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The Role of the Human Visual Cortex in Assessment of the Long-Term Durability of Retinal Gene Therapy in Follow-on RPE65 Clinical Trial Patients.
Ashtari, M, Nikonova, ES, Marshall, KA, Young, GJ, Aravand, P, Pan, W, Ying, GS, Willett, AE, Mahmoudian, M, Maguire, AM, et al
Ophthalmology. 2017;(6):873-883
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Abstract
PURPOSE Gene therapy (GT) has offered immense hope to individuals who are visually impaired because of RPE65 mutations. Although GT has shown great success in clinical trials enrolling these individuals, evidence for stability and durability of this treatment over time is still unknown. Herein we explored the value of functional magnetic resonance imaging (fMRI) as an objective measure to assess independently the longevity of retinal GT. DESIGN Individuals with RPE65 mutations who underwent GT in their worse-seeing eye in a phase 1 clinical trial received a second subretinal injection in their contralateral eye in a follow-on clinical trial. Functional magnetic resonance imaging (MRI) was performed longitudinally to assess brain responses of patients with RPE65 mutations after stimulation of their most recently treated eye before and 1 to 3 years after GT. PARTICIPANTS Seven participants with RPE65 mutations who were part of the follow-on clinical trial gave informed consent to participate in a longitudinal neuroimaging fMRI study. METHODS All participants underwent fMRI using a 3-Tesla MRI system and a 32-channel head coil. Participants' cortical activations were assessed using a block design paradigm of contrast reversing checkerboard stimuli delivered using an MRI-compatible video system. MAIN OUTCOME MEASURES The primary parameters being measured in this study were the qualitative and quantitative fMRI cortical activations produced by our population in response to the visual task. RESULTS Functional MRI results showed minimal or no cortical responses before GT. Significant increase in cortical activation lasting at least 3 years after GT was observed for all participants. Repeated measures analysis showed significant associations between cortical activations and clinical measures such as full-field light sensitivity threshold for white, red, and blue colors; visual field; and pupillary light reflex. CONCLUSIONS Participants with RPE65 mutations showed intact visual pathways, which became responsive and strengthened after treatment. Functional MRI results independently revealed the efficacy and durability of a 1-time subretinal injection. The fMRI results paralleled those recently reported during the long-term clinical evaluations of the same patients. Results from this study demonstrated that fMRI may play an important role in providing complementary information to patients' ophthalmic clinical evaluation and has usefulness as an outcome measure for future retinal intervention studies.
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Repeatability and reproducibility of retinal thickness measurements in diabetic patients with spectral domain optical coherence tomography.
Fiore, T, Androudi, S, Iaccheri, B, Lupidi, M, Giansanti, F, Fruttini, D, Biondi, L, Cagini, C
Current eye research. 2013;(6):674-9
Abstract
BACKGROUND To determine the repeatability and reproducibility of optical coherence tomography (OCT) Spectralis retinal thickness measurements in diabetic patients with clinically significant macular edema (CSME). METHODS Twelve eyes of 12 volunteers (without macular pathology - control group) and 21 eyes of 21 diabetic patients with CSME were included in the study. Reproducibility, repeatability, intraclass correlation coefficients (ICCs) and intrasession correlation coefficients were tested with 20 × 15 degree raster scans consisting of 19 high-resolution line scans that were repeated three times by two experienced examiners. RESULTS In the control group, examining all regions, coefficient of repeatability was less than 1.1%, while coefficient of reproducibility was less than 2.2%. In diabetic patients, examining all regions, coefficient of repeatability was less than 2.6%, while coefficient of reproducibility was less than 2.4%. ICCs were, respectively, greater than or equal to 0.98 in the control group and 0.99 in diabetic patients. Intrasession coefficients of variation were less than 0.4% in the control group and less than 0.5% in diabetic patients. CONCLUSION Retinal thickness measurements are repeatable and reproducible with OCT Spectralis in both the control group and diabetic patients. The results indicate that a change in central subfield thickness exceeding 12 µm and 3% in the diabetic patients is likely to be real.
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Retinal micropseudocysts in diabetic retinopathy: prospective functional and anatomic evaluation.
Forte, R, Cennamo, G, Finelli, ML, Bonavolontà, P, Greco, GM, de Crecchio, G
Ophthalmic research. 2012;(1):6-11
Abstract
AIM: To evaluate the prevalence, progression and functional predictive value of retinal micropseudocysts (MPCs) in diabetic patients. METHODS Prospective controlled observational study. From among all the type 2 diabetic patients evaluated during a period of 5 months between September 2009 and January 2010, we enrolled all patients with retinal MPCs at spectral-domain scanning laser ophthalmoscope/optical coherence tomography (SD-SLO/OCT) not previously treated for diabetic retinopathy. Forty diabetic patients without MPCs served as the control group. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular sensitivity and stability of fixation at SD-SLO/OCT microperimetry were measured monthly for 12 months. RESULTS 22/156 patients with type 2 diabetes (14.1%, 32 eyes) met the inclusion criteria. The 95% confidence interval for the prevalence estimate of MPCs was 12.3-16.6%. Mean BCVA, CRT and central retinal sensitivity at baseline were 77.53 ± 2.2 Early Treatment Diabetic Retinopathy Study letters, 242.31 ± 31.0 µm and 15.95 ± 0.61 dB, respectively. Fixation was stable in all cases. Compared to the control group, eyes with MPCs had similar BCVA but greater CRT (p = 0.01) and reduced macular sensitivity (p = 0.001) at baseline and at each follow-up visit. Over time, CRT remained stable in eyes with MPCs, whereas macular sensitivity progressively decreased. CONCLUSION MPCs in diabetic retinopathy are associated, temporally or causally, with a progressive reduction of macular sensitivity despite a stable BCVA, CRT and fixation.
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Nonmydriatic retinal image review at time of endocrinology visit results in short-term HbA1c reduction in poorly controlled patients with diabetic retinopathy.
Salti, H, Cavallerano, JD, Salti, N, Jawhari, DJ, Haddad, S, Sun, JK, Salti, I, Aiello, LP
Telemedicine journal and e-health : the official journal of the American Telemedicine Association. 2011;(6):415-9
Abstract
OBJECTIVES The objective of this study was to evaluate the effect of discussing retinal findings following nonmydriatic retinal imaging during an endocrinology visit on subsequent HbA1c in poorly controlled diabetic patients with diabetic retinopathy (DR). MATERIALS AND METHODS During a visit to an endocrinologist, patients with DR and documented HbA1c ≥ 8.0% within the preceding month were assigned to either addition of nonmydriatic imaging and discussion of retinal findings or standard endocrinology evaluation alone. Ophthalmology care was otherwise the same in both groups. Changes in HbA1c were evaluated 3 months later. RESULTS One hundred thirteen (94%) of the original 120 subjects completed the study. The mean HbA1c change in the retinal imaging group was a decline of 1.35%, whereas the control group had a 0.26% increase. Controlling for gender, age, duration of diabetes, presence of hypertension, and use of insulin, the difference between groups was significant (p<0.0003). CONCLUSIONS Nonmydriatic imaging and discussion of retinal findings during an endocrinologist visit may contribute, at least in the short term, to improved glycemic control in patients with DR and elevated HbA1c.
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Manual acupuncture for relieving pain associated with panretinal photocoagulation.
Chiu, HH, Wu, PC
Journal of alternative and complementary medicine (New York, N.Y.). 2011;(10):915-21
Abstract
OBJECTIVE The feasibility of manual acupuncture for reducing pain associated with panretinal photocoagulation (PRP) was investigated. METHODS This was a prospective, comparative nonrandomized study on patients with proliferative diabetic retinopathy who were receiving PRP treatment. The protocol of PRP included three sequential sessions of treatment at 2-week intervals. Both the acupuncture (acuPRP) and control groups had no acupuncture in the first session. In the second session, acupuncture was given to the acuPRP group only. The third session of PRP completed the laser treatment course. Acupuncture performed only at GB 37 (Guāngmíng) just before PRP, and the needle was removed after the treatment. An 11-point Likert-type verbal pain score test was given to all patients after each PRP treatment. RESULTS Of 34 patients with proliferative diabetic retinopathy, 18 patients were allocated to the acuPRP group and 16 patients were allocated to the control group. After the first PRP treatment, there was no statistical difference in mean pain scores between the acuPRP and control groups (6.8±1.2 versus 6.3±2.1, respectively, p=0.383). After the second PRP treatment, the mean pain score in the acuPRP group was significantly lower, compared with the control group (3.9±1.8 versus 7.4±1.9, respectively, p<0.0001). Within the group, the mean pain scores were significantly higher during the second PRP treatment, compared with the first PRP treatment, in the control group (p=0.0003). In contrast, the mean pain scores were significantly lower during the second PRP treatment, compared with the first PRP treatment in the acuPRP group (p<0.0001). No adverse reactions or complications were noted. CONCLUSIONS Acupuncture might help reduce pain during PRP treatment. However, further randomized studies are necessary to verify these preliminary results.
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Increases in alpha oscillatory power reflect an active retinotopic mechanism for distracter suppression during sustained visuospatial attention.
Kelly, SP, Lalor, EC, Reilly, RB, Foxe, JJ
Journal of neurophysiology. 2006;(6):3844-51
Abstract
Human electrophysiological (EEG) studies have demonstrated the involvement of alpha band (8- to 14-Hz) oscillations in the anticipatory biasing of attention. In the context of visual spatial attention within bilateral stimulus arrays, alpha has exhibited greater amplitude over parietooccipital cortex contralateral to the hemifield required to be ignored, relative to that measured when the same hemifield is to be attended. Whether this differential effect arises solely from alpha desynchronization (decreases) over the "attending" hemisphere, from synchronization (increases) over the "ignoring" hemisphere, or both, has not been fully resolved. This is because of the confounding effect of externally evoked desynchronization that occurs involuntarily in response to visual cues. Here, bilateral flickering stimuli were presented simultaneously and continuously over entire trial blocks, such that externally evoked alpha desynchronization is equated in precue baseline and postcue intervals. Equivalent random letter sequences were superimposed on the left and right flicker stimuli. Subjects were required to count the presentations of the target letter "X" at the cued hemifield over an 8-s period and ignore the sequence in the opposite hemifield. The data showed significant increases in alpha power over the ignoring hemisphere relative to the precue baseline, observable for both cue directions. A strong attentional bias necessitated by the subjective difficulty in gating the distracting letter sequence is reflected in a large effect size of 2.1 (eta2 = 0.82), measured from the attention x hemisphere interaction. This strongly suggests that alpha synchronization reflects an active attentional suppression mechanism, rather than a passive one reflecting "idling" circuits.
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Quantitative measurement of retinal thickness in patients with diabetic macular edema is useful for evaluation of therapeutic agents.
Funatsu, H, Yamashita, H, Shimizu, E, Mimura, T, Nakamura, S, Hori, S
Diabetes research and clinical practice. 2004;(3):219-27
Abstract
The effect of lisinopril (an angiotensin-converting enzyme inhibitor) on diabetic macular edema (DME) was investigated by quantitative measurement of macular thickness. In a nonrandomized clinical trial, 19 normotensive type 2 diabetic patients with DME prospectively received oral lisinopril therapy for 2 months. Another 10 normotensive type 2 diabetic patients with similar DME were prospectively followed for two months without treatment. Central macular thickness was measured with a retinal thickness analyzer (RTA). In the lisinopril group, visual acuity improved by two lines or more in two out of 19 eyes (11%), was unchanged in 15 eyes (78%), and deteriorated by two lines or more in two eyes (11%). The mean central macular thickness was significantly reduced after 2 months of treatment (381.3 +/- 121.1 microm) compared with that before administration (475.2 +/- 171.0 microm, P = 0.0093). In the control group, central macular thickness was not significantly decreased after 2 months (458.5 +/- 113.7 microm, P = 0.2178) compared with the baseline value (464.7 +/- 152.2). Fluorescein angiography showed that macular leakage was decreased in 10 patients from the lisinopril group (53%) and was unchanged in nine patients (47%). There was a significant difference of central macular thickness between the patients with and without improvement of macular leakage (P = 0.0040). Lisinopril therapy may reduce macular thickness in patients with DME, as shown by this quantitative study. In addition, quantitative measurement of retinal thickness is useful when evaluating therapeutic agents for DME.
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Microscope-induced retinal phototoxicity in cataract surgery of short duration.
Kleinmann, G, Hoffman, P, Schechtman, E, Pollack, A
Ophthalmology. 2002;(2):334-8
Abstract
OBJECTIVE Microscope-induced retinal phototoxicity has been described after prolonged cataract surgery, usually in operations lasting longer than 100 minutes. The purpose of this study was to compare the features of microscope-induced retinal phototoxicity occurring in patients who underwent cataract surgery of short duration and long duration. DESIGN A retrospective nonrandomized comparative trial. PARTICIPANTS Thirty-four patients, whose medical records documented the development of phototoxic lesions in the retina as a result of cataract surgery, were divided into two groups: group A with 14 patients whose operating time was 30 minutes or less, and group B with 20 patients whose operating time was greater than 30 minutes. INTERVENTION All patients underwent either phacoemulsification or extracapsular cataract extraction (ECCE) with implantation of an intraocular lens. RESULTS The mean operating time was 23.1 minutes (range, 11-30 minutes) in group A, and 60.8 minutes (range, 34-123 minutes) in group B. Phacoemulsification was done more often in group A (P = 0.001) and ECCE in group B (P = 0.0003). A final refraction of +/- 1 D was achieved by 12 eyes (86%) in group A and by 12 eyes (60%) in group B (P = 0.11). The correlation between final refraction and duration of the operation was significant; the closer the final refraction approached to emmetropia, the shorter the duration of surgery (r = 0.53; P = 0.001). Diabetic retinopathy was more common in group A (P = 0.03). CONCLUSIONS Phototoxic lesions of the retina may occur during cataract surgery even when the duration of the operation is short. The most relevant associated factors found in this study were correction approximating emmetropia and diabetic retinopathy.