Spotlight on Lattice Degeneration Imaging Techniques

Lattice degeneration (LD), routinely diagnosed with indirect ophthalmoscopy, is one of the most common and clinically significant peripheral retinal findings. In this review, we have summarized the data on currently available imaging techniques which help to improve diagnosis and our understanding of LD pathogenesis. Ultra-wide field imaging provides reliable color fundus capturing for the primary diagnosis of LD and may also be used as a screening tool. Wide-field imaging can be used for targeted documentation of LD lesions using true colors and with minimal optical distortions. Information on the status of the vitreoretinal interface, including detection of retinal holes, detachments, and vitreous tractions, can be obtained with peripheral structural optical coherence tomography (OCT) or scanning laser ophthalmoscopy in retro-mode. These techniques clarify the associated risks of rhegmatogenous retinal detachment. Fundus autofluorescence can provide details on atrophic changes. However, the risk of retinal detachment by means of this technique requires further investigation. OCT angiography may be successfully performed for some lesions. Taken together, OCT and OCT angiography demonstrate thinning of the choroid, alteration of local choroidal microcirculation, and, in severe lesions, involvement of the sclera. OCT angiography confirms loss of retinal microcirculation within LD lesion, which was previously shown with fluorescein angiography. In conclusion, despite relatively simple primary diagnosis, imaging of LD lesions remains challenging due to their peripheral localization. However, several new strategies, including ultra-wide field imaging, peripheral OCT, and scanning laser ophthalmoscopy, make LD imaging possible on a routine basis, improving diagnosis and understanding of LD pathogenesis.

Morphological characteristics of retinal vessels in eyes with high myopia: Ultra-wide field images analyzed by artificial intelligence using a transfer learning system

Purpose

The purpose of this study is to investigate the retinal vascular morphological characteristics in high myopia patients of different severity.

Methods

317 eyes of high myopia patients and 104 eyes of healthy control subjects were included in this study. The severity of high myopia patients is classified into C0-C4 according to the Meta Analysis of the Pathologic Myopia (META-PM) classification and their vascular morphological characteristics in ultra-wide field imaging were analyzed using transfer learning methods and RU-net. Correlation with axial length (AL), best corrected visual acuity (BCVA) and age was analyzed. In addition, the vascular morphological characteristics of myopic choroidal neovascularization (mCNV) patients and their matched high myopia patients were compared.

Results

The RU-net and transfer learning system of blood vessel segmentation had an accuracy of 98.24%, a sensitivity of 71.42%, a specificity of 99.37%, a precision of 73.68% and a F1 score of 72.29. Compared with healthy control group, high myopia group had smaller vessel angle (31.12 ± 2.27 vs. 32.33 ± 2.14), smaller fractal dimension (Df) (1.383 ± 0.060 vs. 1.424 ± 0.038), smaller vessel density (2.57 ± 0.96 vs. 3.92 ± 0.93) and fewer vascular branches (201.87 ± 75.92 vs. 271.31 ± 67.37), all P < 0.001. With the increase of myopia maculopathy severity, vessel angle, Df, vessel density and vascular branches significantly decreased (all P < 0.001). There were significant correlations of these characteristics with AL, BCVA and age. Patients with mCNV tended to have larger vessel density (P < 0.001) and more vascular branches (P = 0.045).

Conclusion

The RU-net and transfer learning technology used in this study has an accuracy of 98.24%, thus has good performance in quantitative analysis of vascular morphological characteristics in Ultra-wide field images. Along with the increase of myopic maculopathy severity and the elongation of eyeball, vessel angle, Df, vessel density and vascular branches decreased. Myopic CNV patients have larger vessel density and more vascular branches.

Silicone oil-induced displacement of subretinal hemorrhage in age-related macular degeneration

PURPOSE

To describe the use of silicone oil (SO) in combination with subretinal recombinant tissue plasminogen activator (rtPA) to achieve dislocation of large subretinal hemorrhage secondary to exudative age-related macular degeneration (AMD).

METHODS

A single-eye 81-year-old woman, known for exudative AMD, presented for a profound vision loss in her left eye since 7 days due to a massive subretinal hemorrhage. She promptly underwent standard three-port pars plana vitrectomy with subretinal injection of rtPA and SO tamponade.

RESULTS

The surgical technique showed favorable anatomical and functional outcomes, achieving a substantial peripheral displacement of blood and visual improvement.

CONCLUSION

This report favorably supports the use of SO in adjunction to subretinal rtPA in selected cases of subretinal hemorrhage secondary to wet AMD.

Non-Mydriatic Ultra-Wide Field Imaging Versus Dilated Fundus Exam and Intraoperative Findings for Assessment of Rhegmatogenous Retinal Detachment

Background: to compare the extent of the detached retina and retinal tears location in rhegmatogenous retinal detachment (RRD) among non-mydriatic ultra-wide field (UWF) imaging, dilated fundus exam (DFE), and intraoperative evaluation. Methods: this retrospective chart review comprised 123 patients undergoing surgery for RRD. A masked retina specialist analyzed the UWF fundus images for RRD area, status of the macula, and presence and location of retinal breaks. The same variables were collected from a database including DFE and intraoperative recordings. Evaluation methods were compared. Results: mean age was 59.8 ± 14.9 years. Best-corrected visual acuity improved from 0.25 ± 0.3 (Snellen) to 0.67 ± 0.3 at 12 months (p = 0.009). The RRD description and assessment of macula status (34.5% macula-on) did not differ between UWF, DFE, and intraoperative examination. The inferior quadrant was involved most frequently (41.5%), followed by the superior (38.9%), temporal (27.8%) and nasal quadrant (14.8%). Intraoperative exam detected 96.7% of retinal tears compared with DFE (73.2%, p = 0.008) and UWF imaging (65%, p=0.003). UWF imaging and DFE did not differ significantly. Conclusion: RRD extent on DFE and UWF images was consistent with intraoperative findings. UWF and DFE detection of peripheral retinal tears was similar, but 25% of retinal breaks were missed until intraoperative evaluation.

Ultra-Widefield Fundus Autofluorescence in Cytomegalovirus Retinitis

Purpose: To study the role of ultra-wide field (UWF) fundus autofluorescence (FAF) in the management of CMV (cytomegalovirus) retinitis.Material and methods: In this prospective, observational, non-randomized study, we followed up patients with active CMV retinitis on UWF fundus photograph (FP) and UWF-FAF.Results: A total of 16 patients (24 eyes) were studied. There were 13 males and mean age of patients was 37 (range 9-56) years. On UWF FP, out of 24 eyes, 13 (54.2%) had granular lesions, 3 (12.5%) had necrotizing pattern, 1 (4.1%) had a frosted branch angiitis (FBA), and 7 (29.2%) had a mixed pattern. UWF-FAF showed better delineation of borders of lesions in 7 eyes (29.1%), larger area of involvement in 8 eyes (33.3%), picked up 7 of 9 (77.77%) eyes of recurrence and helped differentiate cotton wool spots from retinitis lesion in one eye.Conclusion: UWF-FAF is useful in the management of CMV retinitis.

Ultra-wide field imaging of pigmented para-venous retino-choroidal atrophy

OBJECTIVE

To describe the ultra-wide field imaging features of pigmented para-venous retino-choroidal atrophy.

DESIGN

Retrospective review at a tertiary care centre.

PARTICIPANTS

Eight eyes of five patients with pigmented para-venous retino-choroidal atrophy who presented to our retina clinic over last 2 years.

METHODS

Retrospective review of ultra-wide field pseudo-colour and short wave autofluorescence imaging was performed. In vivo histology of the macula and areas of retino-choroidal atrophy was studied with swept source optical coherence tomography (SS-OCT).

RESULTS

The median age was 40 years (range: 22-67 years). Best corrected visual acuity ranged from perception of light to 20/20. The para-venous retino-choroidal atrophy and pigment clumping not only involved the major arcade vessels but also extended into the peripapillary area and retinal periphery. The affected areas demonstrated hypoautofluorescence with sharp hyperautofluorescent borders. Macular atrophy, epiretinal membrane and optic disc pallor were noted in two eyes each. In all cases, the affected pigmentary area had disorganization of inner retinal layers, disruption of outer retinal layers and retinal pigment epithelium and markedly thinned out choroid on swept source optical coherence tomography. Concurrent involvement with retinitis pigmentosa in the fellow eye was noted in two patients.

CONCLUSION

Ultra-wide field imaging of pigmented para-venous retino-choroidal atrophy sheds light onto the widespread retino-choroidal abnormalities. Concurrent disc and macular involvement may jeopardize the visual function. Pigmented para-venous retino-choroidal atrophy may be considered as a self-limited form of retinitis pigmentosa.

Ultra-Wide Field Imaging in Paradoxical Worsening of Tubercular Multifocal Serpiginoid Choroiditis after the Initiation of Anti-Tubercular Therapy

Purpose: To evaluate role of ultra-wide field (UWF) versus conventional imaging in the follow-up and paradoxical worsening (PW) of tubercular (TB) multifocal serpiginoid choroiditis (MSC). Methods: Prospective observational study of patients with TB MSC undergoing UWF imaging, autofluorescence and fluorescein angiography was performed. A circle simulating central 75° field representing conventional imaging was drawn on UWF images. The information yielded by the two modalities, progression of choroiditis lesions and PW was compared. Results: 44 eyes (29 patients, mean age: 30.7 ± 9 years; 23 males) were included. UWF imaging showed additional lesions in 39/44 eyes (88.6%). Overall, 16/44 eyes (36.4%) showed PW; 3/16 eyes (18.7%) showed only peripheral PW, while 10/16 eyes showed both central and peripheral PW. Management was altered in 11 patients (37.93%) based on UWF imaging. Conclusions: UWF is more useful than conventional imaging in identifying additional choroiditis lesions, PW and altering the course of therapy in TB MSC.

Ultra-wide field imaging in the diagnosis and management of adult-onset Coats' disease

BACKGROUND

The conventional fundus imaging covers up to 60 degrees of retina only. Although various montaging techniques can significantly increase the area that can be imaged, it is still difficult to image and document the peripheral retina. The purpose of this study is to describe the use of ultra-wide field imaging in the diagnosis and management of adult-onset Coats' disease.

METHODS

This is a retrospective case series of three patients diagnosed with adult-onset Coats' disease that were treated at the retina clinic of our institute. The case records, conventional and ultra-wide field fluorescein angiograms and optical coherence tomography scans were reviewed.

RESULTS

The ultra-wide field pseudo-colour photographs and fluorescein angiograms were able to provide clinically useful information over and above that provided by conventional imaging. In all three patients, ultra-wide field angiography showed the temporal avascular periphery. In addition, it revealed retinal neovascularisation, peripheral vascular leakage and documented peripheral telangiectasia in selected patients.

CONCLUSION

Ultra-wide field imaging provides information that can help in the diagnosis and management of adult-onset Coat's disease. This may lead to better visual outcomes in Coats' disease.