Distinguishing swept-source optical coherence tomography findings in active toxoplasmic retinochoroiditis

Swept-source Optical Coherence Tomography Angiography in Active and Scarred Toxoplasmic Retinochoroiditis

PURPOSE

To describe optical coherence tomography angiography (OCTA) findings in eyes with active and scarred toxoplasmic retinochoroiditis.

METHODS

OCTA scans in active (25 eyes) and scarred (17 eyes) retinochoroiditis were retrospectively reviewed.

RESULTS

In active lesions, OCTA findings included a non-detectable flow signal area in retinal vascular plexuses and choriocapillaris in all 25 eyes (100%), an abnormal intraretinal vascular process in 2 eyes (8%), and an associated area of retinal flow deficit secondary to branch retinal artery occlusion in one eye (4%). In scarred lesions, OCTA findings included a flow deficit area in retinal vascular plexuses and choriocapillaris in all 17 eyes (100%), a visibility of larger deeper choroidal vessels at the level of choriocapillaris in 9 eyes (53%), and a well-defined intraretinal vascular network in one eye (5.9%). Peripapillary scars were associated on OCTA with wedge-shaped loss of radial peripapillary capillaries with corresponding localized retinal nerve fiber layer defect and visual field loss.

CONCLUSION

OCTA allows to non-invasively detect retinal and choroidal vascular changes in active and scarred toxoplasmic retinochoroiditis.

Case report: A rare appearance of preretinal deposits in a patient with uveitis: multimodal imaging observation

Background

Uveitis is a disease presenting with varied clinical symptoms and potentially devastates visual function. Here, we report a patient with uveitis exhibiting a rare appearance of preretinal deposits (PDs).

Case presentation

A 49-year-old female showed vitreous opacity and perivascular white PDs involving veins and arteries. The interferon-gamma release assay was strongly positive and chest computed tomography showed signs of calcified nodules; other tests were unremarkable. The patient was diagnosed with uveitis and tubercular infection. The patient was given systemic anti-tubercular therapy and steroids, which were subsequently combined with immunosuppressants. The shrinkage of HRD was more sensitively observed with OCT than on photographs during follow-up visits. The right eye was relieved subsequently, but the left eye showed vitreous opacity and responded poorly to the treatment. Three months after the dexamethasone intravitreal implant, the perivascular deposits in the left eye disappeared and the vitreous opacity was relieved.

Conclusion

PDs can appear as spotted deposits in the posterior pole and segmental deposits in the periphery in patients with uveitis, which mainly involves the vitreous cavity and is easily confused with retinal vasculitis. OCT can more sensitively observe the response than other examinations.

Clinical Features and Possible Origin of Preretinal Deposits in Different Ocular Diseases and Events: A Narrative Review

Preretinal deposits (PDs) are a rare condition among fundus diseases. We found that preretinal deposits have some features in common that can provide clinical information. This review affords an overview of PDs in different but related ocular diseases and events, and summarizes the clinical features and possible origin of PDs in related conditions, providing diagnostic clues for ophthalmologists when facing PDs. A literature search was performed using three major electronic databases (PubMed, EMBASE, and Google Scholar) to identify potentially relevant articles published on or before June 4, 2022. Most of the cases in the enrolled articles had optical coherence tomography (OCT) images to confirm the preretinal location of the deposits. Thirty-two publications reported PD-related conditions, including ocular toxoplasmosis (OT), syphilitic uveitis, vitreoretinal lymphoma, human T-cell lymphotropic virus type 1 (HTLV-I) associated uveitis or HTLV-I carriers, acute retinal necrosis, endogenous fungal endophthalmitis, idiopathic uveitis, and exogenous materials. Based on our review, OT is the most frequent infectious disease to exhibit PDs, and silicone oil tamponade is the most common exogenous cause of preretinal deposits. PDs in inflammatory diseases are highly suggestive of active infectious disease and are preferentially accompanied by a retinitis area. However, PDs will largely resolve after etiological treatment in either inflammatory or exogenous conditions.

Stepwise approach for fundus imaging in the diagnosis and management of posterior uveitis

An array of retinochoroid imaging modalities aid in comprehensive evaluation of the immunopathological changes in the retina and choroid, forming the core component for the diagnosis and management of inflammatory disorders such as uveitis. The recent technological breakthroughs have led to the development of imaging platforms that can evaluate the layers of retina and choroid and the structural and functional alteration in these tissues. Ophthalmologists heavily rely on imaging modalities such as dye-based angiographies (fluorescein angiography and indocyanine green angiography), optical coherence tomography, fundus autofluorescence, as well as dye-less angiography such as optical coherence tomography angiograph,y for establishing a precise diagnosis and understanding the pathophysiology of the diseases. Furthermore, these tools are now being deployed with a 'multimodal' approach for swift and accurate diagnosis. In this comprehensive review, we outline the imaging platforms used for evaluation of posterior uveitis and discuss the organized, algorithmic approach for the assessment of the disorders. Additionally, we provide an insight into disease-specific characteristic pathological changes and the established strategies to rule out disorders with overlapping features on imaging.

In vitro and in vivo anti−Toxoplasma activities of HDAC inhibitor Panobinostat on experimental acute ocular toxoplasmosis

Ocular toxoplasmosis (OT) is retinochoroiditis caused by Toxoplasma gondii infection, which poses a huge threat to vision. However, most traditional oral drugs for this disease have multiple side effects and have difficulty crossing the blood-retinal barrier, so the new alternative strategy is required to be developed urgently. Histone deacetylases (HDAC) inhibitors, initially applied to cancer, have attracted considerable attention as potential anti-Toxoplasma gondii drugs. Here, the efficacy of a novel HDAC inhibitor, Panobinostat (LBH589), against T. gondii has been investigated. In vitro, LBH589 inhibited the proliferation and activity of T. gondii in a dose-dependent manner with low toxicity to retinal pigment epithelial (RPE) cells. In vivo, optical coherence tomography (OCT) examination and histopathological studies showed that the inflammatory cell infiltration and the damage to retinal architecture were drastically reduced in C57BL/6 mice upon treatment with intravitreal injection of LBH589. Furthermore, we have found the mRNA expression levels of inflammatory cytokines were significantly decreased in LBH589–treated group. Collectively, our study demonstrates that LBH589 holds great promise as a preclinical candidate for control and cure of ocular toxoplasmosis.