Managing solar retinopathy with suprachoroidal triamcinolone acetonide injection in a young girl: a case report

Background Solar retinopathy is a disease that causes photochemical toxicity in the retinal fovea tissues, leading to an acute decrease of vision. Case presentation This case report is an interventional case of an asymptomatic 17-year-old Caucasian female with a history of suddenly decreased vision due to solar retinopathy. The patient was managed with a custom-made needle injection of triamcinolone acetonide in the suprachoroidal space. Four months post suprachoroidal injection showed an anatomical and functional improvement in the ellipsoid zone layer through optical coherence tomography signal reappearance. In addition, the best-corrected visual acuity had improved from 0.1 to 1.0 on the Snellen chart with the disappearance of the scotoma. However, there was a mild increase in intraocular pressure after this procedure, controlled with topical hypertensive eye drops. Conclusion Suprachoroidal triamcinolone acetonide injection using a custom-made needle showed both functional and anatomical improvement of macular changes post-solar retinopathy, with acceptable safety outcomes in a young female.

Accessing depth-resolved high spatial frequency content from the optical coherence tomography signal

Optical coherence tomography (OCT) is a rapidly evolving technology with a broad range of applications, including biomedical imaging and diagnosis. Conventional intensity-based OCT provides depth-resolved imaging with a typical resolution and sensitivity to structural alterations of about 5–10 microns. It would be desirable for functional biological imaging to detect smaller features in tissues due to the nature of pathological processes. In this article, we perform the analysis of the spatial frequency content of the OCT signal based on scattering theory. We demonstrate that the OCT signal, even at limited spectral bandwidth, contains information about high spatial frequencies present in the object which relates to the small, sub-wavelength size structures. Experimental single frame imaging of phantoms with well-known sub-micron internal structures confirms the theory. Examples of visualization of the nanoscale structural changes within mesenchymal stem cells (MSC), which are invisible using conventional OCT, are also shown. Presented results provide a theoretical and experimental basis for the extraction of high spatial frequency information to substantially improve the sensitivity of OCT to structural alterations at clinically relevant depths.

Fourier-Domain Optical Coherence Tomography Signal Analysis and Numerical Modeling

In this work the theory of the optical coherence tomography (OCT) signal after sampling, in dispersive media, with noise, and for a turbid medium is presented. The analytical theory is demonstrated with a one-dimensional numerical OCT model for (single) reflectors, dispersive media, and turbid media. For dispersive media the deterioration of the OCT axial resolution is quantified analytically and numerically. The OCT signal to noise ratio (SNR) is analyzed in the Fourier-domain and simulated with the numerical model. For an SNR based on the OCT intensity the conventional shot noise limited SNR is derived whereas for an SNR based on the OCT amplitude a 6.7 dB higher SNR is demonstrated. The OCT phase stability is derived in the Fourier-domain as 2SNR−1 and is validated using the numerical OCT model. The OCT single scattering model is simulated with the one-dimensional numerical model and applied to the simulation of an OCT image of a two-layered sample.