Treatment of rhegmatogenous retinal detachment secondary to proliferative diabetic retinopathy

Fifty eyes with rhegmatogenous retinal detachment associated with proliferative diabetic retinopathy were treated surgically. Follow-up examination was from six months to 14 years with an average of 33 months. Successful reattachment of the retina was achieved in 74% of the cases, and visual acuity was preserved or improved in 60%.     

Vitrectomy in the treatment of simple retinal detachment

PURPOSE: To report the indications and results of vitrectomy in the treatment of uncomplicated retinal detachment. METHODS: This retrospective study covered 103 vitrectomies that were carried out during an 8-year period for the treatment of rhegmatogenous retinal detachment without severe proliferative vitreoretinopathy, macular hole, or giant tear. Mean follow-up time was 20.3 months. RESULTS: The indications for vitrectomy were vitreal opacities in 32 cases, unseen or uncertain retinal breaks despite a good retinal view in 9 cases, a difficult arrangement of breaks in 34 cases, severe vitreal traction in 15 cases, and iatrogenic intraocular bleeding in 13 cases, 6 of them referred. In all, retinal breaks were uncertain or invisible in 49 cases. A buckle was used in 83 cases and an internal tamponade in 93. After vitrectomy, the retina was reattached in 76 cases, and after further surgery in 88 (85.4%). With vitrectomy, we were able to confirm or to detect all breaks in 36 cases. Of the 13 intraoperatively unseen breaks, 10 were responsible for vitrectomy failure. Late recurrence after more than 6 months was observed in 5 cases (4.9%). Secondary cataract was observed in 22 (66.6%) of the 33 phakic cases that had been operated on successfully and without complication. CONCLUSION: Our results indicate that vitrectomy is a useful procedure in the management of certain cases of uncomplicated rhegmatogenous retinal detachment. However, secondary cataract is a problem, and the risk of late recurrence needs further evaluation.     

Volumetric analysis of early macular edema with the Heidelberg Retina Tomograph in diabetic retinopathy

OBJECTIVE: This study describes a new method for the quantification of diabetic macular edema by volumetric analysis with the Heidelberg Retina Tomograph (HRT) scanning laser ophthalmoscope. DESIGN: Topographic images of the macula were obtained in 25 consecutive patients who fitted the inclusion criteria. Twenty age-matched control subjects were randomly selected for a similar examination. PARTICIPANTS: Twenty normal control eyes and 32 eyes of 25 patients with diabetes mellitus were studied. INTERVENTION: Patients with diabetes were examined by HRT and slit-lamp biomicroscopy with a contact lens. On HRT, the volumes above reference plane bound by three consecutive circles centered at the fovea (diameter, 1, 2, and 3 mm) were measured. Measurements were repeated three times in a masked fashion, and the mean measurements were used for the analysis. MAIN OUTCOME MEASURES: Visual acuity, macular edema, and volume above reference plane were measured. RESULTS: There were 19 diabetic eyes with clinical macular edema (deemed positives) and 13 without edema (deemed negatives). Diabetic eyes with macular edema had statistically greater volumes above reference plane than did diabetic eyes without edema (P < 0.001) and greater than the control eyes (P < 0.001) for all three circles. There was no statistically significant difference between volumes measured in eyes without macular edema and control eyes (P = 0.42 for the 1-mm diameter circle; P = 0.72 for the 2-mm diameter circle; and P = 0.19 for the 3-mm diameter circle). For the two smallest circles only, the sensitivity of the HRT was 78.94%, and the specificity was 84.61%. None of the patients missed on the two smallest circles would have been positively identified on the 3-mm diameter circle. CONCLUSION: The HRT can detect and quantify macular edema in diabetes by volumetric analysis with the method the authors have described. It is sufficient to measure the volumes above reference plane of two circles centered on the fovea and measuring 1 and 2 mm in diameter because the 3-mm diameter circle does not increase the system's sensitivity.     

Does wavelength matter when photocoagulating eyes with macular degeneration or diabetic retinopathy?

This article reviews the literature about the safety and benefits of two recombinantly derived proteins, bovine somatotropin (bST) and porcine somatotropin (pST), that likely will be used in animal agriculture in the future. When administered to dairy cows, bST increases milk production per cow approximately 15% to 20% and improves productive efficiency approximately 10%. Administration of pST to growing pigs reduces carcass fat content by as much as 70% to 80% and improves productive efficiency 15% to 35%. Because meat is a major source of total fat and saturated fatty acids in the diets of human beings, pST will allow consumers to include leaner, more nutrient-dense pork in their diets and still meet current dietary guidelines. Although these biotechnologies have not yet received regulatory approval from the Food and Drug Administration (FDA) for commercial use, information published by the FDA, the National Institutes of Health, the US Congress Office of Technology Assessment, and the American Academy of Pediatrics, as well as an extensive body of scientific evidence, indicate that these products are safe for the consumer. Nonetheless, it is important that consumers understand the benefits and safety of these biotechnologies. Dietitians can play an important role in providing information to consumers about the safety and benefits of bST and pST.     

Crystalline retinopathy associated with chronic retinal detachment

OBJECTIVE: To describe the presence of crystalline opacities located at the level of the inner retina in patients with chronic retinal detachment. METHODS: We reviewed the clinical records, fundus photographs, and fluorescein angiograms of patients with superficial retinal crystals in the presence of a chronic retinal detachment. RESULTS: Eleven eyes in 11 patients with chronic retinal detachment were found to have these peculiar crystalline opacities on the inner retinal surface. In 5 patients, the crystalline opacities were noted on initial assessment prior to surgery and persisted without change in appearance or number after surgical repair. In 6 eyes, the crystals were not appreciated until after surgical repair of the retinal detachment. The crystals appeared similar in all 11 eyes, were highly refractile, and were located in the posterior pole. Eight of the eyes had retinal detachment associated with retinal dialysis and 6 of these had a history of trauma. There was a definite history of vitreous hemorrhage in 2 eyes. The crystals did not seem to be associated with any visual deficit. CONCLUSIONS: Chronic retinal detachment can be associated with crystals on the inner retinal surface. The cause and composition of these crystals are unknown. They seem to be visually inconsequential and unchanging.     

The role of vitrectomy for diabetic retinopathy

BACKGROUND: Diabetic retinopathy is an important cause of severe vision loss. The risk of vision loss from diabetic retinopathy is substantially reduced by intensive control of diabetes and appropriate laser surgery for proliferative diabetic retinopathy and diabetic macular edema. METHODS: The Diabetic Retinopathy Vitrectomy Study (DRVS) helped identify the indications and most propitious time for performing diabetic vitrectomy for nonresolving vitreous hemorrhage. The DRVS also highlighted the risks and potential complications of vitrectomy surgery. RESULTS: Diabetic persons with severe vision loss from severe proliferative diabetic retinopathy are candidates for vitrectomy after vitreous hemorrhage and severe fibrous changes in the retina. CONCLUSION: In cases in which vision loss occurs, pars plana vitrectomy frequently can restore useful vision, and reduce the risk of vision loss from traction retinal detachment.     

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.     

Late recurrences after successful surgery for retinal detachment with macular hole

Six myopic eyes affected by retinal detachment with macular hole which had been successfully reattached developed recurrent retinal detachment 7-78 months postoperatively. The mean interval between surgery and the recurrent retinal detachment was 13.4 months in five eyes managed with gas tamponade and no choroidal irritation. In an eye managed by scleral buckling with choroidal irritation, the recurrent retinal detachment occurred 78 months postoperatively. The retina was reattached following reoperation in all eyes. However, an eye successfully reattached without choroidal irritation developed four recurrences during the follow-up period. The pathogenesis of late recurrences after successful surgery for retinal detachment with macular hole remains speculative. A number of clinical findings suggest that vitreous traction plays a decisive role.     

Vitrectomy-laser-gas for treating optic disk pits complicated by serous macular detachment

PURPOSE: Optic nerve pit is a rare congenital anomaly. In two third of the patients, the severity of the disease is increased by the apparition of a serous macular detachment, which may compromise the visual prognosis. The aim of this study is to propose a therapy appropriate to such complication. METHODS: A prospective study was performed including 10 patients with a serous macular detachment caused by optic nerve pit. All patients underwent intraocular surgery including vitrectomy, peripapillary photocoagulation and intravitreal injection of gas. The mean postoperative follow-up period was 9.5 months. RESULTS: Therapy success was based on anatomical and functional results. Serous macular detachment reattached in 7 patients out of 10 and a recurrence was observed in one case. Visual acuity improved from 0 to 18 lines of the EDTRS chart (mean increase: 6.7 lines). CONCLUSION: These results confirm that intraocular surgery including vitrectomy-photocoagulation-gas injection is a valuable treatment for serous macular detachment associated with optic nerve pit.     

Screening for diabetic retinopathy. Initiation and frequency

A screening program for diabetic eye disease was established in Iceland in 1980. Diabetics involved in the screening program have a low prevalence of blindness, 1% in type 1 and 1.6% in type 2. We examined ways to make the screening program more efficient by identifying subgroups at low risk of developing eye disease that require treatment and therefore need less frequent screening. We studied whether diabetic eye disease screening programs may be trimmed by excluding children and examining diabetics without retinopathy biannually. Our results indicate that diabetic children under the age of 12 years do not need regular screening for eye disease. Biannual examinations seem to suffice in type 1 and 2 diabetic patients without retinopathy. However, in a setting where the eye clinic is located apart from the diabetes clinics, biannual examinations present practical problems which could result in a less effective screening for diabetic eye disease.     

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.     

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.