Visual Psychophysics / Physiological Optics - ARVO

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ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological Opticsvariation caused by blood cell flow.Methods: Our capillary shadow correction method consists ofdetecting abnormal frames in an AOSLO video, calculating statisticalvalues of temporal intensity variation in each pixel except theabnormal frames, and allocating the pixel value based on thestatistical values in each pixel position for producing the resultantcontrast enhanced AOSLO image. In this study, we recorded AOSLOvideos using Canon prototype AOSLO system with a high wavefrontcorrection efficiency using dual liquid crystal phase modulators. Theimaging light wavelength was 840 nm and the frame rate was 32 Hz.The scan area at the parafovea was 1.1 × 1.1° and was sampled at 400× 400 pixels. The videos were recorded for 2-5 seconds. Theproposed adaptive contrast enhancement method was applied to 15AOSLO videos for 5 healthy subjects including parafoveal capillaryregions (leukocyte preferred paths (LPPs) and plasma-gap capillaries(PGCs)) and macular arteriolovenous region. We calculated thespectral power ratio as a function of frequency between the adaptivecontrast enhanced images and conventional frame averaged imagesparticularly in LPPs, PGCs and macular arteriolovenous regions.Results: The spectral power ratio at a given frequency in LPPs andPGCs of the adaptive contrast enhanced AOSLO images were 1.62and 1.09 on average respectively, because capillary shadows werecorrected by using intensity values when leukocyte or plasma-gappasses. On the other hand, shadows in macular arteriolovenousregions were not corrected because pixel intensity was low in allframes of AOSLO video as the result of erythrocytes next to aleukocyte blocking the imaging light.Conclusions: Our method improved contrast of photoreceptors inretinal capillary shadow region of AOSLO images using blood cellflow information.Commercial Relationships: Hiroshi Imamura, Canon Inc. (E);Takashi Yuasa, Canon Inc. (E); Hiraku Sonobe, Canon Inc (E);Akihito Uji, None; Sotaro Ooto, None; Masanori Hangai, Topcon(F), Canon (F), Nidek (C), Topcon (C); Nagahisa Yoshimura,Canon (C), Canon (F), Nidek (C), Topcon (F), PCT/JP2011/073160(P)Support: the Innovative Techno-Hub for Integrated Medical BioimagingProject of the Special Coordination Funds for PromotingScience and TechnologyProgram Number: 6057 Poster Board Number: B0068Presentation Time: 10:30 AM - 12:15 PMStudy of epimacular membranes using adaptative optics highresolution imagingHassiba Bouakkaz 1 , Sarah Ayello-Scheer 1 , Alexandre Leseigneur 1 ,Celine Devisme 1 , Jose A. Sahel 1, 2 , Michel Paques 1, 2 . 1 CentreHospitalier National d'Ophtalmologie des Quinze Vingts, Paris,France; 2 Institut de la Vision, Paris, France.Purpose: High resolution imaging using adaptative optics (AO)allows an improved viewing of retinal microstructures. Here, weanalyzed the AO features of epimacular membranes (ERMs) beforeand after surgery.Methods: Seven eyes with ERM were included. For each patient, acomplete ophthalmological examination including measurement ofvisual acuity, optical coherence tomography and AO infrared floodimaging (rtx1, ImagineEye, Orsay, France) was performed. In fourpatients these exams were repeated after surgical ablation of themembrane.Results: A very precise viewing of the ERMs and of the underlyingretinal wrinkling was obtained. The ERM surface showed a myriad ofhighly reflective dots, whose reflectance varied with the lightincidence. Around ERMs, radial retinal folds were seen. The peculiaraspect of ERMs at their very beginning, which seemed to developaround vessels, could be identified. By changing focus, it waspossible in three cases to distinguish the ERM itself from theunderlying retinal wrinkling. After surgery, retinal unfolding could bedocumented.Conclusions: Specific interests of AO imaging in ERM patientscomprise the ability to identify the earliest stages of ERMs, whichseem to develop primarily around vessels, and the characterization ofthe optical properties of the ERM surface. The strong dependence ofreflectance to the angle of the incident light suggested that ERMshave a bumpy mosaic-like surface.Commercial Relationships: Hassiba Bouakkaz, None; SarahAyello-Scheer, None; Alexandre Leseigneur, None; CelineDevisme, None; Jose A. Sahel, UPMC/Essilor (P), Second Sight (F);Michel Paques, MerckSerono (C), Roche (C), Sanofi (C)Support: ANR_09_TECS_009_01_IPHOTProgram Number: 6058 Poster Board Number: B0069Presentation Time: 10:30 AM - 12:15 PMParietal morphometry of retinal arterioles in health andhypertension using adaptive opticsEdouard Koch 1, 2 , David Rosenbaumm 3 , Xavier Girerd 3 , FlorenceRossant 4 , Michel Paques 1 . 1 Clinial Investigation Center, Quinze-Vingts Hospital-INSERM, Paris, France; 2 Ophthalmology, VersaillesHospital, Versailles, France; 3 Cardiology, Pitié Salpétrière Hospital,Paris, France; 4 Institut Supérieur d'Electronique de Paris, ISEP, Paris,France.Purpose: Morphological changes affecting the wall of small retinalarteries are recognized surrogates of end-organ damage secondary toaging and/or arterial hypertension. However, direct observation of themicrovascular wall is not feasible with routine imaging techniques.We report here the quantitative analysis of the structure of retinalarterioles (~ 50-150 µm diameter) using adaptive optics (AO) nearinfrared (NIR) imaging (rtx1 camera; ImagineEyes, France) in normoand hypertensive humans.Methods: From OA images, the wall-to-lumen ratio (WLR) wascalculated using a dedicated software. We compared the WLRbetween a control group (n = 20; 30.2 ± 6 years) and a group ofhypertensive subjects (n = 30, 48.1 ± 13 years). Focal lesions(arteriolar narrowing and arteriovenous nickings) were also analyzed.These data were compared to the carotid intima-media thickness(IMT).Results: The WLR was significantly higher in the hypertensivegroup than in controls (0.35 ± 0.071 vs 0.26 ± 0.035, respectively;p=0.017) after correcting for age. The WLR of retinal arterioles wasalso positively correlated to current arterial pressure (r=0.36; p=0.03)and to IMT (p=0.028). Arteriolar narrowing, but not arteriovenousnickings, showed locally increased WLR. Follow-up of patientsunder hypotensive treatment (n=7; mean follow-up 6 months) coulddocument progressive vasodilation in two.Conclusions: Past history of arterial hypertension and current arterialpressure are both associated with increased WLR. Arteriovenousnarrowing and arteriovenous nicking show distinct parietalabnormalities and hence are probably due to distinct pathologicalprocesses. Thickening of large and small arteries are correlated,suggesting some degree of parallelism of the evolution of macro andmicrocirculatory damage. We conclude that AO imaging enables tophenotype the microcirculation with an unprecedented precision andmay improve the understanding and the management of arterialhypertension.Commercial Relationships: Edouard Koch, None; DavidRosenbaumm, None; Xavier Girerd, None; Florence Rossant,None; Michel Paques, MerckSerono (C), Roche (C), Sanofi (C)Support: ANR_09_TECS_009_01_iPhot©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.
ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological OpticsClinical Trial: C10-03Program Number: 6059 Poster Board Number: B0070Presentation Time: 10:30 AM - 12:15 PMInvestigation of the correlation among diameter of retinal vesseland arteriosclerosis risk factors including hypoadiponectinemiaKei Homma 1 , Ryo Kawasaki 2 , Yusuke Tanabe 1 , Koko Saito 1 , AkiraSugano 1 , Atsushi Hozawa 3 , Katou Takeo 4 , Isao Kubota 5 , TakamasaKayama 6 , Hidetoshi Yamashita 1 . 1 Ophthalmology, Yamagata UnivSch of Medicine, Yamagata, Japan; 2 Public Health, Yamagata UnivSch of Medicine, Yamagata, Japan; 3 Tohoku Univ Sch of Medicine,Sendai, Japan; 4 Neurology,Hematology,Metabolism,Endocrinologyand Diabetology, Yamagata Univ Sch of Medicine, Yamagata, Japan;5 Cardiology,Pulmonology,and Nephrology, Yamagata Univ Sch ofMedicine, Sendai, Japan; 6 Neurosurgery, Yamagata Univ Sch ofMedicine, Yamagata, Japan.Purpose: Hypoadiponectinemia caused by visceral fat accumulationis related to hypertension, diabetes, and hyperlipidemia, and is anindependent risk factor for the arteriosclerosis.In this research, the correlation among diameter of retinal vessel andarteriosclerosis risk factors including hypoadiponectinemia wasinvestigated in the population based epidemiological study.Methods: This research was approved by the Ethics committee ofYamgatata University School of Medicine. Fundus photographs weretaken in the subjects who participated in the Takahata study andanalyzed after securing written permission from the subjects. Intotal,1473 subjects were investigated.The estimated retinal artery(CRAE:centaral retinal artery equivalent,the estimated retinal vein(CRVE:central retinal vein equivalent),andAVR (arteliole to venule ratio) were measured from the fundusphotographs used by the vessel diameter measurement dedicatedsoftware (Retinal Analysis,University of Wisconsin,Wisconsin).Characteristics to be inspected were divided into about 4groups, and the vessel diameter of an each part was analyzed.Results: Multiple linear regression analysis showed that CRAEdecreased along with systolic arterial pressure increased(-0.067μm;p=0.039).CRAE increased along with adiponectin levelincreased(0.153μm;p=0.049).CRVE increase was also associatedwith HbA1c,smoking index,and body massindex(3.333μm;p=0.004,0.004μm;p=0.023,0.412μm;p=0.007respectively).Conclusions: Hypoadiponectinemia was an independent risk factorfor CRAE decrease.The results suggest that measurement of retinalblood vessels are a good clinical marker to detect macrovasculardiseases.Commercial Relationships: Kei Homma, None; Ryo Kawasaki,None; Yusuke Tanabe, None; Koko Saito, None; Akira Sugano,None; Atsushi Hozawa, None; Katou Takeo, None; Isao Kubota,None; Takamasa Kayama, None; Hidetoshi Yamashita, Senju (C),Senju (P)Program Number: 6060 Poster Board Number: B0071Presentation Time: 10:30 AM - 12:15 PMNoninvasive Imaging of Retinal Pericytes and Endothelial Cellsin Living Human EyesToco Y. Chui, Thomas Gast, Stephen A. Burns. Optometry, IndianaUniversity, Bloomington, IN.Purpose: To image the retinal vascular pericytes and endothelialcells in living human retina using an adaptive optics scanning laserophthalmoscope (AOSLO).Methods: In vivo arteriolar wall imaging was performed on 8 healthysubjects using the Indiana AOSLO (Ferguson et al, 2010). Vesselwall imaging was performed using systematic control of the positionof a large confocal aperture (Chui et al, 2012). Peripapillary arteriesand arterioles were divided into 4 groups based on their lumendiameters (Gr 1: ≥100µm; Gr 2: 50-99µm; Gr 3: 10-49µm; Gr 4:retinal capillaries).Results: The retinal microvasculature and scattering behavior oferythrocytes were clearly visualized in all 8 subjects. On the smallervessels the pericytes were visualized as distinct cells laying along thelumen of the blood vessel. The smaller vessel pericytes bulgedoutward from the vessel wall resulting in a wall of irregularthickness. For the larger Gr 1 vessels the pericytes were much flatterand formed the outer corrugated layer of a two (or more) layeredvascular wall. While pericytes were readily seen in vessel groups 1,2, and 3, endothelial cells were only visible in Gr 1 vessels - thelargest retinal arteries. Fig 1A shows the fine structure of arteriolarwall in a Gr 1 and Gr 3 vessel. The ratio of pericytes to endothelialcells was approximately 1:1 in the Gr 1 arteries (Fig 1B). Vascularwall components were not identified in the smallest retinal capillaries(Gr 4).Conclusions: Our results show that retinal pericytes can be readilyresolved in normal subjects for arterioles with a lumen diameter>10µm. Our noninvasive imaging approach allows direct assessmentof the cellular structure of the vascular wall in vivo with potentialapplications in retinal vasculopathies such as diabetic retinopathy.Fig1 A) Fine structure of vessel wall in peripapillary arterioles.Asterisks indicate the vessel lumen of a 100µm diameter and 14µmdiameter arteriole. The inner and outer vessel wall linings of thelarger arteriole are indicated by the white arrows. Pericytes (blackarrows) are observed in a precapillary arteriole with a lumen diameterof 14µm. B) Magnified region of the white box on A. Endothelialcells (white arrows) and pericytes (black arrows) are readily seenalong the inner and outer vessel wall linings. Note the one to oneratio of endothelial cells and pericytes.Commercial Relationships: Toco Y. Chui, None; Thomas Gast,None; Stephen A. Burns, NoneSupport: NIH grants R01-EY14375, R01-EY04395, andP30EY019008Program Number: 6061 Poster Board Number: B0072Presentation Time: 10:30 AM - 12:15 PM©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.
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