UNASSIGNED: The fast development of swept-source optical coherence tomography (SS-OCT) and swept-source optical coherence tomography angiography (SS-OCTA) enables both anterior and posterior imaging of the eye. These techniques have evolved from a research tool to an essential clinical imaging modality.
UNASSIGNED: The longer wavelength and faster speed of SS-OCT and SS-OCTA facilitate better visualization of structure and vasculature below pigmented tissue with a larger field of view of the posterior segment and 360-degree visualization of the anterior segment. In the past 10 years, algorithms dealing with OCT and OCTA data also vastly improved the image quality and enabled the automated quantification of OCT- and OCTA-derived metrics. This technology has enriched our current understanding of healthy and diseased eyes. Even though the high cost of the systems currently limited the widespread use of SS-OCT and SS-OCTA at the first beginning, the gap between research and clinic practice got obviously shortened in the past few years.
UNASSIGNED: SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift toward more widespread adoption of new imaging technology in clinical practice.

How to enhance the bioavailability and prolong the residence time of drugs in the eye present the major barriers to traditional eye delivery. Nanotechnology has been widely used in ocular drug delivery systems because of its advantages of minimizing adverse reactions, decreasing the frequency of administration, prolonging the release time, and improving the bioavailability of the drug in the eye. As natural product-based nanostructured systems, bioinspired nanostructured systems have presented as less toxic, easy to prepare, and cost-effective and have potential application value in the field of nanotechnology. A systematic classification of bioinspired nanostructured systems based on their inspiration source and formulation and their brief applications in disease are presented here. A review of recent research progress of the bioinspired nanostructured systems for the treatment of the anterior and posterior segment of ocular disorders is then presented in detail. Finally, current challenges and future directions with regard to manufacturing bioinspired nanomaterials are provided.

Eye drops are the most common and convenient route of topical administration and the first choice of treatment for many ocular diseases. However, the ocular bioavailability of traditional eye drops (i.e., solutions, suspensions, and ointments) is very low because of ophthalmic physiology and barriers, which greatly limits their therapeutic effect. Over the past few decades, many novel eye drop delivery systems, such as prodrugs, cyclodextrins, in situ gels, and nanoparticles, have been developed to improve ophthalmic bioavailability. These novel eye drop delivery systems have good biocompatibility, adhesion, and propermeation properties and have shown superior performance and efficacy over traditional eye drops. Therefore, the purpose of this review was to systematically present the research progress on novel eye drop delivery systems and provide a reference for the development of dosage form, clinical application, and commercial transformation of eye drops.

BACKGROUND: Posterior segment metallic intraocular foreign bodies (IOFBs) are a leading cause of visual morbidity and blindness, especially among young and middle-aged working populations. Here, we aimed to evaluate the surgical outcomes of the removal of such IOFBs that result from injuries.
METHODS: In this retrospective study, 39 patients injured by metallic posterior segment IOFBs and who underwent primary repair procedures, vitrectomies, and IOFBs removal with or without procedures for traumatic cataract removal, scleral buckling and intraoperative tamponade application from January, 2008 to January, 2019. We analyzed the preoperative, intraoperative and postoperative related factors that affect the final visual outcomes.
RESULTS: The mean age of the 39 patients was 40.51 ± 12.48 years with the male being predominent (100%).The mean preoperative vision measured 1.50 [Snellen Equivalent (SE), 20/645] ± 1.12 logMAR with the mean final vision measuring 0.93 (SE, 20/172) ± 1.09 logMAR. The related factors that were determined to affect the final visual outcomes included preoperative vision (P = 0.025), IOFB-related macula injuries (P = 0.001) and the development of postoperative complications (P = 0.005) especially retinal detachment (P = 0.002) with the mean final vision measuring 2.12 (SE, counting finger to hand motion) ±1.23 logMAR. Concerning the preoperative signs, the patients with preoperative endophthalmitis also obtained poor mean final vision measuring 1.30 (SE,20/400) ± 1.40 logMAR.
CONCLUSIONS: IOFB-related macula injuries and postoperative retinal detachment were important related factors of poor final visual prognoses in cases involving posterior segment metallic IOFBs. Removing IOFB as early as possible may prevent preoperative endophthalmitis which could lead poor final visions even without significance.

As a leading cause of vision impairment of the retina, macular edema (ME) has one of the highest clinical demands for treatment. Current treatment of ME relies heavily on invasive techniques resulting in complications and poor patient compliance. To enhance the efficiency of triamcinolone acetonide as eye drop to the posterior segment of the eye, we developed and characterized a novel formulation, namely, triamcinolone acetonide chitosan-coated liposomes (TA-CHL), prepared by the calcium acetate gradient method with some modifications. TA-CHL provided the mean particle size of 135.46 ± 4.49 nm and high entrapment efficiency (90.66 ± 3.21%), exhibited a sustained release profile, excellent physical stability, and no significant toxicity on cornea, conjunctiva, and retina. Optical coherence tomography system (OCT) was used to detect pharmacokinetics of CHL in vivo, indicating that CHL had good potency for drug delivery. Cellular uptake experiments showed CHL had the higher transduction efficiency into HCEC and ARPE-19 than liposomes. TA-CHL was shown to be potentially effective eye drop to contribute to the posterior segment of the eye.

To develop a standardised grading scheme, using standard photos, for spectral-domain ocular coherence tomography (SD-OCT) images of the posterior eye and evaluate the interobserver agreement among trained ophthalmologists in identifying pathological changes.
Subjects were recruited from Liwan District, Guangzhou, with SD-OCT data collection from June 2013 to November 2013 as part of 10-year follow-up visits from the Liwan Eye Study. All subjects underwent SD-OCT imaging of the macula with scanning lines analysed by two ophthalmologists to assess for the presence of 12 different posterior segment lesions. Per cent agreement for each lesion between the graders and quantitative measures of dome-shaped macula (DSM) height and choroidal thickness were calculated.
A total of 679 SD-OCT images from 679 subjects were independently evaluated by the two graders. Each of the 12 lesions was successfully graded as present or absent in over 96% of images. For all lesions, per cent agreement between observers was over 90%, ranging from 90.7% for epiretinal membranes and retinal pigment epithelium thickenings to 99.7% for full thickness macular holes and retinal detachments. Quantitative measurements of DSM height and choroidal thickness at three locations of the eye all exhibited intraclass correlation scores between the two graders of greater than 0.9.
Our study demonstrates high concordance between graders in characterising posterior segment lesions using SD-OCT images, validating the continued use of this imaging modality in the diagnosis of posterior eye disease.

Corticosteroids have been used for treatment of posterior segment eye diseases, but the delivery of drug to the posterior segments is still a problem to resolve. In our study, we explore the feasibility of Sub-tenon\'s Controllable Continuous Drug Delivery to ocular posterior segment. Controllable continuous sub-tenon drug delivery (CCSDD) system, intravenous injections (IV) and sub-conjunctival injections (SC) were used to deliver dexamethasone disodium phosphate (DEXP) in rabbits, the dexamethasone concentration was measured in the ocular posterior segment tissue by Shimadzu LC-MS 2010 system at different time points in 24 h after first dose injection. Levels of dexamethasone were significantly higher at 12, 24 h in CCSDD than two other approaches, and at 3, 6 h in CCSDD than IV in vitreous body (p < 0.01); at 6, 12, 24 h in CCSDD than two other approaches, and at 1, 3 h in CCSDD than IV in retinal/choroidal compound (p < 0.01); at 3, 6, 12, 24 h in CCSDD than two other approaches, and at 1 h in CCSDD than IV in sclera (p < 0.05). The AUC0-24 in CCSDD group is higher than two other groups in all ocular posterior segment tissue. Our results demonstrated that dexamethasone concentration could be sustained moderately higher in the posterior segment by CCSDD than SC and IV, indicating that CCSDD might be a therapeutic alternative to treat a variety of intractable posterior segment diseases.