Characteristics of fundus image in macular telangiectasia type 2

Abstract

Objective To observe the fundus image characteristics of macular telangiectasia type 2 (MacTel type 2) patients. Methods A total of 8 patients (16 eyes) diagnosed of MacTel type 2 were included in this study. There were 4 males and 4 females, age ranged from 44 to 69 years old with a median age of (59.88±7.85) years. All patients received examination of best-corrected visual acuity (BCVA), slit lamp microscope, indirect ophthalmoscopy, fundus color photography, fundus autofluorescence (AF), fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (OCT) and macular pigment optical density (MPOD). Four eyes of 2 patients received OCT angiography examination at the same time. Classification was made according to the Gass and Blodi′s criteria. The follow-up time was from 1 to 19 months with the average time of (11.00±8.91) months. The clinical characteristics were observed and analyzed. Results The BCVA was 0.07 - 0.8. There were 1 eye in stage 1, 1 eye in stage 2, 6 eyes in stage 3, 8 eyes in stage 4. The disease showed a bilateral appearance with a low progression. Fundus features included loss of retinal transparency (14 eyes, 87.5%), blunted retinal venule (15 eyes, 93.75%), pseudo-lamellar hole (5 eyes, 31.25%), pigment proliferation (9 eyes, 56.25%). FFA findings were telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. Spectral domain OCT features included depletion of the retinal inner, outer structures, cavity (7 eyes, 43.75%), and atrophy of the neurosensory retina (9 eyes, 56.25%). On AF, reduced foveal masking due to loss of macular pigment can be observed. The loss of macular pigment could also be seen on MPOD. OCTA showed the increased intervascular spaces, broken regular network of foveal avascular zone (FAZ), right-angled vessel dipping, dilatations, traction of superficial and deep capillary layers in both the superficial and deep layers, especially in the deep layer. Only one eye of one patient proceeded from stage 4 to stage 5. Conclusions Characteristic features of MacTel type 2 included cavities and outer retina atrophy on OCT; loss of MP on MPOD; broken regular network of FAZ, morphological and structural abnormalities of superficial and deep layers of perifoveal capillary network on OCTA. Key words: Retinal Diseases/diagnosis; Macula lutea/injuries; Disease attributes