Tomographic fundus features in pseudoxanthoma elasticum: comparison with neovascular age-related macular degeneration in Japanese patients. Eye (Lond). 2012;26:1086-1094. [PMID: 22653517 DOI: 10.1038/eye.2012.101]

Cross-Sectional Analysis of Outer Retinal Tubulation in Inherited Retinal Diseases: A Multicenter Study

PURPOSE

This study aims to explore genetic variants that potentially lead to outer retinal tubulation (ORT), estimate the prevalence of ORT in these candidate genes, and investigate the clinical etiology of ORT in patients with inherited retinal diseases (IRDs), with respect to each gene.

DESIGN

Retrospective cohort study.

METHODS

A retrospective cross-sectional review was conducted on 565 patients with molecular diagnoses of IRD, confirming the presence of ORT as noted in each patient's respective spectral-domain optical coherence tomography (SD-OCT) imaging. Using SD-OCT imaging, the presence of ORT was analyzed in relation to specific genetic variants and phenotypic characteristics. Outcomes included the observed ORT frequencies across 2 gene-specific cohorts: non-retinal pigment epithelium (RPE)-specific genes, and RPE-specific genes; and to investigate the analogous characteristics caused by variants in these genes.

RESULTS

Among the 565 patients included in this study, 104 exhibited ORT on SD-OCT. We observed ORT frequencies among the following genes from our patient cohort: 100% (23/23) for CHM, 100% (2/2) for PNPLA6, 100% (4/4) for RCBTB1, 100% for mtDNA [100% (4/4) for MT-TL1 and 100% (1/1) for mtDNA deletion], 100% (1/1) for OAT, 95.2% (20/21) for CYP4V2, 72.7% (8/11) for CHM female carriers, 66.7% (2/3) for C1QTNF5, 57.1% (8/14) for PROM1, 53.8% (7/13) for PRPH2, 42.9% (3/7) for CERKL, 28.6% (2/7) for CDHR1, 20% (1/5) for RPE65, 4% (18/445) for ABCA4. In contrast, ORT was not observed in any patients with photoreceptor-specific gene variants, such as RHO (n = 13), USH2A (n = 118), EYS (n = 70), PDE6B (n = 10), PDE6A (n = 4), and others.

CONCLUSIONS

These results illustrate a compelling association between the presence of ORT and IRDs caused by variants in RPE-specific genes, as well as non-RPE-specific genes. In contrast, IRDs caused by photoreceptor-specific genes are typically not associated with ORT occurrence. Further analysis revealed that ORT tends to manifest in IRDs with milder intraretinal pigment migration (IPM), a finding that is typically associated with RPE-specific genes. These findings regarding ORT, genetic factors, atrophic patterns in the fundus, and IPM provide valuable insight into the complex etiology of IRDs. Future prospective studies are needed to further explore the association and underlying mechanisms of ORT in these contexts.

Angioid Streaks Remain a Challenge in Diagnosis, Management, and Treatment

Aim: Angioid streaks (ASs) are a rare retinal condition and compromise visual acuity when complicated with choroidal neovascularization (CNV). They represent crack-like dehiscences at the level of the Bruch's membrane. This objective narrative review aims to provide an overview of pathophysiology, current treatment modalities, and future perspectives on this condition. Materials and Methods: A literature search was performed using "PubMed", "Web of Science", "Scopus", "ScienceDirect", "Google Scholar", "medRxiv", and "bioRxiv." Results: ASs may be idiopathic, but they are also associated with systemic conditions, such as pseudoxanthoma elasticum, hereditary hemoglobinopathies, or Paget's disease. Currently, the main treatment is the use of anti-vascular endothelial growth factors (anti-VEGF) to treat secondary CNV, which is the major complication observed in this condition. If CNV is detected and treated promptly, patients with ASs have a good chance of maintaining functional vision. Other treatment modalities have been tried but have shown limited benefit and, therefore, have not managed to be more widely accepted. Conclusion: In summary, although there is no definitive cure yet, the use of anti-VEGF treatment for secondary CNV has provided the opportunity to maintain functional vision in individuals with AS, provided that CNV is detected and treated early.

Subclinical Angioid Streaks with Pseudodrusen: A New Phenotype of Age-Related Macular Degeneration

INTRODUCTION

To describe subclinical angioid streaks (AS) as a frequent, peculiar age-related macular degeneration (AMD) phenotype, comparing features of eyes with subclinical AS with those of eyes with AMD without AS.

METHODS

This was a retrospective, observational study. Among a patient cohort with AMD, we selected patients without known causes for AS whose eyes showed signs of angioid streaks (AS) on structural optical coherence tomography (OCT) but not on fundus examination. Selected OCT features of AS were Bruch's membrane (BM) breaks and large BM dehiscences.

RESULTS

Among 543 eyes of 274 patients with AMD (mean ± standard deviation: 82 ± 7 years), 73 eyes of 46 patients (81 ± 7 years; p = 0.432) showed AS features on OCT (OCT AS) that were not visible on fundus examination. Estimated prevalence of subclinical age-related AS was 13.4% (95% confidence interval 10.3-16.3%) in this AMD population. Fifty-three eyes (73%) with AS features were affected by peripapillary atrophy, often with a "petaloid-like" pattern, similar to typical features of AS disease. Almost all cases (97%) presented reticular pseudodrusen (RPD), with (41%) or without (59%) drusen showing a significant difference in RPD prevalence in OCT AS eyes in comparison to AMD eyes without subclinical AS using generalized estimating equations (P < 0.001). Among the 73 subclinical AS cases, 71 were affected by late AMD (57 with macular neovascularization, 14 with geographic atrophy), showing a more advanced AMD stage in comparison with AMD eyes without subclinical AS (P < 0.001). The following OCT features were disclosed: BM breaks in 100% of cases and BM dehiscences in 37%.

CONCLUSIONS

Subclinical AS in eyes with AMD is a peculiar phenotype of the disease, with features suggesting a primary involvement of Bruch's membrane and clinical similarities with mild, late-onset pseudoxanthoma elasticum.

The identification of activity of choroidal neovascularization complicating angioid streaks

OBJECTIVES

To inspect the inter-reader agreement of different diagnostic modalities in identifying choroidal neovascularization (CNV) activity secondary to angioid streaks (AS) and to analyze the prevalence of subretinal hyper-reflective material (SHRM) in active CNV.

METHODS

Retrospective study of patients with AS with active CNV; optical coherence tomography (OCT), OCT angiography (OCTA), fundus fluorescein angiography (FFA), and indocyanine green angiography (ICGA) from each patient were collected. Agreement between two readers using different diagnostic modalities is presented as free-marginal kappa (k) and 95% confidence interval (CI).

RESULTS

This study included 19 eyes of 12 patients with active CNV (5 naive and 14 previously treated). Agreement among readers on CNV activity was excellent for OCT (k =0.88; 95% CI 0.71-1.00), good for FFA (k = 0.70; 95% CI 0.46-0.94) and ICGA (k = 0.58; 95% CI 0.31-0.84), and poor using OCTA (k = 0.39; 95% CI 0.11-0.68). SHRM was the most common OCT finding associated with active CNV (100%); fuzzy borders were present in 53% of SHRM cases at baseline.

CONCLUSIONS

Identification of CNV activity in AS is challenging; OCT was the best modality to inspect active CNV. The identification of SHRM contributed to recognizing active CNV. Further studies are needed to assess the role of SHRM in anticipating prognosis and guiding treatment of CNV secondary to AS.

Adaptive Optics Imaging in Patients Affected by Pseudoxanthoma Elasticum

PURPOSE

To describe the retinal findings of patients affected by pseudoxanthoma elasticum (PXE) using a multimodal imaging approach including flood-illumination adaptive optics ophthalmoscopy (AO).

DESIGN

Retrospective case series.

MATERIALS AND METHODS

Patients affected by PXE were retrospectively studied. Clinical data, color, infrared and autofluorescence fundus imaging, optical coherence tomographic scans, and AO examinations were collected. Furthermore, the photoreceptor count was assessed. PXE diagnosis was confirmed by a positive skin biopsy and/or genetic testing.

RESULTS

Twenty-one eyes of 18 patients (11 females and 7 males) were included in the study. In 3 patients, both eyes were studied. The mean age at examination was 37.7 ± 16.4 years (range 14-66) and the mean best-corrected visual acuity (BCVA) was 0.1 ± 0.2 logMAR (range 0-1). We identified 3 types of angioid streaks (AS) using AO: "crack," "band," and "hypopigmented." The first 2 were very similar and they differed in size; the third type showed specific clinical features. Comet lesions appeared as hyper-reflective round lesions on AO imaging. In all eyes, the cone mosaic appeared reduced inside the streaks compared to the neighboring areas (13,532.8 ± 1,366.5 cones/mm² vs 16,817.1 ± 1,263.0 cones/mm² respectively).

CONCLUSION

Using AO imaging in PXE-related retinopathy, we were able to observe the presence of the photoreceptors within the angioid streaks, differentiate 3 types of angioid streaks, based on size and reflective features, and identify the very small crystalline bodies not identifiable using other retinal imaging techniques.

Long-term results of choroidal neovascularization secondary to angioid streaks

PURPOSE

To investigate factors contributing to the visual prognosis of choroidal neovascularization (CNV) secondary to angioid streaks (AS) in a long-term follow-up (> 5 years) study.

METHODS

Twenty-one patients (32 eyes) affected by CNV secondary to AS were enrolled retrospectively and divided into three groups according to the period of CNV recurrence from the final treatment: group A, no recurrence for more than 12 months; group B, no recurrence for 6-12 months; and group C, no recurrence for < 6 months or ongoing. According to the above classification, we assessed best-corrected visual acuity (BCVA), peau d'orange area, the number of photodynamic treatments and/or intravitreal antiangiogenic drug injections, central choroidal thickness (CCT) and central retinal thickness (CRT) using optical coherence tomography, and enlargement of retinal pigment epithelium (RPE) atrophy.

RESULTS

The median follow-up time was 91 months. The median logarithm of the minimum angle of resolution BCVA significantly deteriorated from 0 at baseline to 1 at final follow-up (p < 0.05). Especially, final BCVA in group A showed worst visual outcome despite lowest number of treatments. Peau d'orange areas at baseline were found in 32 eyes (100%). There were no significant differences between initial CRT and final CRT. Median CCT was significantly reduced from 188 μm at baseline to 96 μm at final follow-up (p < 0.05). The median number of treatments was 3.5. Enlargement of RPE atrophy at baseline was found in 31 eyes (96.8%).

CONCLUSIONS

Despite the regression of CNV secondary to AS following treatment, the visual prognosis was poor due to the presence of peau d'orange areas, choroidal thinning, and increased RPE atrophy.

Cellular and Molecular Biomarkers Indicate Premature Aging in Pseudoxanthoma Elasticum Patients

The molecular processes of aging are very heterogenic and not fully understood. Studies on rare progeria syndromes, which display an accelerated progression of physiological aging, can help to get a better understanding. Pseudoxanthoma elasticum (PXE) caused by mutations in the ATP-binding cassette sub-family C member 6 (ABCC6) gene shares some molecular characteristics with such premature aging diseases. Thus, this is the first study trying to broaden the knowledge of aging processes in PXE patients. In this study, we investigated aging associated biomarkers in primary human dermal fibroblasts and sera from PXE patients compared to healthy controls. Determination of serum concentrations of the aging biomarkers eotaxin-1 (CCL11), growth differentiation factor 11 (GDF11) and insulin-like growth factor 1 (IGF1) showed no significant differences between PXE patients and healthy controls. Insulin-like growth factor binding protein 3 (IGFBP3) showed a significant increase in serum concentrations of PXE patients older than 45 years compared to the appropriate control group. Tissue specific gene expression of GDF11 and IGFBP3 were significantly decreased in fibroblasts from PXE patients compared to normal human dermal fibroblasts (NHDF). IGFBP3 protein concentration in supernatants of fibroblasts from PXE patients were decreased compared to NHDF but did not reach statistical significance due to potential gender specific variations. The minor changes in concentration of circulating aging biomarkers in sera of PXE patients and the significant aberrant tissue specific expression seen for selected factors in PXE fibroblasts, suggests a link between ABCC6 deficiency and accelerated aging processes in affected peripheral tissues of PXE patients.

Unique optical coherence tomographic features in age-related macular degeneration

Age-related macular degeneration is a major cause of blindness worldwide characterized by the presence of drusen and leading to retinal pigment epithelium and outer retinal changes in advanced stages. Approximately 10% of eyes with age-related macular degeneration develop neovascular complications and present with retinal or sub-retinal pigment epithelium exudation, hemorrhage, or both. Recent advances in imaging techniques, especially optical coherence tomography (OCT), help in early identification of disease and guide various treatment decisions; however, not all signs are suggestive of ongoing exudation or neovascular activity. Although uncommon, multiple OCT-based signs are reported that may be difficult to appreciate clinically. Prompt identification of these signs such as outer retinal tubulation, cystoid degeneration, or pseudocysts may avoid unnecessary interventions. Moreover, certain OCT-based features involving the choroid, such as prechoridal cleft and choroidal cavern, have also been found in eyes with age-related macular degeneration. We discuss these unique OCT-based signs, their pathogenesis, clinical relevance, and management.

Evaluation of outer retinal tubulations in diabetic macular edema underwent anti-VEGF treatment

AIM

To investigate the incidence and subsequent changes of outer retinal tubulations (ORTs) in diabetic macular edema (DME) underwent anti-vascular endothelial growth factor (VEGF) therapy, and to assess the possibility of ORT as a biomarker of DME severity or response to anti-VEGF therapy.

METHODS

This retrospective and descriptive study included a total of 228 patients (435 eyes) with DME and treated with intravitreal anti-VEGF agents between March 2016 and January 2018. Patients were divided into 2 groups according to the presence of ORTs. High-resolution spectral-domain optical coherence tomography (SD-OCT) images acquired by vertical and horizontal scans and over consecutive visits were analyzed. The evolution of ORT over time, type of fluid and subfoveal photoreceptor integrity on OCT imaging was also assessed.

RESULTS

ORTs were identified in 108 eyes of 435 eyes with an overall incidence rate of 24.83% at baseline. ORTs were prone to locate adjacent to the lesions of exudation and/or cystoid edema and possibly situated in outer nuclear layer (ONL), outer plexiform layer (OPL) and/or inner nuclear layer (INL) in eyes with DME. The formation process of ORT led to focal downward displacement of OPL and INL toward RPE near the lesion. During the follow up, 45 eyes had steady ORTs and 63 eyes had dynamic variants in ORTs, including disappearance, reappearance, collapse, diminution, and enlargement. There were higher proportion of closed ORTs and fewer proportion of forming ORTs in eyes with steady ORTs, which showed a statistically significance when compared with eyes with variant ORTs (P=0.006, P=0.017, respectively). The eyes without ORTs had significantly better final best corrected visual acuity (BCVA) and more BCVA change than those eyes with ORTs in DME patients after anti-VEGF therapy (P=0.023, P=0.009, respectively). The disruption of subfoveal photoreceptor integrity in eyes with ORTs was more serious than that in eyes without ORTs (P=0.013). The proportion of stable vision in eyes with ORTs was significantly higher than that in eyes without ORTs, showing statistical significance (P=0.016). ORTs were associated with worse visual prognosis due to damage of the subfoveal photoreceptor integrity.

CONCLUSION

ORTs have a high incidence and changes over time in DME with anti-VEGF treatment and may be located at various retinal layers. Persistent ORT can be as a negative biomarker of outcome of DME.

Peripapillary comet lesions and comet rain in PXE-related retinopathy

PURPOSE

To study peripapillary comet lesions (PCL) in Italian patients affected with pseudoxanthoma elasticum (PXE).

METHODS

Retrospective review of fundoscopic and swept-source (SS) optical coherence tomography (OCT) images of patients with PXE examined at the Regional Reference Center for Hereditary Retinal Degenerations at the Careggi Teaching Hospital of Florence from 2012 to 2017.

RESULTS

From 148 eyes of 74 patients affected with PXE, we identified 24 eyes of 14 patients (11 were female) with a mean age of 39 years (range, 20-58 years) characterized by peripapillary comet lesions. Of these 24 eyes, 15 eyes (of 10 patients) were characterized by comet rain. The smallest comet lesion at the OCT examination appeared as a focal roundish hyper-reflective alteration at the level of the outer retinal segments and RPE-Bruch's membrane complex; the larger lesions appeared as circular and ovoid structures with hyper-reflective borders in the outer nuclear layer.

CONCLUSION

The comet lesion formation process involves the outer layers of the retina and RPE/Bruch's membrane complex. It consists of a degenerative/rearrangement process of the photoreceptors which occurs in an area of focal altered RPE/Bruch's membrane resembling the outer retinal tubulation.

Optical coherence tomography analysis of evolution of Bruch's membrane features in angioid streaks

PurposeTo describe optical coherence tomography (OCT) features in the Bruch's membrane (BM) of eyes with angioid streaks (AS) and evaluate their evolution over the follow-up.Patients and methodsPatients with AS presenting between March 2016 and September 2016 at two tertiary referral centers were consecutively recruited in this study. Eligibility criteria included prior spectral domain (SD)-OCT images, taken at least 3 months before at the same referral center, with automated eye tracking and image alignment modules. Alterations of BM were described and compared to previous scans over the follow-up. Multimodal imaging was used to identify alteration of retinal pigment epithelium (RPE) and choroid.ResultsThirty-two eyes of 16 consecutive patients with AS were included. BM undulations, mostly observed around the optic nerve head, were found in 19 (59.4%) of 32 eyes. BM breaks were found in 31 (96.9%) out of 32 eyes. Evolution of BM undulations into BM breaks was observed in 5 eyes (15.6%). Choroidal neovascularization (CNV) was observed in 12 eyes (37.5%) during follow-up, typically in areas of BM interruption.ConclusionsBM undulations, probably caused by high stretching forces exerted on the BM around the optic nerve head, seem to precede some BM breaks. BM interruptions may be a preferred way for the growth of CNV, which was identified in one-third of our cases.

Prevalence of outer retinal tubulation in eyes with choroidal neovascularization

Background

Outer retinal tubulations (ORTs) are branching tubular structures located in the outer nuclear layer of the retina. The goal of this study is to determine the prevalence of ORTs observed in eyes with choroidal neovascularization (CNV) undergoing treatment with anti-angiogenic intravitreous injection (IVI) with anti-VEGF (vascular endothelial growth factor) at the Ophthalmology Department of a tertiary hospital in São Paulo, Brazil.

Methods

This is a descriptive study based on medical charts and Spectral-domain Optical Coherence Tomography (Sd-OCT) scans of 142 patients (158 eyes) treated between 2012 and 2014 with IVI of anti-VEGF for CNV. The patients’ data was analysed according to age, gender, pathology, presence of ORTs, and best corrected visual acuity (BCVA). Patients with and without ORTs were compared according to the last BCVA obtained using Chi square corrected by the Yates factor.

Results

ORTs were found in a total of 40 out of 158 eyes (25.31 %) with CNV; in 33 out of 119 eyes (27.7 %) with neovascular age-related macular disease (AMD); in 5 out of 8 eyes (62.5 %) with neovascular angioid streaks; and in 2 out of 12 eyes (16.67 %) with myopic neovascular membranes. Most patients with ORTs had BCVA worse than 20/200, significantly worse BCVA than patients without ORTs.

Conclusions

Recent studies have considered that the presence of ORTs is indicative of a photoreceptor degeneration process and may represent a final stage of multiple retinal degenerative pathologies. The prevalence of ORTs in eyes with CNV has not been well described, especially when considering the Brazilian population treated in a public health care system. In our study, ORTs were observed in only three different pathologies: neovascular AMD, neovascular angioid streaks and myopic neovascular membranes. The correct recognition of ORTs is fundamental for its differentiation from intraretinal cysts, for the latter is related to the activity of neovascular diseases, and usually guides anti-angiogenic therapy. We conclude that ORTs have a high prevalence in the population studied, and their correct identification presents relevant therapeutic implications.

OUTER RETINAL TUBULATION IN ADVANCED AGE-RELATED MACULAR DEGENERATION: Optical Coherence Tomographic Findings Correspond to Histology

PURPOSE

To compare optical coherence tomography (OCT) and histology of outer retinal tubulation (ORT) secondary to advanced age-related macular degeneration in patients and in postmortem specimens, with particular attention to the basis of the hyperreflective border of ORT.

METHOD

A private referral practice (imaging) and an academic research laboratory (histology) collaborated on two retrospective case series. High-resolution OCT raster scans of 43 eyes (34 patients) manifesting ORT secondary to advanced age-related macular degeneration were compared to high-resolution histologic sections through the fovea and superior perifovea of donor eyes (13 atrophic age-related macular degeneration and 40 neovascular age-related macular degeneration) preserved ≤4 hours after death.

RESULTS

Outer retinal tubulation seen on OCT correlated with histologic findings of tubular structures consisted largely of cones lacking outer segments and lacking inner segments. Four phases of cone degeneration were histologically distinguishable in ORT lumenal walls, nascent, mature, degenerate, and end stage (inner segments and outer segments, inner segments only, no inner segments, and no photoreceptors and only Müller cells forming external limiting membrane, respectively). Mitochondria, which are normally long and bundled within inner segment ellipsoids, were small and scattered within shrunken inner segments and cell bodies of surviving cones. A lumenal border was delimited by an external limiting membrane. Outer retinal tubulation observed in closed and open configurations was distinguishable from cysts and photoreceptor islands on both OCT and histology. Hyperreflective lumenal material seen on OCT represents trapped retinal pigment epithelium and nonretinal pigment epithelium cells.

CONCLUSION

The defining OCT features of ORT are location in the outer nuclear layer, a hyperreflective band differentiating it from cysts, and retinal pigment epithelium that is either dysmorphic or absent. Histologic and OCT findings of outer retinal tubulation corresponded in regard to composition, location, shape, and stages of formation. The reflectivity of ORT lumenal walls on OCT apparently does not require an outer segment or an inner/outer segment junction, indicating an independent reflectivity source, possibly mitochondria, in the inner segments.

Incidence of outer retinal tubulation in ranibizumab-treated age-related macular degeneration

PURPOSE

To investigate the incidence of outer retinal tubulation (ORT) in ranibizumab-treated neovascular age-related macular degeneration patients.

METHODS

We included 480 consecutive patients (546 eyes) with neovascular age-related macular degeneration, who were treated with variable-dosing intravitreal ranibizumab, evaluated with spectral domain optical coherence tomography, and followed-up for a minimum period of 6 months. Optical coherence tomographies were evaluated for the first appearance of ORT, precursor signs, and type of underlying lesion. Visual acuity was also recorded.

RESULTS

Outer retinal tubulation was observed in 30% of eyes during a mean follow-up period of 26.7 months (SD, 13.5). Kaplan-Meier survival analysis revealed that the ORT incidence (2.5, 17.5, 28.4, and 41.6% at baseline, after 1, 2, and 4 years, respectively) continuously increased, despite visually effective anti-vascular endothelial growth factor treatment. Outer retinal tubulation was associated with a poorer functional benefit. Lower baseline visual acuity was associated with a higher risk of developing ORT.

CONCLUSION

Incidence of ORT continuously increases despite visually optimal anti-vascular endothelial growth factor treatment of age-related macular degeneration. Outer retinal tubulation might be considered a prognostic factor for functional outcome and is relevant to avoid overtreatment.

From variome to phenome: Pathogenesis, diagnosis and management of ectopic mineralization disorders

Ectopic mineralization - inappropriate biomineralization in soft tissues - is a frequent finding in physiological aging processes and several common disorders, which can be associated with significant morbidity and mortality. Further, pathologic mineralization is seen in several rare genetic disorders, which often present life-threatening phenotypes. These disorders are classified based on the mechanisms through which the mineralization occurs: metastatic or dystrophic calcification or ectopic ossification. Underlying mechanisms have been extensively studied, which resulted in several hypotheses regarding the etiology of mineralization in the extracellular matrix of soft tissue. These hypotheses include intracellular and extracellular mechanisms, such as the formation of matrix vesicles, aberrant osteogenic and chondrogenic signaling, apoptosis and oxidative stress. Though coherence between the different findings is not always clear, current insights have led to improvement of the diagnosis and management of ectopic mineralization patients, thus translating pathogenetic knowledge (variome) to the phenotype (phenome). In this review, we will focus on the clinical presentation, pathogenesis and management of primary genetic soft tissue mineralization disorders. As examples of dystrophic calcification disorders Pseudoxanthoma elasticum, Generalized arterial calcification of infancy, Keutel syndrome, Idiopathic basal ganglia calcification and Arterial calcification due to CD73 (NT5E) deficiency will be discussed. Hyperphosphatemic familial tumoral calcinosis will be reviewed as an example of mineralization disorders caused by metastatic calcification.

Outer retinal tubulation in diabetic macular edema following anti-VEGF treatment

Background

To address the presence and features of outer retinal tubulation (ORT) found in diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF) and to differentiate between ORT and cystoid DME, which have different plans of management.

Methods

This was a retrospective review of a total of 514 patients investigated with spectral domain optical coherence tomography (OCT) in patients with diabetic macular edema treated with anti-VEGF. ORT was seen in 12 eyes of 11 patients. The morphologic characteristics of ORT and its progress over time were examined using OCT data. The retinal images were obtained by horizontal and vertical scans to analyze the possible presence of ORT and to explore their morphologic features and location in the retinal layers.

Results

ORT was seen in DME treated with anti-VEGF. ORT was shown as round or ovoid hyporeflective spaces with hyperreflective borders on the B-scans, measuring 30 to 120 μm high and 30 to 1775 μm wide. The tubules generally remained stable over time. In a retinal practice specializing in advanced diabetic retinopathy clinic, this ORT was seen in 12 eyes of 11 patients during a 12-month period. ORT presented either after receiving 0.05 mL open-label intravitreal injections of 0.5 mg ranibizumab or 1.25 mg bevacizumab.

Conclusion

ORT is found in DME treated with anti-VEGF that may show damage to the outer retina secondary to the severity and chronicity of the DME. ORT may be a result of underlying chronic and severe diabetic macular edema that may occur later possibly secondary to retinal layers rearrangement after several anti-VEGF injections. It is important to differentiate between ORT and cystoids DME. The presence of the ORT entity alone without the presence of DME does not require further anti-VEGF re-injections.

Outer retinal tubulation in the comparison of age-related macular degeneration treatments trials (CATT)

PURPOSE

To determine the prevalence of, risk factors for, and visual acuity (VA) correlations with outer retinal tubulation (ORT) seen on spectral-domain optical coherence tomography (SD OCT) in eyes with neovascular age-related macular degeneration (AMD) after anti-vascular endothelial growth factor (VEGF) therapy.

DESIGN

Prospective cohort study within a randomized clinical trial.

PARTICIPANTS

Patients with SD OCT images at weeks 56 and 104 in the Comparison of AMD Treatments Trials (CATT).

METHODS

Participants in the CATT were assigned randomly to ranibizumab (0.5 mg) or bevacizumab (1.25 mg) treatment and to a monthly or pro re nata (PRN) injection-dosing regimen. A subset of eyes was imaged with SD OCT beginning at week 56. Cirrus 512×128 or Spectralis 20°×20° volume cube scan protocols were used to acquire SD OCT images. Two independent readers at the CATT OCT reading center graded scans, and a senior reader arbitrated discrepant grades. The prevalence of ORT, identified as tubular structures seen on at least 3 consecutive Cirrus B scans or 2 consecutive Spectralis B scans, was determined. The associations of patient-specific and ocular features at baseline and follow-up with ORT were evaluated by univariate and multivariate analyses.

MAIN OUTCOME MEASURES

Outer retinal tubulations.

RESULTS

Seven of 69 eyes (10.1%) at 56 weeks and 64 of 368 eyes (17.4%) at week 104 had ORTs. Absence of diabetes, poor VA, blocked fluorescence, geographic atrophy, greater lesion size, and presence of subretinal hyperreflective material at baseline were associated independently with greater risk of ORT at 104 weeks (P < 0.05). Neither drug nor dosing regimen were associated significantly with ORT. The mean VA of eyes with ORT at week 104 (58.5 Early Treatment Diabetic Retinopathy Study letters) was worse than the mean VA of eyes without ORT (68.8 letters; P < 0.0001).

CONCLUSION

At 2 years after initiation of anti-VEGF therapy for neovascular AMD, ORTs are present in a substantial proportion of eyes. We identified baseline features that independently predict ORTs. It is important to identify ORTs because eyes with ORTs have worse VA outcomes than those without this finding.

Outer retinal tubulation in degenerative retinal disorders

PURPOSE

To demonstrate outer retinal tubulation (ORT) in various degenerative retinal disorders.

METHODS

This was a retrospective review of the multimodal imaging of 29 eyes of 15 patients with various retinal dystrophies and inflammatory maculopathies manifesting ORT. The morphologic features of ORT and its evolution over time were analyzed using spectral-domain optical coherence tomography data.

RESULTS

Outer retinal tubulation was identified as round or ovoid structures with hyperreflective borders in pattern dystrophy (six eyes), acute zonal occult outer retinopathy (five eyes), retinitis pigmentosa (four eyes), Stargardt disease (four eyes), gyrate atrophy (two eyes), choroideremia (two eyes), and various other degenerative conditions. These structures appeared to develop from the invagination of photoreceptors at the junction of intact and atrophic outer retina. During follow-up, the number and distribution of ORT largely remained stable. As zones of atrophy enlarged, the frequency of ORT appeared to increase. The ORT structures were found in <10% of patients with retinitis pigmentosa, Stargardt disease, or pattern dystrophy.

CONCLUSION

Outer retinal tubulation is found in various degenerative retinal disorders that share in common damage to the outer retina and/or retinal pigment epithelium. The presence of ORT may be an indicator of underlying disease stage and severity.

An update on the ocular phenotype in patients with pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is an inherited multi-system disorder characterized by ectopic mineralization and fragmentation of elastic fibers in the skin, the elastic laminae of blood vessels and Bruch's membrane in the eye. Biallelic mutations in the ATP-binding cassette (ABC) transporter gene ABCC6 on chromosome 16 are responsible for the disease. The pathophysiology is incompletely understood. However, there is consent that a metabolic alteration leads to dysfunction in extracellular calcium homeostasis and subsequent calcification of connective tissues rich in elastic fibers. This review summarizes and aims at explaining the variety of phenotypic ocular findings in patients with PXE. Specialized imaging techniques including white light fundus photography, blue light autofluorescence, near-infrared confocal reflectance imaging, high resolution optical coherence tomography, fluorescein and indocyanine green (ICG) angiography have revealed characteristic lesions at the ocular fundus of PXE patients. These include the classic signs of angioid streaks, peau d'orange, comet lesions, and choroidal neovascularizations (CNVs), but also the more recently recognized features such as chorioretinal atrophy, subretinal fluid independent from CNV, pattern dystrophy-like changes, debris accumulation under the retinal pigment epithelium, reticular drusen and a decreased fluorescence on late phase ICG angiography.