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We have combined an anterior segment (AS) optical coherence tomography (OCT) system and a wavefront-based aberrometer with an approach that senses ocular wavefront aberrations using the OCT beam. Temporal interlacing of the OCT and aberrometer channels allows for OCT images and refractive error measurements to be acquired continuously and in real-time. The system measures refractive error with accuracy and precision comparable to that of clinical autorefractors. The proposed approach provides a compact modular design that is suitable for integrating OCT and wavefront-based autorefraction within the optical head of the ophthalmic surgical microscope for guiding cataract surgery or table-top devices for simultaneous autorefraction and ocular biometry.

We acquired 1325 nm OCT images of the sclera and ciliary muscle of human subjects. The attenuation coefficients of the sclera and ciliary muscle were determined from a curve fit of the average intensity profile of about 100 A-lines in a region of interest after correction for the effect of beam geometry, using a single scattering model. The average scleral attenuation coefficient was 4.13 ± 1.42 mm-1 with an age-related decrease that was near the threshold for statistical significance (p = 0.053). The average ciliary muscle attenuation coefficient was 1.72 ± 0.88 mm-1, but this value may be an underestimation due to contributions from multiple scattering. Overall, the results suggest that inter-individual variations in scleral attenuation contribute to variability in the quality of transscleral OCT images of the ciliary muscle and the outcome of transscleral laser therapies.

A procedure for identification of optimal Apparent Diffusion Coefficient (ADC) thresholds for automatic delineation of prostatic lesions with restricted diffusion at differing risk for cancer was developed. The relationship between the size of the identified Volumes of Interest (VOIs) and Gleason Score (GS) was evaluated. Patients with multiparametric (mp)MRI, acquired prior to radical prostatectomy (RP) (n = 18), mpMRI-ultrasound fused (MRI-US) (n = 21) or template biopsies (n = 139) were analyzed. A search algorithm, spanning ADC thresholds in 50 µm2/s increments, determined VOIs that were matched to RP tumor nodules. Three ADC thresholds for both peripheral zone (PZ) and transition zone (TZ) were identified for estimation of VOIs at low, intermediate, and high risk of prostate cancer. The determined ADC thresholds for low, intermediate and high risk in PZ/TZ were: 900/800; 1100/850; and 1300/1050 µm2/s. The correlation coefficients between the size of the high/intermediate/low risk VOIs and GS in the three cohorts were 0.771/0.778/0.369, 0.561/0.457/0.355 and 0.423/0.441/0.36 (p

We present a new in vitro instrument for measuring shape and wavefront aberrations of the primate crystalline lens, both on- and off-axis, while simulating accommodation with a motorized lens stretching system. The instrument merges spectral domain optical coherence tomography (SD-OCT) imaging and ray tracing aberrometry using an approach that senses wavefront aberrations of the lens with the OCT probing beam. Accuracy and repeatability of aberration measurements were quantified. Preliminary experiments on two human and four cynomolgus monkey lenses demonstrate the ability of the system to measure the lens shape, spherical aberration and peripheral defocus, and their changes during simulated accommodation.

Optical coherence tomography (OCT) offers new options for imaging the ciliary muscle allowing direct in vivo visualization. However, variation in image quality along the length of the muscle prevents accurate delineation and quantification of the muscle. Quantitative analyses of the muscle are accompanied by variability in segmentation between examiners and between sessions for the same examiner. In processes such as accommodation where changes in muscle thickness may be tens of microns- the equivalent of a small number of image pixels, differences in segmentation can influence the magnitude and potentially the direction of thickness change. A detailed analysis of variability in ciliary muscle thickness measurements was performed to serve as a benchmark for the extent of this variability in studies on the ciliary muscle. Variation between sessions and examiners were found to be insignificant but the magnitude of variation should be considered when interpreting ciliary muscle results.

The lens equivalent refractive index (RI) is commonly used in calculations of crystalline lens power. However, accurate determination of the equivalent RI in vivo is challenging due to the need of multiple measurements with different ocular biometry devices. A custom extended-depth Spectral Domain-OCT system was utilized to provide measurements of corneal and lens surface curvatures and all intraocular distances required for determination of the lens equivalent RI. Ocular biometry and refraction were input into a computational model eye from which the equivalent RI was calculated. Results derived from human subjects of a wide age range show a decrease in RI with age and demonstrate the capability of in vivo measurements of the equivalent RI with extended-depth OCT.

Two SD-OCT systems and a dual channel accommodation target were combined and precisely synchronized to simultaneously image the anterior segment and the ciliary muscle during dynamic accommodation. The imaging system simultaneously generates two synchronized OCT image sequences of the anterior segment and ciliary muscle with an imaging speed of 13 frames per second. The system was used to acquire OCT image sequences of a non-presbyopic and a pre-presbyopic subject accommodating in response to step changes in vergence. The image sequences were processed to extract dynamic morphological data from the crystalline lens and the ciliary muscle. The synchronization between the OCT systems allowed the precise correlation of anatomical changes occurring in the crystalline lens and ciliary muscle at identical time points during accommodation. To describe the dynamic interaction between the crystalline lens and ciliary muscle, we introduce accommodation state diagrams that display the relation between anatomical changes occurring in the accommodating crystalline lens and ciliary muscle.

Purpose: To assess the long-term outcomes of astigmatic keratotomy (AK) performed with two different techniques in patients with post-penetrating keratoplasty (post-PK) residual astigmatism. Methods: This retrospective comparative case series was performed at Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA. Patients who underwent post-PK AK performed using either 30 kHz femtosecond laser flap mode software (IntraLase/AMO, Irvine, CA)-Group 1-or using 150 kHz femtosecond laser enabled AK software (IntraLase/AMO, Irvine, CA)-Group 2-to create two anterior arcuate corneal incisions were included in this study. Preoperative and long-term postoperative follow-up data, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalence (SE) were analyzed. Results: In group 1 (n=5), the difference in pre- and post-operative UDVA (0.97 ± 0.29 LogMAR to 0.68 ± 0.40 LogMAR, p=0.13), CDVA (0.28 ± 0.27 LogMAR to 0.47 ± 0.48 LogMAR, p=1), SE (-2.0 ± 3.0 diopters (D) to -1.8 ± 1.8 D, p=0.88) were not statistically significant, although UDVA and SE showed clinical improvement. In group 2 (n=6), the difference in pre- and post-operative UDVA (1.20 ± 0.14 LogMAR to 0.82 ± 0.62 LogMAR, p=0.19), CDVA (0.58 ± 0.32 LogMAR to 0.34 ± 0.31 LogMAR, p=0.25), SE (-2.3 ± 4.7 D to -2.9 ± 4.4 D, p=0.25) were not statistically significant. There was no statistical difference regarding postoperative UDVA (p=0.85), CDVA (p=0.93), SE (p=0.51) and surgically induced astigmatism (p=0.13) between the 2 groups. Conclusion: AK performed with both techniques is a safe procedure to correct post-PK residual astigmatism. Both techniques yielded comparable results.