Tamoxifen maculopathy mimicking type-2 macular telangiectasia (MacTel-2)

Vineet Shah; Kiran Chandran; Sachin Desai; Anantharaman Giridhar

doi:10.4103/ijo.IJO_459_22

CASE REPORT

Year : 2022 | Volume : 2 | Issue : 3 | Page : 722-724

Tamoxifen maculopathy mimicking type-2 macular telangiectasia (MacTel-2)

Vineet Shah, Kiran Chandran, Sachin Desai, Anantharaman Giridhar
Department of Vitreoretinal Services, Giridhar Eye Institute, Cochin, Kerala, India

Date of Submission	15-Feb-2022
Date of Acceptance	06-Apr-2022
Date of Web Publication	16-Jul-2022

Correspondence Address:
Dr. Anantharaman Giridhar
Department of Vitreoretinal Services, Giridhar Eye Institute, Cochin, Kerala
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_459_22

Abstract

Tamoxifen citrate is an antiestrogen agent used in the treatment of breast carcinoma. Incidence of ocular toxicity, in the range of 0.9–-11%, has been reported following its use. Since the clinical picture, especially crystals and cavitation, seen in tamoxifen maculopathy resembles type-2 macular telangiectasia (MacTel-2), differentiating them requires detailed multimodal imaging. We present a rare case of tamoxifen maculopathy mimicking MacTel-2 in an Indian patient. A 55-year-old female with a history of breast carcinoma had been taking tamoxifen 20 mg once daily (cumulative dose of 57.6 g) for 8 years. Color fundus photo showed crystals in foveal and parafoveal region. Further multimodal imaging with confocal blue reflectance, spectral domain optical coherence tomography, fundus autofluorescence, and OCT-angiography demonstrated close resemblance to MacTel-2 features. Thus, it is important to elicit a detailed history in female patients with a history of breast carcinoma and seek oncology consultation once tamoxifen toxicity is seen.

Keywords: Confocal blue reflectance, crystals, spectral-domain optical coherence tomography, tamoxifen maculopathy, type-2 macular telangiectasia

How to cite this article:
Shah V, Chandran K, Desai S, Giridhar A. Tamoxifen maculopathy mimicking type-2 macular telangiectasia (MacTel-2). Indian J Ophthalmol Case Rep 2022;2:722-4

How to cite this URL:
Shah V, Chandran K, Desai S, Giridhar A. Tamoxifen maculopathy mimicking type-2 macular telangiectasia (MacTel-2). Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 Aug 13];2:722-4. Available from: https://www.ijoreports.in/text.asp?2022/2/3/722/351193

Tamoxifen citrate is a selective estrogen-receptor-modulator used as an adjuvant therapy for early-stage breast cancer by competitively binding to cytoplasmic estrogen receptors.^[1] The therapeutic dosage starts at 20 mg and increases up to 40 mg daily. Patients using tamoxifen have a 0.9–11% chance of developing ocular toxicity, which includes keratopathy, cataract, optic neuritis, crystalline retinopathy with or without cystoid macular edema (CME) and pseudocystic foveal cavitation.^[2] Tamoxifen maculopathy has been reported to occur after 2–3 years of intake.^[2] White refractive retinal opacities and subepithelial opacities in the cornea have been reported following large doses of the drug (up to 320 mg/day).^[3] Retinal toxicity has also been described following relatively low dose of 10–20 mg daily.^[4]

Macular telangiectasia type 2 (MacTel-2) is a more prevalent clinical entity with strikingly similar clinical presentation to tamoxifen maculopathy.^[2],[5] It is characterized by alterations of macular capillary network and atrophy of neurosensory retina. Typical features of MacTel-2 include abnormal leaky telangiectasia, neurosensory retinal atrophy, intraretinal crystalline deposits, right-angle vessels, pigmented plaques, and late-stage neovascularization.

The aim of this report was to document a case of tamoxifen maculopathy closely resembling findings of MacTel-2 utilizing multimodal imaging.

Case Report

A 55-year-old Indian woman presented with a 4-month history of gradual defective vision in both eyes. Her past history was significant for breast carcinoma (infiltrating ductal carcinoma on histopathology), which was diagnosed 8 years ago. She had undergone a left-sided modified radical mastectomy with radiation and six cycles of chemotherapy. Subsequently, she was put on oral tamoxifen 20 mg daily, which she has been taking for 8 years with a cumulative dose of 57.6 g. The best-corrected visual acuity was 20/40 in both eyes. On examination, the anterior segment was normal, and fundoscopy revealed dull foveal reflex with parafoveal loss of transparency, widely spaced yellowish-white hyperrefractile and nonrefractile crystalline deposits circumferentially at fovea and parafovea [Figure 1]a and [Figure 1]b. The patient underwent further multimodal imaging. Confocal blue reflectance (CBR) demonstrated circular parafoveal hyperreflectance [Figure 1]c and [Figure 1]d with better characterization of crystals on CBR [Figure 1]c and [Figure 1]d and multicolor ([Figure 1]e and [Figure 1]f; white arrow: hyperrefractile crystals, yellow arrow: nonrefractile crystals). Fundus autofluorescence showed bilateral loss of foveal autofluorescence with hyperautofluorescence extending to the temporal parafovea [Figure 2]a and [Figure 2]b. Spectral-domain optical coherence tomography (SD-OCT) demonstrated identical findings in both eyes with an internal limiting membrane drape, hyper-reflective dots in nerve fiber layer, hypo-reflective inner retinal cavitation involving the foveal centre, patchy loss of ellipsoid and interdigitation zone and hyper-reflective outer retinal dots at fovea [Figure 2]c and [Figure 2]d. On optical coherence tomography angiography (OCT-A), few dilated capillaries suggestive of saccular telangiectasia were noted around the foveal avascular zone in deep capillary plexus (DCP) [Figure 2]e and [Figure 2]f. Based on the bilateral clinical findings and cumulative dose of tamoxifen consumed over 8 years, a diagnosis of tamoxifen maculopathy mimicking MacTel-2 was made.

Figure 1: Color fundus photograph demonstrating multiple crystals at fovea and parafovea (a and b). Confocal blue reflectance shows increased parafoveal hyper-reflectance [c and d; yellow open arrows], which along with multicolor shows better depiction and greater number of crystals (c–f) than fundus photo

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Figure 2: Fundus autofluorescence demonstrates bilateral temporal parafoveal hyperautofluorescence (a and b; delineated in red dots). Optical coherence tomography sections show hyperreflective dots in nerve fiber layer (white open arrows), internal limiting membrane drape and hyporeflective foveal inner cavitation (yellow arrows), and patchy loss of photoreceptor line at fovea (red rectangle) (c and d). OCT-angiography deep capillary plexus showing saccular telangiectasias (e and f; circled yellow)

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Discussion

To the best of our knowledge, we describe the first documented case of tamoxifen maculopathy mimicking MacTel-2 in an Indian patient. Both the cavitation and crystalline deposits of tamoxifen toxicity resemble that of MacTel-2. Multimodal imaging aids in their better characterization. A typical distinguishing feature between crystals in MacTel-2 and tamoxifen maculopathy is that they are typically more numerous, oriented in clusters, and located parafoveally with lesser predilection for foveal center in MacTel-2, whereas those in tamoxifen maculopathy are more widely spaced, fewer in number, and involve the foveal center (i.e., it can be easily counted) as demonstrated in our case [Figure 1]e and [Figure 1]f.

In MacTel-2, Müller cell dysfunction and destruction of Müller cell architecture with loss of neurons and central macular thinning is believed to result in a loss of macular pigment and cavitation.^[6] This was further substantiated by the increased parafoveal reflectance on CBR. A foveal cavitation with disruption of the photoreceptor line is seen on optical coherence tomography (OCT) in low-dose tamoxifen therapy, but CME can occur in high-dose therapy.^[7] Thus, the similar CBR and SD-OCT appearances of tamoxifen maculopathy and MacTel-2 suggest a common pathway in their pathogenesis. Tamoxifen inhibits the glutamate transporter of glial cells, resulting in Müller cell dysfunction followed by neuronal and vascular pathologies. Müller cell glutamate-aspartate transporters are crucial for glutamate uptake and recycling in the retina. When these transporters get inhibited, toxicity from glutamate accumulation may result in Müller cell dysfunction and neuronal apoptosis, leading to cavitation.^[8]

FAF also demonstrated intriguing findings, with features resembling MacTel-2. We observed a pattern of autofluorescence very similar to that seen in MacTel-2. Wong et al. described FAF patterns in MacTel-2 as an increase in foveal autofluorescence in the early stages and a mixed pattern of FAF (combined hypo- and hyperautofluorescence) in the advanced stages.^[9] The FAF findings seen in our patient demonstrate early toxicity as evidenced by hyperautofluorescence involving the foveal center and parafoveal area. These findings could be attributed to loss of macular pigment density in the fovea and altered composition of fluorophores in the retinal pigment epithelium.

In addition, OCT-A of tamoxifen retinopathy has shown DCP telangiectasia and right-angled vessels, which resemble the vascular changes seen in MacTel.^[10] Since the Müller cell processes are close to the retinal vasculature in DCP, their dysfunction is thought to be associated with DCP telangiectasia. The distinguishing feature is the smaller and saccular appearance of telangiectasias in tamoxifen maculopathy,^[10] as was seen in our case.

Conclusion

We describe a rare case of tamoxifen maculopathy mimicking MacTel-2. Owing to the similar presentation between them, it is important to elicit a detailed history especially in female patients with a history of breast carcinoma. Thus, oral tamoxifen has to be discontinued in such cases with the advice of an oncologist, and physicians should be aware of the similarities between these two conditions so as to avoid a possible misdiagnosis of MacTel-2.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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