Mapping Retinal and Choroidal Thickness in Unilateral Nongranulomatous Acute Anterior Uveitis Using Three-Dimensional 1060-nm Optical Coherence Tomography

Changes in peripapillary retinal nerve fibre layer and ocular parameters in acute anterior uveitis

CLINICAL RELEVANCE

Acute anterior uveitis (AAU) can lead to the thickening of the peripapillary retinal nerve fibre layer (pRNFL) and induce refractive changes during its active phase.

BACKGROUND

AAU is a common form of uveitis characterised by inflammation in the anterior chamber. A notable prevalence of optical coherence tomography - defined pRNFL thickening was observed among patients with AAU. The alterations in pRNFL thickness and their associations with other relevant ocular parameters in patients with AAU were investigated.

METHODS

A retrospective, consecutive case series was conducted at a specialised uveitis referral clinic in Taiwan. This study gathered data on various demographic characteristics and various ocular parameters, namely anterior chamber cell grading, refractive error, best-corrected visual acuity, intraocular pressure, and optical coherence tomography measurements. A comparative analysis of baseline and subsequent follow-up data was conducted. Additionally, this study examined the correlations between alterations in pRNFL thickness and various ocular parameters. Twenty-one patients with AAU (21 affected eyes/21 unaffected eyes) were examined.

RESULTS

Initial measurements revealed pRNFL thickening in 20 patients. Treatment led to significant improvements in best-corrected visual acuity, intraocular pressure recovery, and pRNFL thickening (p < 0.01). The correlation between changes in pRNFL thickness and best-corrected visual acuity was weak (r = 0.20, p = 0.41). By contrast, a significant negative correlation was identified between changes in pRNFL thickness and refractive error alterations (r =  -0.71, p = 0.01).

CONCLUSION

This study demonstrated that AAU is associated with pRNFL thickening, which in turn is inversely correlated with changes in refractive error alterations throughout the disease course. Monitoring changes in pRNFL thickness can be effective in assessing ocular inflammation status.

Analysis of Peripapillary Retinal Nerve Fiber Layer Thickness in Acute Anterior Uveitis among Children with HLA-B27-Positive Juvenile Idiopathic Arthritis

PURPOSE

The aim of this study was to evaluate changes in the thickness of the peripapillary retinal nerve fiber layer (pRNFL) in children with a diagnosis of juvenile idiopathic arthritis (JIA) who were positive for human leukocyte antigen (HLA)-B27, treated for the first episode of unilateral acute anterior uveitis (AAU).

MATERIALS AND METHODS

This retrospective study included 41 children (aged 5 to 14 years; mean age 8.32 ± 2.4 years) with HLA-B27 positivity and unilateral JIA-AAU, and 40 healthy children. Optical coherence tomography (OCT) imaging was performed during active inflammation and subsequent noninflammatory phases (6 months after the resolution of inflammatory symptoms in the anterior segment of the eye).

RESULTS

There was a marked difference in mean pRNFL thickness between eyes with AU in the active phase, unaffected fellow eyes and the control group (110.22 ± 5.95 μm, 102.39 ± 4.39 μm and 95.83 ± 8.84 μm, respectively; p < 0.001). The thickness of pRNFL in eyes with AU in the active phase in all sectors was greater compared to unaffected fellow eyes (p < 0.001) and normal eyes (p < 0.001). In addition, it was demonstrated that pRNFL thickness was significantly increased in the superior and temporal sectors in the unaffected fellow eyes compared to the control group (128.73 ± 13.16 μm vs. 121.48 ± 13.35 μm and 71.37 ± 4.02 μm vs. 64.98 ± 9.12 μm, respectively). Even during the inactive phase, eyes with AU, compared to the healthy control group, had significantly greater pRNFL thickness in the inferior sector (129.78 ± 11.98 μm vs. 122.3 ± 14.59 μm; p = 0.018), along with the temporal sector (70.88 ± 5.48 μm vs. 64.98 ± 9.12 μm; p = 0.001).

CONCLUSIONS

An increase in pRNFL thickness in children with unilateral JIA-AAU who were positive for HLA-B27 antigen can be observed in both eyes compared to healthy controls, and this change may persist even after the inflammatory symptoms have resolved. Measurements of pRNFL thickness resulting from JIA-AU-associated glaucoma should be performed during quiescent periods to avoid subclinical changes in pRNFL thickness caused by inflammation. However, when reviewing the results, it should be noted that changes in pRNFL parameters may be present despite evidence of a resolution of inflammation.

Retinal optical coherence tomography angiography findings of acute anterior uveitis

PURPOSE

To evaluate the changes in retinal microvasculature in eyes with anterior uveitis (AU) using optical coherence tomography angiography.

METHODS

Foveal avascular zone (FAZ) of superficial capillary plexus (SCP) and deep capillary plexus (DCP), vessel density (VD) of SCP, DCP, and choriocapillaris, and central macular thickness (CMT) and central foveal thickness (CFT) were calculated from 34 healthy and 41 uveitic eyes. The parameters were compared between the two groups.

RESULTS

The deep FAZ was significantly smaller in the eyes with AU during the attack than after recovery and the control group (p = 0.001 and p = 0.003, respectively). The VD in deep capillary plexus (DCP) in eyes with AU during the attack was significantly higher than the control group (p = 0.048). The VD in the foveal sector of DCP in eyes with AU during the attack and after recovery was significantly higher than the control group (p = 0.001 and p = 0.031, respectively). There was no significant difference regarding CMT, CFT, VDs of each segment and each sector, and superficial and deep FAZ between eyes with first uveitis attack and those with recurrent uveitis during the attack and after recovery (p > 0.05).

CONCLUSION

The results of this study show that there is a reduction in the FAZ and an increase in the VD of the DCP of the retina during active AU, and these findings are reversible. Acute AU may affect the macular microvasculature, which is usually temporary, especially in the DCP.

Unilateral acute anterior uveitis with macular edema following the use of sildenafil citrate in a patient with HLA-B27 positivity

Purpose

To present a case of acute anterior uveitis with macular edema associated with sildenafil citrate use in an HLA-B27 positive patient.

Observations

A 54-year-old Caucasian male presented at an ophthalmology tertiary center with complaint of pinkish discoloration, irritation, and photophobia in the left eye (OS). He noted that these symptoms appeared one day after using sildenafil for the first time to treat his erectile dysfunction. The patient had no significant ocular history besides refractive surgery in both eyes (OU) and his medical history was insignificant. Best-corrected visual acuity (BCVA) was 20/20 in the right eye (OD) and 20/25 in OS. Slit-lamp-examination (SLE) demonstrated trace cells and 1+ flare in the anterior chamber (AC) in OS and was nonrevealing in AC in OD. Spectral domain optical coherence tomography (SD-OCT) showed parafoveal subretinal hyperreflective deposits in OU. The patient was diagnosed with acute anterior uveitis (AAU) in the left eye and was placed on topical prednisolone acetate.At 2-week follow-up, the patient reported that his eye symptoms had improved since starting topical steroids but worsened again two days after he had used sildenafil for a second time. In OS, best-corrected visual acuity (BCVA) worsened to 20/40, and SLE revealed 1+ cells and 1+ flare in AC. SD-OCT revealed cystoid macular edema only in OS. Fluorescein angiography showed mild staining around the optic disc and significant macular leakage in OS and minimal macular leakage in OD. Uveitis evaluations revealed that the patient was human leukocyte antigen-27 (HLA-B27) positive. The patient was asked to remain off sildenafil and continue topical prednisolone acetate. At 3-month follow-up, BCVA improved to 20/20 in OS with no evidence of active inflammation.

Conclusions and importance

Sildenafil citrate use might be associated with new onset of intraocular inflammation in predisposed patients. Further studies are necessary to establish this relationship.

The effect of phacoemulsification performed with vitrectomy on choroidal vascularity index in eyes with vitreomacular diseases

This study evaluated the effects of cataract surgery combined with pars plana vitrectomy (ppV) on choroidal vascularity index (CVI) in eyes with epiretinal membrane (ERM) and full thickness macular hole (FTMH). Medical records of 132 eyes with ERM or FTMH were retrospectively reviewed and classified into a ppV group and a ppV combined with cataract surgery group (phaco + ppV group). The CVI were measured at baseline, 1, 3 and 6 months after the surgery, using the selected swept-source (SS) optical coherence tomography (OCT) scan passing through the central fovea, which was then segmented into luminal and stromal area by image binarization. The mean CVI of phaco + ppV group were 61.25 ± 1.97%, 61.66 ± 1.81%, and 62.30 ± 1.92% at baseline, 1 and 3 months, respectively (p < 0.001). The mean CVI of ppV group were 62.69 ± 1.92%, 62.03 ± 1.51%, and 61.45 ± 1.71% at baseline, 1 and 3 months, respectively (p < 0.001). The final CVI were measured at 6 months and compared with the baseline CVI. The mean CVI of phaco + ppV group were 61.21 ± 1.99% at baseline and 60.68 ± 2.02% at 6 months (p < 0.001). The mean CVI of ppV group were 62.93 ± 1.70% at baseline and 61.77 ± 1.74% at 6 months (p < 0.001). Vitrectomy significantly decreases CVI in vitreomacular diseases possibly due to the removal of vitreomacular traction or postoperative oxygenation change in the eye. On the contrary, combined surgery of vitrectomy and cataract surgery significantly increases CVI in the early stage of postoperative period, which suggests choroidal vascular dilatation or congestion due to postoperative inflammation. Although the CVI were measured lower than the baseline in the end, more thorough inflammation control may be essential after combined surgery.

Choriocapillaris: Fundamentals and advancements

The choriocapillaris is the innermost structure of the choroid that directly nourishes the retinal pigment epithelium and photoreceptors. This article provides an overview of its hemovasculogenesis development to achieve its final architecture as a lobular vasculature, and also summarizes the current histological and molecular knowledge about choriocapillaris and its dysfunction. After describing the existing state-of-the-art tools to image the choriocapillaris, we report the findings in the choriocapillaris encountered in the most frequent retinochoroidal diseases including vascular diseases, inflammatory diseases, myopia, pachychoroid disease spectrum disorders, and glaucoma. The final section focuses on the development of imaging technology to optimize visualization of the choriocapillaris as well as current treatments of retinochoroidal disorders that specifically target the choriocapillaris. We conclude the article with pertinent unanswered questions and future directions in research for the choriocapillaris.

Retinal and Choroidal Thickness in relation to C-Reactive Protein on Swept-Source Optical Coherence Tomography

Purpose

To evaluate the relationships between C-reactive protein (CRP) and retinal and choroidal thickness by swept-source optical coherence tomography (SS-OCT).

Methods

The participants included in the prospective cross-sectional study underwent a comprehensive ophthalmic examination. Based on the CRP values, the subjects were divided into the CRP (+) group (CRP ≥ 8.2 mg/L) and the CRP (−) group (CRP < 8.2 mg/L). The retinal and choroidal thickness was compared between the two groups.

Results

This study enrolled 43 right eyes of 43 subjects from the CRP (+) group and 86 right eyes of 86 gender- and age-match subjects from the CRP (−) group. The choroidal thickness in the CRP (+) group was thinner than that in the CRP (−) group except for the outer nasal sector of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. However, the retinal thickness only in the inner temporal sector showed a significant difference. According to Pearson's correlation analysis, the CRP was significantly negatively correlated with the choroidal thickness in all sectors and the retinal thickness only in the inner temporal and outer nasal sectors of the ETDRS grid.

Conclusion

CRP levels are associated with retinal and choroidal thickness. The data related to the retinal and choroidal thickness changes may help understand the pathogenesis of specific ocular abnormalities in patients with systemic inflammation.

Imaging the Choroid: From Indocyanine Green Angiography to Optical Coherence Tomography Angiography

The choroid is the vascular structure nourishing the retinal pigment epithelium and the outer retina and it plays a key role in the homeostasis of the eye both under physiological and pathological conditions. In the last 20 years we have moved from "guessing" what was happening beyond the retinal pigment epithelium to actually visualize structural and functional changes of the choroid in vivo noninvasively. In this review we describe the state of the art of choroidal imaging, focusing on the multiple techniques available in the clinical and research setting including indocyanine green angiography, labeled-cells angiographies, optical coherence tomography (OCT), enhanced depth imaging, swept source OCT, and OCT angiography. In the first section of the article, we describe their main applications and the basic principles to interpret the imaging results. Increasing evidence suggests that the choroid is much more involved than we used to think in many pathological conditions from uveitis to intraocular tumors, from vascular diseases to age-related macular degeneration. All clinicians should hence know which is the most appropriate imaging investigation to explore the choroid in the disease they are dealing with and how to interpret the results. For this reason the second section of this review summarizes the best imaging approach and the most common findings visible on choroidal imaging in different diseases of the eye.

Spatial and spatio-temporal statistical analyses of retinal images: a review of methods and applications

Background

Clinical research and management of retinal diseases greatly depend on the interpretation of retinal images and often longitudinally collected images. Retinal images provide context for spatial data, namely the location of specific pathologies within the retina. Longitudinally collected images can show how clinical events at one point can affect the retina over time. In this review, we aimed to assess statistical approaches to spatial and spatio-temporal data in retinal images. We also review the spatio-temporal modelling approaches used in other medical image types.

Methods

We conducted a comprehensive literature review of both spatial or spatio-temporal approaches and non-spatial approaches to the statistical analysis of retinal images. The key methodological and clinical characteristics of published papers were extracted. We also investigated whether clinical variables and spatial correlation were accounted for in the analysis.

Results

Thirty-four papers that included retinal imaging data were identified for full-text information extraction. Only 11 (32.4%) papers used spatial or spatio-temporal statistical methods to analyse images, others (23 papers, 67.6%) used non-spatial methods. Twenty-eight (82.4%) papers reported images collected cross-sectionally, while 6 (17.6%) papers reported analyses on images collected longitudinally. In imaging areas outside of ophthalmology, 19 papers were identified with spatio-temporal analysis, and multiple statistical methods were recorded.

Conclusions

In future statistical analyses of retinal images, it will be beneficial to clearly define and report the spatial distributions studied, report the spatial correlations, combine imaging data with clinical variables into analysis if available, and clearly state the software or packages used.

Characteristics of retinal layer thickness in acute anterior uveitis: an optical coherence tomography study

PURPOSE

To determine the changes in peripapillary retinal nerve fiber layer (pRNFL), macular and ganglion cell-inner plexiform layer (GC-IPL) thicknesses in patients with acute anterior uveitis (AAU).

METHODS

Patients diagnosed with unilateral non-infectious AAU and normal control were enrolled retrospectively. Optical coherence tomography scans were performed during the initial active phase and inactive phase of AAU. Patients were followed for at least 3 months after resolution of inflammatory activity.

RESULTS

Thirty-seven AAU patients and 40 controls were included. The average RNFL and central macular thickness (CMT) showed significant differences between patients and control groups during active phase (p < 0.001 and p = 0.022, respectively). The average pRNFL thicknesses of affected eyes and fellow eyes during the active phase were 109.4 ± 12.5 μm and 96.5 ± 8.0 μm, respectively (p < 0.001). During the inactive phase, the average thicknesses were 99.3 ± 8.9 μm and 97.0 ± 7.5, respectively; they were not significantly different (p = 0.236). The CMTs of affected and fellow eyes during the active phase were 261.6 ± 24.7 μm and 251.5 ± 17.3 μm, respectively; the difference was significant (p = 0.047). The average GC-IPL thicknesses of affected and fellow eyes were not significantly different (p = 0.061).

CONCLUSIONS

The pRNFL and central macula thickened during the active phase of AAU and decreased to a similar degree with fellow eyes during the inactive phase. Additionally, pRNFL thickness showed a sensitive response to the degree of inflammation in AAU. This suggests that pRNFL thickness may be useful in assessing disease activity.

Role of choroidal thickness assessment in unilateral acute anterior uveitis

Purpose:

The aim of our study was to investigate the change in the subfoveal choroidal thickness in unilateral acute anterior uveitis with treatment. Choroidal inflammation is uncommon but can occur in the acute stage of anterior uveitis.

Methods:

All diagnosed patients with the first episode of unilateral acute anterior uveitis were included in the study conducted for a period of July 2017–July 2018. Choroidal thickness at subfoveal region was measured with spectralis spectral domain optical coherence tomography using enhanced depth-imaging scans. Standardized, masked manual measurement of the choroidal thickness was performed in the center of the ETDRS fields. The unaffected fellow eye of the same patient was taken as a control group and their subfoveal choroidal thickness was measured. Follow up of the patients was done at 2 weeks posttreatment to reevaluate the choroidal thickness.

Results:

A total of 61 eyes of 61 patients with unilateral acute anterior uveitis were included in the study. The mean central subfoveal choroidal thickness was significantly higher (304.82 ± 73.17 μm) as compared to that of controls (251.28 ± 66.38 μm) at presentation (P < 0.001). Following treatment and at two weeks follow up, the subfoveal choroidal thickness significantly reduced from 304.82 ± 73.17 to 274.46 ± 63.82 μm (P < 0.001). Also the subfoveal choroidal thickness was positively correlated with visual acuity (r = 0.22, P < 0.251) before treatment.

Conclusion:

Acute anterior uveitis is associated with an increase in the subfoveal choroidal thickness followed by the significant decrease in choroidal thickness with treatment, suggesting that choroid is also inflamed along with anterior segment inflammation.

Evaluation of choroidal parameters in eyes at the first onset of acute anterior uveitis

BACKGROUND

Little is known about choroidal involvement in anterior uveitis. The aim of our study was to evaluate changes in choroidal thickness and volume in eyes with acute anterior uveitis (AAU) using enhanced depth imaging-optical coherence tomography (EDI-OCT) at baseline and after treatment, which were compared with healthy fellow eyes.

METHODS

For the study, 35 individuals with unilateral acute AAU at the first onset were enrolled. Subfoveal thickness and choroidal volume were measured with EDI-OCT in nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields before and after the completion of treatment. Moreover, axial length measurements of both eye bulbs were determined by optical biometry.

RESULTS

No statistically significant differences in choroidal thickness or choroidal volume were detected between AAU eyes at baseline and after treatment and fellow eyes. Positive correlations between the values of anterior chamber flare and absolute CT changes in both temporal and inferior ETDRS fields, as well as in superior outer ring were detected. Negative correlations between age and both choroidal thickness and choroidal volume were detected in AAU eyes at baseline and after treatment, as well as in fellow eyes.

CONCLUSIONS

Evaluation of the choroid with EDI-OCT does not appear to be a reliable tool for the treatment monitoring of eyes with anterior uveitis.

Choroidal Vascularity Index and Choroidal Thickness in Human Leukocyte Antigen-B27-Associated Uveitis

Purpose: To assess choroidal thicknesses and choroidal vascularity index (CVI) in HLA-B27-associated uveitis.Methods: Medical records of 45 treatment-naive unilateral HLA-B27-associated uveitis patients presenting with first episode and with onset time of < 1-week were reviewed.Results: Mean choroidal thickness was 275.98 ± 71.62 in acute phase and 254.93 ± 73.48 after resolution (p = .003). Mean CVI was 34.75 ± 3.08 in acute phase and 33.56 ± 2.48 after resolution (p < .001). Interestingly, even in fellow eyes, there were relative retinal and choroidal thickening and relative choroidal vascular engorgement in acute phase, but these differences were not significant. Degree of anterior chamber inflammation was correlated with relative choroidal vascular engorgement (p = .001) and choroidal thickening (p = .044).Conclusion: Eyes with acute HLA-B27-associated uveitis exhibited choroidal thickening with increased choroidal vascularity that subsequently decreased after uveitis resolution. These were evident even in patients without posterior segment involvement.