Effect of immunosuppressive therapy on oxygen saturation and diameter of retinal vessels in initial onset acute uveitis associated with Vogt-Koyanagi-Harada disease

Bibliometric analysis of the Vogt‒Koyanagi‒Harada disease literature

PURPOSE

As an autoimmune disease, Vogt‒Koyanagi‒Harada disease (VKHD) is a main type of uveitis in many countries and regions, significantly impacting patient vision. At present, information regarding VKHD is still limited, and further research is needed. We conducted a bibliometric analysis to characterize the overall status, current trends, and current focus of VKHD research.

METHOD

Literature published from 1975 to 2022 was obtained from the Web of Science core collection and analysed with the R-language packages Bibliometrix, VOSviewer, and CiteSpace software.

RESULTS

A total of 1050 papers on VKHD were retrieved from 261 journals, and 16,084 references were obtained from the papers in the original search. The average annual number of published articles was approximately 21.9, and the number of publications rapidly increased after 2004. The journal Ocular Immunology and Inflammation published the most papers on VKHD, while the American Journal of Ophthalmology has the highest citation frequency. The leading countries were Japan, China (PRC), and the United States of America (USA). Yang PZ from Chongqing Medical University was the most prolific and cited author. The most frequently cited study discussed revision of VKHD diagnostic criteria. An analysis of the highest frequency keywords showed that most research focused on the treatment, diagnosis, and pathogenesis of VKHD and its relationship with other related diseases. At present, the most urgent research direction is in the relationship between COVID-19 or COVID-19 vaccines and VKHD and the corresponding mechanisms underlying it.

CONCLUSION

Utilizing dynamic and visualization tools, bibliometrics provides a clear depiction of the research history, development trends, and research hotspots in VKHD It serves as a valuable tool for identifying research gaps and areas that necessitate further exploration. Our study revealed potential directions for future VKHD research, including investigating specific molecular mechanisms underlying the disease, exploring the clinical utility of optical coherence tomography angiography and other diagnostic techniques, and conducting clinical research on novel therapeutic drugs.

Acute uveitic phase of Vogt-Koyanagi-Harada disease: optic nerve head swelling, ocular blood flow and retinal oxygen metabolism

OBJECTIVES

To investigate the association of optic nerve head (ONH) swelling in the acute uveitic phase of Vogt-Koyanagi-Harada (VKH) disease with blood flow velocity in the choroid and ONH and oxygen saturation and diameter of retinal vessels.

METHODS

In this prospective study, 25 patients (50 eyes) were studied. Thirteen patients (26 eyes) had ONH swelling and 12 patients (24 eyes) had no ONH swelling. Laser speckle flowgraphy (LSFG) and retinal oximetry measurements were performed at presentation.

RESULTS

In the ONH, mean blur rate (MBR)-vessel, representing blood flow velocity in retinal vessels, was significantly lower in the eyes affected by ONH swelling, while choroidal MBR was not significantly different. Eyes with ONH swelling had a significantly lower oxygen saturation in retinal venules, a significantly higher arteriovenous oxygen saturation difference and a significantly smaller calibre of retinal arterioles compared with eyes without ONH swelling. There were significant positive correlations between the MBR-vessel of the ONH and venular oxygen saturation and calibre of retinal arterioles. In addition, MBR-vessel of the ONH had a significant negative correlation with arteriovenous oxygen saturation difference.

CONCLUSIONS

The occurrence of ONH swelling in the acute uveitic phase of VKH disease is associated with lower retinal blood flow velocity and smaller calibre of retinal arterioles as well as lower oxygen saturation in retinal venules and higher arteriovenous difference in oxygen saturation.

Non-Invasive Metabolic and Structural Retinal Markers in Patients with Giant Cell Arteritis and Polymyalgia Rheumatica: A Cross-Sectional Study

Giant cell arteritis (GCA) is a potential sight-threatening disease. Although it is associated with polymyalgia rheumatica (PMR), visual loss is not common in PMR. A retinal oximeter can be used to conduct a direct, non-invasive, in vivo assessment of the vascular system. In a cross-sectional study, we measured the retinal oxygen saturation and retinal vessel calibers in GCA patients, PMR patients, and control participants. Twenty GCA patients (38 eyes), 19 PMR patients (33 eyes), and 12 controls (20 eyes) were investigated. Images were analyzed using Oxymap Analyzer software 2.5.0 (Oxymap ehf., Reykjavik, Iceland). Groups were compared using an age- and sex-adjusted linear mixed model regression. The median (IQR) age for GCA patients was 69.0 (66.5–76.5) years, for PMR 69.0 (67.0–72.0) years, and for the controls 75.5 (71.5–81.0) years, respectively. As compared to the controls (115.3 µm), the retinal arterioles were significantly wider in patients with GCA (124.4 µm; p = 0.023) and PMR (124.8 µm; p = 0.049). No difference was found in the retinal venular caliber or vascular oxygen saturation. These results indicate that GCA and PMR patients differ similarly in the retinal arteriolar diameter compared to controls. Further studies are needed in order to clarify the underlying inflammatory mechanisms in retinal arteriolar vessels and if these parameters can be used to predict clinical outcomes.

Alterations in ocular microcirculation and oxygen metabolism in patients with lipemia retinalis

Purpose

The study aims to assess the alterations in retinal oxygen saturation and retinal and choroidal blood flow in lipemia retinalis.

Methods

This was a cross-sectional study on 10 eyes (5 patients) with history of lipemia retinalis. The study comprised 10 eyes with documented history of lipemia retinalis and 10 participants as healthy controls. Patients with a confirmed history of lipemia retinalis were grouped into two cohorts based on their most recent fundus examination: untreated lipemia retinalis (abnormal fundus) and resolved lipemia retinalis (normal fundus). Both retinal arteriolar and venular oxygen saturation were measured using the non-invasive spectrophotometric retinal oximeter (Oxymap T1). The mean blur rate (MBR) of the optic nerve and choroidal blood flow were analyzed using a laser speckle flowgraph (LSFG).

Results

Patients with untreated lipemia retinalis had a significantly higher retinal arteriolar and venular oxygen saturation than that of the other two groups (p < 0.001). Moreover, patients with untreated lipemia retinalis had significantly smaller retinal arteriolar and venular diameters (p < 0.001). On LSFG, there was a significant difference in the overall MBR (p = 0.007) and vessel MBR of the optic nerve between the groups (p = 0.011). The patients with history of lipemia retinalis (untreated and resolved) exhibited a high overall MBR and vessel MBR of the optic nerve than that of the control group. There was a significant elevation of the optic nerve (p = 0.002) and choroidal blowout score (p < 0.001), while the resistivity index of the optic nerve (p = 0.001) and choroids (p = 0.002) was significantly lower in patients with resolved and untreated lipemia retinalis.

Conclusions

There was a significant alteration in retinal oximetry, in untreated lipemia retinalis, and in retinal blood flow, in both the resolved and untreated groups. The increase in retinal blood flow and oxygen saturation may elucidate the preservation of visual acuity and function despite the fundus changes observed in lipemia retinalis.

Vogt-Koyanagi-Harada disease: the step-by-step approach to a better understanding of clinicopathology, immunopathology, diagnosis, and management: a brief review

BACKGROUND

Appraisals of Vogt-Koyanagi-Harada disease (VKH) have become progressively more complete, since its first description in 1906. The availability of new investigational methods has improved our knowledge of the immunopathology, clinicopathology, diagnosis, and management of VKH disease. This review aimed to describe some of the steps that led to better characterization of VKH as a clinical entity.

METHODS

We searched on PubMed for articles that described the history of VKH disease and analyzed the progress in disease appraisal with new investigational and imaging methods. In particular, we searched for articles that investigated the clinicopathology, diagnosis, and management of VKH.

FINDINGS

The following developments were considered essential for improving the appraisal and understanding of VKH: (1) the history of the disease, (2) immunopathological mechanisms, (3) clinicopathology, (4) the importance of distinguishing initial-onset from chronic disease, (5) relevant imaging modalities, among which indocyanine green angiography is crucial, (6) diagnostic criteria that facilitate early diagnosis, and (7) the need for early, prolonged, aggressive treatment that combines steroidal and non-steroidal immunosuppression.

CONCLUSION

Based on these findings, the definition of VKH has improved. VKH disease starts in the choroidal stroma and later involves other structures when it is not diagnosed and treated early. Indocyanine green angiography and enhanced depth imaging optical coherence tomography facilitate early diagnosis and precise monitoring of choroidal inflammation. ICGA is clearly the gold standard for appraisals and follow-ups in VKH disease, however EDI-OCT should be especially considered in those areas where ICGA is not fully available. These modalities have contributed substantially to a "cure" for VKH, when treatment is introduced within the therapeutic window of opportunity.

Clinical implications of retinal oximetry in retinal vein occlusion: a review

PURPOSE

To review retinal vein occlusion (RVO) and its relationship with retinal oxygen saturation via automated retinal oximetry in eyes with RVO.

METHODS

A literature review was performed in PubMed and Medline until October 2021 utilizing specific keywords and cross-matched reference lists.

RESULTS

This review found RVO to be associated with risk factors including age, hypertension, cardiovascular and metabolic conditions, male gender, and glaucoma. These may be attributed to a breakdown of regulatory processes in the retina. Retinal venous oxygen saturation (SvO₂ ) and arteriovenous difference in eyes with central RVO have been found to be reduced and elevated, respectively. The literature indicates variable and contradictory findings in regard to branch RVO and retinal oxygenation. Additionally, ischaemic eyes have been found to have elevated retinal arterial oxygen saturation; however, the literature reports variable results regarding SvO₂ levels. Medications have been suggested to increase SvO₂ in RVO eyes, which may represent an important mechanism for disease management. Ranibizumab is currently the most studied drug for retinal oxygenation in RVO and has been suggested to increase SvO₂ in RVO eyes. In comparison, dexamethasone was found to decrease SvO₂ .

CONCLUSION

The current literature on retinal oxygenation in ischaemic subtypes of RVO and in drug therapies is minimal, and further work is required to expand upon our understanding of how ischaemia and drugs influence retinal oxygenation and clinical outcomes.

Vogt-Koyanagi-Harada disease

PURPOSE OF REVIEW

Here, we provide an overview of Vogt-Koyanagi-Harada disease (VKH), including recent updates in our understanding of disease pathophysiology, classification and therapeutics.

RECENT FINDINGS

Advancements in bioinformatics, metabolomics and genomics investigations continue to illuminate VKH pathogenesis, and may provide insight into future therapeutic options. Multimodal imaging is indispensable in the initial evaluation of VKH, and is becoming increasingly important in understanding disease pathogenesis, as well as monitoring therapeutic response. Enhanced VKH classification criteria, released in 2021, provide standardized guidelines and terminology for clinical and research purposes.

SUMMARY

Modern research and imaging techniques continue to improve our understanding of VKH; more work is needed to further elucidate pathogenic mechanisms and establish optimal therapeutic recommendations.