Spotlight Case: It’s Not Just a Macular Scar
A 58-year-old Asian man was referred for vitreoretinal consultation. He had recently visited an ophthalmologist for a comprehensive exam, complaining of blurred vision in both eyes that had gradually worsened over the past 2 years. He had no history of ocular injury, radiation treatment to the head, or other systemic diseases, but he had smoked for at least the past 10 years. No one in his family had similar vision problems.
His vision was 20/80 in the right eye and 20/60 in the left eye, with normal intraocular pressure (IOP). He had mild nuclear sclerosis cataract in both eyes, and anterior-segment examination in each eye was otherwise unremarkable.
Fundus examination (Figures 1 and 2) in the right eye revealed hyperpigmentary changes associated with multiple crystalline deposits and an appearance of retinal graying at the temporal parafoveal area as well as the fovea. The left eye also showed reduced retinal transparency associated with multiple ectatic vessels in the same area, temporal to the fovea.
OCT of both eyes demonstrated loss of outer retinal reflectivity at the temporal foveal area. In the right eye (Figure 3), OCT also showed an intraretinal hyperreflective lesion with a hyporeflective shadow in that area, associated with hyporeflective spaces in the inner and outer retina. OCT in the left eye (Figure 4) also demonstrated a similar space at the inner retina, associated with an intact internal limiting membrane (ILM).
Figure 3: OCT of the right eye shows a hyporeflective space of the inner retina (A) and outer retina (B) and an intraretinal hyperreflective lesion and its hyporeflective shadow (C). Segmental loss of outer retinal reflectivity (A-C) can also be appreciated.
Fluorescein angiography (FA) of the right eye (Figure 5) showed multiple small hyperfluorescent lesions at the parafoveal area, especially temporal to the fovea, in the early phase. This progressed into more diffuse hyperfluorescence in the late phase, associated with blocked fluorescence at the superotemporal edge of the fovea. A corresponding hyperfluorescence pattern can also be appreciated in the left eye.
Differential diagnosis in a patient with microangiopathy in the macula includes:
- Diabetic retinopathy
- Branch retinal vein occlusion (BRVO)
- Sickle cell maculopathy
- Radiation retinopathy
- Idiopathic macular telangiectasia (MacTel) type 2
The distribution pattern of this microangiopathy—which is limited to the macula and associated with a pigmentary change in the right eye and without the classic finding of cotton-wool spots or dot- or flame-shaped hemorrhages in the peripheral retina—helped rule out diabetic retinopathy and BRVO as etiologies in this case.
Figure 4: OCT of the left eye shows a hyporeflective space underneath the ILM and segmental loss of outer retinal reflectivity.
Because the patient had no history of radiation to the orbit or head, his condition was also unlikely to be due to radiation retinopathy. Since FA did not show the presence of choroidal neovascularization (CNV) or occlusive retinopathy, AMD and sickle cell retinopathy were also excluded as possibilities.
The most likely diagnosis was idiopathic MacTel type 2. Providing additional support for this diagnosis:
- Typical finding of telangiectatic capillaries temporal to the fovea presenting in the early phase of the FA
- Characteristic outer retinal abnormality in association with an intraretinal space and plaque of pigment epithelial hyperplasia appearing as a hyperreflective lesion on OCT
Figure 5: FA of right (A, B) and left (C, D) eyes, early phase, shows multiple small hyperfluorescent lesions temporal to the fovea in both eyes (A, C) which progress to diffuse hyperfluorescence around the fovea in the late phase (B, D). Blocked fluorescence is seen at the superotemporal edge of the right fovea (A, B) which corresponds to the pigmentary change seen in the color fundus photo (Figure 1).
MacTel was first described as idiopathic juxtafoveolar retinal telangiectasis (IJFT) by Gass and Oyakawa. Later, the condition was classified by Yannuzzi into 2 distinct types based on findings from advanced high-speed angiography and OCT:
- Type 1, or aneurysmal telangiectasia (unilateral telangiectatic and aneurysmal retinal vessels, known as Coats’ disease in child patients, with macrocapillaries and macroaneurysms with associated ischemia, lipid deposition, and hemorrhage)
- Type 2, or perifoveal telangiectasia
Our patient’s findings were consistent with MacTel type 2, a bilateral disease of unknown cause with characteristic alteration of the macular vascular network and neurosensory atrophy. Symptomatic patients present with mild gradual central visual loss. Fortunately, because the disease progresses very slowly, patients can often maintain vision of about 20/50 and rarely progress beyond 20/200 in the advanced stages.
Typical fundus findings include:
- Reduced retinal transparency
- Crystalline deposits
- Ectatic capillaries
- Blunted venules
- Retinal pigment plaques
- Foveal atrophy
- CNV membrane (CNVM)
Ectatic capillaries predominantly located temporal to the fovea in the early phase and diffuse hyperfluorescence in the late phase are the hallmark findings on FA.
OCT findings provide more information about disease progression from the earliest change, to temporal enlargement of the foveal pit, to hyporeflective spaces in the inner retina or outer neurosensory retina (Figure 6) and, eventually, atrophy of the retina in later stages. Retinal pigment hyperplasia can be demonstrated on OCT as a hyperreflective intraretinal lesion with associated posterior shadowing.
Figure 6: OCT of the right eye in a different patient shows hyporeflective spaces in both inner and outer retina, reflecting the spectrum of OCT findings in this disease.
A staging system was first developed by Gass and Blodi. Later, to reflect disease pathogenesis, Yannuzzi and Engelbert revised this by counting OCT findings in the staging criteria (Table 1); this simplified the staging as nonproliferative or proliferative, depending on the absence or presence of neovascular membrane formation.
There are no effective treatments for MacTel, as neither laser treatment nor intravitreal steroid and anti-VEGF has shown benefit in the nonproliferative stages. However, transpupillary thermotherapy (TTT) and photodynamic therapy (PDT), which were replaced later by intravitreal anti-VEGF treatment, have shown some promising outcomes in the proliferative stage.
In our patient, nearly all common characteristic findings of MacTel type 2 disease can be appreciated in both eyes. The right eye showed more advanced disease than the left eye. However, because there was no evidence of CNVM formation on FA and OCT, the patient’s disease was still considered to be in the nonproliferative stage in both eyes. No specific treatment was recommended, except for regular eye examinations every 6 to 12 months.
Table 1: Staging of macular telangiectasia type 2
- MacTel type 2 is a rare bilateral eye disease which causes gradually progressive visual loss.
- Telangiectatic vessels, the hallmark finding, are usually located temporal to the fovea and can be appreciated on FA in the early phase of the study.
- FA and OCT are important tools for disease staging.
- MacTel type 2 can be classified in 2 stages, nonproliferative and proliferative, according to the absence or presence of CNVM.
- There are no effective treatments for nonproliferative MacTel type 2.
- PDT, TTT, and intravitreal anti-VEGF injection have been reported to provide some benefit in proliferative MacTel type 2.
- Gass JD, Oyakawa RT. Idiopathic juxtafoveolar retinal telangiectasis. Arch Ophthalmol. 1982;100(5):769-780.
- Yannuzzi LA, Bardal AM, Freund KB, Chen KJ, Eandi CM, Blodi B. Idiopathic macular telangiectasia. Arch Ophthalmol. 2006;124(4):450-460.
- Wu L, Evans T, Arevalo JF. Idiopathic macular telangiectasia type 2 (idiopathic juxtafoveolar retinal telangiectasis type 2A, Mac Tel 2). Surv Ophthalmol. 2013;58(6):536-559. doi:10.1016/j.survophthal.2012.11.007.
- Gass JD, Blodi BA. Idiopathic juxtafoveolar retinal telangiectasis. Update of classification and follow-up study. Ophthalmol. 1993;100(10):1536-1546.
- Engelbert M, Yannuzzi LA. Idiopathic macular telangiectasia type 2: the progressive vasculopathy [published online November 6, 2012]. Eur J Ophthalmol. 2013; 23(1):1-6. doi:10.5301/ejo.5000163.
Dr. Panjaphongse - None.
Dr. Stewart - None.
Dr. Hau - None.
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