Maryland, USA. · Am J Ophthalmol. · Pubmed #11162983 No free full text.
Abstract: PURPOSE: To report our initial experience of inferior limited macular translocation in patients with subfoveal choroidal neovascularization resulting from causes other than age-related macular degeneration. METHODS: We conducted a retrospective study of 23 eyes of 22 patients with choroidal neovascularization involving the foveal center secondary to pathologic myopia (11 eyes), ocular histoplasmosis syndrome (four eyes), angioid streaks (four eyes), idiopathic neovascularization (three eyes), and multifocal choroiditis (one eye), in which the fovea was moved inferiorly by means of limited macular translocation surgery. The mean preoperative best-corrected visual acuity was 20/150, and in five of 23 eyes (21.7%) the visual acuity was 20/80 or better. The major outcome measures were preoperative and postoperative visual acuity, postoperative foveal displacement, and complications related to the surgery. RESULTS: The mean postoperative follow-up was 10.82 months (range, 6 to 18 months). Postoperative best-corrected visual acuity improved by 2 or more Snellen lines of visual acuity in 11 of 23 eyes (47.82%), remained within 1 line in seven of 23 eyes (30.43%), and worsened 2 or more lines of vision in five of 23 eyes (21.74%). The mean postoperative best-corrected visual acuity was 20/100, and in 12 of the 23 eyes (52.17%) the visual acuity achieved was 20/80 or better. Retinal detachment was the most frequent complication and occurred in six eyes (26%). CONCLUSIONS: Our initial experience with limited macular translocation shows that this treatment modality offers the potential to improve visual function in some eyes with subfoveal choroidal neovascularization secondary to myopia, ocular histoplasmosis syndrome, angioid streaks, idiopathic neovascularization, and multifocal choroiditis. Although longer and more complete follow-up is needed, the results of this initial series warrant further studies to define the precise role of macular translocation in the management of these conditions.
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Clinical Conference Human neural retinal transplantation. free! 2000
Humayun MS, de Juan E, del Cerro M, Dagnelie G, Radner W, Sadda SR, del Cerro C. · Department of Ophthalmology, Wilmer Ophthalmological Institute, the Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA. · Invest Ophthalmol Vis Sci. · Pubmed #10967070 links to free full text
Abstract: PURPOSE: A pilot study of human neural retinal transplantation was undertaken to investigate three major issues: whether a safe surgical procedure could be devised for transplantation of neural retinal tissue into the subretinal space, whether the transplant would be accepted in the subretinal space, and whether an improvement in vision could be achieved. METHODS: Eight patients with bare light perception (LP) vision due to retinitis pigmentosa (RP) and one patient with bare LP vision due to advanced neovascular age-related macular degeneration (AMD) received subretinal transplants of human fetal retinal microaggregate suspensions without postoperative systemic immunosuppression. The patient with AMD also received a fetal retinal sheet transplant. The ages of the patients ranged from 31 to 94 years (median, 55 years). The pre- and postoperative evaluations included visual function testing, detailed fundus examinations, fundus photography, fluorescein angiography, macular perimetry using a scanning laser ophthalmoscope (SLO), and full field and focal electroretinograms (ERGs). RESULTS: Three of the eight RP patients demonstrated possible improved light sensitivity during the initial months of follow-up. However, visual improvement disappeared between 3 and 13 months of follow-up. After transplantation, no subject showed any changes in the ERG recordings or SLO macular perimetry relative to their preoperative baseline. No patient experienced a retinal detachment, infection, or extensive bleeding. None of the patients developed retinal vasculitis or intraocular inflammation. In one RP patient, fluorescein angiography and fundus photography documented the formation and maturation of new host retinal vessels in the area of the transplant. CONCLUSIONS: Transplantation of fetal retinal photoreceptor suspensions into the subretinal space was achieved safely in nine subjects. Although a definite positive effect on visual function could not be demonstrated, the apparent high tolerance for graft tissue is promising for future efforts in the field of neural retinal transplantation.
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Article Rapid recurrence of geographic atrophy after full macular translocation for nonexudative age-related macular degeneration. 2005
Khurana RN, Fujii GY, Walsh AC, Humayun MS, de Juan E, Sadda SR. · Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA. · Ophthalmology. · Pubmed #16051364 No free full text.
Abstract: OBJECTIVE: To report the recurrence of geographic atrophy (GA) in a patient with nonexudative age-related macular degeneration (AMD) after full macular translocation. DESIGN: Observational case report. METHODS: Review of the clinical, photographic, and angiographic records of a patient with GA who underwent full macular translocation. MAIN OUTCOME MEASURES: Progression of GA. RESULTS: A 73-year-old man with GA secondary to nonexudative AMD underwent a macular translocation with 360 peripheral retinectomy (MT 360) in his left eye. On postoperative month 4, fundus photography showed subtle alterations of the pigment underneath the translocated foveal region. On postoperative month 9, the visual acuity worsened to preoperative levels and there was frank retinal pigment epithelium atrophy involving the new macular region. CONCLUSIONS: The rapid recurrence and development of GA in the translocated fovea after MT 360 raise new questions regarding the pathogenesis of GA. They also raise concerns regarding the use of MT 360 in the management of nonexudative AMD.
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Article Retinal thickness in normal and RCD1 dogs using optical coherence tomography. 2004
Panzan CQ, Güven D, Weiland JD, Lakhanpal RR, Javaheri M, de Juan E, Humayun MS. · Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA. · Ophthalmic Surg Lasers Imaging. · Pubmed #15580972 No free full text.
Abstract: BACKGROUND AND OBJECTIVE: To compare retinal thickness and retinal nerve fiber layer (RNFL) thickness values obtained by optical coherence tomography (OCT) in normal dogs and dogs with rod-cone dysplasia type 1 (RCD1). MATERIALS AND METHODS: Eight eyes of 6 normal hound-bred dogs and 12 eyes of 6 dogs with RCD1, 2 to 5 years of age, were examined using the Fast RNFL Thickness, Fast Macular Thickness, and line scan protocols of OCT. RESULTS: Retinal thickness was significantly higher in the tapetal fundus than in the non-tapetal fundus, in both normal (P = .0036) and RCD1 (P < .0001) dogs. Superotemporal, superonasal, and inferior retinal thickness values were significantly higher in normal dogs (P < .0001). Area centralis thickness was 183.5 +/- 10.66 microm in normal dogs and 136.16 +/- 13.12 microm in RCD1 dogs (P < .0001). There was no difference in RNFL thickness between normal and RCD1 dogs (P > .05). CONCLUSION: OCT scanning in dogs is considered to be a useful method of evaluation in future retinal studies in this animal model.
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Article Limited macular translocation for the management of subfoveal choroidal neovascularization after photodynamic therapy. 2003
Fujii GY, de Juan E, Humayun MS, Chang TS. · Doheny Retina Institute at the Doheny Eye Center, University of Southern California, Keck School of Medicine, Los Angeles, California 90033, USA. · Am J Ophthalmol. · Pubmed #12504715 No free full text.
Abstract: PURPOSE: To report our initial experience of limited macular translocation in patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration following photodynamic therapy with verteporfin. DESIGN: Interventional case series. METHODS: Retrospective review of four eyes of four consecutive patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration who underwent effective limited macular translocation following photodynamic therapy. The mean logarithm of minimal angle of resolution preoperative best-corrected visual acuity was 20/190 (range, 20/150 to 20/200), and in all eyes the visual acuity was 20/150 or worse. The major outcome measures were postoperative visual acuity and complications related to the surgery. RESULTS: The mean postoperative follow-up was 6.75 months (range, 6-8 months). Postoperative best-corrected visual acuity improved by 2 or more Snellen lines of visual acuity in three of four eyes (75%) and remained within 1 line in one of four eyes (25%). The mean postoperative best-corrected visual acuity was 20/100 (range, 20/40 to 20/150), and in two of the four eyes (50%) the visual acuity achieved was 20/100 or better. No complication was observed. CONCLUSIONS: Limited macular translocation may be a viable option in patients who have previously undergone photodynamic therapy.
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Article Patient selection for macular translocation surgery using the scanning laser ophthalmoscope. 2002
Fujii GY, de Juan E, Sunness J, Humayun MS, Pieramici DJ, Chang TS. · Doheny Retina Institute at the Doheny Eye Center, University of Southern California, Keck School of Medicine, Los Angeles, California. Wilmer Ophthalmological Institute, The Johns Hopkins Hospital. Baltimore, Maryland, USA. · Ophthalmology. · Pubmed #12208725 No free full text.
Abstract: OBJECTIVES: To evaluate the use of the scanning laser ophthalmoscope (SLO) as a predictor for potential visual improvement in eyes with subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) undergoing limited macular translocation. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Consecutive series of 71 eyes of 70 patients with subfoveal CNV secondary to AMD that underwent effective and uncomplicated limited macular translocation at the Wilmer Ophthalmological Institute. METHODS: Evaluation of the fundus microperimetry and fixation pattern was conducted on all patients using the Rodenstock scanning laser ophthalmoscope (G. Rodenstock Instrument GmbH, Munich, Germany) within 72 hours before surgery. MAIN OUTCOME MEASURES: Sensitivity and specificity in addition to positive and negative predictive values of SLO findings for visual outcome after macular translocation. RESULTS: Stable fixation presented the highest positive predictive value for visual acuity equal to or better than 20/100 (30 of 33 = 0.91), and predominantly eccentric fixation had the highest negative predictive value for visual acuity worse than 20/100 (7 of 9 = 0.78). Sensitivity was higher for the presence of predominantly central fixation (42 of 48 = 0.87), and specificity was higher for relatively unstable/unstable fixation (20 of 23 = 0.87). CONCLUSIONS: Eyes with stable and central fixation (without dense central scotoma) good preoperative visual acuity, and short length of symptoms are those with the greatest chance to achieve good vision after macular translocation. The knowledge of the fixation and microperimetry pattern enables better understanding of the macular function in eyes with AMD and may be useful for evaluation of baseline retinal cell viability. Incorporation of these testing modalities may help to optimize patient selection for macular translocation or other future techniques aimed at rescuing photoreceptors.
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Article Morphometric analysis of the macula in eyes with disciform age-related macular degeneration. 2002
Kim SY, Sadda S, Pearlman J, Humayun MS, de Juan E, Melia BM, Green WR. · The Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA. · Retina. · Pubmed #12172115 No free full text.
Abstract: PURPOSE: To evaluate the extent of neural cell death in eyes with disciform age-related macular degeneration. METHODS: Six eyes with disciform degeneration at various stages and five age-matched control eyes were selected for morphometric analysis using digitized light microscopic images. Disciform scars were classified as subneurosensory retinal, subretinal pigment epithelial, or combined lesions. The nuclei of the ganglion cell, inner nuclear, and outer nuclear layers were counted in contiguous 100 microm segments spanning a distance from 1,500 microm nasal to 1,500 microm temporal to the fovea. RESULTS: The outer nuclear layer was most severely attenuated in eyes with disciform scars, demonstrating a 69.4% reduction in cell number relative to control eyes. A loss in retinal ganglion cells (by 7.3%) and an increase in inner nuclear layer cells (by 10%) were observed, but these changes were not significant. Photoreceptor loss was most pronounced when the disciform scar was not covered by the retinal pigment epithelium. CONCLUSION: The nuclei of the outer nuclear layer are significantly attenuated in eyes with disciform age-related macular degeneration, while the ganglion cell and inner nuclear layers are relatively preserved. These findings suggest that replacement of outer nuclear function, by either retinal transplantation or implantation of the intraocular retinal prosthesis, might be a feasible therapeutic option for patients with this condition.
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Article Morphometric analysis of the macula in eyes with geographic atrophy due to age-related macular degeneration. 2002
Kim SY, Sadda S, Humayun MS, de Juan E, Melia BM, Green WR. · Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA. · Retina. · Pubmed #12172114 No free full text.
Abstract: PURPOSE: To evaluate the extent of neural cell death in eyes with geographic atrophy (GA). METHODS: Ten eyes with GA and five age-matched control eyes were selected for morphometric analysis. The nuclei of the ganglion cell, inner nuclear, and outer nuclear layers were counted in contiguous 100-microm segments from 1,500 microm nasal to 1,500 microm temporal to the fovea. RESULTS: The outer nuclear layer was most severely attenuated in eyes with GA, demonstrating a 76.9% reduction relative to control eyes (P < 0.0001). A significant loss of ganglion cells (by 30.7%) was also observed (P = 0.0008). There was no significant difference in the inner nuclear layer cells (P = 0.30). Among the GA eyes, the nuclei in all three layers were significantly reduced in segments in which the retinal pigment epithelium was completely absent (P </= 0.0003). CONCLUSION: Although the nuclei of the outer nuclear layer in eyes with GA were markedly attenuated, the nuclei of the inner nuclear layer were relatively preserved. There was also a significant reduction in ganglion cells in GA eyes, but considerable numbers remained even in the areas of complete retinal pigment epithelium atrophy. This finding suggests that therapies aimed at replacing outer nuclear function (such as neural retinal and retinal pigment epithelium transplantation or implantation of the intraocular retinal prosthesis) may be feasible for restoring vision in these patients.
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Article Inferior limited macular translocation for subfoveal choroidal neovascularization secondary to age-related macular degeneration: 1-year visual outcome and recurrence report. 2002
Fujii GY, de Juan E, Pieramici DJ, Humayun MS, Phillips S, Reynolds SM, Melia M, Schachat AP. · Doheny Retina Institute at the Doheny Eye Center, University of Southern California, Keck School of Medicine, Los Angeles 90033, USA. · Am J Ophthalmol. · Pubmed #12095810 No free full text.
Abstract: PURPOSE: To report the 1-year visual outcomes and incidence of persistent and recurrent choroidal neovascularization (CNV) after limited macular translocation (LMT) for subfoveal CNV in patients with age-related macular degeneration (ARMD). DESIGN: Interventional case series. METHODS: Retrospective review of 102 consecutive eyes of 101 patients that had the inferior limited macular translocation procedure for subfoveal choroidal neovascularization secondary to ARMD. The outcome measures were visual acuity at 12 months after surgery, change in visual acuity from baseline, the proportion of eyes with moderate (3 or more lines) or severe (6 or more lines) visual acuity loss, and cumulative incidence of persistent or recurrent CNV and its impact on visual acuity. Cumulative incidence was estimated using Kaplan-Meier survival analysis methods. Association between persistence and recurrence of CNV and the Snellen visual acuity recorded at each follow-up visit was evaluated using the Wilcoxon rank-sum test. RESULTS: Eighty-six (84.3%) of 102 eyes completed the 1-year follow-up. By 12 months postoperatively, 35 (40.7%) of the 86 eyes achieved visual acuity of 20/100 or better while 34 (39.5%) of the 86 eyes experienced 2 or more Snellen lines of visual improvement. In the 52 eyes with effective translocation and complete laser photocoagulation of the CNV complex with sparing of the sensory fovea, the estimated incidence of recurrence was 34.6% at 12 months (95% confidence interval of 21%-48%). Sixty-five percent of the recurrences were subfoveal and caused a decrease in visual acuity. There was a trend toward worse median change in visual acuity in eyes with persistent or recurrent CNV. CONCLUSIONS: Limited macular translocation for the treatment of subfoveal CNV secondary to ARMD is associated with improvement in visual acuity in approximately 39.5% of eyes and enables complete laser photocoagulation of the neovascular complex with sparing of the sensory macula in approximately 60.4% of eyes that complete 1 year follow-up. Persistence and recurrence of CNV are common after LMT and are important causes of vision loss. Further studies are warranted to more precisely evaluate the risks and benefits of LMT in ARMD.
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Article Effective nasal limited macular translocation. 2001
Fujii GY, de Juan E, Au Eong KG, Harlan JB. · The Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA. · Am J Ophthalmol. · Pubmed #11438073 No free full text.
Abstract: PURPOSE: To describe a case of effective foveal displacement toward the optic disk (nasal limited macular translocation) in a patient with a large subfoveal choroidal neovascularization secondary to age-related macular degeneration. METHODS: Case report. RESULTS: A 77-year-old white man presented with decreased vision of 20/400 due to subfoveal predominantly occult CNV secondary to age-related macular degeneration in the left eye. The CNV, measuring 9 Macular Photocoagulation Study disk areas in size, was centered temporally relative to the fovea with a minimum desired translocation of 650 microm for nasal macular translocation. The patient underwent nasal LMT with punctate retinotomy and temporal chorioscleral infolding, followed by postoperative head-positioning on his right side. Effective LMT was achieved with a postoperative nasal foveal displacement of 1400 microm. The entire CNV was ablated with laser photocoagulation postoperatively. His vision improved to 20/40 6 months postoperatively. CONCLUSION: Nasal LMT is feasible and may be considered in patients with subfoveal CNV centered temporally relative to the fovea.
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Article Transient formed visual hallucinations following macular translocation for subfoveal choroidal neovascularization secondary to age-related macular degeneration. 2001
Au Eong KG, Fujii GY, Ng EW, Humayun MS, Pieramici DJ, de Juan E. · Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21287-9277, USA. · Am J Ophthalmol. · Pubmed #11336950 No free full text.
Abstract: PURPOSE: To report the occurrence of transient formed visual hallucinations following macular translocation. METHODS: Two case reports. RESULTS: Two white women aged 84 and 83 years with bilateral age-related macular degeneration and unilateral subfoveal choroidal neovascularization underwent macular translocation with punctate retinotomy (limited macular translocation) and chorioscleral infolding in the eye with neovascularization. They complained of formed visual hallucinations which began within 24 hours following macular translocation and ceased 7 and 3 days postoperatively, respectively. Their symptoms occurred in the presence of normal cognition, orientation and insight, were not associated with other psychiatric symptoms, and were characteristic of Charles Bonnet syndrome (CBS). CONCLUSION: The temporary deliberate retinal detachment and/or poor vision following macular translocation may be associated with postoperative CBS, and this report extends the spectrum of conditions associated with CBS.
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Article Limited macular translocation for neovascular maculopathy. 2000
Haller JA, Hartranft CD, Fujii GY, Pieramici D, Humayun MS, de Juan E. · Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD 21287, USA. · Semin Ophthalmol. · Pubmed #11309740 No free full text.
Abstract: Subfoveal choroidal neovascularization presents one of the most difficult challenges to vision. No treatment option has yet solved the problem of subretinal hemorrhage and fibrovascular scarring causing permanent photoreceptor degeneration and loss. Limited macular translocation provides a surgical approach to this challenge by moving the fovea onto an adjacent area of relatively normal subretinal space and pigment epithelium in a selected group of patients. The choroidal neovascularization, thus, becomes extrafoveal or juxtafoveal and can be treated with focal laser photocoagulation. This article describes the current technique of limited macular translocation and reviews early results. The procedure offers selected patients a chance to retain useful central vision. About 40% of patients at 6 months are able to read and drive (visual acuity >20/100). Complications including retinal detachment, hemorrhage, and macular folds have decreased with experience. Limited macular translocation is a promising approach to neovascular maculopathy, but needs ongoing careful evaluation.
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Article Histologic correlation of human neural retinal transplantation. free! 2000
del Cerro M, Humayun MS, Sadda SR, Cao J, Hayashi N, Green WR, del Cerro C, de Juan E. · Department of Ophthalmology, University of Rochester School of Medicine, New York, USA. · Invest Ophthalmol Vis Sci. · Pubmed #10967076 links to free full text
Abstract: PURPOSE: To describe the histologic findings of the transplanted eye of a 94-year-old man with neovascular age-related macular degeneration, who 3 years earlier underwent subretinal transplantation of both a fetal neural retinal sheet and a retinal microaggregrate suspension. METHODS: Serial sections of the posterior segment of the eye and the transplanted areas were processed and studied by routine histologic techniques, including both light and transmission electron microscopy (TEM). Transplanted areas were also examined for the presence of glial, neuronal, and photoreceptor cell markers by standard immunohistochemical methods. RESULTS: After transplantation in this patient, there was no visual improvement. Light microscopic examination disclosed survival of the transplanted cells in the subretinal space with no evidence of inflammation or rejection. The neural retinal sheet transplant developed a layered configuration. The retinal pigment epithelium (RPE) was absent over much of the posterior pole, including the area of transplantation. TEM examination and immunohistochemical analysis disclosed the presence of neuronal and glial cells within the transplant. A few transplant neuronal cell processes overlying a focus of residual RPE cells were positive for S-antigen, but well-developed photoreceptor outer segments were not present. CONCLUSIONS: Long-term survival of transplanted neural retinal tissue can be achieved in human patients without immunosuppression. The lack of photoreceptor development in this patient may be the result of absent or dysfunctional RPE. Nonetheless, the long-term survival of grafted tissue in the human subretinal space in the absence of immunosuppressive treatment is promising for future efforts in the field of neural retinal transplantation.
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Article Effective macular translocation without scleral imbrication. 1999
de Juan E, Vander JF. · Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA. · Am J Ophthalmol. · Pubmed #10511045 No free full text.
Abstract: PURPOSE: To describe a case of effective macular translocation accomplished without scleral imbrication or extensive retinotomy. METHODS: A case report of a 59-year-old woman with subfoveal choroidal neovascularization in her left eye who underwent vitrectomy with macular detachment and fluid-air exchange. RESULTS: The macula was translocated approximately 500 microm inferiorly, allowing for photocoagulation of extrafoveal neovascularization. CONCLUSION: Limited macular translocation may be attained without scleral imbrication or significant retinotomy.
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Article Pattern electrical stimulation of the human retina. 1999
Humayun MS, de Juan E, Weiland JD, Dagnelie G, Katona S, Greenberg R, Suzuki S. · Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA. · Vision Res. · Pubmed #10396625 No free full text.
Abstract: Experiments were conducted to study if electrical stimulation of the retinal surface can elicit visual sensation in individuals blind from end-stage retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Under local anesthesia, different stimulating electrodes were inserted through the eyewall and positioned over the surface of the retina. Subjects' psychophysical responses to electrical stimulation were recorded. Subjects perceived simple forms in response to pattern electrical stimulation of the retina. A non-flickering perception was created with stimulating frequencies between 40 and 50 Hz. The stimulation threshold was dependent on the targeted retinal area (macular versus extramacular).
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