The relationship between the amount of posterior displacement of the retinal surface at the temporal disc margin and the reference height(HRef)in analyzing optic disc using Heidelberg Retina Tomograph(HRT;Heidelberg Engineering, Heidelberg, Germany)was evaluated. The displacement was measured as mean height of contour(MHC)in the temporal 40degrees C segment(20degrees C superior and 20degrees C inferior to the horizontal midline)of optic disc. HRef is a value representing the location of the standard reference plane. The accordances of HRef and stereometric parameters between right and left disc were also evaluated. MHC in the temporal 40 degrees C and nasal 40 degrees C segment, HRef, and stereometric parameters of optic disc were measured with the HRT in 244 eyes of 122 subjects. HRef was 0.376+/-0.099 mm in the right disc and 0.385+/-0.090 mm in the left disc. There was good correlation between HRef and MHC in the temporal 40degrees C segment(r=0.97, p<0.01), but poor in the nasal 40 degrees C segment(r=0.29, p<0.01). The accordances of HRef and stereometric parameters increased as the difference of MHC in the temporal 40degrees C segment between right and left disc decreased. HRef was affected by the amount of posterior displacement of the retinal surface at the temporal disc margin, which occurs in instances such as a tilted disc. We should find the method to adjust stereometric parameters to the amount of disc tilt.
Retina* ; Retinaldehyde*

The Naka-Rushton equation, R=R(max) I(n)/(I(n)+K(n)), has been used to describe the luminance-response function of the scotopic electroretinogram. R(max) is the asymptotic value of the b-wave amplitude as a function of stimulus luminance, K is the intensity that produces a b-wave amplitude that is one-half R(max) and n is a dimensionless contant that controls the slope of the function and represents the degree of homogeneity of retinal sensitivity. These three parameters are often used in experimental laboratories, since it can show selective changes in each parameter. The present study describes and compares the parameters of Naka-Rushton equation obtained by using ganzfeld stimuli(R(max)=363+/-32 uv, n=0.86+/-0.06, log K=-2.39+/-0.19 log cd.sec/m2) and direct flash stimuli(R(max)=354+/-28 uv, n=0.80+/-0.06, log K=-2.26+/-0.15 log cd.sec/m2) in 20 eyes of the normal pigmented rabbits respectively. The n values were significantly increased by the ganzfeld light stimuli than by the direct flash stimuli(p<0.05).
Rabbits ; Retinaldehyde

PURPOSE: The authors used the instrument, OCT3, to evaluate the reproducibility and map the macular thickness rapidly in normal subjects METHODS: Macular thickness was measured in 120 eyes of 62 normal subjects, aged 18 to 79 years, with the macular OCT3 map. There was no history of ocular disease in any of the subjects, and routine ophthalmoscopic examination results were normal. RESULTS: The coefficient value for macular thickness was lower than 2%, indicating that OCT3 provides reliable measurements. Macular thickness of normal subjects was 193.4 +/- 14.6 micro meter in the central ring, 273.0 +/- 14.8 micro meter in the inner ring and 238.2 +/- 15.6 micro meter in the outer ring. The nasal and superior quadrants of the inner ring and the nasal quadrant of the outer ring had higher thickness measurements than another. A decrease of retinal thickness was observed in the old group. However, gender did not have a significant effect on the values. CONCLUSIONS: Macular thickness analysis with OCT3 provided a detailed map of the macular thickness. This indicates that the method may provide a sensitive detection of pathologic thickening or thinning of the retina and suggests that the macular thickness decreases with age.
Retina ; Retinaldehyde

Polypoidal choroidal vasculopathy (PCV) is a retinal disorder characterized by aneurismal polypoidal lesions in choroidal vasculature. PCV appears to preferentially affect pigmented individuals and is considerably high among Asians. Most reports on patterns of PCV around Asia are based on a homogenous race (e.g. Chinese, Japanese) and very few descriptions from a multiracial population like those seen in Malaysia. The present study aimed to describe the demographic features, clinical and investigative characteristics of PCV in a multiracial group at Universiti Kebangsaaan Malaysia Medical Centre (UKMMC). Ninety one eyes of 86 PCV patients, comprising of Chinese (65.1%), Malays (31.4%), Indians (2.3%) and Eurasian (1.2%) were retrospectively reviewed. All underwent complete ophthalmic examination and investigations. Mean patient age was 70.4 years with a male preponderance (59.3%), and mostly unilateral presentation (94.1%). The logMAR mean presenting visual acuity was 0.78 ± 0.64. Polypoidal vascular lesions were located generally within the macula area (86.8%), manifesting mainly as submacular hemorrhage (59.3%). Interestingly a number of eyes (43.9%) had associated drusen. Optical coherence tomography largely demonstrated exudative changes (75.9%) and almost all patients (97.7%) had loss of external limiting membrane (ELM) and IS/OS interface. On indocyanine green angiography, majority of eyes had multiple polyps (82.4%) with ‘cluster’ (58.2%) being the commonest configuration. In conclusion, although the patterns of PCV in UKMMC were mainly similar to other Asian patients, a number of our patients had associated drusen. This indicates that PCV in our population could be a variant of neovascular age related macular degeneration and not solely idiopathic in nature.
Retinaldehyde ; Choroid

No abstract available.
Amaurosis Fugax* ; Retinaldehyde*

No abstract available.
Amaurosis Fugax* ; Retinaldehyde*

Confocal scanning laser flowmetry(HRF: Heidelberg Retina Flowmetry) is a new kind of instrument which enables non-invasive two-dimentional mapping of perfusion of the retina and optic disc and to evaluate the clinically available reproducibility of the peripapillary and retinal perfusion measurement with the confocal scanning laser flowmetry, the authors calculate the coefficient of variation (CV) from the parameters(volume, flow, velocity). The authors indicate two region of interest in the peripapillary region and retina, not overlapping the large vessels and measure the parameters three times consecutively(one session) while visiting three times intervalled(three session), thereafter calculate the mean CV of parameters in ten healthy eyes of ten subject. The CV of parameters obtained with the confocal scanning laser flowmetry was low relatively and therefore reproducibility was high as the CV lower, the reproducibility higher. Comparing the CV between one session and three session measurement to know the clinically available measurement frequency, the CV of three session (volume 13%, flow 16.7%, velocity 16%) was lower than the CV of one session (volume 16.7%, flow 20.7%, velocity 20.1%) in the peripapillary region(Students t test; volume p=0.009, flow p=0.03, velocity p=0.016) and the CV of three session (volume 16.7%, flow 20.7%, velocity 17%) was lower than the CV of one session (volume 18.2%, flow 21.8%, velocity 21.7%) in the retina(Students t test; volume p=0.017, flow p=0.0009, velocity p=0.0004). Above the results, the CV of parameters(13~21.8%) in one and three session had relatively high reproducibility. Also the CV between two measurements had a difference statistically but the difference was not so high, the authors concluded the confocal scanning laser flowmetry which have high resolution measure the peripapillary region and retina reproduciblly with only one time visit, three consecutive measurements.
Perfusion* ; Retina ; Retinaldehyde* ; Rheology*

The scanning laser ophthalmoscope was used to measure arm-retinal time(ART) and arteriovenous passage time(AVP) in 27 non-proliferative diabetic retinopathic eyes(NPDR eyes) and 22 normal controls. The ART in NPDR eyes(12.10 +/- 4.21 sec) was similar to that in normal eyes(12.79 +/- 3.59 sec). The AVPs measured from each quadrant were significantly longer in all quadrants in the NPDR eyes (2.41 +/- 0.85 sec in superior temporal quadrant (ST), 2.29 +/- 0.63 sec in inferior temporal one(IT) , 2.41+/-0.88 see in superior nasal one (SN), and 2.30 +/- 0.72 sec in inferior nasal one(IN)) than in normal eyes(1.73 +/- 0.61 sec in ST, 1.81 +/- 0.75 sec in IT, 1.83 +/- 0.58 sec in SN, and 1.83 +/- 0.58 sec in IN). This results suggest that retinal blood flow and its velocity are reduced in NPDR.
Diabetic Retinopathy* ; Ophthalmoscopes* ; Retinaldehyde*

No abstract available.
Retinal Detachment* ; Retinaldehyde*

No abstract available.
Retinal Detachment* ; Retinaldehyde*