Smartphone Slit Lamp Imaging-Usability and Quality Assessment.

PURPOSE: To assess the usability and image quality of a smartphone adapter for direct slit lamp imaging. METHODS: A single-center, prospective, clinical study conducted in the Department of Ophthalmology at the University Hospital Zurich, Switzerland. The smartphone group consisted of 26 medical staff (consultants, residents, and students). The control group consisted of one ophthalmic photographer. Both groups took images of the anterior and the posterior eye segment of the same proband. The control group used professional photography equipment. The participant group used an Apple iPhone 11 mounted on a slit lamp via a removable SlitREC smartphone adapter (Custom Surgical GmbH, Munich, Germany). The image quality was graded independently by two blinded ophthalmologists on a scale from 0 (low) to 10 (high quality). Images with a score ≥ 7.0/10 were considered as good as the reference images. The acquisition time was measured. A questionnaire on usability and experience in smartphone and slit lamp use was taken by all of the participants. RESULTS: Each participant had three attempts at the same task. The overall smartphone quality was 7.2/10 for the anterior and 6.4/10 for the posterior segment. The subjectively perceived difficulty decreased significantly over the course of three attempts (Kendall's W). Image quality increased as well but did not improve significantly from take 1 to take 3. However, the image quality of the posterior segment was significantly, positively correlated (Spearman's Rho) with work experience. The mean acquisition time for anterior segment imaging was faster in the smartphone group compared to the control group (156 vs. 206 s). It was vice versa for the posterior segment (180 vs. 151 s). CONCLUSION: Slit lamp imaging with the presented smartphone adapter provides high-quality imaging of the anterior segment. Posterior segment imaging remains challenging in terms of image quality. The adapter constitutes a cost-effective, portable, easy-to-use solution for recording ophthalmic photos and videos. It can facilitate clinical documentation and communication among colleagues and with the patient especially outside normal consultation hours. Direct slit lamp imaging allows for time to be saved and increases the independence of ophthalmologists in terms of patient mobility and the availability of photographic staff.

Choriocapillaris Flow Density Negatively Correlates With Advancing Age on Spectral-Domain Optical Coherence Tomography Angiography.

BACKGROUND AND OBJECTIVE: To correlate subfoveal choriocapillaris (CC) flow density with age using spectral-domain optical coherence tomography angiography (SD-OCTA). PATIENTS AND METHODS: One hundred eighty-three eyes of 94 subjects (66 female, 28 male) were enrolled. Included were healthy subjects between the ages of 21 and 82 years without any history of vitreoretinal disease. Measurements were obtained with software from the OCT device. Significance was defined as a P value of less than .05. RESULTS: The mean age was 43.43 years ± 17.63 years. Correlation between decreasing CC flow density and increasing age was significant (P < .001), with a mean yearly flow decrease of 0.026%. Subfoveal choroidal thickness decreased with advancing age; however, this did not reach a level of significance (P = .069). CONCLUSION: There is a significantly negative correlation between CC flow density and advancing age in healthy subjects, analyzing direct extracted in-built software values from a commercial SD-OCTA device. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:302-308.].

Choriocapillary Blood Flow in Myopic Subjects Measured With OCT Angiography.

BACKGROUND AND OBJECTIVE: To investigate choriocapillary blood flow in myopic eyes using optical coherence tomography angiography. PATIENTS AND METHODS: Seventy-eight myopic and 79 age-matched healthy eyes were included in this study, with myopia defined as a spherical equivalent refraction (SER) between -1 diopters (D) and -6 D. Quantitative measurements of the choriocapillaris were obtained using the Avanti RTVue XR with AngioVue. Choroidal thickness (CT) was assessed using the single-line enhanced high-definition scan of the same device. RESULTS: CT correlated positively with SER (P = .017) and negatively with bulbus axial length (AL) (P = .180). Subfoveal choriocapillary blood flow did not show any significant correlation with any of the parameters SER, AL, or CT (P = .798, P = .269, and P = .820, respectively). The mean flow signal of the myopic group did not differ significantly from the mean flow signal of the emmetropic control group (P = .266). CONCLUSION: Choriocapillary blood flow seems to retain a constant level with increasing physiological myopia. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e133-e139.].

Optical coherence tomography angiography indicates associations of the retinal vascular network and disease activity in multiple sclerosis.

BACKGROUND: Patients with multiple sclerosis (MS) and clinically isolated syndrome (CIS) may show alterations of retinal layer architecture as measured by optical coherence tomography. Little is known about changes in the retinal vascular network during MS. OBJECTIVE: To characterize retinal vessel structures in patients with MS and CIS and to test for associations with MS disease activity. METHOD: In all, 42 patients with MS or CIS and 50 healthy controls underwent retinal optical coherence tomography angiography (OCT-A) with analysis of the superficial and deep vascular plexuses and the choriocapillaries. We tested OCT-A parameters for associations with retinal layer volumes, history of optic neuritis (ON), and the retrospective disease activity. RESULTS: Inner retinal layer volumes correlated positively with the density of both the superficial and deep vascular plexuses. Eyes of MS/CIS patients with a history of ON revealed reduced vessel densities of the superficial and deep vascular plexuses as compared to healthy controls. Higher choriocapillary vessel densities were associated with ongoing inflammatory disease activity during 24 months prior to OCT-A examination in MS and CIS patients. CONCLUSION: Optic neuritis is associated with rarefaction of the superficial and deep retinal vessels. Alterations of the choriocapillaries might be linked to disease activity in MS.