1
|
Chen Z, Chen B, Hu P, Liu H, Zheng D. A preliminary observation on rod cell photobiomodulation in treating diabetic macular edema. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2022; 2:100051. [PMID: 37846386 PMCID: PMC10577862 DOI: 10.1016/j.aopr.2022.100051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/25/2022] [Accepted: 04/21/2022] [Indexed: 10/18/2023]
Abstract
Purpose To evaluate the safety and effectiveness of photobiomodulation (PBM) in the treatment of diabetic macular edema (DME). Methods It was a single-center, self-controlled prospective study. The clinical records of 12 diabetic retinopathy patients (5 males and 7 females, 20 eyes in total) who were treated with PBM for DME at the Second Affiliated Hospital, Zhejiang University School of Medicine, were analyzed. The mean age was 56 (26-68) years. All the participants received PBM treatment during darkness at night in no less than 5 days per week and no less than 8 h per day. In the baseline check and follow-up checks (1, 2, 6, 10, and 12 months after the start of treatment), the best-corrected visual acuity, the thickness of the retina in the macula, and the changes of the fundus lesions were observed. Wilcoxon signed rank test was used to compare the results before and after treatment. P < 0.05 was considered statistically significant. Results No fundus complication was observed during follow-up checks. In baseline and 12-month follow-up checks, the best-corrected visual acuity was 71.75 ± 12.47 and 79.50 ± 10.85, maximal retinal thickness in macular area was 390.95 ± 77.12 μm and 354.13 ± 55.03 μm, average retinal thickness in macular area was 334.25 ± 36.45 μm and 314.31 ± 33.28 μm, foveal thickness was 287.00 ± 46.79 μm and 265.63 ± 67.14 μm. The best-corrected visual acuity, average retinal thickness in macular area in consecutive follow-up results except that in the 1st month showed significant difference compared with baseline results. There were significant difference between every follow-up result and baseline result of maximal retinal thickness in macular area (P < 0.05). All follow-up results of foveal thickness were not significantly different (P > 0.05) from the baseline result, except that in the 6th month (P = 0.049). Obvious improvement could be observed in retinal fundus fluorescein angiography images. Conclusions PBM is a safe and effective treatment of DME, which deserves further investigation.
Collapse
Affiliation(s)
- Zhiqing Chen
- Eye Centre, The Second Affiliated Hospital of the School of Medicine, Zhejiang University, Hangzhou, China
| | - Binbin Chen
- Eye Centre, The Second Affiliated Hospital of the School of Medicine, Zhejiang University, Hangzhou, China
| | - Peike Hu
- Eye Centre, The Second Affiliated Hospital of the School of Medicine, Zhejiang University, Hangzhou, China
| | - Haipeng Liu
- Research Centre for Intelligent Healthcare, University of Coventry, Coventry, UK
| | - Dingchang Zheng
- Research Centre for Intelligent Healthcare, University of Coventry, Coventry, UK
| |
Collapse
|
2
|
Detecting Diabetic Retinal Neuropathy Using Fundus Perimetry. Int J Mol Sci 2021; 22:ijms221910726. [PMID: 34639066 PMCID: PMC8509347 DOI: 10.3390/ijms221910726] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/18/2021] [Accepted: 09/28/2021] [Indexed: 02/06/2023] Open
Abstract
Fundus perimetry is a new technique for evaluating the light sense in the retina in a point-to-point manner. Light sense is fundamentally different from visual acuity, which measures the threshold for discriminating and perceiving two points or lines, called the minimum cognoscible. The quality of measurement of retinal sensitivity has dramatically increased in the last decade, and the use of fundus perimetry is now gaining popularity. The latest model of fundus perimetry, MP-3, can be used for a wide range of measurements and has an advanced eye tracking system. High background illumination enables accurate measurement of mesopic retail sensitivity. Recent investigations have shown that neuronal damage precedes vascular abnormalities in diabetic retinopathy. The loss of retinal function has also been reported prior to morphological changes in the retina. In this review, the importance of measuring retinal sensitivity to evaluate visual function in the early stages of diabetic retinopathy was discussed. The usefulness of retinal sensitivity as an outcome measure in clinical trials for treatment modalities is also presented. The importance of fundus perimetry is promising and should be considered by both diabetes researchers and clinical ophthalmologists.
Collapse
|
3
|
Rubinstein Y, Weiner C, Chetrit N, Newman H, Hecht I, Shoshany N, Pras E. Effect of light and diurnal variation on macular thickness in X-linked retinoschisis: a case series. Graefes Arch Clin Exp Ophthalmol 2020; 258:529-536. [PMID: 31897705 DOI: 10.1007/s00417-019-04578-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/07/2019] [Accepted: 12/18/2019] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Diurnal variations in foveal thickness have been reported in several ocular pathologies including X-linked retinoschisis (XLRS), but its underlying mechanism is poorly understood. Rods are active under scotopic conditions with high metabolic demand, and its decrease may have positive effect on metabolic activity and macular thickness. The purpose of this study is to evaluate whether exposure to light and diurnal variation influence macular thickness in XLRS patients. METHODS Five patients with clinical suspicion of XLRS underwent RS1 gene sequencing and optical coherence tomography measurements at three consecutive times: morning following sleep in a dark room, morning following sleep in an illuminated room, and late afternoon following sleep in an illuminated room. Central macular thickness (CMT) was compared between measurements, and molecular analysis was performed. RESULTS Five RS1 mutations were identified: p.Gly140Arg, p.Arg141Cys, p.Gly109Glu, p.Pro193Leu, and p.Arg200His in patients 1-5, respectively. Two patients (4-5) had atrophied macula and were excluded from macular thickness variation analysis. A significant decrease in CMT between morning and afternoon measurements was observed in all patients (1-3: mean: 455.0 ± 32 μm to 342.17 ± 39 μm, 25%). Morning measurements following sleep in an illuminated room show a CMT reduction in all eyes of all patients with a mean reduction of 113 μm (mean: 547.17 ± 105 μm to 455.0 ± 32 μm, 17%). CONCLUSIONS Among XLRS patients, CMT decreased at the afternoon compared to the morning of the same day and may be reduced following sleep in an illuminated room. These results help shed light on the pathophysiologic process underlying intraretinal fluid accumulation involved with the disease.
Collapse
Affiliation(s)
- Yair Rubinstein
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel.,Matlow's Ophthalmogenetic Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel
| | - Chen Weiner
- Matlow's Ophthalmogenetic Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel.,Sackler faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noa Chetrit
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel
| | - Hadas Newman
- Sackler faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Idan Hecht
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel. .,Sackler faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Nadav Shoshany
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel.,Matlow's Ophthalmogenetic Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel
| | - Eran Pras
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel.,Matlow's Ophthalmogenetic Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel.,Sackler faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
4
|
Sengupta S, Singh A, Leopold HA, Gulati T, Lakshminarayanan V. Ophthalmic diagnosis using deep learning with fundus images - A critical review. Artif Intell Med 2019; 102:101758. [PMID: 31980096 DOI: 10.1016/j.artmed.2019.101758] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022]
Abstract
An overview of the applications of deep learning for ophthalmic diagnosis using retinal fundus images is presented. We describe various retinal image datasets that can be used for deep learning purposes. Applications of deep learning for segmentation of optic disk, optic cup, blood vessels as well as detection of lesions are reviewed. Recent deep learning models for classification of diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy are also discussed. Important critical insights and future research directions are given.
Collapse
Affiliation(s)
- Sourya Sengupta
- Theoretical and Experimental Epistemology Lab, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada; Department of Systems Design Engineering, University of Waterloo, Ontario, Canada.
| | - Amitojdeep Singh
- Theoretical and Experimental Epistemology Lab, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada; Department of Systems Design Engineering, University of Waterloo, Ontario, Canada
| | - Henry A Leopold
- Theoretical and Experimental Epistemology Lab, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada; Department of Systems Design Engineering, University of Waterloo, Ontario, Canada
| | - Tanmay Gulati
- Department of Computer Science and Engineering, Manipal Institute of Technology, India
| | - Vasudevan Lakshminarayanan
- Theoretical and Experimental Epistemology Lab, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada; Department of Systems Design Engineering, University of Waterloo, Ontario, Canada
| |
Collapse
|
5
|
Sivaprasad S, Vasconcelos JC, Prevost AT, Holmes H, Hykin P, George S, Murphy C, Kelly J, Arden GB. Clinical efficacy and safety of a light mask for prevention of dark adaptation in treating and preventing progression of early diabetic macular oedema at 24 months (CLEOPATRA): a multicentre, phase 3, randomised controlled trial. Lancet Diabetes Endocrinol 2018; 6. [PMID: 29519744 PMCID: PMC5908782 DOI: 10.1016/s2213-8587(18)30036-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND We aimed to assess 24-month outcomes of wearing an organic light-emitting sleep mask as an intervention to treat and prevent progression of non-central diabetic macular oedema. METHODS CLEOPATRA was a phase 3, single-blind, parallel-group, randomised controlled trial undertaken at 15 ophthalmic centres in the UK. Adults with non-centre-involving diabetic macular oedema were randomly assigned (1:1) to wearing either a light mask during sleep (Noctura 400 Sleep Mask, PolyPhotonix Medical, Sedgefield, UK) or a sham (non-light) mask, for 24 months. Randomisation was by minimisation generated by a central web-based computer system. Outcome assessors were masked technicians and optometrists. The primary outcome was the change in maximum retinal thickness on optical coherence tomography (OCT) at 24 months, analysed using a linear mixed-effects model incorporating 4-monthly measurements and baseline adjustment. Analysis was done using the intention-to-treat principle in all randomised patients with OCT data. Safety was assessed in all patients. This trial is registered with Controlled-Trials.com, number ISRCTN85596558. FINDINGS Between April 10, 2014, and June 15, 2015, 308 patients were randomly assigned to wearing the light mask (n=155) or a sham mask (n=153). 277 patients (144 assigned the light mask and 133 the sham mask) contributed to the mixed-effects model over time, including 246 patients with OCT data at 24 months. The change in maximum retinal thickness at 24 months did not differ between treatment groups (mean change -9·2 μm [SE 2·5] for the light mask vs -12·9 μm [SE 2·9] for the sham mask; adjusted mean difference -0·65 μm, 95% CI -6·90 to 5·59; p=0·84). Median compliance with wearing the light mask at 24 months was 19·5% (IQR 1·9-51·6). No serious adverse events were related to either mask. The most frequent adverse events related to the assigned treatment were discomfort on the eyes (14 with the light mask vs seven with the sham mask), painful, sticky, or watery eyes (14 vs six), and sleep disturbance (seven vs one). INTERPRETATION The light mask as used in this study did not confer long-term therapeutic benefit on non-centre-involving diabetic macular oedema and the study does not support its use for this indication. FUNDING The Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research partnership.
Collapse
Affiliation(s)
- Sobha Sivaprasad
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK.
| | - Joana C Vasconcelos
- Imperial Clinical Trials Unit, School of Public Health, Imperial College London, London, UK
| | - A Toby Prevost
- Imperial Clinical Trials Unit, School of Public Health, Imperial College London, London, UK
| | - Helen Holmes
- King's Clinical Trials Unit at King's Health Partners, King's College London, London, UK
| | - Philip Hykin
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Sheena George
- Hillingdon Hospital, Hillingdon Hospitals National Health Service Foundation Trust, Uxbridge, UK
| | - Caroline Murphy
- King's Clinical Trials Unit at King's Health Partners, King's College London, London, UK
| | - Joanna Kelly
- King's Clinical Trials Unit at King's Health Partners, King's College London, London, UK
| | - Geoffrey B Arden
- Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
| | | |
Collapse
|
6
|
Andrawus E, Veildbaum G, Zemel E, Leibu R, Perlman I, Shehadeh N. Light Modulates Ocular Complications in an Albino Rat Model of Type 1 Diabetes Mellitus. Transl Vis Sci Technol 2017; 6:1. [PMID: 28685103 PMCID: PMC5497601 DOI: 10.1167/tvst.6.4.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 04/03/2017] [Indexed: 12/14/2022] Open
Abstract
PURPOSE The purpose of the study was to assess potential interactions of light exposure and hyperglycemia upon ocular complications in diabetic rats. METHODS Streptozotocin-induced (STZ-induced) diabetic rats (N = 39) and non-diabetic rats (N = 9) were distributed into eight groups according to the irradiance and color of the light phase during the 12/12-hour light/dark regime. Follow-up lasted 90 days and included assessment of cataract development and electroretinogram (ERG) recordings. Stress to the retina was also assessed by glial fibrillary acidic protein immunocytochemistry. RESULTS Cataract development was fast in diabetic rats that were exposed to unattenuated white light or to bright colored lights during the light phase. Diabetic rats that were kept under attenuated brown or yellow light during the light phase exhibited slower rate of cataract development. Electroretinogram responses indicated very severe retinal damage in diabetic rats kept under bright colored lights in the blue-yellow range or bright white light during the light phase. Electroretinogram damage was milder in rats kept under bright red light or attenuated yellow or brown light during the light phase. Glial fibrillary acidic protein expression in retinal Müller cells was consistent with ERG assessment of retinal damage. CONCLUSIONS Attenuating white light and filtering out short wavelengths have a protective effect on the eyes of diabetic rats as evident by slower rate of cataract formation and a smaller degree of retinal damage. TRANSLATIONAL RELEVANCE Our findings suggest that special glasses attenuating light exposure and filtering out short wavelengths (400-530 nm) may be beneficial for diabetic patients.
Collapse
Affiliation(s)
- Elias Andrawus
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Gizi Veildbaum
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Rappaport Family Institute for Research in the Medical Sciences, Haifa, Israel
| | - Esther Zemel
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Rappaport Family Institute for Research in the Medical Sciences, Haifa, Israel
| | - Rina Leibu
- Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel
| | - Ido Perlman
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Rappaport Family Institute for Research in the Medical Sciences, Haifa, Israel
| | - Naim Shehadeh
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Rappaport Family Institute for Research in the Medical Sciences, Haifa, Israel.,Department of Pediatrics A and the Pediatric Diabetes Unit, Rambam Health Care Campus, Haifa, Israel
| |
Collapse
|
7
|
Do photoreceptor cells cause the development of retinal vascular disease? Vision Res 2017; 139:65-71. [PMID: 28438678 DOI: 10.1016/j.visres.2017.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
The retinal vasculature is affected in a number of clinically important retinopathies, including diabetic retinopathy. There has been a considerable amount of research into the pathogenesis of retinal microvascular diseases, but the potential contribution of the most abundant cell population in the retina, photoreceptor cells, has been largely overlooked. This review summarizes ongoing research suggesting that photoreceptor cells play a critical role in the development of retinal vascular disease in diabetic retinopathy and other retinopathies.
Collapse
|
8
|
Hansen RM, Moskowitz A, Akula JD, Fulton AB. The neural retina in retinopathy of prematurity. Prog Retin Eye Res 2017; 56:32-57. [PMID: 27671171 PMCID: PMC5237602 DOI: 10.1016/j.preteyeres.2016.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/15/2016] [Accepted: 09/20/2016] [Indexed: 12/26/2022]
Abstract
Retinopathy of prematurity (ROP) is a neurovascular disease that affects prematurely born infants and is known to have significant long term effects on vision. We conducted the studies described herein not only to learn more about vision but also about the pathogenesis of ROP. The coincidence of ROP onset and rapid developmental elongation of the rod photoreceptor outer segments motivated us to consider the role of the rods in this disease. We used noninvasive electroretinographic (ERG), psychophysical, and retinal imaging procedures to study the function and structure of the neurosensory retina. Rod photoreceptor and post-receptor responses are significantly altered years after the preterm days during which ROP is an active disease. The alterations include persistent rod dysfunction, and evidence of compensatory remodeling of the post-receptor retina is found in ERG responses to full-field stimuli and in psychophysical thresholds that probe small retinal regions. In the central retina, both Mild and Severe ROP delay maturation of parafoveal scotopic thresholds and are associated with attenuation of cone mediated multifocal ERG responses, significant thickening of post-receptor retinal laminae, and dysmorphic cone photoreceptors. These results have implications for vision and control of eye growth and refractive development and suggest future research directions. These results also lead to a proposal for noninvasive management using light that may add to the currently invasive therapeutic armamentarium against ROP.
Collapse
Affiliation(s)
- Ronald M Hansen
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - James D Akula
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - Anne B Fulton
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| |
Collapse
|
9
|
de Moraes G, Layton CJ. Therapeutic targeting of diabetic retinal neuropathy as a strategy in preventing diabetic retinopathy. Clin Exp Ophthalmol 2016; 44:838-852. [PMID: 27334889 DOI: 10.1111/ceo.12795] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/22/2016] [Accepted: 06/16/2016] [Indexed: 12/21/2022]
Abstract
Diabetes causes a panretinal neurodegeneration herein termed diabetic retinal neuropathy, which manifests in the retina early and progresses throughout the disease. Clinical manifestations include changes in the ERG, perimetry, dark adaptation, contrast sensitivity and colour vision which correlate with laboratory findings of thinning of the retinal neuronal layers, increased apoptosis in neurons and activation of glial cells. Possible mechanisms include oxidative stress, neuronal AGE accumulation, altered balance of neurotrophic factors and loss of mitohormesis. Retinal neural damage precedes and is a biologically plausible cause of retinal vasculopathy later in diabetes, and this review suggests that strategies to target it directly could prevent diabetes induced blindness. The efficacy of fenofibrate in reducing retinopathy progression provides a possible proof of concept for this approach. Strategies which may target diabetic retinal neuropathy include reducing retinal metabolic demand, improving mitochondrial function with AMPK and Sirt1 activators or providing neurotrophic support with neurotrophic supplementation.
Collapse
Affiliation(s)
| | - Christopher J Layton
- Gallipoli Medical Research Foundation, Brisbane, Queensland, Australia.,University of Queensland School of Medicine, Brisbane, Queensland, Australia.,Greenslopes Private Hospital Ophthalmology Department, Greenslopes Hospital, Brisbane, Queensland, Australia
| |
Collapse
|
10
|
Light adaptation does not prevent early retinal abnormalities in diabetic rats. Sci Rep 2016; 6:21075. [PMID: 26852722 PMCID: PMC4745072 DOI: 10.1038/srep21075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 01/18/2016] [Indexed: 11/23/2022] Open
Abstract
The aetiology of diabetic retinopathy (DR), the leading cause of blindness in the developed world, remains controversial. One hypothesis holds that retinal hypoxia, exacerbated by the high O2 consumption of rod photoreceptors in the dark, is a primary cause of DR. Based on this prediction we investigated whether early retinal abnormalities in streptozotocin-induced diabetic rats are alleviated by preventing the rods from dark adapting. Diabetic rats and their non-diabetic littermates were housed in a 12:12 hour light-dim light photocycle (30 lux during the day and 3 lux at night). Progression of early retinal abnormalities in diabetic rats was assessed by monitoring the ERG b-wave and oscillatory potentials, Müller cell reactive gliosis, and neuronal cell death, as assayed by TUNEL staining and retinal thickness at 6 and 12 weeks after diabetes induction. Maintaining diabetic animals in a dim-adapting light did not slow the progression of these neuronal and glial changes when compared to diabetic rats maintained in a standard 12:12 hour light-dark photocycle (30 lux during the day and 0 lux at night). Our results indicate that neuronal and glial abnormalities in early stages of diabetes are not exacerbated by rod photoreceptor O2 consumption in the dark.
Collapse
|
11
|
Sivaprasad S, Arden G. Spare the rods and spoil the retina: revisited. Eye (Lond) 2016; 30:189-92. [PMID: 26656085 PMCID: PMC4763134 DOI: 10.1038/eye.2015.254] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 11/10/2015] [Indexed: 01/23/2023] Open
Abstract
Visual function improves with oxygen inhalation in people with diabetes even in the absence of visible retinopathy. Rods consume the most oxygen in the retina due to the high metabolic activity required to maintain the dark current. Therefore, Arden hypothesized that in diabetes where oxygen supply may also be affected due to the changes in retinal vasculature, prevention of dark adaptation may be a viable option to prevent or decrease the rate of progression of diabetic retinopathy. Animal experiments have proven that the absence of rods decreases the development of retinal neovascularisation. The same principle applies to panretinal photocoagulation, an established treatment for proliferative diabetic retinopathy. Recently, a few clinical studies have also shown that preventing dark adaptation by suppressing rods with 500-nm light source at night decreases the rate of progression of early diabetic retinopathy and maculopathy in the short-term. We await the results of a large two-year multi-centre trial (CLEOPATRA trial) to evaluate the long-term effects of decreasing dark adaptation by applying a 500nm light source as a mask over eyes with non-central diabetic macular oedema.
Collapse
Affiliation(s)
- S Sivaprasad
- NIHR Moorfields Biomedical Research Centre, London, UK
| | - G Arden
- NIHR Moorfields Biomedical Research Centre, London, UK
| |
Collapse
|
12
|
Abstract
In diabetes, retinal blood flow is compromised, and retinal hypoxia is likely to be further intensified during periods of darkness. During dark adaptation, rod photoreceptors in the outer retina are maximally depolarized and continuously release large amounts of the neurotransmitter glutamate-an energetically demanding process that requires the highest oxygen consumption per unit volume of any tissue of the body. In complete darkness, even more oxygen is consumed by the outer retina, producing a steep fall in the retinal oxygen tension curve which reaches a nadir at the depth of the mitochondrial-rich rod inner segments. In contrast to the normal retina, the diabetic retina cannot meet the added metabolic load imposed by the dark-adapted rod photoreceptors; this exacerbates retinal hypoxia and stimulates the overproduction of vascular endothelial growth factor (VEGF). The use of nocturnal illumination to prevent dark adaptation, specifically reducing the rod photoreceptor dark current, should ameliorate diabetic retinopathy.
Collapse
Affiliation(s)
- David J Ramsey
- Department of Ophthalmology, Lahey Hospital & Medical Center, Tufts University School of Medicine, 41 Mall Road, Burlington, MA, 01805, USA.
| | - G B Arden
- University College London, London, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| |
Collapse
|
13
|
Simó R, Hernández C. Novel approaches for treating diabetic retinopathy based on recent pathogenic evidence. Prog Retin Eye Res 2015; 48:160-80. [PMID: 25936649 DOI: 10.1016/j.preteyeres.2015.04.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/13/2015] [Accepted: 04/21/2015] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy remains as a leading cause of blindness in developed countries. Current treatments target late stages of DR when vision has already been significantly affected. A better understanding of the pathogenesis of DR would permit the development of more efficient preventional/interventional strategies against early stages of DR. In this article a critical review of the state of the art of this issue is provided along with a discussion of problems which have yet to be overcome. Neuroprotection as a new approach for the treatment of the early stages of DR has been particularly emphasized. The development and progression of DR is not homogeneous and, apart from blood glucose levels and blood pressure, it depends on genetic factors which remain to be elucidated. In addition, the role of the pathogenic pathways is not the same in all patients. All these factors should be taken into account in the near future when an individualized oriented treatment for DR could become feasible. The new techniques in retinal imaging acquisition, the identification of useful circulating biomarkers and the individualized analysis of biological samples could facilitate the development of early and personalized therapy in the setting of DR. Finally, it should be noted that only a coordinated action among ophthalmologists, diabetologists, basic researchers, experts in pharmaco-economics and health care providers addressed to the design of rational strategies targeting prevention and the early stages of DR will be effective in reducing the burden and improving the clinical outcome of this devastating complication of diabetes.
Collapse
Affiliation(s)
- Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| | - Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| |
Collapse
|