Head stabilization apparatus for high-resolution ophthalmic imaging.

Head movement must be stabilized to enable high-quality data collection from optical instrumentation such as eye trackers and ophthalmic imaging devices. Though critically important for imaging, head stabilization is often an afterthought in the design of advanced ophthalmic imaging systems, and experimental devices often adapt used and/or discarded equipment from clinical devices for this purpose. Alternatively, those seeking the most stable solution possible, including many users of adaptive optics ophthalmoscopy systems, utilize bite bars. Bite bars can provide excellent stability but are time consuming to fabricate, decreasing imaging efficiency, and uncomfortable for many patients, especially the elderly and/or those with prosthodontics such as dentures who may refuse participation in a study that requires one. No commercial vendors specifically offer head mount solutions for experimental ophthalmic imaging devices, resulting in nearly every custom device having a different solution for this commonly encountered problem. Parallelizing the head stabilization apparatus across different custom devices may improve standardization of experimental imaging systems for clinical trials and other multicenter investigations. Here we introduce a head mount design for ophthalmic imaging that is modular, adjustable, and customizable to the constraints of different experimental imaging configurations. The three points of head contact in our solution provide excellent stabilization across a range of head sizes and shapes from small children to adults, and the ease of adjustment afforded by our design minimizes the time to get participants stabilized and comfortable.

Autofluorescent hyperreflective foci on infrared autofluorescence adaptive optics ophthalmoscopy in central serous chorioretinopathy.

Purpose: To test the hypothesis that hyperreflective foci in central serous chorioretinopathy (CSCR) are autofluorescent and may represent macrophages that have engulfed outer retinal fluorophores from the retinal pigment epithelium (RPE) and photoreceptors. Methods: Enrolled subjects underwent spectral domain and swept-source optical coherence tomography, adaptive optics flood-illumination, and adaptive optics scanning laser ophthalmoscopy (AOSLO), including near-infrared autofluorescence (AO-IRAF). For the AO-IRAF imaging, retinal fluorophores were excited using 795 nm light and collected in an emission band from 814 to 850 nm. Results: In 2 of 3 eyes, a hyperautofluorescent signal was detected with an elliptical shape and punctate, granular aspects surrounded by a hypoautofluorescent halo. The size of these structures in the active case was measured to be 17 ± 4 µm in diameter, with at least 45 individual hyperautofluorescent foci identified from the AO-IRAF montage in the active stage of patient 2. In the asymptomatic case there were fewer structures visible (∼10) and their size was smaller (11 ± 4 µm). These hyper-AF foci were colocalized with hyperreflective foci on OCT and visible in simultaneously acquired confocal AOSLO images in active stage. The hyperautofluorescent foci in the patient with active CSCR disappeared coincident with clinical resolution. Conclusion and importance: We show here the first AO-IRAF images from patients with CSCR, demonstrating hyper-autofluorescent punctate foci, colocalized with hyper-reflective foci on confocal AOSLO images and in OCT. The autofluorescence of these foci may be driven by the accumulation of photoreceptor and RPE fluorophores within macrophages during the active stage of the disease.

Long-term satisfaction with curative treatment and follow-up in prostate cancer survivors.

PURPOSE: In a cross-sectional observational study to explore long-term satisfaction with treatment among men who had undergone radical prostatectomy (RP) or definitive pelvic radiotherapy (RT) for prostate cancer (PCa). METHODS: After mean 7 years from therapy (range: 6-8), 431 PCa-survivors (RP: n = 313, RT: n = 118) completed a mailed questionnaire assessing persistent treatment-related adverse effects (AEs) (Expanded Prostate cancer Index Composite [EPIC-26]) and seven Quality indicators describing satisfaction with the health care service following a most often general practitioner (GP)-led follow-up plan. A logistic regression model evaluated the associations between long-term satisfaction and treatment modality, age, the seven satisfaction-related Quality indicators, and persistent AEs. The significance level was set at p< .05. RESULTS: Four of five (81%) PCa-survivors reported long-term satisfaction with their treatment. In a multivariable model, satisfaction was positively associated with sufficient information about treatment and AEs, patient-perceived sufficient cooperation between the hospital and the GP and sufficient follow-up of AEs (ref.: insufficient). Age ≥70 years (ref.: <70) and a rising summary score within the EPIC-26 sexual domain additionally increased long-term satisfaction. The treatment modality itself (RP versus RT) did not significantly impact on satisfaction. CONCLUSIONS: The majority of curatively treated PCa-survivors are satisfied with their treatment more than 5 years after primary therapy. Sufficient information, improved cooperation between the hospital specialists and the responsible GP and optimized follow-up of AEs may further increase long-term satisfaction among prostatectomized and irradiated PCa-survivors.

Design of a radial multi-offset detection pattern for in vivo phase contrast imaging of the inner retina in humans.

Previous work has shown that multi-offset detection in adaptive optics scanning laser ophthalmoscopy (AOSLO) can be used to image transparent cells such as retinal ganglion cells (RGCs) in monkeys and humans. Though imaging in anesthetized monkeys with high light levels produced high contrast images of RGCs, images from humans failed to reach the same contrast due to several drawbacks in the previous dual-wavelength multi-offset approach. Our aim here was to design and build a multi-offset detection pattern for humans at safe light levels that could reveal transparent cells in the retinal ganglion cell layer with a contrast and acquisition time approaching results only previously obtained in monkeys. Here, we present a new single-wavelength solution that allows for increased light power and eliminates problematic chromatic aberrations. Then, we demonstrate that a radial multi-offset detection pattern with an offset distance of 8-10 Airy Disk Diameter (ADD) is optimal to detect photons multiply scattered in all directions from weakly reflective retinal cells thereby enhancing their contrast. This new setup and image processing pipeline led to improved imaging of inner retinal cells, including the first images of microglia with multi-offset imaging in AOSLO.

Near infrared autofluorescence imaging of retinal pigmented epithelial cells using 663 nm excitation.

PURPOSE: Fundus autofluorescence (AF) using adaptive optics scanning laser ophthalmoscopy (AOSLO) enables morphometric analysis of individual retinal pigmented epithelial (RPE) cells. However, only a few excitation wavelengths in the visible and near-infrared have been evaluated. Visible light excitation (<600 nm) presents additional safety hazards and is uncomfortable for patients. Near-infrared excitation (>700 nm) overcomes those problems but introduces others, including decreased AF signal and cone signatures that obscure RPE structure. Here we investigated the use of an intermediate wavelength, 663 nm, for excitation and compared it to 795 nm. METHODS: Subjects were imaged using AOSLO equipped with a detection channel to collect AF emission between 814 and 850 nm. Two light sources (663 and 795 nm) were used to excite the retinal fluorophores. We recorded 90 s videos and registered them with custom software to integrate AF images for analysis. RESULTS: We imaged healthy eyes and an eye with pattern dystrophy. Similar AF microstructures were detected with each excitation source, despite ~4 times lower excitation power with 663 nm. The signal-to-noise values showed no meaningful difference between 663 nm and 795 nm excitation and a similar trend was observed for image contrast between the two excitation wavelengths. CONCLUSIONS: Lower light levels can be used with shorter wavelength excitation to achieve comparable images of the microstructure of the RPE as have been obtained using higher light levels at longer wavelengths. Further experiments are needed to fully characterize AF across spectrum and determine the optimal excitation and emission bandwidths that balance efficiency, patient comfort, and efficacy.

Multimodal Imaging of Torpedo Maculopathy With Fluorescence Adaptive Optics Imaging of Individual Retinal Pigmented Epithelial Cells.

Torpedo maculopathy (TM) is a rare congenital defect of the retinal pigment epithelium (RPE). The RPE is often evaluated clinically using fundus autofluorescence (AF), a technique that visualizes RPE structure at the tissue level from the intrinsic AF of RPE fluorophores. TM lesions typically emit little or no AF, but this macroscopic assessment is unable to resolve the RPE cells, leaving the organization of the RPE cell mosaic in TM unknown. We used fluorescence adaptive optics scanning laser ophthalmoscopy (AOSLO) to show here for the first time the microscopic cellular-level structural alterations to the RPE cell mosaic in TM that underlie the tissue-level changes seen in conventional clinical imaging. We evaluated two patients with TM using conventional clinical imaging techniques and adaptive optics (AO) infrared autofluorescence (IRAF) in AOSLO. Confocal AOSLO revealed relatively normal cones outside the TM lesion but altered cone appearance within it and along its margins in both patients. We quantified cone topography and RPE cell morphometry from the fovea to the margin of the lesion in case 1 and found cone density to be within the normal range across the locations imaged. However, RPE morphometric analysis revealed disrupted RPE cells outside the margin of the lesion; the mean RPE cell area was greater than two standard deviations above the normative range up to approximately 1.5 mm from the lesion margin. Similar morphometric changes were seen to individual RPE cells in case 2. Multi-modal imaging with AOSLO reveals that RPE cells are abnormal in TM well beyond the margins of the characteristic TM lesion boundary defined with conventional clinical imaging. Since the TM fovea appears to be fully formed, with normal cone packing, it is possible that the congenital RPE defect in TM occurs relatively late in retinal development. This work demonstrates how cellular level imaging of the RPE can provide new insight into RPE pathologies, particularly for rare conditions such as TM.

Simultaneous directional full-field OCT using path-length and carrier multiplexing.

Full-field swept-source optical coherence tomography (FF-SS-OCT) is an emerging technology with potential applications in ophthalmic imaging, microscopy, metrology, and other domains. Here we demonstrate a novel method of multiplexing FF-SS-OCT signals using carrier modulation (CM). The principle of CM could be used to inspect various properties of the scattered light, e.g. its spectrum, polarization, Doppler shift, or distribution in the pupil. The last of these will be explored in this work, where CM was used to acquire images passing through two different optical pupils. The two pupils contained semicircular optical windows with perpendicular orientations, with each window permitting measurement of scattering anisotropy in one dimension by inducing an optical delay between the images formed by the two halves of the pupil. Together, the two forms of multiplexing permit measurement of differential scattering anisotropy in the x and y dimensions simultaneously. To demonstrate the feasibility of this technique our carrier multiplexed directional FF-OCT (CM-D-FF-OCT) system was used to acquire images of a microlens array, human hair, onion skin and in vivo human retina. The results of these studies are presented and briefly discussed in the context of future development and application of this technique.

Kilohertz retinal FF-SS-OCT and flood imaging with hardware-based adaptive optics.

A retinal imaging system was designed for full-field (FF) swept-source (SS) optical coherence tomography (OCT) with cellular resolution. The system incorporates a real-time adaptive optics (AO) subsystem and a very high-speed CMOS sensor, and is capable of acquiring volumetric images of the retina at rates up to 1 kHz. While digital aberration correction (DAC) is an attractive potential alternative to AO, it has not yet been shown to provide resolution allowing visualization of cones in the fovea, where early detection of functional deficits is most critical. Here we demonstrate that FF-SS-OCT with hardware AO permits resolution of foveal cones, imaged at eccentricities of 1° and 2°, with volume rates adequate to measure light-evoked changes in photoreceptors. With the reference arm blocked, the system can operate as a kilohertz AO flood illumination fundus camera with adjustable temporal coherence and is expected to allow measurement of light-evoked changes caused by common path interference in photoreceptor outer segments (OS). In this paper, we describe the system's optical design, characterize its performance, and demonstrate its ability to produce images of the human photoreceptor mosaic.

Optoretinogram: optical measurement of human cone and rod photoreceptor responses to light.

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.

Microstructure of the retinal pigment epithelium near-infrared autofluorescence in healthy young eyes and in patients with AMD.

Retinal pigmented epithelial (RPE) cells are essential for maintaining normal visual function, especially in their role in the visual cycle, and are thought to be one of the first cell classes affected by age-related macular degeneration (AMD). Clinical imaging systems routinely evaluate the structure of the RPE at the tissue level, but cellular level information may provide valuable RPE biomarkers of health, aging and disease. In this exploratory study, participants were imaged with 795 nm excitation in adaptive optics scanning laser ophthalmoscopy (AOSLO) to observe the microstructure of the near-infrared autofluorescence (AO-IRAF) from the RPE layer in healthy retinas and patients with AMD. The expected hexagonal mosaic of RPE cells was only sometimes seen in normal eyes, while AMD patients exhibited highly variable patterns of altered AO-IRAF. In some participants, AO-IRAF structure corresponding to cones was observed, as we have demonstrated previously. In some AMD patients, marked alterations in the pattern of AO-IRAF could be seen even in areas where the RPE appeared relatively normal in clinical imaging modalities, such as spectral domain optical coherence tomography (SD-OCT). AO-IRAF imaging using AOSLO offers promise for better detection and understanding of early RPE changes in the course of AMD, potentially before clinical signs appear.

Acute cerebrovascular event in a dog with polycythemia vera.

A 1-year-old neutered male Labrador retriever mixed breed dog was referred for peracute onset of ataxia and seizures. Hematocrit at presentation was 84%. Magnetic resonance imaging of the brain revealed a lesion in the right caudate nucleus consistent with infarction. Postmortem findings were consistent with polycythemia vera and presumed secondary cerebral infarction.

Événement cérébrovasculaire aigu chez un chien atteint de polycythémie vraie. Un Labrador retriever mâle âgé de 1 an a été référé pour l'apparition suraiguë d'ataxie et de crises d'épilepsie. L'hématocrite était de 84 % à la présentation. L'imagerie par résonance magnétique du cerveau a révélé une lésion dans le noyau caudé droit compatible avec à un infarcissement. Les résultats post mortem étaient conformes à une polycythémie vraie et à un infarcissement cérébral secondaire présumé.(Traduit par Isabelle Vallières).

In vivo retinal imaging for fixational eye motion detection using a high-speed digital micromirror device (DMD)-based ophthalmoscope.

Retinal motion detection with an accuracy of 0.77 arcmin corresponding to 3.7 µm on the retina is demonstrated with a novel digital micromirror device based ophthalmoscope. By generating a confocal image as a reference, eye motion could be measured from consecutively measured subsampled frames. The subsampled frames provide 7.7 millisecond snapshots of the retina without motion artifacts between the image points of the subsampled frame, distributed over the full field of view. An ophthalmoscope pattern projection speed of 130 Hz enabled a motion detection bandwidth of 65 Hz. A model eye with a scanning mirror was built to test the performance of the motion detection algorithm. Furthermore, an in vivo motion trace was obtained from a healthy volunteer. The obtained eye motion trace clearly shows the three main types of fixational eye movements. Lastly, the obtained eye motion trace was used to correct for the eye motion in consecutively obtained subsampled frames to produce an averaged confocal image correct for motion artefacts.

Fibroblast drug scavenging increases intratumoural gemcitabine accumulation in murine pancreas cancer.

OBJECTIVE: Desmoplasia and hypovascularity are thought to impede drug delivery in pancreatic ductal adenocarcinoma (PDAC). However, stromal depletion approaches have failed to show clinical responses in patients. Here, we aimed to revisit the role of the tumour microenvironment as a physical barrier for gemcitabine delivery. DESIGN: Gemcitabine metabolites were analysed in LSL-KrasG12D/+ ; LSL-Trp53R172H/+ ; Pdx-1-Cre (KPC) murine tumours and matched liver metastases, primary tumour cell lines, cancer-associated fibroblasts (CAFs) and pancreatic stellate cells (PSCs) by liquid chromatography-mass spectrometry/mass spectrometry. Functional and preclinical experiments, as well as expression analysis of stromal markers and gemcitabine metabolism pathways were performed in murine and human specimen to investigate the preclinical implications and the mechanism of gemcitabine accumulation. RESULTS: Gemcitabine accumulation was significantly enhanced in fibroblast-rich tumours compared with liver metastases and normal liver. In vitro, significantly increased concentrations of activated 2',2'-difluorodeoxycytidine-5'-triphosphate (dFdCTP) and greatly reduced amounts of the inactive gemcitabine metabolite 2',2'-difluorodeoxyuridine were detected in PSCs and CAFs. Mechanistically, key metabolic enzymes involved in gemcitabine inactivation such as hydrolytic cytosolic 5'-nucleotidases (Nt5c1A, Nt5c3) were expressed at low levels in CAFs in vitro and in vivo, and recombinant expression of Nt5c1A resulted in decreased intracellular dFdCTP concentrations in vitro. Moreover, gemcitabine treatment in KPC mice reduced the number of liver metastases by >50%. CONCLUSIONS: Our findings suggest that fibroblast drug scavenging may contribute to the clinical failure of gemcitabine in desmoplastic PDAC. Metabolic targeting of CAFs may thus be a promising strategy to enhance the antiproliferative effects of gemcitabine.

Digital micromirror device based ophthalmoscope with concentric circle scanning.

Retinal imaging is demonstrated using a novel scanning light ophthalmoscope based on a digital micromirror device with 810 nm illumination. Concentric circles were used as scan patterns, which facilitated fixation by a human subject for imaging. An annular illumination was implemented in the system to reduce the background caused by corneal reflections and thereby to enhance the signal-to-noise ratio. A 1.9-fold increase in the signal-to-noise ratio was found by using an annular illumination aperture compared to a circular illumination aperture, resulting in a 5-fold increase in imaging speed and a better signal-to-noise ratio compared to our previous system. We tested the imaging performance of our system by performing non-mydriatic imaging on two subjects at a speed of 7 Hz with a maximum 20° (diameter) field of view. The images were shot noise limited and clearly show various anatomical features of the retina with high contrast.

In vitro and in vivo assessment of platelet function in healthy dogs during administration of a low-dose aspirin regimen.

OBJECTIVE: To assess the in vitro and in vivo platelet function of healthy dogs during administration of a low-dose aspirin regimen. ANIMALS: 16 dogs. PROCEDURES: Dogs received aspirin (1 mg/kg, PO, q 24 h) for 7 days. Blood and urine samples were collected before (day 1; baseline) and on days 3 and 7 of the low-dose aspirin regimen. Platelet function was evaluated by use of turbidimetric and conventional impedance aggregometry, multiple-electrode impedance aggregometry, a platelet function analyzer (PFA), and determination of urine 11-dehydro-thromboxane B2 concentration. Turbidimetric aggregometry results were compared with the results obtained by the other 4 methods. Fourteen days after cessation of aspirin, platelet-rich plasma was incubated with acetylsalicylic acid and platelet function was assessed by turbidimetric aggregometry to determine whether this technique could accurately identify dogs that responded to the low-dose aspirin regimen. RESULTS: Of the 16 dogs, 13 had turbidimetric and conventional impedance aggregometry results that were decreased by > 25% from baseline on days 3 and 7, and 4 and 7 dogs had PFA closure times > 300 seconds on days 3 and 7, respectively. The median urine 11-dehydro-thromboxane B2 concentration-to-creatinine concentration ratio decreased by 49% between days 1 and 7. Turbidimetric aggregometry results were correlated with conventional impedance aggregometry results. There was poor agreement between the turbidimetric aggregometry and PFA results. The multiple-electrode impedance aggregometry protocol failed to reliably detect aspirin-induced platelet dysfunction. In vitro incubation of platelet-rich plasma with acetylsalicylic acid followed by turbidimetric aggregometry did not predict whether dogs responded to the low-dose aspirin regimen. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the response to a low-dose aspirin regimen varied among healthy dogs.

Anticoagulant effects of inhaled unfractionated heparin in the dog as determined by partial thromboplastin time and factor Xa activity.

OBJECTIVE: To evaluate the anticoagulant effects of inhaled heparin in dogs. DESIGN: This study was conducted in 3 phases. In phase 1, bronchoalveolar lavage fluid (BALf) was collected to generate an in vitro calibration curve to relate heparin concentration to the activated partial thromboplastin time (aPTT). In phase 2, heparin was administered via nebulization to determine the threshold dose needed to prolong systemic aPTT. In phase 3, the local anticoagulant activity of inhaled heparin was determined by measurement of BALf anti-Xa activity and aPTT. SETTING: University teaching hospital. ANIMALS: Six healthy intact female Walker Hounds were used in this study. Two dogs were used for each phase. INTERVENTIONS: Inhaled unfractionated sodium heparin was administered in doses ranging from 50,000 to 200,000 IU. RESULTS: In vitro addition of heparin to BALf caused a prolongation in aPTT. Inhaled heparin at doses as high as 200,000 IU failed to prolong systemic aPTT, and a threshold dose could not be determined. No significant local anticoagulant effects were detected. CONCLUSIONS: Even at doses higher than those known to be effective in people, inhaled heparin appears to have no detectable local or systemic anticoagulant effects in dogs with the current delivery method.

Parallel line scanning ophthalmoscope for retinal imaging.

A parallel line scanning ophthalmoscope (PLSO) is presented using a digital micromirror device (DMD) for parallel confocal line imaging of the retina. The posterior part of the eye is illuminated using up to seven parallel lines, which were projected at 100 Hz. The DMD offers a high degree of parallelism in illuminating the retina compared to traditional scanning laser ophthalmoscope systems utilizing scanning mirrors. The system operated at the shot-noise limit with a signal-to-noise ratio of 28 for an optical power measured at the cornea of 100 µW. To demonstrate the imaging capabilities of the system, the macula and the optic nerve head of a healthy volunteer were imaged. Confocal images show good contrast and lateral resolution with a 10°×10° field of view.

Frequency of the MDR1 mutant allele associated with multidrug sensitivity in dogs from Brazil.

To date, a 4-bp deletion in the MDR1 gene has been detected in more than ten dog breeds, as well as in mixed breed dogs, in several countries, however information regarding this mutation in dogs from Brazil is lacking. For this reason, 103 Collies, 77 Border Collies, 76 Shetland Sheepdogs, 20 Old English Sheepdogs, 55 German Shepherds, 16 Australian Shepherds, and 53 Whippets from Brazil were screened for the presence of the mutation. The heterozygous mutated genotype, MDR1 (+/-), frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 50.5% (95% CI =41.1%-59.9%), 31.3% (95% CI =8.6%-53.2%), and 15.8% (95% CI =7.7%-23.9%), respectively. Homozygous mutated genotype, MDR1 (-/-), was detected only in Collies 35.9%. The MDR1 allele mutant frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 61.2% (95% CI =54.8%-67.5%), 15.6% (95% CI =3.1%-28.2%), and 7.9% (95% CI =3.7%-12.1%), respectively. Additionally, even free of the mutant allele, the maximum mutant prevalence (MMP) in that population, with 95% CI, was 3.8%, 5.2%, 5.4%, and 13.8% for Border Collies, German Shepherds, Whippets, and Old English Sheepdogs, respectively. In this way, this information is important, not only for MDR1 genotype-based breeding programs and international exchange of breeding animals of predisposed breeds, but also for modification of drug therapy for breeds at risk.

Fiber-based polarization-sensitive OCT of the human retina with correction of system polarization distortions.

In polarization-sensitive optical coherence tomography (PS-OCT) the use of single-mode fibers causes unpredictable polarization distortions which can result in increased noise levels and erroneous changes in calculated polarization parameters. In the current paper this problem is addressed by a new Jones matrix analysis method that measures and corrects system polarization distortions as a function of wavenumber by spectral analysis of the sample surface polarization state and deeper located birefringent tissue structures. This method was implemented on a passive-component depth-multiplexed swept-source PS-OCT system at 1040 nm which was theoretically modeled using Jones matrix calculus. High-resolution B-scan images are presented of the double-pass phase retardation, diattenuation, and relative optic axis orientation to show the benefits of the new analysis method for in vivo imaging of the human retina. The correction of system polarization distortions yielded reduced phase retardation noise, and better estimates of the diattenuation and the relative optic axis orientation in weakly birefringent tissues. The clinical potential of the system is shown by en face visualization of the phase retardation and optic axis orientation of the retinal nerve fiber layer in a healthy volunteer and a glaucoma patient with nerve fiber loss.

Identification of canine platelet proteins separated by differential detergent fractionation for nonelectrophoretic proteomics analyzed by Gene Ontology and pathways analysis.

During platelet development, proteins necessary for the many functional roles of the platelet are stored within cytoplasmic granules. Platelets have also been shown to take up and store many plasma proteins into granules. This makes the platelet a potential novel source of biomarkers for many disease states. Approaches to sample preparation for proteomic studies for biomarkers search vary. Compared with traditional two-dimensional polyacrylamide gel electrophoresis systems, nonelectrophoretic proteomics methods that employ offline protein fractionation methods such as the differential detergent fractionation method have clear advantages. Here we report a proteomic survey of the canine platelet proteome using differential detergent fractionation coupled with mass spectrometry and functional modeling of the canine platelet proteins identified. A total of 5,974 unique proteins were identified from platelets, of which only 298 (5%) had previous experimental evidence of in vivo expression. The use of offline prefractionation of canine proteins by differential detergent fractionation resulted in greater proteome coverage as compared with previous reports. This initial study contributes to a broader understanding of canine platelet biology and aids functional research, identification of potential treatment targets and biomarkers, and sets a new standard for the resting platelet proteome.