Diagnostic performance of confocal scanning laser ophthalmoscope imaging and compared with color fundus camera in retinal pigment epithelial detachment of polypoidal choroidal vasculopathy / 中华眼底病杂志

Objective To observe confocal scanning laser ophthalmoscope (cSLO) based retinal imaging and color fundus camera in pigment epithelial detachment (PED) of polypoidal choroidal vasculopathy (PCV).Methods PED of 30 patients (32 eyes) were recruited from June 2016 to June 2017 in the Beijing Tongren Hospital who were detected in high-definition OCT (HD-OCT) and diagnosed as PCV by FFA and ICGA.There were 16 males (17 eyes) and 14 females (15 eyes);aged from 50-83 years,with the mean age of 66.59 years.The photographs of ocular fundus including color fundus camera,cSLO imaging,HD-OCT,FFA and ICGA were analyzed.Multimodal imaging results were regarded as gold standard.Sensitivity and specificity were calculated in serous and hemorrhagic PED diagnosis using color fundus camera and cSLO imaging.The positive number of PED was used to compare between two modes fundus imaging by using x2 test.Results Twenty serous PED eyes,3 hemorrhagic PED eyes and 9 serous/hemorrhagic PED eyes were determined using multimodal imaging.The sensitivity and specificity of color fundus camera were 45％ and 100％ in detecting serous PED and 100％ and 91％ in detecting hemorrhagic PED.The sensitivity and specificity of cSLO imaging were 83％ and 100％ in detecting serous PED and 50％ and 86％ in detecting hemorrhagic PED.The positive number of serous PED in cSLO imaging was significantly higher than color fundus camera (x2=7.752,P=0.011).The positive number of hemorrhagic PED in cSLO imaging shows no obvious difference compared with color fundus camera (x2=1.164,P=0.419).Conclusion The sensitivity and positive number of detecting serous PED with PCV in cSLO fundus imaging were higher than the color fundus camera technology.

Comparison of Blue and Green Confocal Scanning Laser Ophthalmoscope Imaging to Detect Retinal Nerve Fiber Layer Defects

PURPOSE: We detected retinal nerve fiber layer (RNFL) defects using a confocal scanning laser ophthalmoscopy (CSLO) with both blue and green laser sources and evaluated image quality based on laser wavelength. METHODS: This was a retrospective observational case study. Blue and green CSLO images of 181 eyes with suspected glaucoma were evaluated and compared. Three independent observers identified the presence of RNFL defects and determined which CSLO imaging source provided superior visibility of the defect. After assessing the defect imaging by laser source, demographics and image quality indices of optical coherence tomography between blue better and green better groups were analyzed. RESULTS: Both blue and green CSLO showed high discriminating ability for RNFL defects. The discriminating ability of blue CSLO was significantly greater than that of green CSLO (p = 0.004). Among eyes with a detectable RNFL defect, 61.8% were better visualized with the blue laser compared to the green laser. Compared with the blue better group, the green better group was significantly older (p = 0.009), had a greater proportion of females (p = 0.005), had poorer best-corrected visual acuity (p = 0.001), more severe cataracts (p = 0.001), lower signal strength (p = 0.003), and poor image quality indices (p = 0.001). CONCLUSIONS: Both blue and green CSLO imaging was useful for detecting RNFL defects, but blue CSLO was superior to green CSLO in quality of RNFL defect imaging in most patients with clear media.

Detection of drusen in patients with age-related macular degeneration by retro-mode imaging of F-10 confocal scanning laser ophthalmoscopy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To discuss the application value of retro-mode imaging by F-10 confocal scanning laser ophthalmoscope (cSLO) for detecting drusen in patients with age-related macular degeneration (AMD).METHODS:This was a retrospective case study.During the period of October 2015 to December 2016, 67 patients with unilateral AMD (67 affected eyes and 67 fellow eyes) were included in this study.All patients underwent color fundus photography, optical coherence tomography (OCT) and retro-mode imaging by F-10 cSLO.The features of drusen by color fundus photography, OCT and retro-mode imaging were comparatively observed in the affected eyes of patients with unilateral AMD.Positive numbers of drusen in the fellow eyes of patients with unilateral AMD detected by color fundus photography, OCT and retro-mode imaging were calculated and compared.RESULTS:Retro-mode imaging by F-10 cSLO gave easier to identify images of drusen than color fundus photography and OCT in the affected eyes of patients with unilateral AMD.In the fellow eyes of 67 patients with unilateral AMD, retro-mode imaging showed drusen in 56 cases(84%), color funds photography showed drusen in 36 cases(54%), OCT showed drusen in 48 cases(72%), the difference was statistically significant(χ2=14.31, P0.0125).CONCLUSION:Retro-mode imaging by F-10 cSLO provides a non-invasive technique and should be useful for detecting and monitoring drusen in AMD.

Imaging performance and quantitative analysis of confocal scanning laser ophthalmoscope for cystoid macular edema / 中华实验眼科杂志

Background Cystoid macular edema (CME) is caused by many fundus diseases.The noninvasive clinical diagnosis methods for CME are conventional color fundus photography up to now.However,these images can not display the CME range well.Confocal scanning laser ophthalmoscope (cSLO) based retinal imaging can provide clear picture with high contrast.However,whether cSLO imaging is feasible in the quantitative assessment of CME remains unclear.Objective This study was to image the boundary of CME and assess the quantification of CME image from cSLO imaging technology.Methods A series case-observational study was designed.This study protocal was approved by Ethic Committee of Beijing Tongren Hospital.cSLO based retinal imaging technology was carried out on consecutive 24 eyes of 24 patients with clinically diagnosed and OCT confirmed CME in Beijing Tongren Eye Center from August to December 2015 under the informed consent of each individual.The radial scan range was 45°× 45 ° and the line scan level was 49 at macula area.The pseudocolar image,green light reflective image (532 nm) and infrared reflective image (785 nm) were collected.The imaging was analyzed by EasyScan software (version 1.2.2).Fundus color photography and SD-OCT were carried out in each patient.The images were graded by specialists according to the SD-OCT cross sectional results.Results The primary causes of CME included epiretinal membrane (10 eyes),branch retinal vein occlusion (BRVO) (6 eyes),central retinal vein occlusion (CRVO) (4 eyes),diabetic retinopathy (DR) (3 eyes) and CRVO with BRVO (1 eye).A CME image was exhibited on the fundus color photogram with the obscure boundary;while the clear range of CME was displayed by the cSLO imaging.The mean score of CME from pseudocolar image,green light reflective image and infrared reflective image was 3.21±0.78,2.67±0.96 and 2.54±0.83,respectively,which was significantly higher than 1.33±0.82 from the fundus color photography (all at P＜0.01).Conclusions In CME patients,the imaging quality from cSLO-based retinal imaging technology is better than that from traditional fundus color photography.Combined with SD-OCT sectional scan analysis,cSLO-based retinal imaging technology may offer a method to observe and record more fundus details for CME diagnosis.

The Characteristics of Non-Retinal Lesions in the Ultra-Wide Field Scanning Laser Ophthalmoscope Image

PURPOSE: To evaluate various types and; characteristics of non-retinal lesions associated with ultra-wide field scanning laser ophthalmoscope images. METHODS: This retrospective study included 139 eyes of 139 patients with non-retinal lesions observed on color images obtained using Optomap 200Tx (Optos PLC, Dunfermline, Scotland, UK). The non-retinal lesion is a hyperreflective or hyporeflective shadow due to anterior segment of the eye or vitreous except the retina. Types and characteristics of red laser separation, green laser separation and autofluorescence images of non-retinal lesions were evaluated. RESULTS: All non-retinal lesions in images were categorized into 2 groups according to the location of non-retinal lesions. The anterior non-retinal lesions group included corneal opacity, cataract and posterior capsular opacity. The posterior non-retinal lesions group included asteroid hyalosis, posterior vitreous detachment, vitreous opacity and vitreous hemorrhage. Anterior non-retinal lesions were more often hyporeflective in red and green laser separation images (p < 0.001). Posterior non-retinal lesions were more often hyperreflective in green laser separation images and hyporeflective in red laser separation images (p < 0.001). CONCLUSIONS: Ultra-wide field scanning laser ophthalmoscope images can frequently have various shadows from anterior or posterior lesions of the eye. These shadows show a difference in reflectivity depending on their origins. To understand the difference helps in the interpretation of the fundus images.

Influence of disc area on retinal nerve fiber layer thickness measurement by spectral domain optical coherence tomography.

Background: To examine the eff ect of optic disc area on peripapillary RNFLT (retinal nerve fi ber layer thickness) measurement at circle diameter of 3.4 mm around optic nerve head using spectral OCT/SLO (Optical coherence tomography/scanning laser ophthalmoscope). Materials and Methods: In this prospective, cross sectional study, one hundred and two eyes of 102 normal subjects underwent RNFLT and disc area measurement using spectral OCT/SLO. Based on disc area, subjects were divided into three groups i.e., <3 mm2 (32 eyes), 3-4 mm2 (36 eyes) and >4 mm2 (34 eyes). The eff ect of disc area on RNFLT parameters was analyzed using linear regression analysis. Results: The mean and quadrant RNFLT did not show signifi cant correlation with disc area in subjects with disc area of <4 mm2, however in eyes with disc area >4 mm2, average RNFLT, superior and temporal quadrant RNFLT showed negative correlation with disc area, which was statistically signifi cant (P = 0.004, P = 0.005 and P = 0.002, respectively) Conclusion: In healthy eyes of disc area <4 mm2, disc size does not appear to aff ect peripapillary RNFLT measurement by spectral OCT/SLO. Average, superior and temporal quadrant RNFLT measurements were inversely proportional to disc area in eyes with disc area >4 mm2. Hence, RNFLT measurement by OCT in eyes with optic disc area of >4 mm2 should be interpreted carefully.

Identifiable Peripheral Retinal Lesions Using Ultra-Widefield Scanning Laser Ophthalmoscope and Its Usefulness in Myopic Patients

PURPOSE: To investigate identifiable peripheral retinal lesions in patients with myopia or high myopia and to evaluate the usefulness of ultra-widefield scanning laser ophthalmoscope in retina clinic settings. METHODS: We evaluated fundus images of 149 patients acquired using an ultra-widefield scanning laser ophthalmoscope. Manual fundus examination by a retinal specialist was performed and sensitivity and specificity were calculated by comparing the findings of the two different fundus examination methods. RESULTS: Variable peripheral retinal lesions were observed: lattice degeneration (24.1% in myopia, 36.6% in high myopia), white without pressure (17.7% in myopia, 20.7% in high myopia), retinal break (5.1% in myopia, 7.5% in high myopia) and retinal detachment (1.3% in myopia, 4.2% in high myopia). The incidence of lattice degeneration was significantly higher in myopic eyes than in highly myopic eyes (p = 0.043). The examination sensitivities were as follows: lattice degeneration (84.2% in myopia, 91.0% in high myopia), white without pressure (100.0% in both myopia and high myopia), retinal break (75.0% in myopia, 43.8% in high myopia) and retinal detachment (100.0% in myopia, 66.7% in high myopia). The examination specificities were 100.0% in all cases. CONCLUSIONS: Diagnostic sensitivities of ultra-widefield scanning laser ophthalmoscope were 90.8% in patients with myopia, 91.0% in patients with high myopia and 90.9% in totally myopic patients, which were relatively high values. Therefore, the ultra- widefield scanning laser ophthalmoscope is useful as auxiliary equipment for myopic patients in retina clinic settings.

Identifiable Peripheral Retinal Lesions Using Ultra-Widefield Scanning Laser Ophthalmoscope and Its Usefulness in Myopic Patients

PURPOSE: To investigate identifiable peripheral retinal lesions in patients with myopia or high myopia and to evaluate the usefulness of ultra-widefield scanning laser ophthalmoscope in retina clinic settings. METHODS: We evaluated fundus images of 149 patients acquired using an ultra-widefield scanning laser ophthalmoscope. Manual fundus examination by a retinal specialist was performed and sensitivity and specificity were calculated by comparing the findings of the two different fundus examination methods. RESULTS: Variable peripheral retinal lesions were observed: lattice degeneration (24.1% in myopia, 36.6% in high myopia), white without pressure (17.7% in myopia, 20.7% in high myopia), retinal break (5.1% in myopia, 7.5% in high myopia) and retinal detachment (1.3% in myopia, 4.2% in high myopia). The incidence of lattice degeneration was significantly higher in myopic eyes than in highly myopic eyes (p = 0.043). The examination sensitivities were as follows: lattice degeneration (84.2% in myopia, 91.0% in high myopia), white without pressure (100.0% in both myopia and high myopia), retinal break (75.0% in myopia, 43.8% in high myopia) and retinal detachment (100.0% in myopia, 66.7% in high myopia). The examination specificities were 100.0% in all cases. CONCLUSIONS: Diagnostic sensitivities of ultra-widefield scanning laser ophthalmoscope were 90.8% in patients with myopia, 91.0% in patients with high myopia and 90.9% in totally myopic patients, which were relatively high values. Therefore, the ultra- widefield scanning laser ophthalmoscope is useful as auxiliary equipment for myopic patients in retina clinic settings.

Cystoid Macular Edema Detected by Scanning Laser Ophthalmoscopy in Retro-Mode

PURPOSE: To investigate the visualization of cystoid macular edema (CME) using noninvasive retromode imaging by a new scanning laser ophthalmoscope (SLO) and compare to previous imaging modalities. METHODS: The authors of the present study retrospectively reviewed the medical records of 21 eyes of 20 patients with CME due to various etiologies. All eyes were examined with fundus camera, fluorescein angiography (TRC-50EX, Topcon, Tokyo, Japan), SLO (F-10, Nidek, Gamagori, Japan), and spectral-domain optical coherence tomography (OCT) (3D OCT-1000, Topcon, Tokyo, Japan). In the present study the SLO was used in the retro-mode with an infrared laser. RESULTS: Previous fundus photography could not detect CME adequately although SLO retro-mode could show numerous oval or polygonal cystoid spaces more readily. Furthermore, each individual small cystoid space could be detected and the area of each cystoid space could be measured. The area of the largest cystoid space showed a correlation with its height, as measured with OCT (R = 0.606, p = 0.004). The area of the whole foveal cystoid space showed a correlation with central macular thickness, as measured with OCT (R = 0.493, p = 0.023). CONCLUSIONS: A new commercially available SLO (F-10) in the retro-mode can allow us to detect each cystoid space non-invasively and to measure the extent of CME.

Ability of spectral domain optical coherence tomography peripapillary retinal nerve fiber layer thickness measurements to identify early glaucoma.

Purpose: To evaluate the ability of spectral domain optical coherence tomography (OCT) peripapillary retinal nerve fiber layer thickness (RNFLT) parameters to distinguish normal eyes from those with early glaucoma in Asian Indian eyes. Design: Observational cross-sectional study. Materials and Methods: One hundred and seventy eight eyes (83 glaucoma patients and 95 age matched healthy subjects) of subjects more than 40 years of age were included in the study. All subjects underwent RNFLT measurement with spectral OCT/ scanning laser ophthalmoscope (SLO) after dilatation. Sensitivity, specificity and area under the receiving operating characteristic curve (AROC) were calculated for various OCT peripapillary RNFL parameters. Results: The mean RNFLT in healthy subjects and patients with early glaucoma were 105.7 ± 5.1 μm and 90.7 ± 7.5 μm, respectively. The largest AROC was found for 12 o’clock- hour (0.98), average (0.96) and superior quadrant RNFLT (0.9). When target specificity was set at ≥ 90% and ≥ 80%, the parameters with highest sensitivity were 12 o’clock -hour (91.6%), average RNFLT (85.3%) and 12 o’ clock- hour (96.8 %), average RNFLT (94.7%) respectively. Conclusion: Our study showed good ability of spectral OCT/ SLO to differentiate normal eyes from patients with early glaucoma and hence it may serve as an useful adjunct for early diagnosis of glaucoma.

Characteristics of fundus autofluorscence in patients with atrophic age-related macular degeneration / 中华实验眼科杂志

Background The early diagnosis and treatment is vital for the age-related macular degeneration (AMD).Previous examining methods were fundus fluorescein angiography(FFA)and optical coherence tomography (OCT).However,a new diagnostic technique,fundus autofluorescence(FAF),is applying in ophthalmology.objective This study was to observe the FAF characteristics of atrophic AMD. Methods Thirty-nine eyes of 28 patients with atrophic AMD were diagnosed and collected in our hospital and classified based on the criteria of Chen Song.FAF was performed by a confocal scanning laser ophthalmoscope(Heidelberg Retina Angiograph 2,HRA2).Characteristics of FAF images were compared with FFA images or color fundus photographs.Written informed consent was obtained from each patient prior to the examination. Results Areas with abnormal increased or decreased FAF signals were consisted or unconsisted with funduscopically visible alterations.Seven manifestations of FAF were found in the eyes with preatrophic stage of atrophic AMD,including slight change,focal increase pattern,patchy pattern,linear pattern,lacelike pattern,reticular pattern,and speckled pattern.In atrophic stage of atrophic AMD,geographic atrophy showed a well-defined hypoautofluorescence area;while non-geographic atrophy showed a ill-defined hypoautofluorescence area.There were three abnormal FAF patterns(focal,band and diffuse)in the junctional zone of geographic atrophy and diffuse pattern in the junctional zone of non-geographic atrophy. Conclusion FAF imaging is helpful for the diagnosis of atrophic AMD as a new non-invasive technique.

The Comparison of SLO Retromode Images with Conventional Fundus Photography for the Detection of Drusen

PURPOSE: To compare SLO (scanning laser ophthalmoscope) retromode images with conventional color fundus photography for the detection of drusen. METHODS: We obtained color fundus photography and SLO retromode images of the ten fellow eyes of ten patients with unilateral exudative age-related macular degeneration (AMD) and twenty eyes of 20 patients who had only drusen without exudative AMD. The numbers of druse in each image were compared within the same retinal boundary. RESULTS: In the fellow eyes of unilateral exudative AMD, an average number of 63.1 +/- 81.9 drusen in color fundus photography and an average number of 141.3 +/- 124.1 drusen in SLO retromode images were detected (p = 0.005). In the eyes with only drusen, an average number of 57.0 +/- 43.9 drusen in color fundus photography and an average number of 112.2 +/- 82.0 drusen in SLO retromode images were detected (p = 0.000). In the presence of media opacity like cataract, drusen were better detected in SLO retromode images than they were in color fundus photography. CONCLUSIONS: About twice as many drusen were detected in SLO retromode images than in color fundus photography. Drusen were also better detected in SLO retromode images in cases of media opacity. SLO retromode images might provide more sensitive images for the detection of drusen than does color fundus photography.

Quantitative evaluation of experimental choroidal neovascularization by confocal scanning laser ophthalmoscopy: fluorescein angiogram parallels heparan sulfate proteoglycan expression

The objective of the present study was to develop a quantitative method to evaluate laser-induced choroidal neovascularization (CNV) in a rat model using Heidelberg Retina Angiograph 2 (HRA2) imaging. The expression of two heparan sulfate proteoglycans (HSPG) related to inflammation and angiogenesis was also investigated. CNV lesions were induced with argon laser in 21 heterozygous Zucker rats and after three weeks a fluorescein angiogram and autofluorescence exams were performed using HRA2. The area and greatest linear dimension were measured by two observers not aware of the protocol. Bland-Altman plots showed agreement between the observers, suggesting that the technique was reproducible. After fluorescein angiogram, HSPG (perlecan and syndecan-4) were analyzed by real-time RT-PCR and immunohistochemistry. There was a significant increase in the expression of perlecan and syndecan-4 (P < 0.0001) in retinas bearing CNV lesions compared to control retinas. The expression of these two HSPG increased with increasing CNV area. Immunohistochemistry demonstrated that the rat retina damaged with laser shots presented increased expression of perlecan and syndecan-4. Moreover, we observed that the overexpression occurred in the outer layer of the retina, which is related to choroidal damage. It was possible to develop a standardized quantitative method to evaluate CNV in a rat model using HRA2. In addition, we presented data indicating that the expression of HSPG parallels the area of CNV lesion. The understanding of these events offers opportunities for studies of new therapeutic interventions targeting these HSPG.

Two Types of Retinal Capillary Path in Humans using Fluorescein Leukocyte Angiography

PURPOSE: To explain hypothesis that there are two types of human retinal capillary pathways. One is simple type and the other is complex type. The former plays a role in blood flow regulation and the latter does capillary function itself. METHODS: We measured the length, tortousity, and flow velocity of human retinal capillaries using Fluorescein Leukocyte Angiography (FLA) with a Scanning Laser Ophthalmoscope (SLO) on two healthy adult male volunteers. We studied distribution and pathways of human retinal capillaries on the posterior pole. RESULTS: The lengths of capillaries were distributed with two peak incidence. One was 70 microgram and the other 240 microgram. There was no relationship between capillary length and tortousity. The correlation between capillary length and leukocyte velocity showed that the shorter capillary group has a wide range of velocity but the longer group has a narrow range of velocity. CONCLUSIONS: Two types of retinal capillary pathways exist on human retina. Compared with two types of capillaries on the cat retina described by Ben-nun et al, we found that the shorter capillary type plays a role in blood flow regulation and the longer type in capillary function itself.

Influence of Diabetes Mellitus on the Morphometric Analysis of the Optic Nerve Head

To evaluate the influence of diabetes mellitus (DM)on the optic nerve head topographic parameters, each group of 101 patients with open-angle glaucoma (OAG)and 91 control subjects was divided into two subgroups according to the presence or absence of DM.We compared the optic nerve head topographic parameters among groups using Topographic Scanning System (TopSSTM software version 2.2, LDT, Inc., U.S.A.);53 nonglaucomatous eyes without DM (normal group), 38 nonglaucomatous eyes with DM, 67 OAG eyes without DM, and 34 OAG eyes with DM. In the group with OAG without DM, mean contour depth, cup shape, neuroretinal rim area (NRRA), NRRA/disc area were significantly smaller but, effective area and cup/disc area were signifcantly larger than normal group (p<0.05, Student t-test).In nonglaucomatous group, the presence of diabetes showed statistically significant decrease in mean contour depth, cup shape, NRRA, NRRA/disc area ratio (p<0.05).It also showed increase in effective area and cup/disc ratio (p<0.05).These changes were similar to those reported for glaucomatous optic nerve damage.In the group with OAG, the presence of diabetes did not show statistically significant differences in the optic nerve head topographic parameters. In this study, we tried to measure the diabetic changes of the optic nerve head quantitatively using the confocal scanning laser ophthalmoscope (TopSSTM). These results suggest that the diabetic changes should be considered in the evaluation of the optic nerve head parameters for the screening or early diagnosis of open-angle glaucoma when using TopSSTM.

A Study on Microcirculation Time Including Retinal Periphery in Diabetic Retinopathy using the Fluorescein Angiography

On video fluorescein angiogram, it is known that arm-to-retinal circulation(ART)influences retinal macrocirculation and arterio-venous passage time(AVP)influences microcirculation.In diabetic retinopathy(DR), midperiphery involved earlier than posterior pole.However, there has been no study on the circulation of the entire retinal circulation including the peripheral retina. The authors conducted a prospective study by performing fluorescein angiography on 19 controls and 19 DR patients in order to measure the ART, AVP and venous filling time(VFT). The VFT correspond to the circulation of the peripheral retina. In the DR group, the retina circulation time was compared with the existence of proliferative diabetic retinopathy(PDR), distribution of nonperfusion area and beading vessels. There was no significant difference between diabetic group and the control group in the ART.AVP was 1.8+/-0.7sec in the control group and 2.5+/0.7sec(p=0.04)in the DR group and venous filling time was 6.4+/-2.4sec and 8.9+/-1.5sec(p=0.006)respectively. Patients with PDR showed prolongation only in VFT compared to patients with non-proliferative diabetic retinopathy(NPDR). In addition, patients presenting with nonperfusion areas and beading of vessels showed longer prolongation of VFT than of AVP. In conclusion, the VFT is delayed in DR compared to control group and in PDR compared to NPDR. The VFT can be utilized as an indicator of DR to measure the retinal circulation including the peripheral retina.

Criteria to Determine the Relevance of the Changes of Disc Parameter to the Progress of the Disease

The purpose of this study is to establish the criteria to discriminate whether the difference of the optic disc parameters compared actually reflects the progress of the disease or it is merely caused by the intraexaminer or interexaminer error. Using the confocal scanning laser ophthalmoscope (TopSS), one eye of each of 20 healthy adults were exmained by the same examiner and one eye of each of 10 adults were examined by different examiners for two consecutive days. The results out of these repeated examinations were analysed to obtain 95%confidence intervals by analysis of the change of the 12 optic disc parameters, and to determine whether the results have been influenced by the disc size or the disc tilt. The criteria to differentiate actual progression of disease from potential errors of the test were obtained. In addition, it was confirmed that changes in the parameters were not influenced by the disc size or the contour tilt. In conclusion,the outcomes of this study can be utilized as a guiding criteria when judging the relevance of the parameter changes to the progress of the disease.

Evaluation of Retinal Visual Acuity Using SLO in Young Healthy Volunteers

We have attempted to measure parafoveal retinal acuity directly on the exact retinal locus, while observing the retinal image in real time using the scanning laser ophthalmoscope(SLO 101, Rodenstock, Munish, Germany). By the SLO Visumetry software(Rodenstock v. 3.0), thirty eyes of healthy volunteers were examined in 20degrees image field. Using Snellen E as stimulus, the examination was performed from the fovea by the radial pattern. The maximal retinal distance point, which responded to stimulus, was recorded by the pixel, and the distance(mm) from the fovea was calculated by the Bennett formula. The maximum distance from the fovea at the given stimulus size was achieved as follows: 0.32+/-0.01mmat the 15 x15 arc of minute(0.333), 0.63+/-0.01mm at the 17 x17 arc of minute(0.294), 1.05+/-0.03 mmat 20 x 20 arc of minute(0.25), and 1.44+/-0.0 5 mmat the 23 x23 arc of minute(0.217). It was also revealed that the horizontal maximal distance from fovea at given stimulus size was statistically superior to the vertical maximal distance(p<0.05). In conclusion we were able to establish the normal range of parafoveal retinal acuity in healthy volunteers. It may serve as the baseline for subsequent study of retinal pathology and functional evaluation as well as its treatment.

Diagnostic Criteria, Its Sensitivity, and Specificity with the Confocal Scanning Laser Ophthalmoscope TopSSTM

This study was conducted to establish glaucomatous diagnostic criteria and to investigate its sensitivity and specificity with the confocal scanning laser ophthalmoscope(TopSSTM) on the basis of the normal values of the optic disc parameters in previous study. Abnormal ratio of optic disc parameters were analysed in 80 primary open angle glaucoma eyes - the subjects were divided into three groups according to visual field defects, each group of mild, moderate, and severe. and then glaucomatous diagnostic critera was established. According to this diagnostic criteria, we calculated its sensitivity and specificity. We established the glaucomatous diagnostic criteria with high sensitive five parameters(1/2 depth area, C/D ratio, neuroretinal rim area(NRRA), volume above, and notching), the established criteria are 1) If NRRA is decreased, one of the four parameters is abnormal. 2) If NRRA is normal, notching and one of the other three parameters are abnormal. Notching was defined as decreased neuroretinal area at either 6 o/c or 12 o/c sector. With this criteria, the sensitivity was 89.7% in mild group and 100% in moderate and severe groups and the specificity was 89.1% in normal groups. This criteria showed high sensitivity and specificity in the diagnosis of glaucoma, so as to be useful in the early detection of glaucomatous spticdisc changes.

Relationship between Optic Disc Parameters and Myopic Refractive Errors in Myopia

Myopic discs(range: -0.5D) which were taken a confocal scanning laser ophthalmoscope(HRT, Heidelberg Engineering) were analyzed to determine the relationship between optic disc parameters and myopic refractive errors. Regression analysis and coefficient variation were used for a statistic tool. The disc area was not correlated with the myopic refractive error(p=0.21) and showed 16.0% of coefficient of variation. Cup area, cup disc area ratio, rim area, cup volume, rim volume, mean cup depth, maximum cup depth and cup shape measure showed statistically significant correlation with myopic refractive error, respectively(p<0.05). Among these parameters, rim area varied least(within all myopic eyes) with 16.5% of coefficient of variation. As the rim area is the most stable optic disc parameter interindividually in myopic population, it seem to be valuable for follow-up evaluation when a glaucomatous damage is suspected in myopic eyes by calculating its expected normal value with a regression equation.