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.

Type-3 macular neovascularization in a case of long-standing macular telangiectasia type-2.

We report a rare case of type-3 macular neovascularization (MNV) in an established case of macular telangiectasia type-2 (MacTel). A 49-year-old healthy Indian woman was diagnosed with MacTel (Gass and Blodi stage 3 in the right eye [OD] and stage 2 in the left eye [OS]) in our retina clinic in January 2004. She was subsequently seen 10 years later with MacTel progression in OD (stage 4) and drusenoid changes in both eyes. She recently complained of sudden onset diminution of vision in OS of 1 week duration. The best-corrected visual acuity, when she attended this day, was 20/500 (OD) and 20/60 (OS). Fundus revealed pigment deposition in the macula in OD and a large pigment epithelial detachment (PED) in OS with drusen in both eyes, suggesting coexisting age macular degeneration (AMD) and MacTel (stage 4 OD; stage 2 OS) bilaterally. Multimodal imaging with spectral-domain optical coherence tomography showed drusen, a large trapezoid PED with central apical disruption, outer retinal hyperreflective material, intraretinal fluid, and inner retinal cavitation. Indocyanine green angiography revealed "hotspot" at center of the PED with hairpin-loop vessels. Optical coherence tomography angiography demonstrated network at apex of the PED. These features confirmed a diagnosis of type-3 MNV (classical retinal angiomatous proliferation [RAP] lesion) in OS along with features of AMD and MacTel. There was resolution of intraretinal fluid and reduction in height of PED following three loading doses of intravitreal ranibizumab in OS. Although type-3 neovascularization has been described in MacTel, to the best of our knowledge, this is the first documentation of classical RAP features of MNV with all described multimodal imaging features. The type-3 neovascularization typically described in association with MacTel is retinal-retinal, retinal-subretinal, and retinochoroidal anastomosis (RCA). Although RAP is also associated with RCA, the features seen in our case, i.e., triad of erosion at the roof of PED, inverted flap in the PED, and hotspot in the center of PED, have not been documented in association with MacTel.

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.

OUTER FOVEAL DEFECTS IN TYPE-2 MACULAR TELANGIECTASIA.

PURPOSE: To report characteristics of outer foveal defects (OFDs) in type-2 macular telangiectasia (MacTel) on spectral domain optical coherence tomography. METHODS: This was a single-center observational study. From a registry of 745 patients with MacTel, patients with OFDs were characterized. All patients underwent multimodal imaging including color fundus photography, confocal blue reflectance, fundus autofluorescence, and spectral domain optical coherence tomography. Staging of eyes was done using the Gass and Blodi classification. Spectral domain optical coherence tomography characteristics in the central 1 mm of the macula in eyes with OFD are reported. RESULTS: Outer foveal defect was observed in 21 eyes of 15/745 (2%) patients with MacTel. These defects were bilateral in 6/15 (40%) patients and seen in stage 2 MacTel eyes. In order of prevalence, foveal parameters seen in OFD included hyper-reflective dots in outer retina in 19/21 (90%), ellipsoid zone loss in 18/21 (86%) eyes, interdigitation zone loss in 17/21 (81%) eyes, outer retinal hyporeflective cavitation in 14 (67%) eyes, hyporeflective cavitation at foveal pit in 8 (38%) eyes, and loss of external limiting membrane in 1 (5%) eye. The mean baseline length of the foveal ellipsoid zone loss was 240.17 ± 117.249 µm. The mean baseline central subfield thickness was 155.43 ± 17.215 µm. A total of 8/11 eyes (73%) showed an increase in size of OFD on follow-up. CONCLUSION: Outer foveal defect in MacTel eyes is characterized predominantly by foveal loss of ellipsoid zone and interdigitation zone with relative preservation of external limiting membrane.

Microvascular changes precede visible neurodegeneration in fellow eyes of patients with asymmetric type 2 macular telangiectasia.

IMPORTANCE: Macular telangiectasia type 2 (MacTel) is bilateral disease with characteristic alterations of the macular capillary network along with decreased macular pigment in the parafoveal area. The purpose of this study was to highlight that some eyes show microvascular changes which precede any visible neuronal changes on spectral-domain optical coherence tomography (SD-OCT). METHODS: This observational study was conducted at a tertiary eye institute. From a registry of 630 patients with MacTel, we identified 4 patients with typical MacTel characteristics in only one eye with no visible changes on colour photographs or SD-OCT in the fellow eye. These 4 patients had findings of MacTel documented by colour fundus photograph, multicolour imaging (MCI), fundus autofluorescence (FAF), confocal blue reflectance (CBR), SD-OCT, and OCT-Angiography (OCT-A) in one eye. OCT-A was performed in MacTel patients using the High-resolution Spectralis (Heidelberg Engineering) module with a full-spectrum probabilistic approach and we employed a 30° x 15° (~8.8 mm × 4.4 mm) scan pattern covering the macula. MCI was done at the end so as to avoid fading the confocal blue reflectance hyperreflectivity seen in MacTel. RESULTS: On OCT-A, all 4 fellow eyes showed telangiectasia and foveal avascular zone changes in the superficial and deep capillary plexuses with no changes on SD-OCT. None of the eyes showed typically increased reflectance on CBR around the foveal area. CONCLUSION: These findings show that microvascular changes on OCT-A may occur before visible neurodegenerative changes on OCT, providing new insights into the course of the disease.

Bilateral simultaneous Central Retinal Artery Occlusion (CRAO) in a patient with Systemic Lupus Erythematosus (SLE).

PURPOSE: The objective of the study is to report a rare case of severe vaso-occlusive retinopathy with bilateral simultaneous Central Retinal Artery Occlusion (CRAO) in a patient with Systemic Lupus Erythematosus (SLE). OBSERVATIONS: A female patient aged 22 years, presented with a sudden onset of painless diminution of vision in both eyes for three weeks. She had systemic features of SLE for six months at the time of the study. A diagnosis of bilateral CRAO was made after an examination of the fundus and by ruling out other causes of severe vaso-occlusion based on clinical and angiogram findings. Her antiphospholipid antibody (APLA) levels were normal. The visual prognosis was poor even after treatment with intravenous steroids and panretinal photocoagulation. CONCLUSION AND IMPORTANCE: This case highlights the importance of bilateral CRAO as an initial presentation of severe systemic disease. This case demonstrates that despite apparent normal APLA levels, a state of hypercoagulability can exist in SLE patients. In addition, it demonstrates that severe vaso-occlusive complications such as CRAO, which results in blindness, can also develop in a patient with apparently well-controlled SLE. Therefore, it is important to take cognizance of this sight-threatening complication in SLE patients at initial presentation. A holistic approach to management, both systemic and ocular, is required to prevent sight-threatening complications from vaso-occlusion. Early and aggressive intervention can be beneficial in the prevention of severe visual loss.