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Biomedical subjects

D S Fong

Publications and source records attributed to D S Fong.

16 recordsLinked to original sources
PubMed1999

Causes of severe visual loss in the early treatment diabetic retinopathy study: ETDRS report no. 24. Early Treatment Diabetic Retinopathy Study Research Group.

PURPOSE: To describe the causes of and risk factors for persistent severe visual loss occurring in the Early Treatment Diabetic Retinopathy Study (ETDRS). METHODS: The ETDRS was a randomized clinical trial investigating photocoagulation and aspirin in 3,711 persons with mild to severe nonproliferative or early proliferative diabetic retinopathy. Severe visual loss, defined as best-corrected visual acuity of less than 5/200 on at least two consecutive 4-month follow-up visits, developed in 257 eyes (219 persons). Of these 257 eyes, 149 (127 persons) did not recover to 5/200 or better at any visit (persistent severe visual loss). Ocular characteristics of these eyes were compared with those of eyes with severe visual loss that improved to 5/200 or better at any subsequent visit. Characteristics of patients with severe visual loss that did and did not improve and those without severe visual loss were also compared. RESULTS: Severe visual loss that persisted developed in 149 eyes of 127 persons. In order of decreasing frequency, reasons recorded for persistent visual loss included vitreous or preretinal hemorrhage, macular edema or macular pigmentary changes related to macular edema, macular or retinal detachment, and neovascular glaucoma. Compared with all patients without persistent severe visual loss, patients with persistent severe visual loss had higher mean levels of hemoglobin A1c (10.4% vs 9.7%; P = .001) and higher levels of cholesterol (244.1 vs 228.5 mg/dl; P = .0081) at baseline. Otherwise, patients with persistent severe visual loss were similar to patients with severe visual loss that improved and to those without severe visual loss. CONCLUSIONS: Persistent severe visual loss was an infrequent occurrence in the ETDRS. Its leading cause was vitreous or preretinal hemorrhage, followed by macular edema or macular pigmentary changes related to macular edema and retinal detachment. The low frequency of persistent severe visual loss in the ETDRS is most likely related to the nearly universal intervention with scatter photocoagulation (either before or soon after high-risk proliferative diabetic retinopathy developed) and the intervention with vitreous surgery when clinically indicated.

Aspirin↗
PubMed1999

Decreased prevalence of retinopathy of prematurity in an inner-city hospital.

BACKGROUND AND OBJECTIVE: Improvements in care of low birth weight preterm infants has led to an increased survival of this population. It is not known whether the improved care has decreased the prevalence of retinopathy of prematurity (ROP), or whether the survival of even smaller infants has increased the prevalence. The purpose of this study was to determine the prevalence of ROP in an inner-city hospital during two time periods to determine whether the prevalence is changing. PATIENTS AND METHODS: The frequency and characteristics of ROP were compared between a 10-month observation period in 1995-1996 and published data from a similar time period in 1988-1989. RESULTS: There were fewer cases of ROP per live births less than 1500 g during 1995-1996 compared with 1988-1989 (P< .0001). This included both mild and severe ROP. When the two racial subgroups were examined separately, there was a statistically significant decline for the black (P < .001) but not the Hispanic population (P = .12). The Mantel-Haenszel chi2 test confirmed that the decline was statistically significant when the two groups were combined (P < .001). CONCLUSIONS: In this population, the prevalence of ROP appears to have decreased between 1995-1996 and 1988-1989. The subgroup experiencing the biggest decline was black infants. Other studies should be performed to investigate whether the frequency of ROP has also declined in other settings.

California↗
PubMed1998

Exudative retinal detachment in X-linked retinoschisis.

X-linked retinoschisis is a vitreoretinal dystrophy characterized by foveal and peripheral retinoschisis in the nerve fiber layer. Although many associated peripheral retinal findings have been reported, few reports have described massive exudative retinal detachments in patients with X-linked retinoschisis. The authors report the unusual occurrence of Coats'-like exudative retinopathy in two patients with X-linked retinoschisis. Both patients had peripheral massive exudative retinal detachments.

Adult↗
PubMed1997

Subretinal fibrosis in diabetic macular edema. ETDRS report 23. Early Treatment Diabetic Retinopathy Study Research Group.

OBJECTIVE: To describe the characteristics of and risk factors for subretinal fibrosis (SRF) in patients with diabetic macular edema. PATIENTS AND METHODS: A total of 109 eyes (in 96 persons) with SRF, defined as a mound or sheet of gray to white tissue beneath the retina at or near the center of the macula, were identified during the Early Treatment Diabetic Retinopathy Study, which is a randomized clinical trial of photocoagulation and aspirin treatment in patients with mild to severe nonproliferative or early proliferative diabetic retinopathy. The patients and the ocular characteristics of these 109 eyes, all of which had clinically significant macular edema, were compared with those of 5653 eyes in which clinically significant macular edema, but not SRF, was observed during the trial. RESULTS: In 9 of 109 eyes, the development of SRF may have been directly related to focal photocoagulation. Seventy-four percent of the eyes in which SRF developed had very severe hard exudates in the macula prior to the development of SRF, while this level of hard exudates was seen in only 2.5% of the eyes with clinically significant macular edema in which SRF did not develop (P < .001). Of the 264 eyes with this level of hard exudates at baseline (n = 29) or during follow-up (n = 235), SRF developed in 30.7% of the eyes, while this complication developed in only 0.05% of 5498 eyes with clinically significant macular edema without this level of hard exudates. CONCLUSIONS: Subretinal fibrosis is an infrequent complication of diabetic macular edema. Although it has been reported to be associated with photocoagulation burn intensity, in only 9 of 109 eyes in which SRF developed was it located adjacent to a photocoagulation-related scar (among 4823 eyes that received focal photocoagulation for treatment of macular edema). The strongest risk factor for the development of SRF is very severe hard exudate.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Is myopia related to amplitude of accommodation?

PURPOSE: To report the association between amplitude of accommodation and refractive error. METHODS: Refractive error and amplitudes of accommodation were measured in 1,148 eyes of 696 patients as part of the Early Treatment Diabetic Retinopathy Study. RESULTS: Eyes with myopia, defined as those with a refractive error of -0.75 diopter or more, have lower accommodative amplitudes (P = .005). After multivariate logistic regression analysis adjusting for age, occupation, and white race, lower amplitudes of accommodation remained associated with myopia (P = .03). CONCLUSIONS: Eyes with lower amplitudes of accommodation must use more of their accommodative reserve for near work. Myopia may be an adaptation that develops in eyes with reduced accommodative amplitudes.

Accommodation, Ocular↗
PubMed1997

Intraorbital air simulating an intraocular foreign body.

PURPOSE: To present an ultrasonographic finding that simulated an intraocular foreign body after repair of a ruptured globe. METHOD: Case report. An ultrasonogram of a post-trauma eye was correlated with a computed tomographic scan. RESULTS: B-scan ultrasonography was performed on an eye after repair of a corneoscleral laceration. The ultrasonogram showed a highly reflective echo source suggestive of a foreign body; however, an orbital computed tomographic scan demonstrated that the lesion was intraorbital air. CONCLUSION: Although a highly reflective echo source in the presence of a ruptured globe may suggest a foreign body, the presence of orbital air should also be considered when interpreting ultrasonograms used in the preoperative and postoperative management of globe trauma.

Adult↗
PubMed1995

Cardiovascular autonomic neuropathy and proliferative diabetic retinopathy.

PURPOSE: To determine prospectively whether cardiovascular autonomic neuropathy is a risk factor for proliferative diabetic retinopathy. METHODS: A five-year follow-up study of 88 diabetic persons was performed at a center providing primary and specialized care for diabetes. Participants were white, insulin-dependent patients with diabetes of 15 to 21 years' duration. The primary end point was the presence of proliferative diabetic retinopathy, seen either on fundus photography or ophthalmologic examination. Cardiovascular autonomic neuropathy was measured at baseline by using a standard protocol. RESULTS: Fourteen patients developed proliferative diabetic retinopathy during follow-up. One measure of cardiovascular autonomic neuropathy, the 30:15 ratio, the heart rate variation at the 30th beat compared with that at the 15th beat, was lower among patients with proliferative diabetic retinopathy (P = .0049) The risk of proliferative diabetic retinopathy in patients with an abnormal cardiovascular autonomic neuropathy index was 2.59, although the estimate was not statistically significant because of the small number of patients who developed proliferative diabetic retinopathy. CONCLUSIONS: This study provides prospective evidence that cardiovascular autonomic neuropathy is associated with proliferative diabetic retinopathy. In addition to ocular determinants of proliferative diabetic retinopathy, systemic risk factors also should be considered when examining patients with diabetes mellitus.

Adolescent↗
PubMed1993

Spontaneous hyphema associated with anterior uveitis.

Few reports have described hyphema in association with anterior uveitis. Five cases of anterior chamber haemorrhage are reported in patients with five different anterior uveitic entities: Reiter's syndrome, juvenile chronic arthritis, ankylosing spondylitis, idiopathic anterior uveitis, and herpes simplex. Hyphema has been reported in association with idiopathic non-granulomatous anterior uveitis, but not with the other four entities. In three cases, iris rubeosis was present. In two cases the patients were taking non-steroidal anti-inflammatory agents. The hyphemas occurred at times of heightened inflammation and resolved spontaneously without complication in all but one case, a boy with idiopathic uveitis who required surgery to remove the blood. The clinical outcome of these cases provides evidence that conservative medical management is usually sufficient.

Adult↗
PubMed1987

Secular decline in death rates due to ischemic heart disease in Mexican Americans and non-Hispanic whites in Texas, 1970-1980.

Although the decline in ischemic heart disease mortality is now entering its third decade, there has been no definitive information on the experience of Mexican Americans, the nation's second largest minority group. Earlier studies carried out in the 1970s were hampered by the unavailability of satisfactory population data beyond 1970. In the present study we have used 1970 and 1980 census data to compute death rates in Mexican Americans and non-Hispanic whites from Texas for the periods 1969-1971 and 1979-1981. All four sex-ethnic groups showed statistically significant declines in death rates due to all causes, due to total ischemic heart disease, and due to acute myocardial infarction between 1969-1971 and 1979-1981. Declines in the latter two causes of death were least marked in Mexican American men. This sex-ethnic group was also the only one that failed to show a decline in death rates due to chronic ischemic heart diseases. The fact that Mexican Americans have been shown to be less well informed about and less likely to adopt lifestyle changes aimed at reducing heart disease risk than non-Hispanic whites may account for the less striking mortality decline observed in Mexican American men, but is harder to reconcile with the apparent equal decline in Mexican American women compared with non-Hispanic whites.

Adult↗