METHYLATION-ASSOCIATED PATHWAYS IN MACULAR TELANGIECTASIA TYPE 2 AND OPHTHALMOLOGIC FINDINGS IN PATIENTS WITH GENETIC METHYLATION DISORDERS.

PURPOSE: Serine (Ser) and glycine (Gly) levels were reported to differ between patients with macular telangiectasia type 2 (MacTel) compared with healthy controls. Because they are closely related to methylation metabolism, this report investigates methylation-associated metabolite levels in patients with MacTel and retinal changes in monogenetic methylation disorders. METHODS: Prospective, monocentric study on patients with MacTel and healthy controls underwent a standardized protocol including a blood draw. Methylation-associated metabolite levels in plasma were determined using targeted quantitative metabolomics. Furthermore, patient records of cystathionine beta-synthase, methylenetetrahydrofolate reductase, and methylmalonic aciduria and homocystinuria type C protein (MMACHC) deficiency were screened for reported retinal changes. RESULTS: In total, 29 patients with MacTel and 27 healthy controls were included. Patients with MacTel showed lower plasma Ser ( P = 0.02 and P = 0.01) and Gly ( P = 0.11 and P = 0.11) levels than controls. Principal component analyses revealed that methylation-associated metabolite, especially homocysteine, contributed to a distinct clustering of patients with MacTel. No retinal changes were seen in cystathionine beta-synthase (n = 1) and methylenetetrahydrofolate reductase (n = 2) deficiency, while two patients with MMACHC (n = 4) deficiency displayed extensive macular dystrophy. CONCLUSION: Patients with MacTel show distinct clustering of methylation-associated metabolite compared with controls. Of the three homocystinurias, only MMACHC resulted in macular dystrophy, possibly due to distinct compensatory pathways.

Epiretinal neovascular membrane in Macular Telangiectasia type 2: Multimodal imaging diagnosis.

PURPOSE: To characterize an epiretinal neovascular membrane (ERNM) through multimodal imaging in the context of a patient with Macular Telangiectasia type 2 (MacTel) and ipsilateral concomitant ocular ischemic syndrome (OIS). METHODS: Case report, with ultra-wide field (UWF) retinography, fluorescein angiography (FA), swept source optical coherence tomography (ss-OCT), and OCT-angiography (OCTA). Written informed consent for patient information and images to be published was provided by the patient. Approval from the Research Ethics Committee of the Hospital was obtained for publication. CASE REPORT: Yearly follow up of a 51 year-old-female patient with advanced bilateral MacTel showed new punctate hemorrhages in all four quadrants of her right eye (OD). OCTA showed an ERNM in the superficial capillary plexus of the same eye and FA confirmed the ERNM and demonstrated peripheral ischemia. Carotid ultrasound was performed and complete right carotid artery occlusion was confirmed. These findings allowed the diagnosis of an ERNM associated with Mactel and OIS. CONCLUSIONS: Interestingly, this case shows an ERNM diagnosed by multimodal imaging in a patient with advanced MacTel and a concomitant OIS. Mactel is a neurodegenerative disease which in its neovascular stage has been associated with macular neovascular membranes, but also ERNM have recently been described by OCTA.

Developing a Continuous Severity Scale for Macular Telangiectasia Type 2 Using Deep Learning and Implications for Disease Grading.

PURPOSE: Deep learning (DL) models have achieved state-of-the-art medical diagnosis classification accuracy. Current models are limited by discrete diagnosis labels, but could yield more information with diagnosis in a continuous scale. We developed a novel continuous severity scaling system for macular telangiectasia (MacTel) type 2 by combining a DL classification model with uniform manifold approximation and projection (UMAP). DESIGN: We used a DL network to learn a feature representation of MacTel severity from discrete severity labels and applied UMAP to embed this feature representation into 2 dimensions, thereby creating a continuous MacTel severity scale. PARTICIPANTS: A total of 2003 OCT volumes were analyzed from 1089 MacTel Project participants. METHODS: We trained a multiview DL classifier using multiple B-scans from OCT volumes to learn a previously published discrete 7-step MacTel severity scale. The classifiers' last feature layer was extracted as input for UMAP, which embedded these features into a continuous 2-dimensional manifold. The DL classifier was assessed in terms of test accuracy. Rank correlation for the continuous UMAP scale against the previously published scale was calculated. Additionally, the UMAP scale was assessed in the κ agreement against 5 clinical experts on 100 pairs of patient volumes. For each pair of patient volumes, clinical experts were asked to select the volume with more severe MacTel disease and to compare them against the UMAP scale. MAIN OUTCOME MEASURES: Classification accuracy for the DL classifier and κ agreement versus clinical experts for UMAP. RESULTS: The multiview DL classifier achieved top 1 accuracy of 63.3% (186/294) on held-out test OCT volumes. The UMAP metric showed a clear continuous gradation of MacTel severity with a Spearman rank correlation of 0.84 with the previously published scale. Furthermore, the continuous UMAP metric achieved κ agreements of 0.56 to 0.63 with 5 clinical experts, which was comparable with interobserver κ values. CONCLUSIONS: Our UMAP embedding generated a continuous MacTel severity scale, without requiring continuous training labels. This technique can be applied to other diseases and may lead to more accurate diagnosis, improved understanding of disease progression, and key imaging features for pathologic characteristics. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Unusual anterior and posterior segment features of coats disease.

PURPOSE: To report the clinical course and management of unusual anterior and posterior segment features of Coats disease and their relation to the age of the patients to increase the awareness towards these rare clinical features rarely described in the current literature. METHODS: A retrospective descriptive review of 45 eyes of 45 patients affected by Coats disease was conducted at the Retinoblastoma Referral Center and Ophthalmology Unit of the University of Siena in Italy analyzing data from 2000 to 2022. Medical records and images were revised to find some cases presenting unusual anterior and posterior segment features in patients affected by Coats disease.We identified therefore 4 unusual clinical conditions: retinal macrocysts, anterior chamber cholesterolosis, fovea-sparing Coats disease and secondary vasoproliferative tumor. RESULTS: Two patients presented with retinal macrocyst (2/45 = 4.4%), one with anterior chamber cholesterolosis (1/45 = 2.2%), two with fovea sparing Coats disease (2/45 = 4.4%) and one with vasoproliferative tumor associated (1/45 = 2.2%) for a total of six (6/45 = 13.3%) patients manifesting unusual anterior or posterior segment features in Coats disease. CONCLUSION: Unusual anterior and posterior segment features of Coats disease such as retinal macrocyst and anterior chamber cholesterolosis have been more frequently reported in younger children while fovea-sparing and vasoproliferative tumors have been more commonly described in older patients. Age is then a strong prognostic marker which allows to distinguish two different phenotypes of Coats disease: patients younger and older than 3 years old with more aggressive and milder phenotype respectively.

Long-term efficacy and complications of intravitreal anti-vascular endothelial growth factor agents combined with ablative therapies in juvenile Coats disease: a five year follow-up study.

PURPOSE: To evaluate the long-term safety and efficacy of adjuvant intravitreal anti-VEGF therapy in juvenile Coats disease. METHODS: This retrospective, observational study included a total of 62 eyes in 62 pediatric patients with juvenile Coats disease treated with intravitreal anti-VEGF agents followed for a mean of 67.08 months (ranged from 60 to 93 months). All affected eyes were managed initially with one session of ablative treatment plus adjuvant intravitreal anti-VEGF agent (0.5 mg/0.05 ml ranibizumab or conbercept). Ablative treatment was repeated if telangiectatic retinal vessels were not completely regressed or recurred. Anti-VEGF therapy was repeated if subretinal fluid or macular edema still existed. Treatments above were repeated every 2 to 3 months. We reviewed clinical and photographic records of patients including the demographics, clinical characteristics and interventions. RESULTS: At final visit, all 62 affected eyes had partially or completely disease resolution; none progressed to advanced stage namely neovascular glaucoma or phthisis bulbi, respectively. No ocular or systemic side effects related to intravitreal injections were observed during follow-up. In terms of 42 affected eyes that could cooperate with visual examination, best corrected visual acuity improved in 14 (14/42, 33.3%) eyes, stabled in 25 (25/42, 59.5%) eyes, and worsened in 3 (3/42, 7.1%) eyes. In the field of complications, 22 (22/62, 35.5%) eyes developed cataracts; 33 (33/62, 53.2%) eyes developed vitreoretinal fibrosis, of whom 14 (14/33, 42.4%) eyes in the subgroup of stage 3B developed progressive TRD; 40 (40/62, 64.5%) eyes developed subretinal fibrosis. Multivariate regression analysis showed increased clinical stage may be associated with the development of vitreo- and subretinal fibrosis (adjusted odds ratio:16.77,17.59; 95% CI:4.50-62.53, 3.98-77.86, respectively, all P < 0.001). CONCLUSION: Adjuvant intravitreal ranibizumab or conbercept combined with ablative therapies may be a long-term safe and effective treatment for juvenile Coats disease.

Epiretinal membrane formation and optic disc vascularisation in type 2A macular telangiectasia (MacTel).

PURPOSE: To describe a rare clinical finding of epiretinal membrane (ERM) and abnormal optic disc vascularisation in type 2A macular telangiectasia (MacTel). CASE DESCRIPTION: A 52-year-old asymptomatic healthy male was examined in the retina clinic. In both eyes, corrected visual acuity was 20/20, N6. Anterior segment examination and intraocular pressure were both normal in both eyes. RESULTS: The right eye's dilated fundus examination revealed loss of retinal transparency and superficial intraretinal crystals. A thick ERM extending from the optic disc to the macula obscured the details of the underlying perifoveal region in the left eye fundus. The diagnosis of bilateral type 2 MacTel was confirmed by confocal blue reflectance imaging, fluorescein angiography (FA), and macular optical coherence tomography (OCT). The left eye macular OCT scan also revealed a thick ERM without causing significant retinal traction. Furthermore, FA of the left eye revealed early hyperfluorescence with intense late leakage at the inferior aspect of the optic disc, giving the impression of abnormal optic disc vascularisation. No other cause for the disc vascularisation could be identified. OCT scan through the area with the optic disc leakage revealed a tuft of irregular hyperreflective tissue lying over the ERM. OCT angiography imaging confirmed the vascularity within the tuft of hyperreflective tissue over the ERM. Over a two-year period, no changes in clinical or imaging features were observed. CONCLUSION: In type 2A MacTel eyes, ERM formation and abnormal disc vascularisation are uncommon findings. More histopathologic research is needed to characterise these membranes.

Surgical Management of Full-Thickness Macular Holes in Macular Telangiectasia Type 2: A Global Multicenter Study.

PURPOSE: To report on macular hole repair in macular telangiectasia type 2 (MacTel2). DESIGN: Global, multicenter, retrospective case series. PARTICIPANTS: Patients undergoing surgery for MacTel2-associated full-thickness macular hole (MTMH). METHODS: Standardized data collection sheet distributed to all surgeons. MAIN OUTCOME MEASURES: Anatomic closure and visual outcomes of MTMH. RESULTS: Sixty-three surgeries in 47 patients with MTMH were included from 30 surgeons. Mean age was 68.1 years, with 62% female, 72% White, 21% East or South Asian, 2% African American, and 2% Hispanic or Latino. Procedures included 34 internal limiting membrane (ILM) peeling alone, 22 ILM flaps, 5 autologous retinal transplantations (ARTs), 1 retinotomy, and 1 subretinal bleb. For ILM peeling, preoperative visual acuity (VA) was 0.667 ± 0.423 logarithm of the minimum angle of resolution (logMAR). Minimum hole diameter (MHD) was 305.5 ± 159.4 µm (range, 34-573 µm). Sixteen of 34 ILM peels (47%) resulted in MTMH closure. At postoperative month 6, VA was stable at 0.602 ± 0.516 logMAR (P = 0.65). VA improved by at least 2 lines in 43% and at least 4 lines in 24%. For ILM flaps, preoperative VA was 0.878 ± 0.552 logMAR. MHD was 440.8 ± 175.5 µm (range, 97-697 µm), which was significantly larger than for ILM peels (P < 0.01). Twenty of 22 ILM flaps (90%) resulted in MTMH closure, which was significantly higher than for ILM peels (P < 0.01). At postoperative month 6, VA improved to 0.555 ± 0.405 logMAR (P < 0.05). VA improved by at least 2 lines in 56% and at least 4 lines in 28%. For ARTs, preoperative VA was 1.460 ± 0.391 logMAR. MHD was 390.2 ± 203.7 µm (range, 132-687 µm). All 5 ARTs (100%) resulted in MTMH closure. At postoperative month 6, VA was stable at 1.000 ± 0.246 logMAR (P = 0.08). Visual acuity improved at least 2 lines in 25%. CONCLUSIONS: Surgical closure of macular holes improved VA in 57% of MTMHs. Internal limiting membrane flaps achieved better anatomic and functional outcomes than ILM peeling alone. Autologous retinal transplantation may be an option for refractory MTMHs. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Relevance of multicolor imaging, its component channels, and fundus autofluorescence in describing macular telangiectasia type-2 (MacTel) lesion characteristics.

PURPOSE: The aim of the study was to describe imaging characteristics and detection rates of phenotypic features in macular telangiectasia type-2 (MacTel) on multicolor (MC), blue reflectance (BR), green reflectance (GR), infrared reflectance (IR), and fundus autofluorescence (FAF) and to evaluate sensitivity, specificity, and predictive values across modalities. METHODS: In this monocentric observational study, 282 eyes of 148 patients with MacTel underwent color fundus photograph, MC, BR, GR, IR, FAF, spectral-domain optical coherence tomography (SD-OCT), OCT-angiography (OCT-A), and fundus fluorescein angiography (FFA). Grading was done by two graders qualitatively and quantitatively for the presence of the following prespecified MacTel findings [crystals, right-angle vessels (RAVs), plaques, subretinal neovascularization (SRNV), and MacTel area]. Across each imaging modality, the detection rate of RAVs and SRNV was compared with reference standard OCT-A (RAVs and SRNV) and FFA (SRNV), whereas that of plaques was compared with reference standard SD-OCT. RESULTS: MC identified overall MacTel characteristics in 92.7% of eyes. Regarding the presence, number, and quadrants of RAVs and the presence and number of crystals, MC and GR had superior detection rates as well as the highest sensitivity and negative predictive value. Retinal plaques were better detected using FAF (97%), followed by MC (88%). In proliferative MacTel, SRNV was identified in 86% and 79% of eyes on MC and IR, respectively. While BR clearly delineated MacTel area in 100% eyes, FAF was able to ascertain a larger area of involvement in proliferative MacTel. CONCLUSION: The findings demonstrate the ability of MC, its component channels, and FAF to describe MacTel characteristics qualitatively and quantitatively.

Proximal nailfold videocapillaroscopy findings of patients with idiopathic macular telangiectasia type 2.

PURPOSE: Idiopathic macular telangiectasia type 2 (IMT) is a neurodegenerative disease characterized by bilateral, idiopathic, and perifoveal retinal telangiectatic vessel formations. We aimed to compare proximal nailfold videocapillaroscopy (NV) findings between patients with IMT and healthy individuals and evaluate the optical coherence tomography angiography (OCTA) parameters of the patients with IMT according to their NV findings. METHODS: The study included 43 patients with IMT and 92 healthy controls of similar age and gender without any additional diseases. The OCTA and NV findings of the patients and controls were examined. RESULTS: The mean age was 59.76 ± 5.73 years in the IMT group and 58.23 ± 4.96 years in the control group. Of the 43 patients with IMT, 19 were found to have increased capillary tortuosity, six had microhemorrhage, and 18 had bizarre capillaries (P < 0.001). In the IMT group, the total vascular density value of the superficial capillary plexus was higher among the patients with capillary microhemorrhage (P = 0.001), and the subfoveal choroidal thickness was lower among those with increased capillary tortuosity and bizarre capillaries (P = 0.04 and P = 0.07, respectively). CONCLUSION: This is the first study in which the NV findings of patients with IMT were compared with those of a control group. We found higher rates of increased capillary tortuosity, microhemorrhage, and bizarre capillaries in the IMT group compared to the controls. We consider that this situation is caused by microvascular damage. We also think that IMT is a systemic disease that affects both proximal nailfold capillaries and eye vessels.

Subfoveal Nodule Affecting Visual Prognosis in Coats Disease.

PURPOSE: To investigate the characteristics of subfoveal nodules in Korean patients with Coats disease and their association with visual outcomes. METHODS: A retrospective analysis was conducted within the medical records of patients with stage 2B or 3A1 Coats disease, including clinical features, imaging, presence of either a subfoveal nodule or macular fibrosis, and visual outcome. RESULTS: Twelve patients were present with stage 2B or 3A1 Coats disease, and nine patients (75%) presented with subfoveal nodule. Between the group without subfoveal nodule and the group with subfoveal nodule, there were no significant differences in age (mean, 14.0 ± 1.7 years vs. 27.7 ± 21.8 years; p = 0.482), sex (all men), stage of the disease (stage 2B: three patients vs. eight patients, p > 0.999; stage 3A1: none vs. one patient, p > 0.999), extension of retinal exudation (mean, 7.7 hours vs. 4.1 hours; p = 0.209) and peripheral telangiectasia (mean, 3.7 hours vs. 4.2 hours; p = 0.727), and follow-up duration (mean, 65.0 months vs. 46.1 months; p = 0.600). There were significantly more patients with severe visual loss (≤20 / 200) among the patients with subfoveal nodule (none vs. seven patients, p = 0.045), and the cause for severe visual loss was macular fibrosis in all cases. Macular fibrosis developed significantly more frequently in the patients with subfoveal nodule (none vs. seven = patients, p = 0.045). CONCLUSIONS: This study is the first study covering the analysis of subfoveal nodules in Korean patients with Coats disease. The existence of a subfoveal nodule at the initial diagnosis serves as an indicator predicting the development of macular fibrosis and a less favorable visual outcome in the patients with Coats disease. A multicenter study with a larger patient pool and further studies toward the therapeutic approach for the subfoveal nodule and macular fibrosis are needed.

Longitudinal anatomical and visual outcome of macular telangiectasia type 2 in Asian patients.

Limited information regarding the anatomical and visual prognosis of macular telangiectasia (MacTel) type 2 in the Asian population is currently available. Herein, we conducted a retrospective longitudinal analysis of Japanese patients diagnosed with MacTel type 2. Disease progression was evaluated using the Simple MacTel Classification developed by Chew EY et al. in 2023, and its association with visual changes was analyzed. Sixteen eyes of eight Japanese patients were included in the study, with an average follow-up period of 8.2 ± 3.9 years (range, 2.2-14.0). At the initial visit, 7 (44%) and 5 (31%) eyes were classified as Grade 2 (central ellipsoid zone break) and Grade 3 (noncentral pigment), respectively. The proportion of eyes that progressed by 1 or 2-steps in grade after 1, 3, 5, 8, and 12 years was 0%, 14%, 43%, 70%, and 100%, or 0%, 7%, 7%, 30%, and 75%, respectively. The visual acuity significantly deteriorated during the follow-up period, particularly in the two eyes with full-thickness macular holes (FTMH). Three out of 7 patients exhibited low serum serine concentrations, although no apparent correlation with anatomical or visual outcomes was observed. Overall, this cohort demonstrated chronic disease progression, both anatomically and functionally, in eyes with MacTel type 2, with FTMH potentially associated with greater visual loss.

Lifting the White Walker's curse-Management of Coats' disease.

Background: Coats' disease, described by George Coats in the early 1900s, is an idiopathic unilateral retinal vascular abnormality with exudation occurring in young males. It is characterized by retinal telangiectasia with intraretinal or subretinal exudation. Coats' disease is mostly diagnosed in the first to the second decade of life, with a common presentation of leukocoria. Younger patients have a more severe presentation and are associated with poor visual prognosis. Management of Coats' disease varies from observation, cryotherapy with anti-VEGFs (Vascular Endothelial Growth Factor), and surgery to enucleation. The mode of treatment depends on the age of presentation, the severity of the disease, and the stage of the disease. Through this video, we describe the clinical features, pathology, and surgical management of a 2-year-old child with grade 3B of Coats' disease. Purpose: To demonstrate successful surgical management of grade 3B of Coats' disease in a 2-year-old boy. Synopsis: Coats' disease mostly presents with a diagnostic dilemma due to its varied presentation. Early detection and treatment are the keys to salvaging the eye as well as the vision, hence, avoiding dreadful complications such as neovascular glaucoma or phthisis bulbi. We demonstrate successful surgical management of a child who presented with grade 3B of Coats' disease. Highlights: Through this video, we aim to describe the clinical features, pathology, and surgical management of a 2-year-old child with grade 3B of Coats' disease. Combination of external drainage with vitrectomy, challenges faced, and the importance of visual rehabilitation postoperatively. Video Link: https://youtu.be/0obpVTOkKKs.

Efficacy and Safety of Anti-Vascular Endothelial Growth Factor Drugs for Coats' Disease Treatment: A Systematic Review.

Purpose: The efficacy and safety of anti-vascular endothelial growth factor (anti-VEGF) treatment for Coats' disease remains controversial. This study was designed to evaluate the efficacy and safety of anti-VEGF treatment for Coats' disease. Methods: PubMed, Embase, The Cochrane Library, Clinical Trials, CNKI, and WanFang databases were systematically searched for clinical efficacy and safety studies on anti-VEGF treatment for Coats' disease through June 2021. Study selection, data extraction, and quality assessment were independently performed by 2 reviewers. Quality assessments were performed using the Joanna Briggs Institute Critical Appraisal tools and GRADE-CERQual. Results: A total of 1,501 articles were retrieved and reviewed, of which 24 case series involving 378 patients (range: 3-67 patients each with 3-71 eyes) were included in the analysis. No randomized controlled trials, case-controlled studies, or cohort studies were available for analysis. Most patients were male (60.0%-92.9%), aged 1.35-42.3 years, with a median follow-up time ranging from 3 to 63 months. Among the 24 case series, 22 reported changes in the visual acuity (VA) after anti-VEGF treatment and 21 reported safety outcomes. The results showed that VA improved in 73 patients (37.63%), was stable in 89 (45.87%), and worsening VA was observed in 12 cases (6.19%). The most common adverse event was fibrotic changes (n = 35). Systemic complications were not observed. Conclusions: The results of this study indicate that anti-VEGF drugs provide an effective and relatively safe treatment strategy for Coats' disease. However, conducting well-designed, prospective, randomized clinical trials are necessary to confirm our findings.

Coats' Disease in a Patient With Cornelia de Lange Syndrome: Management With Laser and Bevacizumab.

Cornelia de Lange syndrome is a congenital disorder with multisystem abnormalities including multiple ocular findings. The authors report a case of Coats' disease in a patient with Cornelia de Lange syndrome who was successfully treated with laser and intravitreal bevacizumab. This case demonstrates the importance of fluorescein angiography in making the diagnosis and directing treatment and the efficacy of combined laser with intravitreal anti-vascular endothelial growth factor therapy for persistent vascular leakage associated with Coats' disease in Cornelia de Lange syndrome. [J Pediatr Ophthalmol Strabismus. 2023;60(4):e45-e48.].

Relative Ellipsoid Zone Reflectivity in Macular Telangiectasia Type 2.

Purpose: The relative ellipsoid zone reflectivity (rEZR) has been proposed as an innovative biomarker for photoreceptor integrity. This study evaluates the rEZR in macular telangiectasia type 2 (MacTel) eyes of different disease stages. Methods: The mean rEZR (ratio ellipsoid zone [EZ]/external limiting membrane [ELM] reflectivity [arbitrary units {AUs}], grey level range = 0-1) was analyzed for an entire spectral domain optical coherence tomography volume scan (global) and for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid (topographic) in patients with MacTel and controls. MacTel disease severity was classified according to Gass and Blodi. Results: Linear mixed-model analysis of 145 eyes of 74 patients and 50 eyes of 25 controls revealed globally lower, yet not statistically significant, rEZR values in MacTel eyes. Topographically, most pronounced decreases were found in stages 3 and 4/5 for the temporal inner (coefficient estimates [CEs] = -25.4 [-38.2; -12.6] and -34.1 [-48.7; -19.6] AU, both: P < 0.001), the inferior inner (-29.9 [-44.6; -15.6] and -35.3 [-52.1; -18.5] AU, both: P < 0.001), the nasal inner (-21.5 [-35.52; -7.4] and -31.6 [-47.6; -15.6] AU, P = 0,003 and P < 0.001), and in the superior inner subfield of stage 4/5 (-25.0 [-42.0; -7.9] AU, P = 0.004). Conclusions: The rEZR showed association with disease severity and the predilection area of MacTel. Given the current understanding of the pathophysiological concept of MacTel, these findings underscore the value of the rEZR as a potential novel biomarker for outer retinal integrity. Longitudinal studies are demanded to better characterize its value as a biomarker for early photoreceptor alterations and disease progression in MacTel.

FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY IN PATIENTS WITH MACULAR TELANGIECTASIA TYPE 2 WITH AND WITHOUT DIABETES.

PURPOSE: Macular telangiectasia type 2 (MacTel) is a vision-altering retinal disease with a high prevalence of diabetes. Differences between patients with MacTel with and without diabetes were investigated using fluorescence lifetime imaging ophthalmoscopy (FLIO). METHODS: Eighty-six patients with MacTel (59 ± 12 years) were included. 40 patients (46%) did not have diabetes, 16 patients (19%) were prediabetic, and 30 patients (35%) were diabetic. Of these, seven had diabetic retinopathy. 18 diabetic patients without MacTel and 42 age-matched healthy controls were included. FLIO lifetimes (FLTs) were obtained in short (SSC, 498-560 nm) and long (LSC, 560-720 nm) spectral channels from different areas of interest using a Heidelberg Engineering FLIO. RESULTS: Fundus autofluorescece lifetimes did not show significant differences when comparing diabetic with nondiabetic MacTel eyes (MacTel zone, SSC, diabetic: 243 ± 65 ps; nondiabetic: 232 ± 51 ps; P = 1.0; LSC, diabetic: 327 ± 66 ps; nondiabetic: 309 ± 54 ps; P = 0.582). Longitudinal changes were similarly unrelated to diabetes status. A nonsignificant trend of increased FLT progression with higher body mass index was found. Fundus autofluorescece lifetimes in diabetic patients without MacTel were significantly shorter within the MacTel zone and longer in the periphery compared with diabetic patients with MacTel. CONCLUSION: Although MacTel has a high prevalence of diabetes, FLTs from the MacTel zone are unrelated to diabetes. Fluorescence lifetime imaging ophthalmoscopy retains diagnostic abilities in patients with MacTel even in the presence of prediabetes, diabetes, and advanced diabetic retinopathy. The lack of diabetic FLT changes in the periphery of diabetic patients with MacTel is an interesting finding that needs further investigation.

ABNORMALITIES IN THE RETINAL CAPILLARY PLEXUSES IN COATS DISEASE IN ADULTHOOD ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To describe and quantify the abnormalities of the retinal capillary plexuses using optical coherence tomography angiography in Coats disease. METHODS: Retrospective study. Eleven eyes of 11 patients with Coats disease (9 men and two women aged 32-80 years) compared with nine fellow eyes and 11 healthy control eyes. Horizontal bands of contiguous 3 × 3 mm optical coherence tomography angiograms of the superficial vascular plexus and deep capillary complex were acquired from the optic disk to 6 mm temporal to the fovea, through areas with telangiectasia visible on fluorescein angiography in 9 cases. RESULTS: The vascular density was significantly decreased in both plexuses in eyes with Coats disease compared with normal and fellow eyes within the 6 mm temporal to the fovea (superficial vascular plexus: 21.5 vs. 29.4%, P = 0.00004 and vs. 30.3%, P = 0.00008; deep capillary complex, 16.5 vs. 23.9%, P = 0.00004 and vs. 24.7%, P = 0.00008, respectively). The fractal dimension was also significantly decreased in eyes with Coats disease (superficial vascular plexus: 1.796 vs. 1.848 P = 0.001 and vs. 1.833, P = 0.003; deep capillary complex: 1.762 vs. 1.853, P = 0.003 and vs. 1.838, P = 0.004, respectively). CONCLUSION: Retinal plexuses' vascular density was decreased in Coats disease, including in areas with no visible telangiectasia.

FURTHER EVIDENCE AGAINST BILATERAL MANIFESTATION OF COATS DISEASE IN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF THE MACULA.

PURPOSE: Recent studies have questioned the traditional view, which regards Coats disease as a strictly unilateral entity. Applying optical coherence tomography angiography, this prospective, monocentric study investigates quantitative capillary changes of the macula associated with Coats disease. METHODS: Twenty-four eyes (4 untreated, 8 pre-treated) of 12 patients with stage 2 Coats disease (age range: 9-61 years) and 15 eyes of healthy, age-matched controls from the University of Muenster Medical Center, Germany received macular optical coherence tomography angiography measurements of the superficial, deep, and choriocapillary capillary plexus. Flow density and parameters related to the foveal avascular zone were compared between Coats eyes and fellow eyes, and between fellow eyes and control eyes. Additional subanalyses investigated changes based on disease stage. RESULTS: Flow density did not differ between fellow eyes of Coats disease patients and control eyes in any of the parameters investigated. Comparison of Coats eyes to their respective fellow eyes revealed Coats disease to be associated with lower flow density in superficial, deep, and choriocapillary capillary plexus regions, irrespective of disease stage (all P < 0.03). There were no noticeable differences regarding the size or symmetry of the foveal avascular zone. CONCLUSION: In light of the recent discussion around the unilateral character of Coats disease, this trial provides evidence against a bilateral presentation of vascular changes in the macula.

Relation of interdigitation zone changes and right-angle vessels in Macular Telangiectasia Type-2 (MacTel).

BACKGROUND: To study the relation between interdigitation zone (IDZ) and right-angle vessel (RAV) in Macular Telangiectasia Type-2 (MacTel). METHODS: A total of 43 eyes of 38 patients with presence of definite RAV on colour fundus photograph (Gass and Blodi-only stage-3) were confirmed on multimodal imaging. The relation of IDZ changes and associated ellipsoid zone (EZ) alterations on spectral-domain optical coherence tomography (OCT) with RAV were studied at baseline and these OCT changes were followed up in 15 eyes over a mean of 3.86 years. RESULTS: A total of 58 RAVs were found in the 43 eyes and 53/58 (91.3%) RAVs were associated with IDZ alterations in 39 eyes. On follow-up, IDZ attenuation progressed to IDZ loss and subsequent EZ attenuation and loss. A pre-existing IDZ loss was associated with subsequent EZ defect (P = 0.002). In 36 eyes that had OCT angiography, eyes with RAV showed deep capillary plexus telangiectasia in all 36 (100%) eyes and 32/36 (89%) eyes showed IDZ changes with or without EZ loss. CONCLUSIONS: IDZ attenuation and/or loss are associated with RAV and may serve as predictor of EZ loss in MacTel.