Comparison of non-mydriatic retinal photography with ophthalmoscopy in 2159 patients: mobile retinal camera study.

OBJECTIVE--To determine whether non-mydriatic Polaroid retinal photography was comparable to ophthalmoscopy with mydriasis in routine clinic screening for early, treatable diabetic retinopathy. DESIGN--Prospective study of ophthalmoscopic findings according to retinal camera screening and ophthalmoscopy and outcome of referral to ophthalmologist. SETTING--Outpatient diabetic clinics of three teaching hospitals and three district general hospitals. PATIENTS--2159 Adults selected randomly from the diabetic clinics, excluding only those registered as blind or those in wheelchairs and unable to enter the screening vehicle. MAIN OUTCOME MEASURES--Numbers of patients and eyes correctly identified by each technique as requiring referral with potentially treatable retinopathy (new vessel formation and maculopathy) and congruence in numbers of microaneurysms, haemorrhages, and exudates reported. RESULTS--Camera screening missed two cases of new vessel formation and did not identify a further 12 but indicated a need for referral. Ophthalmoscopy missed five cases of new vessel formation and indicated a need for referral in another four for other reasons. Maculopathy was reported in 147 eyes with camera screening alone and 95 eyes by ophthalmoscopy only (chi 2 = 11.2; p less than 0.001), in 66 and 29 of which respectively maculopathy was subsequently confirmed. Overall, 38 eyes received laser treatment for maculopathy after detection by camera screening compared with 17 after ophthalmoscopic detection (chi 2 = 8.0; p less than 0.01). Camera screening underestimated numbers of microaneurysms (chi 2 = 12.9; p less than 0.001) and haemorrhages (chi 2 = 7.4; p less than 0.01) and ophthalmoscopy underestimated hard exudates (chi 2 = 48.2; p less than 0.001). CONCLUSIONS--Non-mydriatic Polaroid retinal photography is at least as good as ophthalmoscopy with mydriasis in routine diabetic clinics in identifying new vessel formation and absence of retinopathy and is significantly better in detecting exudative maculopathy.     

Pituitary Ablation for Diabetic Retinopathy

Pituitary ablation was performed on 26 patients with advanced diabetic retinopathy by pituitary stalk section (nine patients) or transphenoidal hypophysectomy (17 patients). After a latent period varying from six to 12 months, retinal hemorrhages disappeared, vitreous hemorrhages stopped and new vessels regressed. Eight of 10 patients followed up for more than a year had a complete remission, although in one of two patients whose ablation was incomplete the retinopathy remained active. Preoperative visual acuity levels were preserved in 47 of 50 eyes of patients followed up for a mean period of 12 months. Three patients have died, two from causes related to their operation. Twenty of the survivors have continued in their usual occupation. Pituitary ablation is effective in preventing the progressive visual deterioration usually associated with advanced diabetic retinopathy.     

Transcaruncular orbital decompression for management of compressive optic neuropathy in thyroid-related orbitopathy

This study was conducted to assess the outcome of transcaruncular orbital decompression to treat compressive optic neuropathy in thyroid-related orbitopathy. It involved a retrospective, noncomparative case series of 18 eyes of 10 consecutive patients with documented vision loss secondary to thyroid-related orbitopathy. Bony decompression of the orbital apex was performed via a transcaruncular approach. Main outcome measures were visual acuity, color vision, presence of diplopia, and reduction of exophthalmos. Of 18 eyes, 16 (89 percent) had improved visual acuity after the operation. One eye had no improvement and one had worsening of vision in the setting of diabetic retinopathy. Color vision was improved in 12 eyes (67 percent). Five of the patients did not have diplopia before the operation; none of these patients developed double vision after intervention. Exophthalmos was decreased by an average of 2.6 mm. The authors conclude that transcaruncular orbital decompression for compressive optic neuropathy in thyroid-related orbitopathy is successful in restoring visual function. Compared with other approaches used for decompression surgery, the transcaruncular approach offers direct access to the medial wall and orbital apex without a cutaneous incision or disruption of the medial canthus. In addition, this approach allows a controlled, graded removal of the ethmoidal air cells and reduced recovery time.     

Oral glycine administration attenuates diabetic complications in streptozotocin-induced diabetic rats

Diabetes mellitus is a disease characterized by impaired glucose metabolism that leads to retinopathy, brain micro-infarcts and other complications. We have previously shown that oral glycine administration to diabetic rats inhibits non-enzymatic glycation of hemoglobin and diminishes renal damage. In this work, we evaluated the capacity of the amino acid glycine (1% w/v, 130 mM) to attenuate diabetic complications in streptozotocin (STZ)-induced diabetic Wistar rats and compared them with non-treated or taurine-treated (0.5% w/v, 40 mM) diabetic rats. Glycine-treated diabetic rats showed an important diminution in the percentage of animals with opacity in lens and microaneurysms in the eyes. Interestingly, there was a diminished expression of O-acetyl sialic acid in brain vessels compared with untreated diabetic rats (P<0.05). Additionally, peripheral blood mononuclear cells isolated from glycine-treated diabetic rats showed a better proliferative response to PHA or ConA than those obtained from non-treated diabetic rats (P<0.05). Glycine-treated rats had a less intense corporal weight loss in comparison with non-treated animals. Our results suggest that administration of glycine attenuates the diabetic complications in the STZ-induced diabetic rat model, probably due to inhibition of the non-enzymatic glycation process.     

Automatic non-proliferative diabetic retinopathy screening system based on color fundus image

Background

Non-proliferative diabetic retinopathy is the early stage of diabetic retinopathy. Automatic detection of non-proliferative diabetic retinopathy is significant for clinical diagnosis, early screening and course progression of patients.

Methods

This paper introduces the design and implementation of an automatic system for screening non-proliferative diabetic retinopathy based on color fundus images. Firstly, the fundus structures, including blood vessels, optic disc and macula, are extracted and located, respectively. In particular, a new optic disc localization method using parabolic fitting is proposed based on the physiological structure characteristics of optic disc and blood vessels. Then, early lesions, such as microaneurysms, hemorrhages and hard exudates, are detected based on their respective characteristics. An equivalent optical model simulating human eyes is designed based on the anatomical structure of retina. Main structures and early lesions are reconstructed in the 3D space for better visualization. Finally, the severity of each image is evaluated based on the international criteria of diabetic retinopathy.

Results

The system has been tested on public databases and images from hospitals. Experimental results demonstrate that the proposed system achieves high accuracy for main structures and early lesions detection. The results of severity classification for non-proliferative diabetic retinopathy are also accurate and suitable.

Conclusions

Our system can assist ophthalmologists for clinical diagnosis, automatic screening and course progression of patients.

     

Retinal blood flow in diabetic retinopathy.

OBJECTIVES--(a) To report on the basic parameters of retinal blood flow in a population of diabetic patients with and without retinopathy and non-diabetic controls; (b) to formulate a haemodynamic model for the pathogenesis of diabetic retinopathy from this and other studies. DESIGN--Laser-Doppler velocimetry and computerised image analysis to determine retinal blood flow in a large cross sectional study. SETTING--Diabetic retinopathy outpatient clinic. SUBJECTS--24 non-diabetic controls and 76 diabetic subjects were studied (63 patients with insulin dependent diabetes, 13 with non-insulin dependent diabetes). Of the diabetic subjects, 12 had no diabetic retinopathy, 27 had background retinopathy, 13 had pre-proliferative retinopathy, 12 had proliferative retinopathy, and 12 had had pan-retinal photocoagulation for proliferative retinopathy. MAIN OUTCOME MEASURES--Retinal blood flow (microliters/min) and conductance (rate of flow per unit of perfusion pressure). RESULTS--In comparison with non-diabetic controls (9.52 microliters/min) and diabetic patients with no diabetic retinopathy (9.12 microliters/min) retinal blood flow was significantly increased in all grades of untreated diabetic retinopathy (background 12.13 microliters/min, pre-proliferative 15.27 microliters/min, proliferative 13.88 microliters/min). There was a significant decrease in flow after pan-retinal photocoagulation in comparison with all the other groups studied (4.48 microliters/min). Conductance of the retinal circulation was higher in the untreated diabetic retinopathy groups. These results were independent of age, sex, type of diabetes, duration of diabetes, glycated haemoglobin concentration, blood glucose concentration, blood pressure, and intraocular pressure. CONCLUSIONS--Retinal blood flow is significantly increased in diabetic retinopathy in comparison with non-diabetic controls and diabetic subjects with no retinopathy. This has implications for controlling hypertension and hyperglycaemia as a strategy in reducing morbidity from diabetic retinopathy.     

Treatment of renal failure from diabetic nephropathy with cadaveric homograft

We report two patients with terminal renal failure secondary to diabetic nephropathy treated with cadaveric kidney transplantation. Neither of these patients had peripheral vascular disease or peripheral neuropathy. There was a proliferative diabetic retinopathy with hemorrhages and exudates in one patient and only background diabetic changes in the ocular fundi of the other; there have been no significant changes in visual acuity or retinopathy in either patient following the transplantation. Both have good kidney function after 8 and 15 months and are completely rehabilitated.The requirement for insulin decreased in both patients during the period of renal insufficiency and increased following transplantation; this seemed to be related to the large dose of steroids given because now that a maintenance level of steroids has been established, both patients require the same dosage of insulin as they did before the onset of renal insufficiency.     

消栓通络胶囊辅助治疗单纯型糖尿病视网膜病变的临床疗效研究

目的：探讨消栓通络胶囊治疗单纯型糖尿病视网膜病变的临床效果。方法：选取68例（68眼）糖尿病视网膜病变患者,随机分为照组和试验组,其中对照组34例（34眼）,给予基础治疗;试验组34例（34眼）,在对照组基础上加用消栓通络胶囊口服进行治疗。观察两组患者治疗后视网膜改变、视力的改善及自觉症状改善情况,并检测两组患者视网膜黄斑厚度及血流变指标。结果：治疗后,两组自觉症状的改善率比较差异无统计学意义（P〉0．05）,试验组视网膜改变、视力改善的总有效率显著高于对照组（P〈0．05）,视网膜黄斑厚度显著小于对照组（P〈0．05）,血流变指标的改善率显著高于对照组,差异均有统计学意义（P〈0．05）。结论：消栓通络胶囊辅助治疗单纯型糖尿病视网膜病变的患者疗效好,能改善患者的眼底血液循环,促进出血点、黄斑吸收。     

Regenerative Therapeutic Potential of Adipose Stromal Cells in Early Stage Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of blindness in working-age adults. Early stage DR involves inflammation, vascular leakage, apoptosis of vascular cells and neurodegeneration. In this study, we hypothesized that cells derived from the stromal fraction of adipose tissue (ASC) could therapeutically rescue early stage DR features. Streptozotocin (STZ) induced diabetic athymic nude rats received single intravitreal injection of human ASC into one eye and saline into the other eye. Two months post onset of diabetes, administration of ASC significantly improved “b” wave amplitude (as measured by electroretinogram) within 1–3 weeks of injection compared to saline treated diabetic eyes. Subsequently, retinal histopathological evaluation revealed a significant decrease in vascular leakage and apoptotic cells around the retinal vessels in the diabetic eyes that received ASC compared to the eyes that received saline injection. In addition, molecular analyses have shown down-regulation in inflammatory gene expression in diabetic retina that received ASC compared to eyes that received saline. Interestingly, ASC were found to be localized near retinal vessels at higher densities than seen in age matched non-diabetic retina that received ASC. In vitro, ASC displayed sustained proliferation and decreased apoptosis under hyperglycemic stress. In addition, ASC in co-culture with retinal endothelial cells enhance endothelial survival and collaborate to form vascular networks. Taken together, our findings suggest that ASC are able to rescue the neural retina from hyperglycemia-induced degeneration, resulting in importantly improved visual function. Our pre-clinical studies support the translational development of adipose stem cell-based therapy for DR to address both retinal capillary and neurodegeneration.     

Comparison of Combined and Sequential Surgery for Proliferative Diabetic Retinopathy: A Single Surgeon Study

Purpose

To compare the results of combined and consecutive surgeries to treat proliferative diabetic retinopathy and cataract.

Methods

Retrospective comparative study. Forty-one patients with proliferative diabetic retinopathy (PDR) were enrolled. Twenty-nine eyes for the combined surgery group and twelve eyes for the sequential group were included. All surgeries were performed by one surgeon. Phacoemulsification was performed using a clear cornea incision. The vitrectomy was performed using a 20-gauge vitreous cutter.

Results

The best corrected visual acuity (BCVA) and intra- and post-operative complications were the main outcome measures. In the combined surgery group, the BCVA increased in 18 (62.1%) eyes, while eight (27.6%) eyes remained stable and three (10.3%) eyes decreased. Postoperative complications included fibrinous exudation in nine eyes, macular edema in three eyes and vitreous hemorrhage in three eyes. In the sequential surgery group, the BCVA increased in seven (58.3%) eyes, remained the same in four (33.3%) eyes and was reduced in one (8.3%) eye. Postoperative complications included macular edema in two eyes, neovascular glaucoma in two eyes and vitreous hemorrhage in one eye.

Conclusions

Both combined and sequential surgeries are safe and effective for treating PDR and cataracts. The combined surgery had a higher incidence of fibrinous exudation.     

正常猕猴与人视网膜血管的比较

目的比较正常猕猴与人视网膜血管的异同,为进一步利用猕猴建立动物模型来研究视网膜血管打下基础。方法取健康成年猕猴眼球6只和人角膜移植供体剩余眼杯8只的视网膜,用ADP酶法进行血管染色,对两者视网膜血管的走行、血管分级、毛细血管分层以及黄斑区血管拱环等进行比较,测量结果进行统计学检验。结果猕猴与人的视网膜铺片经ADP酶法染色后见视网膜血管自穿出视盘后的一级血管逐渐分支变细,直至五级血管即毛细血管;在视盘旁、赤道部、周边部两者血管面积百分比没有差异;视盘旁血管分为多层,赤道部有两层,且深浅层间相互交通,周边部仅见一层毛细血管且较稀疏;两者黄斑区毛细血管均较密集,有形态完整呈不规则状的血管拱环,血管面积百分比以及血管拱环的面积、周长和直径没有差异。结论猕猴与人在视网膜血管走行、分级、毛细血管分层以及黄斑区血管拱环等多方面有良好的相似性,可用作人类视网膜血管、尤其是黄斑区视网膜血管研究的良好动物模型。     

A New Blind Cave Fish Population of Genus Astyanax: Geography, Morphology and Behavior

A new population of blind, cave dwelling tetra fish of the genus Astyanax was discovered in Granadas Cave, in the Balsas drainage, southern México. All blind Mexican tetras previously described are from Tampico and San Luis Potosí, northern México. The discovery of a new blind morph thus represents an independent colonization and convergent adaptation to the cave environment by this fish. Individuals of this population display variability of their troglomorphic features. Some individuals presented asymmetrical degeneration of the eyes, where one was normal, but the other somewhat reduced in size and complexity. Loss of pigmentation and eye reduction, although sometimes correlated, were not always linked; reduced eyes were found on pigmented fish and unpigmented fish often possessed normal eyes. Some individuals had reduced lens size or an absence of lens altogether. Retina is highly modified with photoreceptors sometimes absent. Eye reduction was correlated with a diminished size of the optic lobes and an increase of the prosencephalon. Modifications of the skull involve closing in of the circumorbital series of bones. Certain aspects of behavior are also modified.     

Prevalence of retinopathy in a diabetic clinic.

In a prospective study lasting 14 months an attempt was made to measure the visual acuity and examine the fundi, after mydriasis, of all patients attending the diabetic clinic of a district general hospital. Of 704 patients, 160 (22.7%) had some evidence of retinopathy, and 52 (7.4%) of these were already attending an ophthalmologist. A further 18 (2.6%) were known to have retinopathy and were being followed up in the diabetic clinic. Ninety (12.8%) new patients with diabetic retinopathy were discovered. Most had minimal changes, but 30 (4.3%) were considered to have changes severe enough to be referred to an ophthalmologist. Twenty-two (2.1%) underwent, or were awaiting, photocoagulation, and half of these had had no visual symptoms when first seen. Although some of these patients were already being treated or observed for retinopathy, it is encouraging that relatively few new patients needing treatment for retinopathy were discovered. If retinopathy could be detected early enough physicians might be able to deal with it and so ease pressure on ophthalmological services.     

Prevention of blindness by screening for diabetic retinopathy: a quantitative assessment.

Diabetic retinopathy is an important cause of blindness in the Western World. A review of the randomised trials of laser photocoagulation of the retina as a method of preventing blindness from this disorder showed that this treatment is very effective, reducing the risk of blindness by 61% in a treated eye. As only one eye is needed for sight the reduction in blindness in a population will be greater than 61% because the effect of treatment in one eye is not always identical with the effect in the other eye. For analysis this reduction was taken as 73%, representing the average of the minimum and maximum estimates (61% and 85%). The effectiveness of this treatment suggests that there is the potential for a national screening programme to bring about a major reduction in blindness from this cause. A quantitative assessment of the effect of screening indicated that a programme in which patients with diabetes mellitus are systematically referred to ophthalmic opticians for a retinal examination could detect 88% of all diabetics with serious retinopathy and that 87% of these cases would be treatable. Screening and early treatment of retinopathy would prevent deterioration of visual acuity and could reduce the risk of blindness due to diabetic retinopathy by an estimated 56% (0.73 X 0.88 X 0.87). The findings suggest that an effectively managed community based screening programme encompassing detection, referral, treatment, and follow up would prevent about 260 new cases of blindness in diabetics under the age of 70 each year in England and Wales. This would represent over 10% of all cases of blindness in adults in this age group.     

Visual Evoked Response in Diagnosis of Multiple Sclerosis

The diagnostic value of the pattern-evoked response has been assessed in 73 patients referred because of suspected multiple sclerosis. Altogether 52 had delayed responses. Fifty-one patients in the group satisfied McAlpine''s criteria for diagnosing definite, probable, or possible multiple sclerosis. Of these, all but two had delayed responses in one or both eyes, while only three of the remaining 22 patients had delays. In those patients with multiple sclerosis but without any history of optic neuritis the incidence of delayed responses was only slightly less. Of 51 patients with delayed responses 23 had normal discs. Thus subclinical lesions of the visual pathways can be readily detected with this test. The high incidence of abnormal pattern responses, even in patients with no other ocular signs or symptoms, suggests that the test is of value in establishing the diagnosis.     

Detection of Neovascularization Based on Fractal and Texture Analysis with Interaction Effects in Diabetic Retinopathy

Diabetic retinopathy is a major cause of blindness. Proliferative diabetic retinopathy is a result of severe vascular complication and is visible as neovascularization of the retina. Automatic detection of such new vessels would be useful for the severity grading of diabetic retinopathy, and it is an important part of screening process to identify those who may require immediate treatment for their diabetic retinopathy. We proposed a novel new vessels detection method including statistical texture analysis (STA), high order spectrum analysis (HOS), fractal analysis (FA), and most importantly we have shown that by incorporating their associated interactions the accuracy of new vessels detection can be greatly improved. To assess its performance, the sensitivity, specificity and accuracy (AUC) are obtained. They are 96.3%, 99.1% and 98.5% (99.3%), respectively. It is found that the proposed method can improve the accuracy of new vessels detection significantly over previous methods. The algorithm can be automated and is valuable to detect relatively severe cases of diabetic retinopathy among diabetes patients.     

Adeno-Associated Virus Mediated Delivery of a Non-Membrane Targeted Human Soluble CD59 Attenuates Some Aspects of Diabetic Retinopathy in Mice

Diabetic retinopathy is the leading cause of visual dysfunction in working adults and is attributed to retinal vascular and neural cell damage. Recent studies have described elevated levels of membrane attack complex (MAC) and reduced levels of membrane associated complement regulators including CD55 and CD59 in the retina of diabetic retinopathy patients as well as in animal models of this disease. We have previously described the development of a soluble membrane-independent form of CD59 (sCD59) that when delivered via a gene therapy approach using an adeno-associated virus vector (AAV2/8-sCD59) to the eyes of mice, can block MAC deposition and choroidal neovascularization. Here, we examine AAV2/8-sCD59 mediated attenuation of MAC deposition and ensuing complement mediated damage to the retina of mice following streptozotocin (STZ) induced diabetes. We observed a 60% reduction in leakage of retinal blood vessels in diabetic eyes pre-injected with AAV2/8-sCD59 relative to negative control virus injected diabetic eyes. AAV2/8-sCD59 injected eyes also exhibited protection from non-perfusion of retinal blood vessels. In addition, a 200% reduction in retinal ganglion cell apoptosis and a 40% reduction in MAC deposition were documented in diabetic eyes pre-injected with AAV2/8-sCD59 relative to diabetic eyes pre-injected with the control virus. This is the first study characterizing a viral gene therapy intervention that targets MAC in a model of diabetic retinopathy. Use of AAV2/8-sCD59 warrants further exploration as a potential therapy for advanced stages of diabetic retinopathy.     

Renal transplantation in diabetics nephropathy.

Forty diabetics who had developed end-stage renal failure from diabetic nephropathy and underwent renal transplantation have been followed up from one to six years. After one and two years 63% and 42% survived (45% and 33% respectively with functioning kidneys). Older patients, those with coronary and peripheral vascular disease, and those with severe neuropathy are prone to higher postoperative morbidity and mortality. The presence of advanced retinopathy, on the other hand, does not appear to influence the outcome.     

红参粉末治疗糖尿病视网膜病变的临床观察

目的：观察红参粉末治疗糖尿病视网膜病变的临床效果。方法：随机选取2012年1月至2012年12月在我院接受治疗的2型糖尿病合并糖尿病视网膜病变（Diabetic Retinopathy,DR）患者103例。其中30例（57眼）仅采用常规方法治疗,即对照组;其余73例（125眼）在常规治疗的基础上加用红参粉末,即观察组。治疗180天后,观察并比较两组患者的视力、眼底镜、荧光血管造影等检查结果的变化情况。结果：在观察组中,患者经红参粉末治疗后的视力与治疗前相比有所提高,差异具有统计学意义（P〈0．05）;而对照组中,患者治疗前后的视力变化无统计学意义（P〉0．05）;观察组治疗有效率为76．7％,而对照组治疗有效率为46．7％,差异有显著意义（P〈0．05）。观察组中,男性DR患者治疗有效率为68．8％、女性为92．0％;早期DR治疗有效率为85．4％、晚期为65．1％;糖尿病病程不超过10年的DR患者治疗有效率为88．9％、超过10年的为64．9％,差异均具有统计学意义（P〈0．05）。结论：尽早的发现和及时的治疗可减少糖尿病患者视网膜病变的发生率,从而避免因视网膜病变而引起的严重的视力下降,甚至失明。红参粉末治疗糖尿病视网膜病变有显著的临床效果,特别是对早期糖尿病视网膜病变的疗效更佳,值得临床推广。     

One eye but no vision: cave fish with induced eyes do not respond to light

One of the most intriguing questions in evolutionary biology is the degree to which behavior is a necessary consequence of morphology. We explore this issue by examining phototactic behavior in epigean (eyed surface-dwelling) and troglomorphic (blind cave) forms of the teleost Astyanax fasciatus whose eyes were modified during embryogenesis by removing one or both lens vesicles from the epigean form or by transplanting the lens vesicle from an epigean fish into the optic cup of a blind cave form. Lens removal results in eye degeneration and blindness in adult epigean fish, whereas lens transplantation stimulates growth of the eye, inducing the development of optic tissues in the normally eyeless adult cave fish. Photoresponsiveness was examined by placing fish in an aquarium with one half illuminated and the other half dark and scoring their presence in the illuminated or dark half. Both the eyeless epigean fish and cave fish with induced eyes are indifferent to the illumination whereas the surface forms are scotophilic, suggesting that optic development and phototactic behavior are decoupled.