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Resume Introduction L’etendue de la chirurgie pancreatique pour cancer rend la survenue de fuites chyleuses (FC) assez frequente. Recemment une definition consensuelle de FC a ete etablie par l’International Study Group of Pancreatic Surgery (ISGPS). Le but de cette etude etait d’analyser les facteurs de risque et le traitement des FC apres chirurgie pancreatique. Methodes Au total, 228 patients ayant un drainage sereux ou chyleux apres chirurgie pancreatique ont ete inclus dans cette etudes de donnees collectees prospectivement entre janvier 2014 et decembre 2016. Les facteurs de risque et les traitements des FC etaient compares. Une analyse du sous-groupe de patients ayant eu l’ablation des drains malgre une FC persistante etait effectuee avec une etude de la necessite d’un drainage percutane ou une reintervention dans les 3 mois postoperatoires. Resultats Soixante patients ayant eu une FC etaient analyses. Parmi eux, 41 ont eu un regime pauvre en graisses pendant une duree mediane de 12 jours. Le type de traitement n’avait pas d’effet sur la duree du drainage (p = 0,29) et la morbidite (p = 0,15). De plus la morbidite postoperatoire n’etait pas augmentee chez les patients ayant eu une ablation des drains malgre une FC persistante (p = 0,84). Aucun de ces patients n’avait eu un drainage percutane ou une reintervention pour collection postoperatoire. Conclusions Le regime pauvre en graisse n’est probablement pas un traitement efficace des FC. De futures etudes sont necessaires pour explorer l’effet et la necessite d’un traitement des FC.

Summary Purpose With increasing soft tissue clearance in pancreatic cancer surgery, postoperative chyle leak (CL) has become a more commonly observed complication. Recently, a new consensus definition was established by the International study group of pancreatic surgery (ISGPS). The aim of the present analysis was to evaluate risk factors and treatment options of patients with CL after pancreatic surgery. Methods Two hundred and twenty-eight patients with serous or chylous drainage after pancreatic surgery were included in this analysis of a prospectively collected database between 01/2014 and 12/2016. Risk factors for CL and treatment options were compared. A subgroup analysis on those patients, who had drain removal despite of persistent CL with respect to the need of subsequent percutaneous drainage or reoperation within three months postoperatively, was performed. Results Sixty patients with CL were identified. Of those, 41 patients were treated with medium-chain triglyceride-diet, with a median duration of therapy of 12 days. In patients with CL, the type of treatment had no effect on time to drain removal (P = 0.29) and morbidity (P = 0.15). Furthermore, morbidity was not increased in patients who had their drains removed despite persistent CL (P = 0.84). None of the latter patients had percutaneous drainage or reoperation for CL after removal of the surgical drains. Conclusions Dietary treatment may not be very effective in treating CL. Further research is warranted to explore the effect and necessity of CL treatment.

Heinrich Muller was a nineteenth-century German retinal anatomist who, during his short career, was one of the discoverers of the rod photopigment rhodopsin and neuroglia in the retina, now known as Muller cells. He also described the ocular muscles and double foveae of some birds. An important, but largely neglected, insight by Muller was to combine careful psychophysical measurements and geometrical optics to find the location of the photosensitive layer of the retina in the living eye. Here, we provide translated passages from Muller's (1855) publication and compare his entoptic observations with retinal imaging using optical coherence tomography. Muller correctly deduced from his careful experiments that vision is initiated in the photoreceptors located in the back of the retina.

Optical and neural changes in the aging human visual system are reviewed in terms of factors that can influence the study of light-mediated effects on circadian physiology. All aspects of early stage visual mechanisms change continuously from the first days of life, and these changes must be understood when investigating both conscious and unconscious visual responses to light throughout the life span.

Im aktuellen klinischen Alltag haben zystische Pankreaslasionen (PCNs) einen zunehmend relevanten Stellenwert, da sie aufgrund der sich stetig verbessernden Bildgebung haufig als Zufallsbefund diagnostiziert werden. Man unterscheidet zwischen nichtneoplastischen und neoplastischen Pankreaszysten, wobei letztere in unterschiedlicher Auspragung zur malignen Entartung neigen und damit als Vorlauferlasionen des duktalen Adenokarzinoms des Pankreas (PDAC) gelten. Zur Differenzialdiagnose werden neben einer genauen Anamnese und Untersuchung vor allem bildgebende Verfahren wie die Computertomographie (CT) und Magnetresonanztomographie (MRT) sowie der endoskopische Ultraschall mit Feinnadelaspiration herangezogen. Die Indikationen zur chirurgischen Resektion dieser Lasionen richten sich nach den aktuellen europaischen Leitlinien, deren Inhalte sind jedoch nicht evidenzbasiert, sondern stutzen sich auf Erkenntnisse und Empfehlungen von Experten. Gemas den Konsensusempfehlungen kann die asymptomatische seros-zystische Neoplasie (SCN) als serose Lasion mit niedriger Tendenz zur Entartung beobachtet werden. Im Gegensatz dazu sollten alle muzinos-zystischen Neoplasien (MCN) >4 cm sowie alle solid-pseudopapillaren Neoplasien (SPN) reseziert werden. Intraduktal papillar-muzinose Neoplasien (IPMNs), die aufgrund ihres Bezugs zum Pankreasgangsystem in Haupt(MD)- oder Seitengang(BD)-IPMNs unterteilt werden, sollten als MD-IPMN und als Mixed-type(MT)-IPMN reseziert werden. Das Entartungsrisiko der BD-IPMN ist variabler und abhangig von Risikofaktoren, die klinisch und bildmorphologisch definiert werden. Das therapeutische Management erfolgt daher individuell nach Risikoabschatzung. Um die Indikationsqualitat bei PCNs quantifizieren zu konnen und damit auch zu einer optimierten Versorgung beizutragen, werden dringend prospektive Langzeitstudien benotigt.

Die Implementierung technologischer Innovationen in der Chirurgie wie roboterassistierte Eingriffe, neuartige Implantate, Navigation oder moderne Visualisierungstechniken stellen fur Klinken eine okonomische Herausforderung dar, da sie selten per se kostendeckend sind. Im deutschen DRG(„diagnosis related groups“)-System sind die Kosten zahlreicher neuartiger Technologien und Innovation in der Chirurgie kurzfristig und auch oft mittel- und langfristig nicht oder nicht ausreichend gedeckt. Dieser Ubersichtsartikel beschreibt die okonomischen Aspekte chirurgischer Innovationen und zeigt mogliche Wege fur Kliniken auf, die Kosten zu decken. In einem simulierten Fallbeispiel wird veranschaulicht, inwieweit das aktuelle deutsche DRG-Tarifsystem die Kosten minimal-invasiver Techniken (laparoskopisch, roboterassistiert) im Rahmen einer elektiven Sigmaresektion bei benigner Indikation widerspiegelt.

Brown is a contrast color that depends on complex combinations of chromatic and achromatic signals. We measured brown perception with variations in chromaticity and luminance in center-surround configurations. In Experiment 1, the dominant wavelength and saturation in terms of S -cone stimulation were tested with five observers in a fixed surround luminance ( 60 c d / m 2 ). A paired-comparison task required the observer to select the better exemplar of brown in one of two, simultaneously presented, stimuli (1.0° center diameter; annulus of 9.48° outer-diameter). In Experiment 2, the same task was tested with five observers in which surround luminance was varied (from 13.1 to 99.6 c d / m 2 ) for two center chromaticities. The results were a set of win–loss ratios for each stimulus combination and converted to Z -scores. An ANOVA did not reveal a significant main effect of the observer factor but revealed a significant interaction with red/green ( a ∗ ) [but not with the dominant wavelength and the S -cone stimulation (or b ∗ )]. Experiment 2 revealed observer variation in interactions with surround luminance and S -cone stimulation. The averaged data plotted in 1976 L ∗ a ∗ b ∗ color space indicate that high Z -score values widely distribute in the area of a ∗ from 5 to 28 and b ∗ over 6. The balance of the strength between yellowness and blackness differs among observers owing to the amount of induced blackness required for the best brown.

In vivo functional imaging of human photoreceptors is an emerging field, with compelling potential applications in basic science, translational research, and clinical management of ophthalmic disease. Measurements of light-evoked changes in the photoreceptors has been successfully demonstrated using adaptive optics (AO) coherent flood illumination (CFI), AO scanning light ophthalmoscopy (SLO), AO optical coherence tomography (OCT), and full-field OCT with digital AO (dAO). While the optical principles and data processing of these systems differ greatly, and while these differences manifest in the resulting measurements, we believe that the underlying physiological processes involved in each of those techniques are likely the same. AO-CFI and AO-SLO systems are more widely used than OCT systems. However, those systems produce only two-dimensional images and so, less can be said about the anatomical and physiological origins of the observed signal. OCT signal, on the other hand, provides 3D imaging but at a cost of high volume of data, making it impractical to clinical purposes. In light of this, we employed a combined AO-OCT-SLO system–with point-for-point correspondence between the OCT and SLO images–to measure functional responses simultaneously with both and investigate SLO retinal functional biomarkers based on OCT response. The resulting SLO images reveal reflectance changes in the cones which are consistent with those previously reported using AO-CFI and AO-SLO. The resulting OCT volumes show phase changes in the cone outer segment (OS) consistent with those previously reported by us and others. We recapitulate a model of the cone OS previously proposed to explain AO-CFI reflectance changes, and show how this model can be used to predict the signal in AO-SLO. The limitations of the model is also discussed in this manuscript.

Accurate and reproducible OCT angiography (OCTA) measurements are highly dependent on the overall phase stability of the sample. Raster-scanning OCT systems are vulnerable to eye motion, which makes phase correlation impossible if the retinal displacement is too large. Numerical methods exist to correct components of phase shifts due to the axial movement, but that due to lateral movement bigger, then imaging spot are not generally correctable. Real-time eye tracking provides a method to reduce the phase shifts caused by lateral eye movement. Here we report the advancements on monitoring ocular metrics during OCTA acquisition and its effects on image quality.

Background An increasing body of evidence suggests that microbiota may promote progression of pancreatic ductal adenocarcinoma (PDAC). It was hypothesized that gammaproteobacteria (such as Klebsiella pneumoniae) influence survival in PDAC, and that quinolone treatment may attenuate this effect. Methods This was a retrospective study of patients from the Massachusetts General Hospital (USA) and Ludwig-Maximilians-University (Germany) who underwent preoperative treatment and pancreatoduodenectomy for locally advanced or borderline resectable PDAC between January 2007 and December 2017, and for whom a bile culture was available. Associations between tumour characteristics, survival data, antibiotic use and results of intraoperative bile cultures were investigated. Survival was analysed using Kaplan-Meier curves and Cox regression analysis. Results Analysis of a total of 211 patients revealed that an increasing number of pathogen species found in intraoperative bile cultures was associated with a decrease in progression-free survival (PFS) (-1·9 (95 per cent c.i. -3·3 to -0·5) months per species; P = 0·009). Adjuvant treatment with gemcitabine improved PFS in patients who were negative for K. pneumoniae (26·2 versus 15·3 months; P = 0·039), but not in those who tested positive (19·5 versus 13·2 months; P = 0·137). Quinolone treatment was associated with improved median overall survival (OS) independent of K. pneumoniae status (48·8 versus 26·2 months; P = 0·006) and among those who tested positive for K. pneumoniae (median not reached versus 18·8 months; P = 0·028). Patients with quinolone-resistant K. pneumoniae had shorter PFS than those with quinolone-sensitive K. pneumoniae (9·1 versus 18·8 months; P = 0·001). Conclusion K. pneumoniae may promote chemoresistance to adjuvant gemcitabine, and quinolone treatment is associated with improved survival.

Noninvasive, objective measurement of rod function is as significant as that of cone function, and for retinal diseases such as retinitis pigmentosa and age-related macular degeneration, rod function may be a more sensitive biomarker of disease progression and efficacy of treatment than cone function. Functional imaging of single human rod photoreceptors, however, has proven difficult because their small size and rapid functional response pose challenges for the resolution and speed of the imaging system. Here, we describe light-evoked, functional responses of human rods and cones, measured noninvasively using a synchronized adaptive optics optical coherence tomography (OCT) and scanning light ophthalmoscopy (SLO) system. The higher lateral resolution of the SLO images made it possible to confirm the identity of rods in the corresponding OCT volumes.

Neuroendocrine tumors (NETs) are rare neoplasms, which represent complex challenges in diagnosis and treatment. Even in the metastatic stage there are important differences in the type of tumor in comparison to gastrointestinal and pancreatic adenocarcinomas. Therefore, the disease courses are substantially different depending on the grade of differentiation. Even in the metastatic stage the 5‑year survival rates of G1 tumors is up to 83%. Approximately 20% of small intestine NETs additionally show hormone activity, which can compromise survival and the quality of life. For individual treatment decisions the special tumor biology of these tumors must be taken into consideration more so than for other tumor entities. Surgery always becomes important for these tumors when a R0 resection appears possible. Oligometastasis of the liver and the lymph drainage system can be meaningfully approached by surgical treatment. In selected patients with an isolated liver involvement, a liver transplantation can be considered; however, even tumor debulking can lead to improvement in the quality of life and survival, especially for hormone active tumors with a carcinoid syndrome which cannot be conservatively controlled. The aim of this review is to present the value of surgical treatment options in the case of (oligo)metastasized NETs.

We present noninvasive depth-resolved imaging of human retinal and choroidal microcirculation with an ultrahigh-speed (1.7 MHz A-scans/s), Fourier-domain mode locked (FDML) swept-source optical coherence tomography (SS-OCT) system having a central wavelength of 1065 nm. Three OCT angiography (OCTA) motion based contrast methods, namely phase variance (PV), amplitude decorrelation (AD) and Joint Spectral and Time domain OCT (STdOCT) were implemented. The OCTA imaging was performed with a field of view of 16° (5 mm × 5 mm) and 30° (9 mm × 9 mm), on the retina. A qualitative comparison of images obtained with all three OCTA methods is demonstrated using the same eye of a healthy volunteer. Different parameters, namely acquisition time, scanning area, and scanning density, are discussed. The phase-variance OCTA (PV-OCTA) method produced relatively better results than the other two. Different features regarding the retinal and choroidal vessels are described in different subjects.

Background Approximately 11% of the German population are convinced that certain moon phases and moon signs may impact their health and the onset and clinical course of diseases. Before elective surgery, a considerable number of patients look to optimize the timing of the procedure based on the lunar cycle. Especially patients awaiting living donor kidney transplantation (LDKT) commonly look for an adjustment of the date of transplantation according to the moon calendar. This study therefore investigated the perioperative and long-term outcome of LDKT dependent on moon phases and zodiac signs. Methods Patient data were prospectively collected in a continuously updated kidney transplant database. Two hundred and seventy-eight consecutive patients who underwent LDKT between 1994 and December 2009 were selected for the study and retrospectively assigned to the four moon phases (new-moon, waxing-moon, full-moon, and waning-moon) and the corresponding zodiac sign (moon sign Libra), based on the date of transplantation. Preexisting comorbidities, perioperative mortality, surgical outcome, and long-term survival data were analyzed. Results Of all LDKT procedures, 11.9, 39.9, 11.5, and 36.5% were performed during the new, waxing, full, and waning moon, respectively, and 6.2% during the moon sign Libra, which is believed to interfere with renal surgery. Survival rates at 1, 5, and 10 years after transplantation were 98.9, 92, and 88.7% (patient survival) and 97.4, 91.6, and 80.6% (graft survival) without any differences between all groups of lunar phases and moon signs. Overall perioperative complications and early graft loss occurred in 21.2 and 1.4%, without statistical difference (p > 0.05) between groups. Conclusion Moon phases and the moon sign Libra had no impact on early and long-term outcome measures following LDKT in our study. Thus, concerns of patients awaiting LDKT regarding the ideal time of surgery can be allayed, and surgery may be scheduled independently of the lunar phases.

OSA is aware that some authors, as a condition of their funding, must publish their work under a Creative Commons license. We therefore offer a CC BY license for authors who indicate that their work is funded by agencies that we have confirmed have this requirement. Authors must enter their funder(s) during the manuscript submission process. At that point, if appropriate, the CC BY license option will be available to select for an additional fee. Maximum likelihood difference scaling was used to measure suprathreshold contrast response difference scales for low-frequency Gabor patterns, modulated along luminance and L–M color directions in normal, protanomalous, and deuteranomalous observers. Based on a signal-detection model, perceptual scale values, parameterized as 𝑑�′, were estimated by maximum likelihood. The difference scales were well fit by a Michaelis–Menten model, permitting estimates of response and contrast gain parameters for each subject. Anomalous observers showed no significant differences in response or contrast gain from normal observers for luminance contrast. For chromatic modulation, however, anomalous observers displayed higher contrast and lower response gain compared to normal observers. These effects cannot be explained by simple pigment shift models, and they support a compensation mechanism to optimize the mapping of the input contrast range to the neural response range. A linear relation between response and contrast gain suggests a neural trade-off between them. National Eye Institute; Agence Nationale de la Recherche

In vivo visualization and quantification of choriocapillaris vascular anatomy is a fundamental step in understanding the relation between choriocapillaris degradation and atrophic retinopathies, including geographic atrophy. We describe a process utilizing ultrahigh-speed swept-source optical coherence tomography and a custom-designed “local min-max normalized masking” algorithm to extract in vivo anatomical metrics of the choriocapillaris. We used a swept-source optical coherence tomography system with a 1.6 MHz A-scan rate to image healthy retinas. With the postprocessing algorithm, we reduced noise, optimized visibility of vasculature, and skeletonized the vasculature within the images. These skeletonizations were in [Formula: see text] agreement with those made by skilled technicians and were, on average, completed in 18.6 s as compared to the 5.6 h technicians required. Anatomy within the processed images and skeletonizations was analyzed to identify average values ([Formula: see text]) of flow void radius ([Formula: see text]), flow void area [Formula: see text]), vessel radius [Formula: see text]), branch-point to branch-point vessel length [Formula: see text]), and branches per branch-point [Formula: see text]. To exemplify the uses of this tool a retina with geographic atrophy was imaged and processed to reveal statistically significant [Formula: see text] increases in flow void radii and decreases in vessel radii under atrophic lesions as compared to atrophy-free regions on the same retina. Our results demonstrate a new avenue for quantifying choriocapillaris anatomy and studying vasculature changes in atrophic retinopathies.

Rods contribute crucially to human vision and their dysfunction precedes cones’ in several retinal diseases. Here we describe light-evoked, functional responses of human rods and cones, measured noninvasively using adaptive optics optical coherence tomography.

We describe the details of a multimodal retinal imaging system which combines adaptive optics (AO) with an integrated scanning light ophthalmoscopy (SLO) and optical coherence tomography (OCT) imaging system. The OCT subsystem consisted of a swept-source, Fourier-domain mode-locked (FDML) laser, with a very high A-scan rate (1.6MHz), whose beam was raster scanned on the retina by two scanners-one resonant scanner and one galvanometer. The high sweep rate of the FDML permitted the SLO and OCT to utilize the same scanners for in vivo retinal imaging and, unlike existing multimodal systems, concurrently acquired SLO frames and OCT volumes with approximate en face correspondence at a rate of 6Hz. The AO provided diffraction-limited cellular resolution for both imaging channels.

Objective optical assessment of photoreceptor function may permit earlier diagnosis of retinal disease than current methods such as perimetry, electrophysiology, and clinical imaging. Recent work with adaptive optics (AO) flood imaging, conventional OCT and phase-sensitive full-field OCT have revealed apparent changes in photoreceptor outer segment (OS) length in response to visible stimuli. In this work, we describe an AO-OCT system designed to measure these stimulus-evoked OS length changes. The OCT subsystem consisted of a Fourier-domain mode-locked laser that acquires A-scans at 1.64MHz and an AO subsystem providing diffraction-limited imaging with a closed-loop correction rate of 20Hz. To our knowledge this is the highest-speed AO-OCT system developed to date. Visible stimuli were delivered using a LED-based Maxwellian view channel incorporated into the system. In a dark-adapted healthy subject, 1-deg square volumetric images were acquired at a rate of 32Hz. Images were acquired for 10s, with a 10ms bleaching stimulus flash with variable intensity. Strip-based registration was used to track individual cones in the volume series, and time series of the resulting depth-resolved complex signal were analyzed. Stimulus-evoked changes in the morphology of OS and RPE were observed in the M-scan amplitude. In the M-scan phase, the difference between the IS/OS and COST was shown to increase in response to the stimulus flash, and the magnitude of the phase change depended upon flash intensity. These results suggest that cone OS elongates in response to visible stimuli, and that the length change scales with stimulus intensity.

For over 150 years, spectrally selective filters have been proposed to improve the vision of observers with color vision deficiencies [1]. About 6% of males and

Reliable duration perception of external events is necessary to coordinate perception with action, precisely discriminate speech, and for other daily functions. Visual duration perception can be heavily influenced by concurrent auditory signals; however, age-related effects on this process have received minimal attention. In the present study, we examined the effect of aging on duration perception by quantifying (1) duration discrimination thresholds, (2) auditory temporal dominance, and (3) visual duration expansion/compression percepts induced by an accompanying auditory stimulus of longer/shorter duration. Duration discrimination thresholds were significantly greater for visual than auditory tasks in both age groups, however there was no effect of age. While the auditory modality retained dominance in duration perception with age, older adults still performed worse than young adults when comparing durations of two target stimuli (e.g., visual) in the presence of distractors from the other modality (e.g., auditory). Finally, both age groups perceived similar visual duration compression, whereas older adults exhibited visual duration expansion over a wider range of auditory durations compared to their younger counterparts. Results are discussed in terms of multisensory integration and possible decision strategies that change with age.

Metastasis is the major cause of death in patients with colorectal carcinoma (CRC). The most common sites of metastasis are the liver and the peritoneum. Peritoneal carcinomatosis is often considered the end stage of the disease after the tumor has spread to the liver. However, almost half of CRC patients with peritoneal carcinomatosis do not present with liver metastasis. This brings up the question of whether peritoneal spread can still be considered as the end stage of a metastasized CRC or whether it should just be interpreted as a site of metastasis alternative to the liver. This review tries to discuss this question and summarize the current status of literature on potential characteristics in tumor biology in the primary tumor, i.e., factors (transcription factors and direct and indirect E-cadherin repressors) and pathways (WNT, TGF-β, and RAS) modulating EMT, regulation of EMT on a posttranscriptional and posttranslational level (miRNAs), and angiogenesis. In addition to tumor-specific characteristics, factors in the tumor microenvironment, immunological markers, ways of transport of tumor cells, and adhesion molecules appear to differ between hematogenous and peritoneal spread. Factors such as integrins and exosomal integrins, cancer stem cell phenotype, and miRNA expression appear to contribute in determining the metastatic route. We went through each step of the metastasis process comparing hematogenous to peritoneal spread. We identified differences with respect to organotropism, epithelial-mesenchymal transition, angiogenesis and inflammation, and tumor microenvironment which will be further elucidated in this review. A better understanding of the underlying mechanisms and contributing factors of metastasis development in CRC has huge relevance as it is the foundation to help find specific targets for treatment of CRC.

Angiographic imaging of the human eye with optical coherence tomography (OCT) is becoming an increasingly important tool in the scientific investigation and clinical management of several blinding diseases, including age-related macular degeneration and diabetic retinopathy. We have observed that OCT angiography (OCTA) of the human choriocapillaris and choroid with a 1.64 MHz A-scan rate swept-source laser yields higher contrast images as compared to a slower rate system operating at 100 kHz. This result is unexpected because signal sensitivity is reduced when acquisition rates are increased, and the incident illumination power is kept constant. The contrast of angiography images generated by acquiring multiple sequential frames and calculating the variation caused by blood flow, however, appears to be improved significantly when lower-contrast images are taken more rapidly. To demonstrate that the acquisition rate plays a role in the quality improvement, we have imaged five healthy subjects with a narrow field of view (1.2 mm) OCTA imaging system using two separate swept-source lasers of different A-line rates and compared the results quantitatively using the radially-averaged power spectrum. The average improvement in the contrast is 23.0% (+/-7.6%). Although the underlying cause of this enhancement is not explicitly determined here, we speculate that the higher-speed system suppresses the noise contribution from eye motion in subjects and operates with an inter-scan time that better discriminates the flow velocities present in the choroid and choriocapillaris. Our result informs OCT system developers on the merits of ultrahigh-speed acquisition in functional imaging applications.

Objective optical assessment of photoreceptor function may permit earlier diagnosis of retinal disease than current methods such as perimetry, electrophysiology, and clinical imaging. In this work, we describe an adaptive optics (AO) optical coherence tomography (OCT) system designed to measure functional responses of single cones to visible stimuli. The OCT subsystem consisted of a raster-scanning Fourier-domain mode-locked laser that acquires A-scans at 1.64MHz with a center wavelength of 1063nm, and an AO subsystem providing diffraction-limited imaging. Analysis of serial volumetric images revealed phase changes of cone photoreceptors consistent with outer segment elongation and proportional to stimulus intensity, as well as other morphological changes in the outer segment and retinal pigment epithelium.