Felipe T. da Silva

Enhanced depth imaging optical coherence tomography in long-standing Vogt–Koyanagi–Harada disease

Aim To evaluate the choroidal thickness (CT) in patients with long-standing Vogt–Koyanagi–Harada (VKH) disease using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods A prospective case–control study developed at a tertiary centre at São Paulo, Brazil. EDI-OCT images were obtained in 16 patients (30 eyes) with VKH disease who had had the disease for more than 6 months since disease onset, and in 17 normal individuals controlled by age (32 eyes). Comprehensive ophthalmic examination and EDI-OCT evaluation were performed. CT was measured at the fovea and at 1000 µm intervals from the foveal centre in both temporal and nasal directions. CT was correlated with disease duration, clinical disease activity and fundus-based disease severity. Results Mean subfoveal CT was 333 µm (±85.8) in controls and 250.7 µm (±93.3) in VKH patients (p=0.002). The choroid was significantly thinner in patients when compared to controls in all but one nasal point. In patients, the CT measurements at the foveal centre presented a negative correlation with disease duration (p<0.001). No significant difference in CT measurements was observed between eyes with and without clinical inflammation (p=0.42). There was a trend towards more severe fundus changes being associated with a thinner choroid (p=0.28). Conclusions Patients with VKH and long-standing disease had thinner choroids when compared to controls. Progressive choroidal thinning related to disease duration was observed at the macula of these patients. Whether this finding is part of the natural history of the disease or the result of a clinically undetected choroidal inflammation remains to be determined.

Fundus-Based and Electroretinographic Strategies for Stratification of Late-Stage Vogt-Koyanagi-Harada Disease Patients

PURPOSE To propose an analytic framework for ocular fundus alterations in late-stage Vogt-Koyanagi-Harada (VKH) disease, to describe the characteristics of overall retinal function as measured with full-field electroretinography (ERG), and to correlate the intensity of the fundus changes with full-field ERG alterations and to stratify patients accordingly. DESIGN Cross-sectional case series. METHODS Forty-seven eyes of 26 patients with late-stage VKH disease (> 6 months past disease onset) followed-up at the University of São Paulo School of Medicine underwent fundus photography within 2 months of a full-field ERG examination, both according to predefined protocols. Fundus pictures were evaluated by two observers regarding diffuse fundus depigmentation, nummular lesions, pigment clumps, and subretinal fibrosis, and an overall analysis classified the fundus changes as mild, moderate, or severe. Full-field ERG results were analyzed according to fundus-based stratification and also were stratified into 3 groups solely on the basis of decreasing amplitudes (ERG based or cluster stratification). The concordance between fundus-based and full-field ERG-based stratification strategies was estimated. RESULTS Overall fundus grading showed substantial interobserver concordance (kappa = 0.78). Comparison of full-field ERG parameters of the three fundus-based stratified groups showed diffusely diminished amplitudes with preservation of implicit times (P < .05). Fundus-based and full-field ERG-based stratification strategies also showed substantial concordance (kappa = 0.68). CONCLUSIONS The analytic framework for fundus findings proposed in this study seems reproducible and useful, because the severity categories do correlate with retinal function as measured by full-field ERG. This system may allow more precise exchange of information between practitioners as well as researchers with regard to identifying patients with greater retinal compromise rapidly as well as in comparison of outcomes of different treatment regimens.

Vogt-Koyanagi-Harada disease: review of a rare autoimmune disease targeting antigens of melanocytes

Vogt-Koyanagi-Harada disease (VKHD) is a rare granulomatous inflammatory disease that affects pigmented structures, such as eye, inner ear, meninges, skin and hair. This disease is mainly a Th1 lymphocyte mediated aggression to melanocytes after a viral trigger in the presence of HLA-DRB1*0405 allele. The absence of ocular trauma or previous intraocular surgery sets VKHD appart from sympathetic ophthalmia, its main differential diagnosis. The disease has an acute onset of bilateral blurred vision with hyperemia preceded by flu-like symptoms. The acute uveitic stage is characterized by a diffuse choroiditis with serous retinal detachment and optic disc hyperemia and edema. Fluorescein angiography in this phase demonstrates multiple early hyperfluorescent points. After the acute uveitic stage, ocular and integumentary system pigmentary changes may appear. Ocular findings may be accompanied by lymphocytic meningitis, hearing impairment and/or tinnitus in a variable proportion of patients. Prompt diagnosis followed by early, aggressive and long-term treatment with high-dose corticosteroids is most often ensued by good visual outcomes. However, some patients may experience chronic uveal inflammation with functional eye deterioration. The current review discusses the general features of VKHD, including epidemiology, classification into categories, differential diagnosis and current therapeutic approaches.

Indocyanine green angiography findings in patients with long-standing Vogt-Koyanagi- Harada disease: a cross-sectional study

BackgroundTo investigate indocyanine green angiography (ICGA) findings in patients with long-standing Vogt-Koyanagi-Harada (VKH) disease and their correlation with disease activity on clinical examination as well as with systemic corticosteroid therapy.MethodsTwenty-eight patients (51 eyes) with long-standing (≥6 months from disease onset) VKH disease whose treatment was tapered based only in clinical features were prospectively included at a single center in Brazil. All patients underwent standardized clinical evaluation, which included fundus photography, fluorescein angiography and ICGA. Clinical disease activity was determined based in the Standardization in Uveitis Nomenclature Working Group. Fisher exact test and logistic regression models were used for statistical analysis.ResultsDisease-related choroidal inflammation on ICGA was observed in 72.5% (31 of 51 eyes). Angiographic findings suggestive of (choroidal and/or retinal) disease activity were not observed on FA. Clinically active disease based on clinical evaluation was observed in 41.2% (21 of 51 eyes). In these 21 eyes, disease-related choroidal inflammation on ICGA was observed in 76.2% (16 of 21 eyes); in the remaining eyes (without clinical active disease) disease-related choroidal inflammation on ICGA was observed in 70.0% (21 of 30 eyes). In respect to systemic corticosteroid therapy, 10 patients (18 of 51 eyes) were under treatment with prednisone. In these 10 (18 of 51 eyes) patients, disease-related choroidal inflammation on ICGA was observed in 83.3% (15 of 18 eyes); in the remaining patients (33 of 51 eyes) disease-related choroidal inflammation on ICGA was observed in 66.7% (22 of 33 eyes).ConclusionICGA findings suggestive of disease-related choroidal inflammation were observed in a considerable proportion of patients with long-standing VKH disease, independent of the inflammatory status of the disease on clinical examination or current use of systemic corticosteroid. Therefore, the current study reinforces the crucial role of ICGA to assist the management and treatment of patients with long-standing VKH disease.

Fundus autofluorescence as a marker of disease severity in Vogt-Koyanagi-Harada disease.

icant past medical history presented to KK Women’s and Children’s Hospital, Singapore, on 21 October 2015 complaining of fever and a ‘black dot’ in her left upper eyelid for 3 days. She just returned from Malaysia with close contact with dogs during the trip. On examination, there was left upper eyelid erythema, oedema and the presence of a dog tick at the eyelid margin (Fig. 1A). Anterior segment examination was unremarkable. A procedure was performed under informed consent with topical tetracaine anaesthesia. Thermal energy was applied using a portable monopolar cautery device to the tick’s body (Fig. 1B), facilitating en bloc removal by inducing detachment of the tick. Microscopic examination of the organism revealed that it belonged to the genus Ixodes (Fig. 1C). There were no complications, and the patient recovered uneventfully. Ocular manifestations of ticks include conjunctivitis, keratitis, uveitis as well as embedment of the organism in the meibomian gland orifice presenting as a mass, oedema and erythema at the eyelid margin. Early removal of tick from its host is crucial as the risk of disease transmission increases significantly after 24 hr of attachment. Therefore, an efficient method of tick removal is crucial to avoid vector transmission of infectious diseases and localized inflammation and infection. There had been several methods of tick removal described in the literature. However, none of these methods is superior in terms of safety and efficacy profile (Fig. 1D). Many chemicals have been studied for tick removal. Compounds such as deodorized kerosene resulted in voluntary detachment in approximately 25% of the ticks that were treated (Knight et al. 1962). However, the use of chemical compounds can pose potential danger of toxicity to the ocular tissues. Chemical eradication of the organism may also precipitate regurgitation by the tick and transmission of infectious agents to its host (Flicek 2007). The use of forceps for direct mechanical tick removal could result in retained mouthparts in ocular tissues as well as fragmentation of its body which would then require further excision, complicating the removal process (Flicek 2007). Blepharoplasty incision allowing for an en bloc excision of the organism has been described (Love et al. 2001). However, this procedure is more invasive with a risk of ocular tissue loss and disruption of the ocular architecture. Tick removal using portable monopolar diathermy is a novel technique to the best of our knowledge. It is simple to perform, requiring only a few sequential thermal burns to the tick body to induce its detachment. This avoids trauma to the surrounding ocular tissues and need for excision. However, this technique might be more suitable for less tenacious ticks with shallow bites. Monopolar cautery for tick removal may be a superior and relative safe novel technique for en bloc removal of tick with minimal trauma to the surrounding ocular tissues.