Recovery of macular cone photoreceptors in Vogt-Koyanagi-Harada disease

Reduced contrast sensitivity function and outer retina thickness in convalescent Vogt-Koyanagi-Harada disease

BACKGROUND

To evaluate contrast sensitivity function (CSF) in convalescent Vogt-Koyanagi-Harada (VKH) disease and investigate the relationship between CSF and chorioretinal thickness in VKH patients with and without sunset glow fundus (SGF).

METHODS

This is a cross-sectional study. Seventy-six eyes of VKH patients and 56 eyes of normal controls were evaluated. Patients were divided into SGF and non-SGF groups. The best-corrected visual acuity (BCVA) of all the participants was ≤0.0 logMAR. Their CSF and macular chorioretinal thickness were measured with quantitative CSF (qCSF) and Optical Coherence Tomography (OCT) and compared using repeated measures analysis of variance at the group level. Relationships between CSF and macular chorioretinal thickness were evaluated using generalized estimating equations.

RESULTS

The CSF was significantly impaired in the SGF group compared to that in the control group (p = 0.001), especially at medium and high spatial frequencies. No significant CSF difference was found between the non-SGF group and control group, nor between the SGF and non-SGF groups. Compared to the controls, outer retinal thickness (ORT) in both VKH subgroups was significantly reduced (P < 0.001 or 0.005, respectively), although their outer nuclear layer thickness (ONLT) and choroidal thickness (CT) were not significantly different (both P = 1.000, P = 0.829 or 0.112, respectively). We found no significant correlation between CSF metrics and outer retinal thickness.

CONCLUSIONS

Despite good recovery of visual acuity, reduced CSF and outer retina thickness were found in convalescent VKH patients. CSF may be an important and sensitive metric to evaluate functional vision in VKH disease.

SS OCT and OCT-A Findings in Convalescent Inactive Vogt-Koyanagi-Harada Disease

PURPOSE

This study aimed to determine predictive factors for low final visual acuity in patients with inactive Vogt-Koyanagi-Harada (VKH) disease using Swept-source OCT and OCT-angiography (OCT-A).

METHODS

We conducted a prospective longitudinal study, including 21 patients (42 eyes), who were followed up for the first 24 months after disease onset. Patients were included at the acute phase and subsequently treated. Sequential qualitative and quantitative changes in OCT and OCT-A were assessed. Analytical statistical methods were employed to determine predictive factors for final visual acuity.

RESULTS

Structural alterations including focal parafoveal outer nuclear layer atrophy, ellipsoid zone disruption, interdigitation zone disruption, and irregular and thickened retinal pigment epithelium line were observed in 57.1% of eyes at month 3, with no significant improvement over time. The presence of flow voids at months 6, 12, and 24 was significantly associated with low final visual acuity. Serous retnal detachment at presentation emerged as an independent risk factor for structural changes detected by SS-OCT during the first 2 years of the disease. Optic disc edema was predictive factor for both structural SS-OCT and OCT-A changes.

CONCLUSION

This study underscores the importance of monitoring flow voids to predict final visual acuity and highlights the impact of serous retinal detachment at presentation on structural changes in patients with inactive VKH disease.

Bacillary Layer Detachment in Acute Vogt-Koyanagi-Harada Disease

Objectives

To evaluate the frequency and treatment response of eyes with bacillary layer detachment (BLD) in acute Vogt-Koyanagi-Harada (VKH) disease using spectral-domain optical coherence tomography (SD-OCT).

Materials and Methods

We retrospectively reviewed the medical records of 58 eyes of acute VKH patients with at least 6 months of follow-up between January 2009 and March 2021. SD-OCT, color fundus photographs, and fluorescein angiography images were analyzed in all patients.

Results

The study included 58 eyes of 29 patients. BLD was detected in 33 of the 58 eyes (56.9%) at baseline. Mean serous retinal detachment (SRD) height was 918.50±336.64 μm in the BLD group and 215.33±167.83 μm in the group without BLD (p<0.05). A positive correlation was found between SRD height and the presence of BLD (r=0.783, p<0.05). BLD was significantly more common in patients with a baseline SRD height greater than 500 μm (p<0.05). As subfoveal central choroidal thickness (CCT) could not be measured by enhanced depth imaging-OCT at baseline due to extreme choroidal thickness in all eyes, the earliest post-treatment CCT measurements were analyzed. At the completion of pulse steroid therapy, mean CCT was 425±82.87 μm in the BLD group and 385.58±82.87 μm in the group without BLD (p=0.04). The mean time to BLD resolution was 12.88±6.5 days (range: 2-26).

Conclusion

BLD is a common tomographic finding in eyes with acute VKH disease and can be differentiated from the associated SRD through careful SD-OCT analysis. Though it is mostly observed in patients with more serious disease, the presence of BLD has no negative effect on long-term visual function.

Bilateral Complete Loss and Partial Regeneration of Photoreceptor Layers in a Pediatric Vogt-Koyanagi-Harada (VKH) Case

Vogt-Koyanagi-Harada (VKH) disease is a multisystem autoimmune disease affecting melanocyte-containing tissues in the eyes, meninges, ear, and skin. As far as we are aware, this is a unique case report documenting the regeneration of the photoreceptor layer after bilateral complete loss of the photoreceptor layer in a child with VKH. We report a case of a 12-year-old male with no significant past medical history who presented during the chronic stage of incomplete VKH. He was found to have a complete loss of photoreceptor layer in both eyes during a work-up to confirm the aforementioned disease. Upon receiving his first pulse dose of 500 mg IV methylprednisolone as a treatment course, he developed severe steroid-induced hyperglycemia (random blood glucose of 17.6 mmol/L). Additionally, a brain MRI revealed pituitary gland changes compatible with diabetes insipidus, which is a combination that was mentioned once in the literature before. A review of the systems did not suggest any other systemic diseases. The patient's elevated blood sugar level was managed by a pediatrician, and it normalized. At his last visit, optical coherence tomography (OCT) showed hypertrophy/regeneration of the photoreceptor layer. This case report indicates that retinal photoreceptor layer regeneration can be sometimes observed with follow-up after the resolution of inflammation and uveitis.

Reflectance adaptive optics findings in a patient with Vogt-Koyanagi-Harada disease

Purpose

To describe the reflectance adaptive optics scanning laser ophthalmoscopy (AOSLO) findings in different stages of Vogt-Koyanagi-Harada (VKH) disease and correlate them to visual gain post treatment. Confocal (cAOSLO) and non-confocal split-detector AOSLO (sdAOSLO) were used to assess longitudinally the status of the photoreceptors in a patient with VKH managed on corticosteroid and immunomodulatory therapy.

Observation

A 32-year-old Japanese American female presented with a 2-week history of blurred vision in both eyes (OU) and worsening headache previously diagnosed as a case of VKH and treated with high dose oral prednisone. At the time of presentation, though vision was improving, and frank serous retinal detachments were absent, spectral domain optical coherence tomography (SD-OCT) showed presence of residual subretinal fluid with disruption of the photoreceptor inner segments and outer segments (IS/OS) involving OU. The photoreceptor mosaic at the foveal center appeared very sparse with large areas devoid of visible photoreceptors on cAOSLO, in agreement with the SD-OCT data. sdAOSLO imaging over the same location shows a higher number of contiguous photoreceptors. After imaging, the patient was started on mycophenolate mofetil as steroid-sparing long-term therapy. Three months later, visual acuity improved to 20/20 OU, and SD-OCT showed almost complete resolution of subretinal fluid with significant improvement of the IS/OS SD-OCT signal, OU. cAOSLO imaging revealed a contiguous photoreceptor mosaic without gaps and of normal appearance.

Conclusions and Importance

VKH patients may demonstrate transient photoreceptor abnormalities on SD-OCT and cAOSLO imaging. sdAOSLO imaging revealed intact photoreceptor segments in areas that appeared as voids on cAOSLO, which later showed structural recovery on SD-OCT and cAOSLO. Therefore, sdAOSLO may predict potential for improvement in patients wherein there appears to be photoreceptor loss in cAOSLO and/or SD-OCT.

Associations between functional and structural measurements in non-acute Vogt-Koyanagi-Harada disease

PURPOSE

To evaluate associations between functional and structural measurements in patients with non-acute VKHD.

METHODS

In this cross-sectional study, 16 non-acute VKHD patients (32 eyes; 14 female) were evaluated with multifocal electroretinogram (mfERG), standardized automated perimetry (SAP) and optical coherence tomography (OCT)examinations. All included patients had a minimum 12 months of follow-up from acute onset and were participants of an ongoing prospective study since acute phase with systematic clinical imaging evaluations and electroretinogram examinations within a predefined treatment. Age- and gender-matched controls were included. Main outcomes were functional and structural abnormalities and their correlation; secondary outcome was correlation of these findings with clinical characteristics, including fundus abnormalities.

RESULTS

SAP and mfERG parameters were significantly worse in patients than in controls. Fourteen eyes (43.7%) had disrupted ellipsoid zone (EZ); visual acuity (VA) was similar between eyes with intact or disrupted EZ. Eyes with intact and disrupted EZ differed significantly concerning N1 and P1 amplitudes and N1 peak time values on mfERG and mean sensitivity (MS), central sensitivity (CS), foveal threshold, visual field index, mean deviation (MD) and pattern standard deviation values on SAP. The area under the curve on receiver operating curves for P1 amplitude was 0.81 (cut-off value = 34.7 nV/deg² ) and for MD value was 0.84 (cut-off value = -5.2 dB). Central retinal thickness (CRT) significantly correlated with N1 and P1 amplitudes and P1 peak time values on mfERG (r = 0.354, r = 0.442 and r = -0.405, respectively) and MD, MS, CS and fovea threshold (log values) on SAP (r = 0.372, r = 0.406, r = 0.431 and r = 0.414, respectively). Statistically significant associations were found with the presence of peripapillary atrophy and recurrent anterior uveitis with a worse MD value (p = 0.004 and p < 0.001, respectively).

CONCLUSION

In non-acute VKHD, disrupted EZ and reduced CRT were correlated with impaired mfERG and SAP parameters, even in patients with good VA.

BACILLARY LAYER DETACHMENT IN ACUTE VOGT-KOYANAGI-HARADA DISEASE: A Novel Swept-Source Optical Coherence Tomography Analysis

PURPOSE

To report the frequency, optical coherence tomography (OCT) findings, and visual and anatomic outcomes of patients with acute Vogt-Koyanagi-Harada disease presenting with the bacillary layer detachment (BLD) (intraretinal split at the photoreceptor inner segment myoid).

METHODS

This was a retrospective analysis of a consecutive series of patients with Vogt-Koyanagi-Harada disease having a minimum follow-up of 6 months. All patients had swept-source OCT, fluorescein angiography, and indocyanine green angiography performed at baseline. The characteristics of serial swept-source OCT were recorded and analyzed.

RESULTS

Sixty-two subjects (42 women; age: 34.2 ± 12 years) with Vogt-Koyanagi-Harada disease were included. 118 eyes (95.2%) had serous retinal detachment at presentation. 112 eyes (94.9%) showed the BLD at baseline. In 8 of 112 (7.1%) eyes with the BLD, the external limiting membrane at the anterior aspect of the BLD showed focal discontinuity. The interdigitation zone at the base of the BLD showed discontinuity in 53 of 112 (47.3%) eyes with the BLD. The ellipsoid zone could not be identified as a separate hyperreflective line at the base of the BLD in 102 of 112 eyes (91.1%). Bacillary layer detachments resolved within 3.4 ± 1.3 days after intravenous methylprednisolone therapy with improvement in the best-corrected visual acuity from 0.96 to 0.4 logarithm of the minimum angle of resolution (20/184 Snellen's equivalent) (P < 0.001). Resolution of serous retinal detachment was observed after 5.9 ± 2.6 days.

CONCLUSION

In eyes with acute Vogt-Koyanagi-Harada disease, the BLD is a common finding and represents a split in the photoreceptor layer at the inner segment myoid and can be differentiated from serous retinal detachment using swept-source OCT. In addition, resolution of the BLD and photoreceptor recovery can be evaluated using serial swept-source OCT.

Adaptive optics: principles and applications in ophthalmology

This is a comprehensive review of the principles and applications of adaptive optics (AO) in ophthalmology. It has been combined with flood illumination ophthalmoscopy, scanning laser ophthalmoscopy, as well as optical coherence tomography to image photoreceptors, retinal pigment epithelium (RPE), retinal ganglion cells, lamina cribrosa and the retinal vasculature. In this review, we highlight the clinical studies that have utilised AO to understand disease mechanisms. However, there are some limitations to using AO in a clinical setting including the cost of running an AO imaging service, the time needed to scan patients, the lack of normative databases and the very small size of area imaged. However, it is undoubtedly an exceptional research tool that enables visualisation of the retina at a cellular level.