Purpose To determine whether high-resolution retinal imaging measures of macular structure correlate with visual function over 36 months in retinal degeneration (RD) patients and normal subjects. Methods Twenty-six eyes of 16 RD patients and 16 eyes of 8 normal subjects were studied at baseline; 15 eyes (14 RD) and 11 eyes (6 normal) were studied 36 months later. Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) was used to identify regions of interest (ROIs) with unambiguous cones at baseline to measure cone spacing. AOSLO images were aligned with spectral-domain optical coherence tomography (SD-OCT) and fundus-guided microperimetry results to correlate structure and function at the ROIs. SD-OCT images were segmented to measure inner segment (IS) and outer segment (OS) thickness. Correlations between cone spacing, IS and OS thickness and sensitivity were assessed using Spearman correlation coefficient ρ with bootstrap analyses clustered by person. Results Cone spacing (ρ = 0.57, P < 0.001) and macular sensitivity (ρ = 0.19, P = 0.14) were significantly correlated with eccentricity in patients. Controlling for eccentricity, cone spacing Z-scores were inversely correlated with IS (ρ = −0.29, P = 0.002) and OS thickness (ρ = −0.39, P < 0.001) in RD patients only, and with sensitivity in normal subjects (ρ = −0.22, P < 0.001) and RD patients (ρ = −0.38, P < 0.001). After 36 months, cone spacing increased ( P < 0.001) and macular sensitivity decreased ( P = 0.007) compared to baseline in RD patients. Conclusions Cone spacing increased and macular sensitivity declined significantly in RD patients over 36 months. High resolution images of cone structure correlated with retinal sensitivity, and may be appropriate outcome measures for clinical trials in RD.

Retinitis pigmentosa (RP) causes progressive photoreceptor loss resulting from mutations in over 80 genes. This study identified the genetic cause of RP in three members of a non-consanguineous pedigree. Detailed ophthalmic evaluation was performed in the three affected family members. Whole exome sequencing (WES) and whole genome sequencing (WGS) were performed in the three affected and the two unaffected family members and variants were filtered to detect rare, potentially deleterious variants segregating with disease. WES and WGS did not identify potentially pathogenic variants shared by all three affected members. However, WES identified a previously reported homozygous nonsense mutation in KIZ (c.226C>T, p.Arg76*) in two affected sisters, but not in their affected second cousin. WGS revealed a novel 1.135 kb homozygous deletion in a retina transcript of C21orf2 and a novel 30.651 kb heterozygous deletion in CACNA2D4 in the affected second cousin. The sisters with the KIZ mutation carried no copies of the C21orf2 or CACNA2D4 deletions, while the second cousin with the C21orf2 and CACNA2D4 deletions carried no copies of the KIZ mutation. This study identified two independent, homozygous mutations in genes previously reported in autosomal recessive RP in a non-consanguineous family, and demonstrated the value of WGS when WES fails to identify likely disease-causing mutations.

Our sense of depth perception is mediated by spatial filters at different scales in the visual brain; low spatial frequency channels provide the basis for coarse stereopsis, whereas high spatial frequency channels provide for fine stereopsis. It is well established that monocular blurring of vision results in decreased stereoacuity. However, previous studies have used tests that are broadband in their spatial frequency content. It is not yet entirely clear how the processing of stereopsis in different spatial frequency channels is altered in response to binocular input imbalance. Here, we applied a new stereoacuity test based on narrow-band Gabor stimuli. By manipulating the carrier spatial frequency, we were able to reveal the spatial frequency tuning of stereopsis, spanning from coarse to fine, under blurred conditions. Our findings show that increasing monocular blur elevates stereoacuity thresholds ‘selectively’ at high spatial frequencies, gradually shifting the optimum frequency to lower spatial frequencies. Surprisingly, stereopsis for low frequency targets was only mildly affected even with an acuity difference of eight lines on a standard letter chart. Furthermore, we examined the effect of monocular blur on the size tuning function of stereopsis. The clinical implications of these findings are discussed.

AIM: To evaluate the image quality of a telemedicine screening program for retinal disease using a nonmydriatic camera among rural island communities in Bocas del Toro, Panama. METHODS: In June 2018, a group of three medical students volunteered at clinics operated by the Floating Doctors in the province of Bocas del Toro, Panama. Non-mydriatic images of the retina were obtained using the Pictor Plus (Volk Optical, Mentor OH), randomized, and sent to two board-certified ophthalmologists at the University of California, Irvine for analysis using a modified version of the FOTO-ED scale. Inter-rater reliability was calculated using the kappa statistic. RESULTS: Seventy patients provided a total of 127 images. Average image quality was 3.31, and most frequent image quality was 4/5 on the FOTO-ED scale. Thirty patients had at least one eye image with ideal quality (42.86%), while only one patient had no adequate photos taken (1.43%). However, high quality images were obtained in both eyes in only 12 patients (17.14%). The inter-rater reliability between the two ophthalmologists was 0.614. CONCLUSION: Further improvements are necessary to acquire higher quality images more reliably. This may include further training and experience or mydriasis.

This session addresses the latest developments in infrared, visible and ultraviolet sensors. New developments in the flashgate fabrication of backside illuminated CCDs will be reported by James Janesick. These have been of increasing importance for scientific use in the UV, EUV, and soft X-ray regions of the spectrum. The flash fabrication allows high built-in fields which enhance the sweep-out of carriers, so as to achieve extremely high quantum efficiencies. Nakamura et al. will report a non-destructive readout MOS imager which also features charge gain at each pixel. Wadsworth et al. have succeeded in fabricating a 640 megapixel/sec 512x512 interline transfer virtual phase CCD imager with less than a 500 psec frame time. This device has 64 output channels and operates with a parallel register clock having a 300ns pulse width.Kataoka will discuss three-dimensional optical integrated sensor implementation using (SOI) technology with specific application to modelling of the retina. Multilayer levels of photodetectors digitizers, and select logic layers will be discussed.Orihara and Oda will discuss detailed design considerations for dual channel read-out registers for high density CCD image sensors. This has become increasingly important for high density sensors that must be free of ultra-fine patterning and where low power consumption is desired.The use of SO1 technology for image sensing will also be discussed by Senda et al. with an emphasis on the reduction of smear noise and improving the noise equivalent exposure as a result of reduced sense-line capacitance.Three dimensional analytic modelling of photovoltaic detector arrays has been achieved and shown to agree with experimental results for relative spectral response, for both Hg0.775 Cd0.225 Te and InSb diode detectors. The paper deals primarily with photocurrent crosstalk in arrays operated in the photovoltaic mode.