Ultra-wide-field fundus imaging of acute retinal necrosis: clinical characteristics and visual significance

Diagnostic and therapeutic challenges in acute retinal necrosis; an update

Acute retinal necrosis (ARN) is a rare but severe ophthalmic pathology defined by panuveitis, retinal necrosis, and high rates of retinal detachment. ARN may lead to poor visual outcomes even if promptly diagnosed and treated. ARN may present with a wide spectrum of clinical findings compatible with panuveitis including anterior uveitis, scleritis, vitritis, necrotizing retinitis, occlusive vasculitis, and optic disc edema. The American Uveitis Society introduced clinical criteria in 1994 for the diagnosis of ARN, while more recent criteria have been proposed by the Standardization of Uveitis Nomenclature (SUN) Working Group and the Japanese ARN Study Group. Multimodal imaging is a valuable tool in evaluating patients with ARN, particularly in unusual cases, while utilizing retinal imaging and applying AI algorithms in these areas of clinical research could be highly beneficial. Over the last few years, significant progress has been made in achieving timely diagnosis and treatment. The precise identification of the viral cause in suspected ARN cases has been greatly enhanced by the advancements in PCR techniques and flow cytometry used for intraocular fluids. systemic (intravenous or oral) antivirals with adjunctive intravitreal antiviral therapy are recommended as first-line therapy to reduce disease severity, the risk of vision loss, and retinal detachment incidence. Although aciclovir was the first existing antiviral agent, at present many clinicians prefer high-dose valaciclovir orally or intravenous aciclovir combined with intravitreal foscarnet. Despite significant progress in diagnosing and treating ARN, further research is needed to improve visual outcomes in this challenging clinical condition.

Factors at the initial visit associated with poor visual outcomes in patients with acute retinal necrosis

BACKGROUND/OBJECTIVE

Acute retinal necrosis (ARN) is a vision-threatening disease caused by herpesvirus infection. This study aimed to investigate the visual prognostic factors that could be determined at the initial visit.

SUBJECTS AND METHODS

This retrospective study included 34 patients with ARN. Logistic regression analysis was employed to evaluate the associations between poor final visual outcomes and various factors, including poor initial visual acuity, presence of retinal detachment at the initial visit, posterior extension of necrotizing retinitis, and circumferential extension of necrotizing retinitis. Posterior extension was evaluated with three zonings, from the periphery (zone 3), mid-periphery (zone 2), and macula (zone 1). Circumferential extension was evaluated according to the degree of necrotizing retinitis lesions using ultra-wide fundus imaging.

RESULTS

The mean logarithm of the minimum angle of resolution was 0.63 ± 0.68 at the initial visit and 0.83 ± 0.65 at 12 months after the initial visit. Seven patients had a retinal detachment. The distribution of posterior extension at the initial visit was 5 in zone 1, 20 in zone 2, and 9 in zone 3. The average of necrotizing retinitis lesion angle was 249 ± 115°. The logistic regression analysis revealed that participants with wide angles of necrotizing retinitis were associated with final poor vision, with an odds ratio of 1.28 per 30° increase (95%CI: 1.00-1.65, p = 0.03).

CONCLUSIONS

Assessment of the widespread circumferential extension of white necrotizing retinal lesions at the initial visit is a crucial risk factor for the visual prognosis in ARN.

Experts Opinion: OCTA vs. FFA/ICG in Uveitis - Which Will Survive?

Will optical coherence tomography angiography (OCTA) replace invasive imaging techniques like fundus fluorescein angiography (FFA) and indocyanine green (ICG) angiography entirely? While OCTA is being increasingly applied in the field of medical retina, will we see this change in the subspeciality of uveitis? In this article, five uveitis specialists with renowned imaging expertise answer to 10 specific questions to address this issue. The final verdict based on the comments of the experts suggests that FFA and ICG cannot be replaced by OCTA in uveitis, at least for now. While OCTA can offer new insights into the pathogenesis of certain inflammatory conditions and help in the diagnosis of complications like inflammatory choroidal neovascularisation, multimodal imaging is still the preferred approach in the assessment of patients with uveitis.

A Straightforward Bifurcation Pattern-Based Fundus Image Registration Method

Fundus image registration is crucial in eye disease examination, as it enables the alignment of overlapping fundus images, facilitating a comprehensive assessment of conditions like diabetic retinopathy, where a single image's limited field of view might be insufficient. By combining multiple images, the field of view for retinal analysis is extended, and resolution is enhanced through super-resolution imaging. Moreover, this method facilitates patient follow-up through longitudinal studies. This paper proposes a straightforward method for fundus image registration based on bifurcations, which serve as prominent landmarks. The approach aims to establish a baseline for fundus image registration using these landmarks as feature points, addressing the current challenge of validation in this field. The proposed approach involves the use of a robust vascular tree segmentation method to detect feature points within a specified range. The method involves coarse vessel segmentation to analyze patterns in the skeleton of the segmentation foreground, followed by feature description based on the generation of a histogram of oriented gradients and determination of image relation through a transformation matrix. Image blending produces a seamless registered image. Evaluation on the FIRE dataset using registration error as the key parameter for accuracy demonstrates the method's effectiveness. The results show the superior performance of the proposed method compared to other techniques using vessel-based feature extraction or partially based on SURF, achieving an area under the curve of 0.526 for the entire FIRE dataset.

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.

Surgical Outcomes of Acute Retinal Necrosis-Related Retinal Detachment in Polymerase Chain Reaction-Positive Patients: A Single-Center Experience

PURPOSE

To evaluate the clinical features, operative techniques, and surgical outcomes of patients who underwent surgery for acute retinal necrosis (ARN)-related retinal detachment (RD).

DESIGN

Retrospective, longitudinal, consecutive case series.

PARTICIPANTS

Patients with polymerase chain reaction-positive ARN presenting from 2011 to 2021 who underwent vitreoretinal surgery for ARN-related RD at our institution.

METHODS

Univariate, multivariate, and survival analyses were used to determine predictors of anatomic and functional outcomes.

MAIN OUTCOME MEASURES

Single-surgery anatomic success rate, recurrent RD, and visual acuity (VA) at 1 year.

RESULTS

Thirty-four eyes of 34 patients (32.4% women, mean age, 45.1 ± 20.4 years) were included for analysis with a median follow-up of 2.5 years (interquartile range [IQR], 0.8-5.5 years). Presenting VA was 1.1 ± 0.8 logarithm of the minimum angle of resolution (LogMAR) (Snellen ∼20/250). The median time from presentation to RD surgery was 1.7 months (IQR, 0.8-4.1 months), and the mean preoperative VA was 1.6 ± 0.8 LogMAR (Snellen ∼20/800). Small-gauge pars plana vitrectomy (PPV) with or without a scleral buckle (SB) was performed for all eyes with an overall single-surgery success rate of 63.6%, with no statistically significant differences in visual/anatomic outcomes between PPV and PPV/SB cases. Silicone oil was used for tamponade in 33 (97.1%) cases and was removed in 10 (30.3%) with good anatomic and final functional outcomes (Snellen ∼20/80). Independent predictors of recurrent RD included the female sex (hazard ratio, 8.38; 95% confidence interval, 2.03-34.68; P < 0.01) and zone 1 retinitis involvement at presentation (hazard ratio, 10.95; 95% confidence interval, 2.12-56.48; P < 0.01). The mean VA at 1 year (VA_1year) and at the final follow-up both had a Snellen equivalent of 20/640 (P > 0.05 for both compared with preoperative VA, respectively). Eyes that achieved single-surgery success had VA_1year of 20/200 versus hand movements in those with single-surgery failure (P < 0.01). On multivariate linear regression, younger age (P = 0.04) and better presenting VA (P < 0.01) were both associated with better VA_1year.

CONCLUSIONS

Moderate single-surgery anatomic success can be achieved with modern vitreoretinal surgical techniques for ARN-related RD, although visual outcomes remain poor. Further studies investigating interventions for increasing single-surgery success rates, for the inflammatory complications of ARN, and for preventing ARN-related RD are needed.

Application of mydriasis and eye steering in ultrawide field imaging for detecting peripheral retinal lesions in myopic patients

PURPOSE

To compare mydriatic and eye-steering ultrawide field imaging (UWFI) with standard non-mydriatic UWFI examination in detecting peripheral retinal lesions in myopic patients.

METHODS

Cross-sectional, observational study. 220 eyes of 110 myopic patients with known peripheral retinal lesions in at least one eye under Goldmann three mirror contact lens examination were recruited. Non-mydriatic standard and eye-steering UWFI images were taken centrally and with eye-steering technique in upper, lower, nasal and temporal gazes under Optomap UWFI (Daytona, Optos, UK). Mydriatic standard and eye-steering UWFI was captured in central gaze and four different peripheral gazes. Sensitivity of detecting peripheral retinal lesions under different UWFI settings was compared.

RESULTS

141 (64.09%) eyes were with peripheral retinal lesions. The sensitivity for detecting peripheral lesions from low to high was 41.84% (95% CI 33.62% to 50.54%) under non-mydriatic standard UWFI setting, 52.48% (95% CI 44.08% to 60.75%) under mydriatic standard setting, 75.18% (95% CI 67.21% to 82.06%) under non-mydriatic eye-steering setting and 86.52% (95% CI 79.76% to 91.69%) under mydriatic eye-steering setting. Both mydriasis and eye-steering technique increased sensitivity of detecting peripheral lesions with statistical significance (p<0.001). By applying eye-steering technique, sensitivity of detecting lesions located in superior and inferior quadrants witnessed a greater increase compared with other two quadrants (p<0.05). Neither spherical equivalence (p>0.05) nor axial length (p>0.05) was an independent influence factor for detecting peripheral lesions.

CONCLUSIONS

Eye-steering technique and mydriasis could both efficiently improve the sensitivity of detecting peripheral retinal lesions in myopic patients. Lesions of superior and inferior quadrants benefited more from eye-steering technique.

Therapeutic prognostic factors associated with retinal detachment and visual outcomes in acute retinal necrosis

BACKGROUND

Acute retinal necrosis (ARN) is a fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of vision loss. Prognostic factors associated with the treatment of ARN have not been comprehensively identified. This study aimed to determine therapeutic prognostic factors associated with long-term clinical outcomes in eyes with ARN.

METHODS

This retrospective cohort study included patients with ARN who were treated between 2005 and 2019 in two tertiary ophthalmology departments in Seoul, Korea. Multiple logistic regression analysis was performed to investigate prognostic factors associated with late-onset retinal detachment (RD) and vision loss (<20/200).

RESULTS

Sixty-one eyes with ARN with an average follow-up of 63.5 months were included. Surgical intervention of vitrectomy (odds ratio [OR], 0.04; 95% confidence interval [CI], 0.004-0.47) and intraoperative prophylactic laser use (OR, 0.14; 95% CI, 0.02-0.81) were independently associated with a decreased risk of late RD. The factors independently associated with an increased risk of vision loss were worse initial visual acuity (OR, 3.28; 95% CI, 1.50-7.21), zone 1 involvement of necrotic retinitis (OR, 10.84; 95% CI, 1.62-72.41), and late-onset RD (OR, 5.38; 95% CI, 1.92-31.54).

CONCLUSION

Vitrectomy and/or prophylactic intraoperative laser treatment may be effective treatment options in preventing delayed RD associated with an increased risk of vision loss in eyes with ARN.

Differential Diagnosis of Vitritis in Adult Patients

The term "vitritis" refers to the presence of a cellular infiltration of the vitreous body, usually in the context of an intraocular inflammation, but not exclusively. Intermediate uveitis is the most prominent cause of vitritis, including infectious and auto-immune/auto-inflammatory etiologies. Corticosteroids and immunosuppressive therapies should not be started before ruling out the infectious causes of vitritis, especially in immunosuppressed individuals. Other situations can mimic intermediate uveitis such as amyloidosis and ocular tumors. Primary intraocular lymphoma should always be suspected in case of vitreous infiltrations in individuals aged over 50 years.

RETINAL DETACHMENT AFTER ACUTE RETINAL NECROSIS AND THE EFFICACIES OF DIFFERENT INTERVENTIONS: A Systematic Review and Metaanalysis

PURPOSE

To estimate the rate of retinal detachment (RD) after acute retinal necrosis (ARN) and evaluate the efficacies of different interventions.

METHODS

The databases Medline and EMBASE from inception to March 2020 were searched to identify the relevant studies. R software version 3.6.3 was used to perform the statistical analyses. Results in proportion with 95% confidence interval were calculated using generalized linear mixed models.

RESULTS

Sixty-seven studies involving 1,811 patients were finally included. The pooling results suggested the general RD rate of ARN was 47%. The RD rate increased with the extent of retinitis and was slightly lower when involved Zone III. The RD rate was 37% for herpes simplex virus ARN and 46% for varicella-zoster virus ARN; 52% for immunocompetent patients and 39% for immunocompromised patients. Retinal detachment presented in 2% of eyes at the first visit. Systemic antiviral therapy could lower the RD rate significantly from 67% to 43%, and prophylactic vitrectomy could lower the RD rate significantly from 45% to 22%. Systemic antiviral therapy plus vitrectomy achieved the lowest RD rate to 18%. Although the efficacy of prophylactic laser or intravitreal antiviral therapy was still limited. Prophylactic vitrectomy might significantly increase the incidence of proliferative vitreoretinopathy from 7% to 32%.

CONCLUSION

About half of the eyes might develop RD during the entire course of ARN. Systemic antiviral therapy and prophylactic vitrectomy are effective interventions to prevent RD, whereas the roles of prophylactic laser or adjunctive intravitreal antiviral therapy are still unclear. Varicella-zoster virus ARN and cases with extensive retinitis might need intensified interventions.

Ultra-wide field retinal imaging: A wider clinical perspective

The peripheral retina is affected in a variety of retinal disorders. Traditional fundus cameras capture only a part of the fundus even when montaging techniques are used. Ultra-wide field imaging enables us to delve into the retinal periphery in greater detail. It not only facilitates assessing color images of the fundus, but also fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and red and green free images. In this review, a literature search using the keywords "ultra-widefield imaging", "widefield imaging", and "peripheral retinal imaging" in English and non-English languages was done and the relevant articles were included. Ultra-wide field imaging has made new observations in the normal population as well as in eyes with retinal disorders including vascular diseases, degenerative diseases, uveitis, age-related macular degeneration, retinal and choroidal tumors and hereditary retinal dystrophies. This review aims to describe the utility of ultra-wide field imaging in various retinal disorders.

Visual outcome and poor prognostic factors in acute retinal necrosis syndrome

OBJECTIVE

To evaluate the impact of selected clinical parameters on the mid-/long-term visual outcome of patients with acute retinal necrosis (ARN)

DESIGN

A retrospective cohort study

SETTING

Two University Hospitals (Parma, Italy; Lausanne, Switzerland).

PARTICIPANTS

Thirty-nine non-HIV patients (39 eyes) with ARN, as confirmed by polymerase chain reaction on intraocular samples. The following potential predictors were tested using linear regression models: age, sex, etiology, best-corrected visual acuity (BCVA) on admission, delay between ARN symptom onset and treatment initiation, and surgery (performed or not).

MAIN OUTCOME

BCVA at the final follow up

RESULTS

Thirty-nine of 39 non-HIV patients (22 men and 17 women; mean age, 50 years) diagnosed with ARN were enrolled in the study. Etiologies were: varicella-zoster virus in 25 eyes (64%), herpes simplex viruses in the remaining 14 eyes. The average follow-up duration was 19 ± 13 months. All patients had undergone systemic antivirals; surgery was performed in 16 eyes. The mean delay between onset of visual symptoms and antiviral treatment initiation was 15 ± 31 days (range, 1-180 days). The mean BCVA at baseline was 0.83 ± 0.75 logMAR, while the mean final BCVA was 0.75 ± 0.81 logMAR. Both initial BCVA and treatment delay (TD) were significantly correlated with the final BCVA (p < 0.05).

CONCLUSIONS

Initial BCVA and TD seem to be significant predictors of mid-/long-term visual outcome in non-HIV patients affected by ARN.