Full panretinal photocoagulation and early vitrectomy improve prognosis of florid diabetic retinopathy

BACKGROUND: Florid diabetic retinopathy (FDR) is a rare form of proliferative diabetic retinopathy (PDR) that is characterized by a bilateral rapidly progressive, very severe ischemic retinopathy. Florid diabetic retinopathy was reported to carry a high risk of blindness. This study was conducted to determine whether visual prognosis of FDR can be improved by appropriate photocoagulation and surgical management. METHODS: The authors retrospectively studied 20 patients (40 eyes) who were treated from October 1978 to February 1994. Systemic risk factors, visual acuity, complete ocular examination, and fundus findings, as well as fluorescein angiography, were analyzed with respect to photocoagulation and surgical management. Mean follow-up was 3.6 years. RESULTS: All patients had poorly controlled type I diabetes (mean duration, 13.5 years), which often was associated with systemic complications. Mean initial visual acuity was equal to or better than 20/40 in 32 eyes (80%). During the course of the study, high-risk PDR was observed in 38 eyes (95%) and vitreous hemorrhage occurred in 26 eyes (65%). Extensive full subconfluent panretinal photocoagulation was performed completely in 37 eyes (92.5%). Vitrectomy was necessary in 15 eyes (37.5%). Macular edema was present in 30 eyes (75%). Major complications included retinal detachment that required surgery (2 eyes, 5%) and neovascular glaucoma (2 eyes, 5%). However, final visual acuity was equal to or better than 20/40 in 23 eyes (57.5%) and less than 5/200 in only 4 eyes (10%). CONCLUSION: These results suggest that aggressive treatment of FDR with extensive panretinal photocoagulation and early vitrectomy, when necessary, may result in a much better prognosis than has been reported previously.     

Diode versus argon-green laser panretinal photocoagulation in proliferative diabetic retinopathy: a randomized study in 44 eyes with a long follow-up time

A clinical randomized study using argon-green (532 nm) and diode (810 nm) lasers was carried out on 44 eyes (34 patients) affected by proliferative diabetic retinopathy (PDR), with the aim of evaluating the long-term effects of diode panretinal photocoagulation. Of the total 44 eyes, 22 were randomized to argon laser treatment (ALT) and 22 to diode laser treatment (DLT). The mean follow-up time was 25 +/- 5 months in the ALT group versus 24 +/- 4 months in the DLT group. In the ALT group 20 eyes (91%) showed regression of PDR whereas 2 eyes (9%) deteriorated. In the DLT group regression of neovascularization was observed in 22 eyes (100%). These results show that the long-term efficacy of diode laser PRP in the treatment of PDR is similar to that of argon-green laser PRP.     

Effective mechanisms of laser photocoagulation for neovascularization in diabetic retinopathy

The present study compared the effect of acetaminophen, ibuprofen and misoprostol on PGE2 synthesis and orthodontic tooth movement. Guinea pigs were randomly assigned into one of three test groups or a control group. Each group received study treatments every 12 hours as an orthodontic force was applied to the maxillary incisors. Direct linear measurements of tooth separation were recorded at days 2, 4, 6, 10, and 11, and inflammatory exudate from the periodontal ligament (PDL) space was extracted and quantitatively analyzed radioimmunologically for the presence of PGE2 at days 4 and 9. Comparing the concentration of PGE2 in sample extracts, a significant difference (P = 0.001) was found among drug groups. A highly significant difference was found between the mean tooth separation among the various drug groups (P < 0.001). At day 11 the misoprostol group exhibited 4.49 +/- 0.49 mm of separation; ibuprofen 2.56 +/- 0.11 mm, and the control and acetaminophen groups exhibited similar degrees of tooth separation: 3.31 +/- 0.07 mm and 3.31 +/- 0.08 mm, respectively. A highly significant difference occurred between the mean rates of tooth separation among the various drug groups after day 8 (P < 0.001). Results of this study suggest that acetaminophen is the analgesic of choice for the relief of minor discomfort associated with orthodontic treatment.     

Influence of panretinal photocoagulation on the ocular pulse curve

Afipia clevelandensis is a recently described gram-negative bacterium whose potential pathogenic role in human disease is under investigation. Only one strain, from the pretibial lesion of a patient hospitalized with necrotizing pancreatitis for 5 months, has been isolated. Using an indirect immunofluorescence assay to detect anti-A. clevelandensis antibodies, we found a seroprevalence of 1.5% among 30,194 sera routinely submitted for laboratory diagnosis of rickettsial diseases. However, among the 52 patients who were clinically evaluable and who exhibited detectable antibodies against A. clevelandensis, 42% were eventually diagnosed as certainly or probably having brucellosis and 15% were eventually diagnosed as certainly or probably having Yersinia enterocolitica O:9 infection, which is the serotype most often encountered in Europe. Western immunoblotting and cross-adsorption tests showed that an 11.5-kDa proteinase K-labile band and a 21-kDa proteinase-stable band, presumably lipopolysaccharide, were responsible for cross-reactivity among A. clevelandensis, Brucella abortus, and Y. enterocolitica O:9. Other diagnoses included nosocomial infections and various community-acquired diseases for which the role of A. clevelandensis remains undefined. Physicians and clinical microbiologists should be aware of this cross-reactivity in future assessments of the role of A. clevelandensis in human pathology.     

Evidence for photoreceptor changes in patients with diabetic retinopathy

PURPOSE: To determine whether the rod and cone photoreceptors are affected in patients with diabetic retinopathy. METHODS: Twelve patients with diabetes and varying levels of retinopathy and nine age-similar control observers participated in this study. Two-color (500 versus 650 nm) dark-adapted thresholds were measured as a function of retinal eccentricity. Full-field flash electroretinograms were obtained using brief, high-intensity flashes. Dark-adapted rod-isolated (Wratten 47B filter) and light-adapted cone-isolated (Wratten 26 filter) electroretinographic responses were measured as a function of flash intensity. The a-wave data were fitted with a model based on photopigment transduction to obtain values for the parameters of Rmax (the maximal response) and log S (sensitivity). Standard clinical 30-Hz flicker electroretinographic responses were also measured. RESULTS: Psychophysically measured dark-adapted thresholds were elevated primarily at eccentricities of 5 degrees and 10 degrees from the fovea. Analysis of rod and cone a-wave data showed that Rmax was normal in most of the patients, but log S was reduced. Analysis of b-wave and oscillatory potential parameters showed rod and cone postreceptoral abnormalities, including changes in the rod-isolated semisaturation constant (log k), cone-mediated 30-Hz flicker, and cone-isolated oscillatory potentials. The electrophysiological results were not significantly correlated with blood glucose or glycosylated hemoglobin level. CONCLUSIONS: The results provide evidence for rod and cone receptoral and postreceptoral deficits in patients with diabetic retinopathy. The photoreceptor changes are primarily in the log S (sensitivity) parameter and are attributed to transduction abnormalities.     

Newly developed diabetic retinopathy and its preceding changes in biological markers

To disclose the chronological changes prior to the manifestation of diabetic retinopathy (DR), we analyzed the time course of biological markers among apparently healthy diabetic subjects in a case-control study of 21,579 adults who had undergone comprehensive health examinations for > or = 10 years. We identified 54 cases who had newly developed DR, and selected 108 adults without fundus abnormalities, matching them for sex, age, and fasting plasma glucose (FPG) at the onset of the patient group's retinopathy as a referent group from the same population. In a multivariate analysis, a high average FPG (> 175 mg/dl) and a final-year FPG reduction (< -3%) were significantly associated with a 5.4 (95% CI, 1.8-15.7)- and 5.0 (95% CI, 1.0-24.7)-fold increased risk of DR, respectively. Thus, we surmised that sustained hyperglycemia and a subsequent drop in FPG might promote retinopathy in non-insulin dependent diabetes mellitus.     

Cataract surgery and YAG-laser capsulotomy following vitrectomy for diabetic retinopathy

The present study was initiated to assess time-course and risk factors for the development of cataract and posterior-capsule opacification as well as complications of cataract surgery and YAG-laser capsulotomy following vitrectomy for diabetic retinopathy. The charts of all patients undergoing vitrectomy for diabetic retinopathy during a 5-year period in a university eye hospital were retrospectively reviewed. The course of 306 consecutive eyes in which the lens was retained during vitrectomy was analyzed for subsequent cataract surgery and YAG-laser capsulotomy. The first 6 months after cataract or YAG-laser surgery were examined for the occurrence of complications. Data were analyzed with regard to the time course using Kaplan-Meier life-table analysis. The proportion of eyes that underwent cataract surgery after vitrectomy increased nearly linearly with time, approaching 75% after 5 years. Silicone tamponade (relative risk 1.9; P = 0.0005) and transscleral retinal cryotherapy (relative risk 1.4; P = 0.003) were risk factors for subsequent cataract surgery. No significant cataractogenous effect of intravitreal gas as compared with balanced salt solution was found. YAG-laser capsulotomy was performed in 60% of vitrectomized diabetic eyes within 2 years but in only 10% of nondiabetic controls (P < 0.0001). Within 6 months of extracapsular cataract surgery with implantation of an intraocular lens (IOL) in 54 eyes, no serious complication was observed. After YAG-laser capsulotomy, vitreous hemorrhage occurred within 6 months in 6 of 21 eyes. In conclusion, cataract surgery was performed in 75% of the phakic eyes within 5 years of vitrectomy for diabetic retinopathy. Posterior capsular opacification is particularly common in this subset of eyes. No serious complication was observed after extracapsular cataract surgery with IOL implantation, but YAG-laser capsulotomy was associated with an increased risk for vitreous hemorrhage.     

Occurrence of changes in the eye in diabetic retinopathy with significant myopia

The optic disc and retinal neovascularization are less prominent and less frequent in myopic eyes in patients suffering from diabetes mellitus. The exact mechanisms of this phenomenon are not well known, but there is some evidence that there is a reduced blood flow in myopic eyes which is associated with less damaged microcirculation in eyes of patients with diabetes mellitus. The aim of our study was to evaluate the correlation between myopic refractive error and degree of diabetic retinopathy. We conducted a retrospective study in a group of randomized patients, divided into the following groups according to their refractive error: emmetropia (30 eyes), myopia simplex (30 eyes) and high myopia, over -6.5 dsph (21 eyes). Among patients with high myopia, seven had monocular myopia. All patients suffered from non insulin dependent diabetes mellitus for more than ten years, and their average age was 52.37-3.48 years. We did not observe patients with rubeosis iridis and neovascular glaucoma or patients with myopia less than -2.0 dsph. Our results indicated that there was no significant difference in the appearance of fundus between the studied groups. In all patients the incidence rate of non proliferative and proliferative diabetic retinopathy was the same as well as the absence of retinopathy (Fisher's test). The only exception were the patients with monocular myopia over -13.o dsph who had no signs of diabetic retinopathy in myopic eye, while the other, emmetropic eye, showed various stages of retinopathy, from severe non proliferative to proliferative. Some of the risk factors which influence the incidence rate of ocular complications in diabetic patients are well known, as are duration of diabetes mellitus, blood sugar level, blood pressure, ocular pressure and eye perfusion. On the other hand, it is also known that amblyopia, optic atrophy, low blood pressure in central retinal artery and retinitis pigmentosa are ocular conditions which are not associated with proliferative diabetic retinopathy. It was also noticed that complications of diabetes in high myopic eyes are less prominent than in emmetropic eyes. This finding is in harmony with our results. Sultanov et al. observed diabetic changes in the retina in 40.9% of myopic refraction patients, 65.2% of emmetropia cases and 70.4% of hypermetropia cases. The severity of involvement was less in myopia than in other types of refraction. In medium severe myopia, no proliferative diabetic retinopathy was observed, and in high myopia (10 eyes) no diabetic involvement of the fundus oculi was found. In anisometropia diabetic symptoms on the myopic side were either absent or poorly manifest. The possible cause of such findings could be the changes in retinal perfusion in myopic eyes and eyes in patients with diabetes mellitus. In 1973 a lower blood flow was detected in the retina and the choroid, proportionally to the degree of myopia. In 1982, Perkins indicated that the circulation time and pulsation rate in the central retinal artery in myopic eyes were reduced proportionally to the degree of myopia. In cases with early diabetic retinopathy Coscas detected a lesser blood flow in retinal veins. On the other hand, it has been found that high blood pressure increases the risk of diabetic retinopathy. These data suggest that the reduced blood flow in high myopia is a protective factor regarding the occurrence of complications in diabetes. Anisometropia and amblyopia in cases with monocular myopia, which presents a particular group in our study, could be factors which also prevent the occurrence of proliferative diabetic retinopathy. Instead of conclusion, we would like to point out that pathophysiologic mechanisms of these phenomena are not discussed enough. It is, nevertheless, important to appropriately examine the fundus in patients with high myopia and diabetes mellitus, because if the complications appear, they may be disastrous and must be treated immediately.     

Automated static perimetry as a screening method for evaluation of retinal perfusion in diabetic retinopathy

Differential diagnosis of syncope and seizures frequently imposes a major problem, particularly if interictal examinations are normal. We performed orthostatic testing combined with surface electroencephalography (EEG) and non-invasive measurements of cerebral blood flow velocity. Ten healthy controls, ten patients with confirmed diagnosis of epilepsy and 25 patients with history of syncope of unknown origin were examined. The following parameters were evaluated continuously and simultaneously during orthostatic challenge: computerized EEG with synchronous video-monitoring, transcranial Doppler sonography (TCD), heart rate and blood pressure. Isolated cerebrovascular dysregulation (i.e. a drop in cerebral perfusion despite the absence of a significant drop in peripheral blood pressure) occurred in 2/10 controls, 3/10 patients with epilepsy and 11/25 patients with syncope of unknown origin. The combined EEG and TCD measurements represent a new approach to the work-up of patients with otherwise unexplained syncope, helping us to understand the interdependence of neuronal activity and peripheral/cerebrovascular autoregulation under postural stress.     

Retinal changes mimicking diabetic retinopathy in two nondiabetic, growth hormone-treated patients

A role for GH in the pathogenesis of diabetic retinopathy has long been postulated. Previous clinical studies, however, have been confounded by hyperglycemia. We have identified 2 cases of retinopathy associated with exogenous GH therapy in nondiabetic patients. Cases were identified through the MedWatch drug surveillance system of the U.S. Food and Drug Administration. Causality by concomitant medications was excluded by a search of the literature and the FDA data base. The first patient, an obese, 31-yr-old male with traumatic hypothalamic injury, presented with nonproliferative retinopathy and macular edema, resulting in decreased visual acuity (OD 20/40-1; OS count fingers), which required laser surgery. Human GH had been initiated at 0.009 mg/ kg.day, 14 months earlier, and titrated to 0.017 mg/kg.day. The second patient, a nonobese, 11-yr-old girl receiving GH for the management of short stature in Turner's Syndrome, presented with neovascularization. GH doses were 0.033 mg/kg.day for the first 17 months and 0.043 mg/ kg.day for the following 5 months. Cumulative laboratory and clinical observations suggest that GH and related peptides have a role in retinal pathology independent of the degree of glucose tolerance.     

The course of nonproliferative diabetic retinopathy following ECCE with posterior chamber IOL implantation

A prospective study on the effect of ECCE + IOL implantation on the course of diabetic retinopathy (DR) in 59 eyes showed that in one to three years following surgery, progression of DR, including the development of newly formed one, occurred in 28.8% of the eyes. This was more marked in patient with IDDM (IDDM-46%, NIDDM-24%) as well as in eyes with pre-operative BDR (pre-operative BDR-62.5%, no pre-operative BDR-16.3%). Final visual acuity was better in eyes without pre-operative DR as well as in eyes that did not show progression of the retinopathy.     

Ophthalmologic management of diabetic retinopathy

Changes in lung mechanics were measured in asthmatic adults before and after a 10-day course of daily and a three-week course of alternate day adrenocortical steroid therapy. All patients improved after the 10 days of therapy. This response continued during the a.m. measurements on the alternate day regimen with further improvement through the afternoon of the treatment day. In the afternoon of the day off corticosteroid therapy there was a deterioration in flow rates.     

The study on changes of macular light sensitivity before and after photocoagulation for diabetic macular edema

OBJECTIVE: The study was designed to determine whether laser photocoagulation could damage macular visual function in treatment of diabetic macular edema. METHODS: A prospective clinical trial was taken to determine the effects of argon green (514.5nm) laser photocoagulation on macular light sensitivity (MLS) by comparing the self MLS pairing data collected from a Humphrey automatic visual field analyzer before and after the procedure. Nineteen eyes of 15 patients with diabetic macular edema consistent with its diagnostic criteria were enrolled in this study, a follow-up period being 3 months. RESULTS: The mean MLS at the photocoagulation area, non-photocoagulation area, 5 degrees and 13 degrees eccentricity were significantly decreased within 1 week after the treatment, the drops of MLS were 1.85 dB, 1.05 dB, 0.99 dB, 1.66 dB respectively (P < 0.05). The mean reduction of MLS at the fovea within 1 week after the treatment has no statistical significance. The MLS gradually recovered at the 1st and 3rd month after photocoagulation, and the visual acuities in most of the cases were stable or increased. CONCLUSIONS: MLS is affected little by laser photocoagulation, and photocoagulation can reduce the risk of visual loss or increase visual acuity in an eye with diabetic macular edema.     

The plasma levels of endothelin in diabetic retinopathy and their changes after treatment with doxium

Apolipoprotein E (APOE) has been identified as a major susceptibility marker for Alzheimer's disease (AD) and it has been proposed that a common polymorphism in the alpha1-antichymotrypsin (ACT) gene increases the risk of developing AD, when the combination of ACT/AA genotype and APOE epsilon4 allele segregate together. The ACT polymorphism was analysed in 218 sporadic late-onset AD patients and 101 healthy control subjects from Eastern Finland. Samples of the ACT polymorphism were divided into three subgroups according to their APOE genotypes and the genotyping of samples was done using the polymerase chain reaction (PCR) method. Any association between the AD group and the controls was tested with the chi2 test. Our data failed to detect any effect of polymorphism in the ACT genotypes associated with the APOE alleles, suggesting that in this population ACT does not increase the risk of AD.     

Prevention of blindness in diabetic retinopathy]

PURPOSE: This study aimed to determine the clinical significance of echogenic amniotic fluid. METHODS: We prospectively studied 19 twin pregnancies in which the amniotic fluid in 1 sac was anechoic and that in the other sac was echogenic. Morphologic characteristics of amniotic fluid were assessed from samples taken at amniocentesis or upon delivery within 48 hours after sonographic examination. RESULTS: In twins with echogenic amniotic fluid, assessment revealed clear fluid in 6 cases (32%), vernix caseosa in 12 (63%), and meconium in 1 (5%). In co-twins with anechoic amniotic fluid, assessment revealed clear fluid in 9 cases (47%), vernix caseosa in 6 (32%), and meconium in 4 (21%). CONCLUSIONS: Echogenic amniotic fluid on prenatal sonography is not predictive of meconium.