Photoreceptor loss in age-related macular degeneration

PURPOSE: The authors showed previously that parafoveal rods, but not cones, decrease during the course of adulthood in donor eyes that were screened to exclude the grossly visible macular drusen and pigmentary disturbances typical of age-related macular degeneration (AMD). Because AMD begins in the parafovea, this selective loss of rods actually may be subclinical AMD not yet visible in the fundus. If so, AMD must have a predilection for rods over cones. The authors tested this hypothesis by determining the relative numbers of cones and rods in donor eyes with mid-to late-stage AMD and in age-matched controls. METHODS: Thirteen eyes (from seven donors) with grossly visible macular drusen and pigmentary disturbances were either wholemounted for photoreceptor counts or sectioned through the fovea for histopathology and carbonic anhydrase histochemistry to label red-green cones. Eyes were assigned to AMD or control groups on the basis of histopathology and clinical history. RESULTS: Five nonexudative AMD (NE-AMD) eyes from three donors showed sparing of foveal cones and loss of rods and cones in the parafovea. In two donors, rod loss exceeded cone loss at most parafoveal locations, and in one donor, rod density was normal and cone density was reduced. In eight exudative AMD (EX-AMD) eyes from five donors, photoreceptors surviving along the margins of and overlying disciform scars were largely cones. CONCLUSIONS: Photoreceptors are lost in NE-AMD as well as in the more severe exudative form, consistent with functional and clinical studies. The authors propose that rods die in older eyes without evidence of overt retinal pigment epithelial disease. In persons susceptible to AMD, the retinal pigment epithelium becomes dysfunctional. Secondarily, rod loss continues and cones begin to degenerate. Eventually, only degenerate cones remain; ultimately, all photoreceptors may disappear.     

Focal proliferations of retinal pigment epithelium. Risk factor in senile macular degeneration

BACKGROUND: Clinical studies have demonstrated the relevance of focal RPE proliferations in early AMD as risk factors for visual loss caused by late AMD. Angiographically these focal RPE proliferations are characterized as small hypofluorescent spots with hyperfluorescent rim without leakage. Corresponding to histological and experimental studies they can be interpreted as small areas of occult choroidal neovascularizations covered by proliferated RPE cells. The characterization of the long-term prognosis of these lesions was the aim of the present study. PATIENTS AND METHODS: Ninety-eight patients (52 female, 46 male) were reexamined clinically and angiographically with a follow-up of 2-12 years (mean 6.5 years). RESULTS: Visual loss of two lines or more could be observed in 64.5% of patients with final visual acuity less than 20/100 in 24.5% of patients. Morphologically the changes in visual acuity were related to the progression towards classical choroidal neovascularizations in 32.7% of patients. In addition 11.2% of patients demonstrated a regression of the small occult membrane with the development of small areas of RPE atrophy covering the size of the original occult neovascularization. In 10.2% of the patients enlargement of the lesion was observed, resulting in a large occult choroidal neovascularization without signs of classical membranes, and in 45.9% of patients the clinical and angiographical situation was unchanged. The most important prognostic factor correlating with visual loss was the presence of a disciform lesion in the fellow eye and of multiple drusen in the examined eye. Other factors like the size or location of the focal RPE proliferation and the duration of follow-up did not correspond with visual loss. CONCLUSIONS: Focal RPE proliferations in early AMD interpreted as small occult choroidal neovascularizations are associated with a high risk of visual loss. Especially if these lesions are associated with multiple drusen and a disciform lesion in the fellow eye, nearly all patients are at risk for visual loss. These changes may therefore characterize a special high-risk group for future prophylactic treatments in early AMD, but because of the high risk for the development of classical choroidal neovascularizations in this group, these results are also very important for the planning of prophylactic laser trials for drusen in early AMD.     

Physical and linkage mapping of human chromosome 17 loci to dog chromosomes 9 and 5

We performed fluorescein and indocyanine green (ICG) angiographies in 56 patients with central serous chorioretinopathy, and studied the choroidal lesions. In the early phase, choroidal filling with ICG was delayed in 77% in the area including focal leakage. Hypofluorescent findings around the site of focal leakage persisted through the phase in 23%, and we think this finding was caused by filling defect of the choriocapillaris. In the late phase, choroidal tissue staining by ICG was present in 82% in the area including focal leakage. Multiple areas of choroidal staining were also present in unaffected areas in 43% and in 62% of fellow eyes. Choroidal tissue staining by ICG was revealed in 48% in the area of choroidal filling delay, and this finding persisted after focal leakage had disappeared following photocoagulation. We think this finding was caused by choroidal vascular hyperpermeability. These findings suggest that choroidal circulatory disturbance and choroidal vascular hyperpermeability play a causative role in damage to the retinal pigment epithelium in central serous chorioretinopathy.     

Reducing inequities through participatory research and community empowerment

PURPOSE: To analyze the indocyanine green angiographic findings of drusen in the early stages of age-related macular degeneration. METHODS: Sixty-nine eyes of 53 consecutive patients with drusen but without exudative complications of age-related macular degeneration were studied. Drusen were classified into four groups: hard drusen, drusen derived from clusters of hard drusen (hard cluster-derived drusen and soft cluster-derived drusen), membranous drusen, and regressing drusen. An additional category was constituted by reticular pseudodrusen that could be associated with drusen of either the inner or outer macula. Results of contact lens biomicroscopy and fluorescein angiography were compared with findings on indocyanine green angiography. RESULTS: Hard drusen, either isolated hard drusen or hard cluster-derived drusen, were hyperfluorescent during indocyanine green angiography; in contrast, all sizes of soft drusen derived from clusters of hard drusen were hypofluorescent throughout the angiogram. Membranous drusen, visible on biomicroscopy and fluorescein angiography, were not visible during indocyanine green angiography. Regressing drusen may have showed hyperfluorescence at the early stages of indocyanine green angiography, but associated calcium and pigmentation were hypofluorescent. Reticular pseudodrusen were visible on red-free photographs; on midphase and late-phase indocyanine green angiography using the scanning laser ophthalmoscope only, reticular pseudodrusen were seen as a pattern of hypofluorescent dots. CONCLUSION: The indocyanine green angiographic findings add to and support the clinicopathologic classification of drusen. Indocyanine green angiography may help to distinguish the different types of drusen and may thus be of use in evaluating the risk of progressive age-related macular degeneration in patients with drusen.     

Laser photocoagulation for macular soft drusen. Updated results

PURPOSE: To update the results of a study on the disappearance of macular soft drusen after laser treatment in the natural evolution of age-related macular degeneration. METHODS: A total of 46 patients with confluent soft drusen and pigmentary changes were studied prospectively. Group 1 was composed of 30 patients with bilateral drusen; the authors randomly assigned one eye of each patient for treatment and the fellow eye for the control. In 16 patients a choroidal neovascular membrane was present in one eye, and treatment was applied to the fellow eye (group 2). Argon green laser treatment was applied directly to the soft drusen in the temporal macula. RESULTS: All treated drusen disappeared in a mean of 3.5 months after treatment, and untreated drusen disappeared in all but three patients in an average of 8.5 months. After an average period of 3 years, only one control eye and none of the treated eyes in group 1 developed a choroidal neovascular membrane (P = 0.500). In group 2, neovascularization occurred in 18% of the patients. The initial improvement in Snellen acuity after subfoveal drusen disappearance diminished as a consequence of cataract progression. CONCLUSIONS: Although no definitive conclusions should be made because of the small number of patients studied, results seem to show that this treatment does not reduce the risk of choroidal neovascularization in the treated eye of patients with a history of exudative disease in the fellow eye. It may be effective in patients with high-risk bilateral soft drusen, that is, in less advanced stages of the disease.     

Visual acuity and scar size in eyes with age-related subfoveal choroidal neovascular lesions, 30 months after radiation therapy

PURPOSE: In a study to determine the effectiveness of ionizing radiation on the deterioration of visual acuity (VA) due to choroidal neovascularisation (CNV) the affected eyes of 10 patients were treated with a total dose of 24 Gy (6 Gy fractions). A special lens-sparing technique was used to avoid cataract development. During 30 months of follow-up the visual acuity (VA) and scar size (SS) of the treated eyes and fellow eyes of all 10 patients were evaluated. RESULTS: After 30 months of follow-up 5 eyes showed a stable VA and fluorescein angiogram (FA) appearance. Concerning 4 out of 5 eyes with progressive disease, the 4 eyes treated with radiation therapy had better VA and smaller SS as compared with the untreated fellow eyes with exudative AMD. CONCLUSIONS: The results suggest that 24 Gy either stabilizes or delays the deleterious effects of CNV on the visual acuity. Until now no late side effects have been observed.     

The use of confocal scanning laser tomography in the evaluation of retinal elevation in age-related macular degeneration

OBJECTIVE: To evaluate the feasibility of using confocal scanning laser tomography in the analysis of macular topography in patients with subfoveal choroidal neovascularization associated with age-related macular degeneration (AMD) and to analyze quantitatively the changes in topography after local strontium-plaque radiation therapy. DESIGN: Prospective case series. PARTICIPANTS: A total of 16 eyes with subfoveal choroidal neovascular membranes (CNVM) treated with strontium-90 (90Sr)-plaque radiation therapy and 16 fellow eyes of 16 patients were examined. INTERVENTION: Confocal scanning laser analysis of macular surface topography before and after irradiation of the macula was performed. MAIN OUTCOME MEASURES: Parameters describing the height and volume of the retinal elevation in the macula were measured. RESULTS: The maximum height of the macular lesion at baseline was 0.25 mm (standard deviation [SD], 0.12 mm) in eyes showing regression of the CNVM during follow-up and 0.34 mm (SD, 0.19 mm) in eyes showing continued growth of the CNVM. During follow-up, a mean decrease in the maximum height of the macular lesion ranging from 0.03 to 0.10 mm occurred in eyes with regression of the CNVM, whereas the mean maximum height increased by 0.07 to 0.15 mm during follow-up visits in eyes with continued growth of the CNVM. All parameters describing the mean height and volume of the lesion also decreased significantly in patients showing angiographic regression, whereas they increased or remained unchanged in patients with continuous growth of the CNVM despite irradiation. The corresponding parameters also were higher in fellow eyes with untreated CNVM than in eyes without exudative AMD. CONCLUSIONS: Confocal scanning laser tomography can be used to monitor the amount of the change in neurosensory detachment in AMD. The parameters obtained by confocal scanning laser tomography correlate with CNVM perfusion after 90Sr-plaque radiation therapy. This technology is a useful tool for objective evaluation of morphologic change after institution of new therapeutic methods for the treatment of AMD.     

Pre-injection fluorescence in indocyanine green angiography

PURPOSE: To verify whether infrared pre-injection fluorescence can be observed in patients undergoing indocyanine green (ICG) angiography. METHODS: Infrared fundus photographs were taken before dye injection for 450 consecutive patients undergoing ICG angiography for different chorioretinal disorders. The authors used a high-resolution videoangiography system with the standard ICG filters inserted (overlap, < 0.5%) and the highest flash intensity. RESULTS: Pre-injection fluorescence was detected in 184 patients (40.8%). It was a strong fluorescence in 75 patients (40.7%) and a faint fluorescence in 109 (59.2%). When fluorescence was strong, it simulated vascular filling on the ICG angiogram. Pre-injection fluorescence resulted from the following lesions: (1) old grayish subretinal hemorrhages (35 patients); (2) lipofuscin-like deposits (65 patients); (3) pigmented choroidal neovascular membranes (72 patients); and (4) serous retinal detachments lasting from several months or years (12 patients). Highly reflecting white lesions were not fluorescent. CONCLUSION: Pre-injection fluorescence of chorioretinal lesions is frequently detectable in patients with diseases requiring ICG examination. A pre-injection photograph may help to avoid misinterpretation of the angiograms. The authors' findings may be interpreted as pseudofluorescence or autofluorescence. Pigments contained in pathologic structures of the ocular fundus may be the source of autofluorescence emissions in the near-infrared range.     

Prevalence of positive urinary dipstick analysis (leucocyte esterase, nitrite, haemoglobin, or glucose) in a population of 3645 adult subjects--consequence for measurement of urinary albumin excretion rate

A 10-year-old boy presented with typical fundus findings of frosted branch angitis in both eyes. Fluorescein angiography showed late-phase hyperfluorescence in some active areas of vascular lesions. Indo-cyanine green (ICG) angiography showed similar but less extensive hyperfluorescence along the frosted vessels and in the disc. ICG angiography also showed filling delay in the choriocapillaris. These findings suggest that frosted branch angitis is a manifestation of inflammation in the retina and the choroid. Laboratory studies showed increase in the toxoplasma titer at 1:10,240 and in the serum levels of alpha 1 and alpha 2 globulin. Frosted branch angitis in this case seemed to be the consequence of local allergic reaction, or immune complex deposition, presumably due to toxoplasma infections.     

Recombinant GM2-activator protein stimulates in vivo degradation of GA2 in GM2 gangliosidosis AB variant fibroblasts but exhibits no detectable binding of GA2 in an in vitro assay

OBJECTIVE: To examine choroidopathy in patients with Beh?et disease. DESIGN: Prospective clinical study. PARTICIPANTS: Thirty-three patients (63 eyes) with Beh?et disease. INTERVENTION: Patients underwent simultaneous indocyanine green (ICG) and fluorescein angiography with a double detector of scanning laser ophthalmoscopy. MAIN OUTCOME MEASURES: Angiographic findings recorded on videotapes were evaluated. The relation of angiographic findings with systemic activity and aqueous inflammation was also analyzed. RESULTS: Fluorescein angiography showed leakage in varying degrees from retinal vessels in 30 patients (53 eyes, 84%). The ICG angiographic findings were choroidal vascular wall staining in 16 eyes (25%), hyperfluorescent spots in 42 eyes (66%) and hypofluorescent plaques in 22 eyes (35%), both of which were not evident with fluorescein, leakage from choroidal vessels in 3 eyes (5%), and irregular filling of choriocapillaris in 11 eyes (17%). These findings did not have a statistically significant correlation with the presence or absence of aqueous inflammation or oral aphthous ulcerations. CONCLUSIONS: The patients with Beh?et disease showed choroidal abnormalities, which could be revealed only by ICG angiography, but not with funduscopy or fluorescein angiography. Simultaneous ICG and fluorescein angiography would be useful for examining choroidal lesions in Beh?et disease.     

Role of indocyanine green fluorescence videoangiography in evaluation of subretinal disease

BACKGROUND: Indocyanine green (ICG) is a sterile, water-soluble, tricarbocyanine dye that can be used in fundus angiography as an adjunct to sodium fluorescein. It has a peak spectral absorption of 805 nm in blood plasma or blood, as compared with fluorescein, which has a peak spectral absorption of 465 nm. Because the absorption and emission of ICG lies around 835 nm, transmission of energy by the retinal pigment epithelium (RPE) and serosanguinated material is more efficient in this region than in the region of visible light energy. ICG has the property of being approximately 98% bound to blood protein, disallowing extravasation of excessive dye in the highly fenestrated choroidal vasculature. METHODS: The characteristics of ICG are discussed, including administration and dosage, adverse reactions and use of infrared filters for fundus photography. In addition, two cases are presented to illustrate the clinical application of ICG for diagnosis and treatment of choroidal neovascular membranes. RESULTS: ICG videoangiography can be used to reveal subfoveal choroidal neovascular membranes not previously identified with fluorescein; angiograms can also be used to dramatically highlight retinal and choroidal changes. CONCLUSIONS: The use of ICG for fundus videoangiography provides a more accurate and complete evaluation in certain cases of subretinal and choroidal disease.     

Evaluation of fluorodeoxyglucose positron emission tomography in the management of soft-tissue sarcomas

OBJECTIVE: This study aimed to determine whether clinical tests of ocular function and macular appearance independently can help to predict which patients with unilateral neovascular age-related macular degeneration (AMD) will have a choroidal neovascular membrane (CNVM) develop in their fellow eye. DESIGN: The study design was a prospective cohort study. PARTICIPANTS: One hundred twenty-seven patients with unilateral neovascular AMD observed for up to 4.5 years participated. INTERVENTION: Functional measurements included visual acuity, macular visual field, glare recovery time, and foveal electroretinogram amplitude and implicit time. MAIN OUTCOME MEASURE: The age-adjusted proportion of patients having a CNVM develop over follow-up assessed by the Cox proportional hazards model with stepwise selection was measured. RESULTS: On average, 8.8% of patients had a CNVM develop each year. Independent risk factors for the fellow eye were its glare recovery time in minutes (relative risk = 1.30, confidence interval = 1.10-1.54, P = 0.003) and its extent of visible macular abnormalities on a four-point scale (relative risk = 1.62, confidence interval = 1.06-2.59, P = 0.03). Of the fellow eyes that converted, the interval to have a CNVM develop was inversely related to the foveal electroretinogram implicit time. CONCLUSIONS: A slower recovery from glare and more extensive funduscopic changes appear to be independent risk factors for the development of a CNVM in the fellow eyes of patients with unilateral neovascular AMD. A slower foveal electroretinogram implicit time may be a sign of early stage CNVM development, perhaps because of outer retinal ischemia. These results have clinical management implications, particularly for those patients at high risk of having a potentially treatable form of AMD develop.     

Choroidal neovascularization in second eyes of patients with unilateral exudative age-related macular degeneration

PURPOSE: To evaluate patients with unilateral occult choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) for the nature of the neovascularization which develops in the fellow eyes. METHODS: Patients with newly diagnosed unilateral occult CNV were followed prospectively for the development of CNV in the fellow eye. Patients were classified based on the type of occult CNV in the first eye: (1) those with associated serous pigment epithelial detachment (serous PED) and (2) those without. Demographic and clinical data, including the type of CNV in the second eyes, were compared. RESULTS: Choroidal neovascularization developed in 115 patients in the second eye. Fifty-six patients had occult CNV with a serous PED (also termed vascularized PED) in the first eye, and 59 patients had occult CNV without serous PED. The two groups did not differ significantly in the demographic and the clinical features evaluated. Well-delineated (or classic) CNV developed in the fellow eye of one patient in each group. Of the remaining 55 patients with vascularized PED in the first eye, the same type of occult CNV developed in 48 (87%) patients in the second eye. Of 58 (84%) patients in the second group, the same type of occult CNV developed in the second eye of 49 patients. This symmetric distribution of type of CNV between eyes is highly significant (P < 0.001). CONCLUSIONS: Eyes with occult CNV secondary to AMD can be classified by the presence or absence of an associated serous PED. Patients with unilateral occult CNV have a significant risk of occult CNV developing in the second eye, and the type of occult disease in the first eye is highly predictive of the type of neovascularized disease in the second eye. These findings are important with respect to natural history, and possibly to the treatment response and visual prognosis of patients with neovascularized AMD.     

Vitelliform macular degeneration

Six patients had macular vitelliform lesions similar to those in Best's vitelliform foveal dystrophy but all had normal electro-oculograms (EOG) and no familial involvement. Two patients had an exudative form of degenerative chroidopathy. The remining four had vitelliform lesions of unknown etiology. Fluorescein angiography demonstrated slight hyperfluorescence through rarefied retinal pigment epithelium but no leakage occurred from perifoveal retinal capillaries. The diagnosis of vitelliform foveal dystrophy should be restricted to those patients who have the morphologic lesions, and abnormal EOG, and a contributory family history.     

Indocyanine green angiography in choroidal osteoma

BACKGROUND: Choroidal osteoma is a rare choroidal tumor; knowledge of its indocyanine green characteristics is limited. METHODS: The fundus photographs and the fluorescein and indocyanine green angiograms of three patients were reviewed. Each patient was examined at least twice with a follow-up varying from 10 to 60 months. RESULTS: Late-phase fluorescein angiograms allow assessment of the extension of the osteoma as it is variably hyperfluorescent due to tumor staining combined with a variable degree of overlying retinal pigment epithelial changes. The hypofluorescent area observed in the early phase of the indocyanine green angiogram corresponds with the extent of the osteoma but the borders may be difficult to demarcate. In the late phase of the indocyanine green angiogram, hypofluorescence due to choriocapillaris loss and hyperfluorescence due to leakage from abnormal choroidal vessels are combined. Infrared angiography high-lights abnormal choroidal vessels and vascular spiders present on the tumor surface. It is difficult to differentiate these choroidal vascular anomalies from subretinal neovascularization. CONCLUSIONS: We find no homogeneous pattern either on fluorescein or on infrared angiography. The findings may change with follow-up, indicating changes within the tumor or the surrounding tissue that are still poorly understood.     

Idiopathic polypoidal choroidal vasculopathy of the macula

OBJECTIVE: The authors evaluated the clinical, fluorescein, and indocyanine green (ICG) angiographic characteristics of the macular variant of idiopathic polypoidal choroidal vasculopathy (IPCV). DESIGN: Observational case series. PARTICIPANTS: The records, photographs, and fluorescein and ICG angiograms of eight eyes of seven patients with IPCV lesions confined to the macula were reviewed. MAIN OUTCOME MEASURES: The visual acuity, fundus examination, fluorescein and ICG angiographic characteristics, and clinical course were compared. RESULTS: All patients demonstrated polypoidal lesions arising from macular choroidal vessels on ICG angiography. One patient had bilateral lesions. These lesions appeared hyperfluorescent in the early phases of both fluorescein and ICG angiography. Late-phase leakage was seen in cases associated with subretinal fluid or exudate. None of these patients demonstrated polypoidal lesions arising from the peripapillary choroidal circulation or peripapillary choroidal neovascularization. Three eyes with polypoidal lesions that were associated with subretinal fluid and exudates were treated with photocoagulation. Five eyes were not treated. Final visual acuity ranged from 20/20 to hand motions. Severe visual loss was associated with vitreous and subretinal hemorrhage, but this resolved without permanent severe visual loss in several cases. CONCLUSIONS: In the macular variant of IPCV, ICG and fluorescein angiography demonstrate characteristic macular polypoidal lesions without evidence of peripapillary lesions. The vascular origin of these polypoidal lesions appears to be the macular choroidal circulation. This is distinguished from classic IPCV, in which lesions appear to arise from the peripapillary choroidal circulation. Visual prognosis appears to be good, with most patients retaining visual acuity of 20/80 or better. If subretinal fluid or exudates reduce visual acuity, photocoagulation should be considered.     

Angiographic and histological evaluation of porcine retinal vascular damage and protection with perfluorocarbons after massive air embolism

BACKGROUND AND PURPOSE: We have previously shown that perfluorocarbon emulsions (PFEs) reduce the severity of cerebral injury (indicated by infarct, reduced blood flow, and depressed EEG) induced by air embolism during cardiopulmonary bypass (CPB). This study used retinal fluorescein angiography to define the mechanisms of cerebral injury and to determine the efficacy of PFEs in cerebral protection. These angiographic findings were correlated to previously reported histologic findings. METHODS: Twenty domestic pigs underwent CPB with a prime of standard crystalloid or PFE (5 mg/kg) and crystalloid. After 10 minutes on CPB, a single (5 mL/kg) or double (2x2.5 mL/kg) bolus of room air or saline (control) was delivered via the right carotid artery. Retinal fluorescein angiograms were captured at 4 time points: baseline, air insult, postbypass, and postreperfusion. Following euthanasia, both eyes were removed and the retinas isolated for histological analysis with horseradish peroxidase (HRP), as previously reported. RESULTS: In control pigs, postreperfusion angiograms showed small nonperfused areas, and retinal whole mounts demonstrated vascular damage as previously reported. In 5 PFE-primed animals, postreperfusion angiograms showed hyperfluorescence, but angiograms and HRP mounts were otherwise not significantly different from baseline. Severely hyperfluorescent vessels observed angiographically also showed a correlation with HRP extravasation but were not consistently indicative of severe vascular damage. CONCLUSIONS: Retinal fluorescein angiography and retinal staining with HRP indicate that mechanisms of cerebral air embolism include nonperfusion, vascular leakage and spasm, red blood cell sludging, and hemorrhage. Priming with PFE prevented many of the sequelae associated with air embolism.     

Indocyanine green angiography of multifocal choroiditis

PURPOSE: The purpose of the study is to determine indocyanine green (ICG) angiographic characteristics of patients with multifocal choroiditis (MC) and to identify features that may assist in the differentiation of MC from other ocular inflammatory diseases. METHODS: After complete ophthalmologic examination, fluorescein angiography and ICG angiography were performed in a series of 14 patients with MC. The ICG findings were then correlated with the clinical and fluorescein angiographic appearance of these patients to determine specific characteristics and distinguishing features of the entity. These findings then were compared with those of angiographic patterns observed in patients with ocular histoplasmosis syndrome to determine whether differentiating features could be identified. RESULTS: Fourteen (50%) of the 28 eyes were found to have large hypofluorescent spots in the posterior pole on ICG angiography, which, in most cases, did not correspond to clinically or fluorescein angiographically detectable lesions. Seventeen (61%) had smaller hypofluorescent lesions (approximately 50 pm in size) in the posterior pole on the ICG study. In seven eyes exhibiting enlarged blind spots on visual field testing, ICG angiography showed confluent hypofluorescence surrounding the optic nerve. The ICG angiogram was found useful in evaluating the natural course in two patients with MC as well as a response to oral prednisone therapy in four others. The ICG angiographic findings differed from those seen in patients with ocular histoplasmosis. CONCLUSIONS: Indocyanine green angiography can provide information that is not detectable by clinical or fluorescein angiographic examination in patients with MC. This information may prove useful in differentiating this condition from the ocular histoplasmosis syndrome, provide a better understanding of the natural course and progression of the disease, and provide a potential adjunct in the clinical evaluation of patients undergoing therapeutic regimens for active inflammatory lesions.     

Involvement of the frontal ventrolateral orbital cortex in descending inhibition of nociception mediated by the periaqueductal gray in rats

OBJECTIVE: To improve the characterisation of chest pain by comparing symptoms in patients with normal and abnormal coronary angiograms. STUDY DESIGN: Prospective case-control study. SETTING: Single tertiary cardiac referral centre. PATIENTS: 65 consecutive patients with chest pain and completely normal coronary angiograms recruited over a period of one year, and 65 sex matched patients with significant stenoses at angiography. MAIN OUTCOME MEASURES: Standardised chest pain questionnaires. RESULTS: 61 of 65 patients (94%) and every control reported chest pain on exertion. There were no important differences in the site, quality, and radiation of pain but three symptoms had discriminatory value expressed in binary fashion ("typical" v "atypical"): the consistency with which pain was reproduced by exercise (typical, score index 10/10), the duration of pain episodes (typical, five minutes), and the frequency of pain at rest (typical, 10% all pain episodes). All three symptoms were atypical in 21 (32%) patients with normal coronary angiograms, but only one patient with an abnormal coronary angiogram. Patients with no typical features had a 2% chance of an abnormal coronary angiogram if aged under 55 years or 12% if aged 55 years or more. The additional impact of exercise stress testing was low. CONCLUSIONS: Chest pain characteristics which separate patients with normal coronary angiograms from patients with obstructive coronary heart disease can be defined objectively. This may allow improvements in referral patterns for specialist opinion or angiography, and in characterisation of patients in research studies.     

Elevated levels of IL-8 in dengue hemorrhagic fever

AIMS: To characterise retinal function using electrophysiological and psychophysical tests in 17 patients with helicoidal peripapillary chorioretinal degeneration. METHODS: The electroretinogram (ERG) was recorded using gold foil corneal electrodes. The electro-oculogram (EOG) was recorded using a standard protocol. Dark adaptometry was recorded with an SST-1 dark adaptometer and colour vision assessed with Ishihara plates and Farnsworth D-15. RESULTS: All subjects had a recordable ERG. The amplitudes and implicit times of the a- and b-waves were within normal limits at all luminances in five subjects (age 21-70 years, mean 40 years). The ERG of six (age 26-55 years, mean 40.7 years) had subnormal amplitudes at all luminances, but normal implicit times, and six (age 38-81 years, mean 60.7 years) had abnormal ERGs with marked reduction of a- and b-waves, and delayed implicit times of the b-wave. The implicit times of the a-wave were normal in all subjects. A reduction in the b/a wave ratios was not found, nor was there selective loss of scotopic, mixed rod/cone, or cone responses. The light/dark ratio of the EOG was subnormal (150-185%) or abnormal (below 150%) in all but three subjects. Two patients with normal EOG showed normal ERGs in both eyes, but one had subnormal ERGs in both eyes. The scotopic sensitivity was normal in all subjects and dark adaptation showed a normal time course. Colour vision was normal in all patients. CONCLUSION: The results suggest that in most cases the function of the retinal pigment epithelium is affected by this disease before any changes in the function of the sensory retina are detectable by our methods, and that retinal dysfunction is focal rather than diffuse.