Macular Telangiectasia type 2: two case reports and review of the literature.

Author: Claudia Azpitarte (Spain)

Co-authors: Sofia Corte-Alonso, Marta Pradas, Gabriel Arcos-Villegas

Purpose

To present 2 cases, follow-up images with OCT (Optical Coherence Tomography) and review of literature of patients who developed a type 2 macular telangiectasia.

Setting/Venue

Ophthalmology Department, Fundación Jimenez Diaz University Hospital, Madrid, Spain.

Methods

Macular Telangiectasia type 2 (MacTel2) is a progressing neovascular degenerative disease of the macula that commonly appears bilaterally as a gradual loss of vision and can present metamorphopsia and paracentral scotomas. Its prevalence is 0.1% in people above 40 years old and it usually appears in the sixth decade of life. It affects both genders and it is genetically determined. MacTel2 can lead to neovascularization and be misdiagnosed as age-related macular degeneration. It can also be confused with a pseudo-lamellar macular hole among others. For ophthalmologists, it is a challenging diagnosis that needs to be taken into account as it is a disease that can lead to useless and invasive treatments like antiVEGF if it is not properly diagnosed.

Results

Case 1: A 63-year-old woman was referred to our ophthalmology department after two years of intravitreal injections with antiVEGF in her left eye (OS). Her best-corrected visual acuity (BCVA) was 0.7 (decimal scale) in her right eye (RE) and 0.3 in her OS. The funduscopy revealed a macular granular alteration in both eyes (BE). The OCT showed a disruption in the external layers in the temporal subfoveal region in BE. The fundus autofluorescence (FAF) revealed granular hiperautofluorescence temporally to the fovea in the RE and granular ring hiperautofluorescence in the LE. The multicolor image revealed altered blue reflectance and ring alteration in BE. Case 2: A 61-year-old man was referred to the retina section diagnosed of a macular pseudohole in his RE. The patient referred metamorphopsia that had increased in the last weeks. The BCVA was 0.4 in his RE and 0.8 in his OS. The funduscopy was normal. The OCT revealed a disruption of the subfoveal external layers in the RE. FAF revealed a temporal granular hiperautofluorescence and multicolor image showed altered blue reflectance with temporal alteration in BE. Both patients were diagnosed of MacTel2 and informed of the disease, the natural progression and the lack of treatment.

Conlusions

MacTel type 2 is a bilateral but asymmetric disease in which macular capillary network and neurosensory atrophy are the main features. The physiopathology remains unknown but the main actual theory is a neurodegenerative disease of Muller cells, which are responsible for angiogenesis, neuroprotection and photoreceptor survival. This would affect the retinal blood vessels leading to a waste of photoreceptors in late stages. Changes in the disease normally occur in the temporal juxtafoveal area. The OCT can show irregular retinal clefts that simulate macular edema, but these cystic changes are probably due to tissue loss rather than active exudation. If cavities develop in the inner retina, they can be confused with a pseudo-lamellar macular hole. Recent studies reveal signs in OCT angiography such as blue light reflectance imagining and measurement of macular pigment optical density that can detect early signs of the disease. The earliest signs in the SD-OCT of the fellow eye are thinning of the fovea and temporal parafoveal regions with hyperreflective outer dots. Many attempts to treat MacTel type 2 have been made unsuccessfully. Recent articles suggest that nondamaging retinal laser therapy could be useful by activating Müller cells and conferring a neuroprotective effect.

Financial Disclosure

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