Pseudocystic foveal cavitation in tamoxifen retinopathy

Drug exposure and risk factors of maculopathy in tamoxifen users

Tamoxifen, a pivotal therapy for hormone receptor-positive breast cancer, is known for its efficacy in reducing breast cancer recurrence and mortality. However, concerns about potential ocular complications, particularly maculopathy, have emerged. This study aims to investigate the risk and associated factors of diverse macular conditions in tamoxifen users, considering drug exposure, demographics, and systemic diseases. A nationwide cohort of tamoxifen users, comprised of 14,267 tamoxifen users, was analyzed using the health insurance review and assessment database in South Korea. Demographic and clinical characteristics were examined, and the cumulative incidence of macular diseases was stratified by age and cumulative tamoxifen dosage. We conducted logistic regression analysis to identify potential risk factors among clinical variables such as age, sex, indications for tamoxifen use, and systemic diseases associated with various macular conditions. Additionally, Cox proportional hazard models were used to determine the baseline clinical characteristics predictive of these macular conditions, with subsequent calculation of hazard ratios. Cumulative incidences of overall macular diseases, other maculopathy excluding common macular diseases, and macular edema were 26.4, 11.4, and 6.5%, respectively. The incidence of various macular conditions increased with age and the cumulative tamoxifen dose. Age, cumulative dose group, and liver diseases demonstrated significant associations with overall macular diseases and maculopathy excluding common macular diseases in multivariate logistic regression analyses (all P < 0.05). Furthermore, age emerged as significant predictive factors of maculopathy in Cox proportional hazard models. Tamoxifen-induced maculopathy poses a concern for prescribing physicians and ophthalmologists, and this study provides valuable insights into its risk and risk factors. This study may contribute to evidence-based guidelines for tamoxifen maculopathy screening, emphasizing the importance of considering age, cumulative dose, and liver diseases for recommendation on screening timing and frequency.

Nationwide Screening Practices for Tamoxifen Retinal Toxicity in South Korea: A Population-Based Cohort Study

(1) Background/Objectives: To investigate the nationwide screening practices and trends in tamoxifen retinal toxicity (tamoxifen retinopathy) in South Korea using national health insurance claims data. (2) Methods: A total of 43,848 patients who started tamoxifen therapy between 2015 and 2020 and had no prior ophthalmic diseases or other conditions requiring screening for retinopathy were included. The annual numbers of tamoxifen users and new initiators of tamoxifen therapy were assessed. The screening examinations were separated into baseline (first ophthalmic examination after tamoxifen administration) and subsequent monitoring examinations. The timing and modalities for the baseline and subsequent monitoring examinations performed between 2015 and 2021 were assessed in tamoxifen users. (3) Results: The annual number of tamoxifen users increased over the study period from 54,056 in 2015 to 81,720 in 2021. The number of patients who underwent ophthalmic examination after tamoxifen administration was 8961 (20.4%). Baseline screening was performed in 6.5% of patients within 1 year of use, and subsequent monitoring was performed in 27.8% of patients who underwent baseline screening. Funduscopy or fundus photography was performed most commonly for baseline screening and subsequent monitoring (99.0% and 98.6%, respectively), while optical coherence tomography was performed only in 21.9% and 29.6% of baseline and monitoring examinations, respectively. The average number of monitoring examinations per year was 0.68 ± 0.45. Although the annual percentage of patients receiving a baseline examination within 1 year gradually increased over time, the percentage of those with subsequent monitoring performed within 1 year was similar over the study period. (4) Conclusions: Our finding, appropriate screening in a small proportion of patients receiving tamoxifen, suggests the need to promote awareness among healthcare professionals and develop a standardized approach for screening for tamoxifen retinopathy.

En face OCT analysis of Bietti's crystalline dystrophy

Objective

To describe the multimodal imaging features, including en face optical coherence tomography (OCT), of Bietti's crystalline dystrophy (BCD).

Methods

Wide field fundus photography, autofluorescence (FAF) imaging, and cross sectional and en face OCT were performed in a case of BCD. The level of the crystals in the retina were analyzed.

Results

A 42-year-old patient was referred for retinal evaluation with nyctalopia, photophobia and metamorphopsia. Retinal examination and wide field color fundus photography were remarkable for bilateral crystalline deposits in the posterior pole and midperipheral retina. Wide field FAF showed extensive nummular atrophy of the retinal pigment epithelium (RPE) in the macula and periphery. Spectral-domain (SD) OCT illustrated bilateral chorioretinal atrophy in the macula. En face SD OCT captured the hyperreflective crystals in various retinal layers, depending on the selected segmentation. The patient was diagnosed with BCD and genetic testing confirmed the diagnosis (CYP4V positive for two variants).

Conclusion

In this case report, we describe the multimodal imaging features of Bietti's Crystalline Dystrophy. Wide field FAF illustrated diffuse nummular RPE atrophy in the posterior pole and periphery and en face OCT captured the hyperreflective crystals in different layers of the retina.

Phenomenology of spontaneous closure in degenerative and mixed type lamellar macular hole

PURPOSE

To the describe OCT imaging characteristics of a cohort of patients showing spontaneously closing degenerative or mixed type lamellar macular holes (LMH) and to compare them to the ones of a sex and age matched group showing stable lesions.

METHODS

Patients diagnosed with degenerative and mixed type LMHs showing OCT-documented spontaneous anatomical closure were retrospectively selected from 3 specialized retina centres. An equal number of age and sex matching subjects were randomly selected among patients with anatomically stable lesions.

RESULTS

Eleven (11) spontaneously closing (SC group) and 11 stable (ST group) degenerative LMH with a mean follow up of 4 years were recruited. Hyperreflective inner border (HIB) and linear hyperreflectivity in the outer plexiform layer (LHOP) at baseline were significantly more prevalent in SC group in processed images (respectively p = 0.007 and p = 0.003). A borderline significance in lamellar hole associated epiretinal proliferation (LHEP) at last follow up was detected (p = 0.085). As for mixed type LMH, 10 patients for SC group and 10 for ST group were recruited. LHOP at baseline in processed images was significantly more prevalent in SC group (p = 0.005).

CONCLUSIONS

Spontaneously closing LMHs show higher prevalence of HIB and LHOP at the beginning of the closing process, a difference which is enhanced by image processing. These signs might be a signal of microglial and Muller cells coordinated activation.

Tamoxifen retinopathy: A comprehensive review

Tamoxifen is a selective estrogen receptor modulator used mainly for the treatment of breast cancer. Based on the case reports and studies performed to date on the retinal toxicity of tamoxifen, retinopathy appears to occur in as many as 12% of patients taking 20 mg tamoxifen a day for over 2 years. Of this 12%, as many as half develop symptomatic changes in visual acuity. Retinal changes consist primarily of crystalline deposits, cystoid macular edema, hyperreflective deposits in the inner retinal layers, and telangiectasia. Tamoxifen retinopathy is currently managed by discontinuing tamoxifen therapy as the cancer prognosis permits; however, discontinuing therapy demonstrates little to no improvement in visual acuity once visual changes have taken place. Intravitreal injections of steroids or antivascular endothelial growth factor therapy have been performed, but require further studying before conclusions can be made. Until then, optical coherence tomography screening for retinal changes should be performed every 6 months for patients who have been on tamoxifen therapy for 2 years or more. This way, patients can become aware of retinal changes, and their physicians can consider adjusting tamoxifen therapy before they risk developing changes in visual acuity.

Foveal cone loss in tamoxifen maculopathy: a case report

BACKGROUND

Tamoxifen is used in low dose concentrations (20-40 mg per day) as a therapy for breast cancer but is known to have ocular side effects. In this case report, the foveal cone integrity in a tamoxifen-treated patient who complained of a small central scotoma in the left eye while reading was examined using high resolution adaptive optics imaging.

CASE PRESENTATION

Both eyes of a 54-year-old Caucasian, non-hispanic female who had been treated with tamoxifen for 1.5 years were examined using various imaging modalities including fundus photography, fundus autofluorescence, fluorescein angiography, spectral-domain optical coherence tomography, and adaptive optics scanning laser ophthalmoscopy. Clinical spectral-domain optical coherence tomography showed a very small disruption to the photoreceptor layer at the fovea in the left eye only. However, adaptive optics scanning laser ophthalmoscopy imaging revealed foveal cone loss in both eyes, but to a lesser extent in the right eye. Inner retinal changes were not observed in either eye.

CONCLUSION

The area of cone loss was similar in size to a single newsprint letter when projected onto the retina, matching the patient's description of a scotoma in the left eye. Given the isolated loss of foveal cone photoreceptors with the absence of previously reported inner retinal and vascular changes, our results may indicate the earliest retinal changes associated with tamoxifen retinopathy.

Unilateral Tamoxifen-Induced Retinopathy as a Consequence of Breast Cancer Treatment—Multimodal Imaging Value

Tamoxifen is a drug used in breast cancer therapy, which inhibits the division of neoplastic cells targeting estrogen receptors. The drug is generally well-tolerated and its use does not cause serious side-effects. The standard dose of the drug is 20 mg once a day for 3 to 5 years. Available epidemiological data have shown that the incidence of ocular toxicity of tamoxifen ranges between 0.9% and 12.0% and increases with higher tamoxifen dose. A rare known complication of tamoxifen use is the development of retinopathy. We present a case of 57-year-old woman presented to an ophthalmologist with decreased visual acuity in her right eye. She has been treated with tamoxifen 20 mg daily for 7 years for breast cancer. Clinical examination and multimodal imaging methods help confirm the diagnosis of unilateral tamoxifen associated retinopathy (TAR). Optical coherence tomography angiography (OCTA) was crucial in the diagnostic process and differential diagnosis, especially in differentiating it from type 2 macular telangiectasias. The correct diagnosis of TAR is very important in deciding the treatment option of tamoxifen. Based on our diagnosis, the oncologist recommended another course of treatment. Tamoxifen therapy was discontinued and switched to letrozole 2.5 mg once a day. The patient attends ophthalmological examination regularly. Visual acuity, OCT and OCTA results remain stable.

Tamoxifen induced maculopathy presenting like macular telangiectasia type 2 in a patient with breast cancer

INTRODUCTION

Drug-induced crystalline maculopathy has been reported secondary to tamoxifen use for breast cancer treatment. It could be misdiagnosed as macular telangiectasia type 2 (MacTel type 2).

CASE REPORT

A 56-year-old woman with a history of diabetes mellitus and breast cancer was referred to our clinic with painless, bilateral, gradual onset of central vision loss for several months. The fundus examination showed the macular pigmentary change in both eyes and a few refractile crystalline deposits in the parafoveal area in the left eye. However, the rest of the retina was normal in both eyes.

MANAGEMENT AND OUTCOME

With the diagnosis of tamoxifen-induced maculopathy, the drug was discontinued and supplementary treatment was started.

DISCUSSION

In this report, patient medical and drug history was an important and powerful measure. Due to the side effects of long-term use of tamoxifen, we need further studies on the need for retinal screening in these patients.

Tamoxifen retinopathy

Tamoxifen (TAM) is a selective estrogen receptor modulator that is used in the treatment of breast cancer. As there are estrogen receptors in the retina, retinal pigment epithelium, and choroid, these tissues may also be affected by TAM. We describe the reported effects of TAM on the retina and choroid. Medical databases were searched using relevant keywords and the results were extracted and pooled. The incidence of retinal/choroidal toxicity ranged from 0.9% to 12%. There was a wide range for the time of exposure before the development of TAM retinopathy (3 weeks to 13 years). While functional measurements may be appropriate for assessment of TAM retinopathy, they have not been effective for screening patients. There is no generally accepted screening modality, but serial funduscopy and optical coherence tomography imaging seem to be the most reasonable approach for detecting early TAM-induced retinal toxicity.

Tamoxifen Retinopathy and Macular Telangiectasia Type 2: Similarities and Differences on Multimodal Retinal Imaging

PURPOSE

Tamoxifen-induced retinopathy (TR) and macular telangiectasia type 2 (MacTel) share a highly similar retinal phenotype. In this study, we aimed to evaluate differences and similarities that may point toward underlying mechanisms linking both disease entities.

DESIGN

Retrospective, cross sectional study.

SUBJECTS

Patients diagnosed with MacTel or TR.

METHODS

Patients underwent multimodal retinal imaging, including color fundus photography, spectral-domain OCT, fundus autofluorescence, fluorescein angiography, and OCT angiography (if available). Age, age of onset, best-corrected visual acuity, and bilaterality of changes were evaluated. Patients' eyes were graded for different morphologic characteristics by 4 experienced graders.

MAIN OUTCOME MEASURES

Phenotypical characterization and comparison of frequencies of retinal characteristics of TR and MacTel on multimodal imaging.

RESULTS

Twenty-eight eyes of 14 patients with TR and 118 eyes of 59 patients with MacTel were included. Age, age of onset, and best-corrected visual acuity were similar in both cohorts. All but 1 patient showed bilateral changes. In patients with MacTel, neurodegenerative changes and vascular alterations were equally present, whereas in patients with TR, neurodegenerative changes usually prevailed. Predilection sites within the central retina differed between the 2 diseases: most findings in patients with TR were limited to the foveal center, whereas changes in patients with MacTel were present throughout a slightly larger region ("MacTel area"), with an epicenter temporal to the foveal center. Distinct morphologic features included the distribution of retinal crystals, the size and position of ellipsoid zone breaks, and the presence of hyperreflective changes on OCT images. Focal hyperpigmentation and neovascular membranes were only present in eyes with MacTel.

CONCLUSIONS

Macular telangiectasia and TR share a highly similar retinal phenotype, especially in early disease stages. Subtle differences on multimodal retinal images may help distinguish between these 2 disease entities. Our findings indicate the involvement of Müller cells in both diseases, which may explain the observed phenotypic characteristics and similarities.

Partial thickness subfoveal hole in a patient treated with tamoxifen: a case report and review of the literature

BACKGROUND

We describe a patient presenting with a partial thickness subfoveal hole in the right eye after tamoxifen treatment for breast cancer.

CASE PRESENTATION

A 76-year-old Caucasian female presented with a 1-day history of acute central scotoma and blurry vision in the right eye. The patient had been receiving oral tamoxifen for 5 years as adjuvant treatment for stage I lobular breast cancer. Her past ocular history was significant for complete, uneventful, and bilateral posterior vitreous detachment. Clinical examination and optical coherence tomography revealed a new, partial thickness subfoveal hole sparing the inner retinal layers. Observation was recommended. At the last follow-up examination, 1 year after the initial presentation, the subfoveal hole remained stable and visual acuity remained stable.

CONCLUSION

Tamoxifen has been associated with a plethora of ophthalmic adverse events, including macular holes, some of which are partial thickness subfoveal holes. Holes with this almost unique morphology are uncommon, and eye care professionals should be aware of this association given the frequency of tamoxifen use, as well as the low success rate of surgical repair with pars plana vitrectomy.

Tamoxifen retinopathy and macular telangiectasia: A comparative case series

PURPOSE

To report a case series of tamoxifen retinopathy (TR) with and without type 2 macular telangiectasia (MacTel) and compare their clinical and imaging findings.

METHODS

Retrospective comparative study. Female patients with tamoxifen use or with clinical diagnosis of type 2 MacTel were divided into 4 groups: Group A-tamoxifen use without retinopathy; Group B-tamoxifen use with retinopathy; Group C-type 2 MacTel with tamoxifen use and Group D-type 2 MacTel without tamoxifen use. Clinical and image analysis was conducted.

RESULTS

There were 6 patients (11 eyes) in group A, 8 (13 eyes) patients in Group B, 2 patients (4 eyes) in Group C and 8 patients (14 eyes) in Group D respectively. TR patients were young, showed retinal crystals, perifoveal greying and no retinal pigment clumps (RPC) on examination. Foveal contour irregularity (n = 13, 100%) and outer retinal layer damage (n = 11, 85%) were common OCT findings seen in TR. In group C, all eyes showed 360° middle retinal layer (MRL) hyperreflectivity (100% vs 86%) and presence of outer retinal hyporeflective cavitation (100% vs 43%) on OCT compared to patients in group D. Abnormal autofluoroscence, detection and leakage from the telangiectatic vessels on fluorescein and OCT angiography was seen in type 2 MacTel disease.

CONCLUSION

Patients with TR showed retinal crystals and outer retinal hyporeflective foveal cavitation on OCT. Patients with type 2 MacTel having with tamoxifen intake showed hyporeflective outer retinal foveal cavitation and 360° perifoveal MRL hyperreflectivity on OCT. RPC was observed exclusively in the type 2 MacTel group.

Retinal Toxicity Induced by Chemical Agents

Vision is an important sense for humans, and visual impairment/blindness has a huge impact in daily life. The retina is a nervous tissue that is essential for visual processing since it possesses light sensors (photoreceptors) and performs a pre-processing of visual information. Thus, retinal cell dysfunction or degeneration affects visual ability and several general aspects of the day-to-day of a person's lives. The retina has a blood-retinal barrier, which protects the tissue from a wide range of molecules or microorganisms. However, several agents, coming from systemic pathways, reach the retina and influence its function and survival. Pesticides are still used worldwide for agriculture, contaminating food with substances that could reach the retina. Natural products have also been used for therapeutic purposes and are another group of substances that can get to the retina. Finally, a wide number of medicines administered for different diseases can also affect the retina. The present review aimed to gather recent information about the hazard of these products to the retina, which could be used to encourage the search for more healthy, suitable, or less risky agents.

One-year follow-up of optical coherence tomography angiography microvascular findings: macular telangiectasia type 2 versus tamoxifen retinopathy

PURPOSE

To compare microstructural and microvascular changes in eyes with macular telangiectasia type 2 (MacTel2) and in those with tamoxifen retinopathy (TR) at baseline and at the 1-year follow-up using optical coherence tomography (OCT) and OCT angiography (OCTA).

METHODS

We followed up patients diagnosed with MacTel2 or TR for at least 1 year. We included 17 patients with MacTel2 (31 eyes) and 15 with TR (25 eyes) who discontinued tamoxifen use after a TR diagnosis. We performed OCT and OCTA at baseline and after 1 year.

RESULTS

Patients with MacTel2 and TR showed intraretinal cavitation, ellipsoid zone (EZ) loss, and capillary telangiectasia in the superficial and deep plexuses. EZ disruption predominantly affected the temporal region in MacTel2 (32%) and was limited to the foveal center in TR (24%). Vascular density (VD) was significantly reduced within the deep temporal parafovea and superficial fovea in MacTel2 and TR eyes, respectively. After 1 year, the MacTel2 eyes showed enlarged EZ loss, proliferative vascular invasion, and increased VD (p = 0.021) in the temporal deep plexus compared with TR eyes.

CONCLUSIONS

After 1-year follow-up, the MacTel2 eyes showed proliferative vascular remodeling, particularly in the temporal parafovea of the deep plexus with EZ loss progression, whereas the TR eyes maintained their baseline capillary rarefaction.

[Effects of systemic drugs on the development of drug-induced retinopathy]

This article reviews information on possible adverse events occurring in the organ of vision - in particular, the retina - after using systemic drugs, discusses the drugs that lead to drug-induced retinopathy most often, and describes histomorphological changes and modern understanding of the pathogenesis of damage to retinal structures.

Evaluation of Optic Nerve Head Parameters and Electro-Physiology Among Breast Cancer Patients on Tamoxifen

Introduction

To evaluate if early tamoxifen toxicity can be detected by comparing pre-and post-treatment optic nerve head parameters and visual function using Heidelberg Retinal Tomograph III (HRT III) and Pattern Visual Evoked Potential (Pattern VEP).

Method

This is a prospective study involving 76 eyes of 38 breast cancer patients treated with tamoxifen in Hospital Universiti Sains Malaysia, Kelantan, Malaysia. These patients were examined by a single doctor and the investigations were done by a single technician. The visual acuity, optic nerve function, visual field, optic nerve head parameters on HRT III and Pattern VEP were assessed. The examination was performed before and three months after treatment initiation.

Results

There was no tamoxifen ocular toxicity found three months post-treatment with tamoxifen. There was no change in visual acuity and optic nerve function post-treatment initiation. There were no statistically significant changes found in optic nerve head parameters on HRT III and P 100 peak latency and amplitude on Pattern VEP.

Conclusion

Ocular toxicity is a recognized complication of tamoxifen treatment. Tamoxifen optic neuropathy is a potentially irreversible, visually disabling complication. Tamoxifen ocular toxicity was not found three months after tamoxifen treatment initiation among estrogen receptor (ER)-positive breast cancer patients. No early changes in optic nerve head parameters and P 100 peak latency and amplitude changes were found after three months of treatment. A longer duration of monitoring with HRT III and Pattern VEP may be needed to adequately observe for early, subclinical changes in optic nerve head parameters and visual function among tamoxifen users.

Update on Retinal Drug Toxicities

Purpose of Review

This review aims to provide an update on the clinical presentations and diagnostic findings of drug-induced retinal toxicities.

Recent Findings

Several newly FDA-approved medications have been associated with acute retinal toxicities, including brolucizumab, MEK inhibitors, ulixertinib, and FGFR inhibitors. Additionally, as previously believed-to-be well-tolerated medications, such as pentosan sulfate sodium, anti-retroviral therapies, and certain intraoperative ocular medications, are used more frequently or for longer periods of time, associated toxic retinopathies and inflammatory reactions have been reported. Finally, advances in ocular imaging have revealed novel findings in hydroxychloroquine and tamoxifen maculopathies.

Summary

Discovery of new medications, increased frequency of use, and longer-term use have led to increased reports of retinal toxicities. Advances in retinal imaging have allowed for earlier detection of subclinical changes associated with these medications, which may help prevent progression of disease. However, more research is needed to determine the point at which vision loss becomes irreversible. Risks and benefits must be assessed prior to discontinuation of the offending, but potentially lifesaving, therapy.

Retinal toxicities of systemic anticancer drugs

Newer anticancer drugs have revolutionized cancer treatment in the last decade, but conventional chemotherapy still occupies a central position in many cancers, with combination therapy and newer methods of delivery increasing their efficacy while minimizing toxicities. We discuss the retinal toxicities of anticancer drugs with an emphasis on the mechanism of toxicity. Uveitis is seen with the use of v-raf murine sarcoma viral oncogene homolog B editing anticancer inhibitors as well as immunotherapy. Most of the cases are mild with only anterior uveitis, but severe cases of posterior uveitis, panuveitis, and Vogt-Koyanagi-Harada-like disease may also occur. In the retina, a transient neurosensory detachment is observed in almost all patients on mitogen-activated protein kinase kinase (MEK) inhibitors. Microvasculopathy is often seen with interferon α, but vascular occlusion is a more serious toxicity caused by interferon α and MEK inhibitors. Crystalline retinopathy with or without macular edema may occur with tamoxifen; however, even asymptomatic patients may develop cavitatory spaces seen on optical coherence tomography. A unique macular edema with angiographic silence is characteristic of taxanes. Delayed dark adaptation has been observed with fenretinide. Interestingly, this drug is finding potential application in Stargardt disease and age-related macular degeneration.

Macular Abnormalities Associated With 5α-Reductase Inhibitor

Importance

The neuroprotective action of sex hormones has been described. Data on the association between 5α-reductase inhibitor (5-ARI), a male sex hormone antagonist, and macular abnormalities are lacking to date.

Objective

To assess the association between the use of 5-ARI for treatment of benign prostate hypertrophy and/or androgenic alopecia in men and macular abnormalities on optical coherence tomography imaging.

Design, Setting, and Participants

This retrospective case-control, cross-sectional study included electronic health record data from 31 male patients who showed foveal cavitation on spectral-domain optical coherence tomography imaging from January 1, 2016, to June 30, 2019.

Exposures

Receipt of 5-ARI for at least 2 years as treatment of benign prostate hypertrophy and/or androgenic alopecia.

Main Outcomes and Measures

Clinical data and multimodal imaging findings and the proportion of 5-ARI users.

Results

Among 31 male patients with foveal cavitation, 5-ARI was used for 10 of 14 patients (71.4%) with macular abnormalities of unknown origin and for 2 of 17 patients (11.8%) with macular abnormalities of well-known specific origin (P = .001). The mean age of these 14 patients was 74.7 years (range, 60.1-88.0 years). In the 15 eyes of 10 patients who had received 5-ARI for macular abnormalities of unknown origin, mean (SD) age was 72.8 (7.5) years, mean (SD) length of time receiving 5-ARI was 72.3 (39.2) months, and mean (SD) logMAR visual acuity was 0.08 (0.10) (Snellen equivalents, 20/24 [20/25]). Optical coherence tomography imaging showed a disease spectrum ranging from tiny foveal cavitation to an impending macular hole. Of the total male patients, 80.0% (8 of 10) had no symptoms.

Conclusions and Relevance

The findings suggest that macular abnormalities associated with 5-ARI are characterized by cystoid abnormalities and foveal cavitation in male patients, which may progress to outer foveal defect and macular hole. These macular abnormalities associated with a male sex hormone antagonist suggested by this investigation warrant further corroboration.

The role of multimodal imaging and vision function testing in ABCA4-related retinopathies and their relevance to future therapeutic interventions

The aim of this review article is to describe the specific features of Stargardt disease and ABCA4 retinopathies (ABCA4R) using multimodal imaging and functional testing and to highlight their relevance to potential therapeutic interventions. Standardised measures of tissue loss, tissue function and rate of change over time using formal structured deep phenotyping in Stargardt disease and ABCA4R are key in diagnosis, and prognosis as well as when selecting cohorts for therapeutic intervention. In addition, a meticulous documentation of natural history will be invaluable in the future to compare treated with untreated retinas. Despite the familiarity with the term Stargardt disease, this eponymous classification alone is unhelpful when evaluating ABCA4R, as the ABCA4 gene is associated with a number of phenotypes, and a range of severity. Multimodal imaging, psychophysical and electrophysiologic measurements are necessary in diagnosing and characterising these differing retinopathies. A wide range of retinal dystrophy phenotypes are seen in association with ABCA4 mutations. In this article, these will be referred to as ABCA4R. These different phenotypes and the existence of phenocopies present a significant challenge to the clinician. Careful phenotypic characterisation coupled with the genotype enables the clinician to provide an accurate diagnosis, associated inheritance pattern and information regarding prognosis and management. This is particularly relevant now for recruiting to therapeutic trials, and in the future when therapies become available. The importance of accurate genotype-phenotype correlation studies cannot be overemphasised. This approach together with segregation studies can be vital in the identification of causal mutations when variants in more than one gene are being considered as possible. In this article, we give an overview of the current imaging, psychophysical and electrophysiological investigations, as well as current therapeutic research trials for retinopathies associated with the ABCA4 gene.

Bilateral Macular Hole Related to Tamoxifen Low-Dose Toxicity

Bilateral macular hole is a rare secondary effect of tamoxifen, a condition which is probably underdiagnosed. We describe the case of a 63-year-old woman who had received low-dose treatment with tamoxifen for 10 years. She presented with a best-corrected visual acuity of 20/40 in both eyes and bilateral macular hole with posterior hyaloid attachment. No reflective deposits were observed. A 23-gauge pars plana vitrectomy with internal limiting membrane peeling and gas tamponade was performed in the right eye with no anatomical or functional improvement. The most accepted mechanism of macular hole related to tamoxifen is Müller cell toxicity with retinal tissue loss. Therefore, it seems that the standard procedure used in idiopathic macular hole is not the optimal choice, due to a different pathogenic mechanism.

Optical Gap Biomarker in Cone-Dominant Retinal Dystrophy

PURPOSE

To characterize the progression of optical gaps and expand the known etiologies of this phenotype.

DESIGN

Retrospective cohort study.

METHODS

Thirty-six patients were selected based on the identification of an optical gap on spectral-domain optical coherence tomography (OCT) from a large cohort of patients (N = 746) with confirmed diagnoses of inherited retinal dystrophy. The width and height of the gaps in 70 eyes of 36 patients were measured by 2 independent graders using the caliper tool on Heidelberg Explorer. Measurements of outer and central retinal thickness were also evaluated and correlated with gap dimensions.

RESULTS

Longitudinal analysis confirmed the progressive nature of optical gaps in patients with Stargardt disease, achromatopsia, occult macular dystrophy, and cone dystrophies (P < .003). Larger changes in gap width were noted in patients with Stargardt disease (78.1 μm/year) and cone dystrophies (31.9 μm/year) compared with patients with achromatopsia (16.2 μm/year) and occult macular dystrophy (15.4 μm/year). Gap height decreased in patients with Stargardt disease (6.5 μm/year; P = .02) but increased in patients with achromatopsia (3.3 μm/year) and occult macular dystrophy (1.2 μm/year). Gap height correlated with measurements of central retinal thickness at the fovea (r = 0.782, P = .00012). Interocular discordance of the gap was observed in 7 patients. Finally, a review of all currently described etiologies of optical gap was summarized.

CONCLUSION

The optical gap is a progressive phenotype seen in an increasing number of etiologies. This progressive nature suggests a use as a biomarker in the understanding of disease progression. Interocular discordance of the phenotype may be a feature of Stargardt disease and cone dystrophies.

Tamoxifen Induced Pachychoroid Pigment Epitheliopathy with Reversible Changes After Drug Discontinuation

We report a case of breast cancer with clinically significant retinal toxicity induced by 7 years’ Tamoxifen consumption in which patient’s visual acuity and paraclinical findings remarkably improved after drug discontinuation. A 49-year-old woman with a history of breast cancer and Tamoxifen consumption was referred to our clinic for evaluation and treatment of gradual and progressive decrease visual acuity of both eyes (more prominent in right eye). Funduscopy showed bilateral macular pigmentary changes, with diffused tiny yellow crystals and reduced macular tessellation. On spectral-domain optical coherence tomography (SD-OCT), there was retinal pigment epithelium (RPE) abnormality and ellipsoid zone discontinuity accompanied by retinal thinning and choroidal thickness that was more prominent in the right eye. One year after discontinuation of the drug, visual acuity was significantly improved and SD-OCT revealed some surprising recoveries in the photoreceptor layers especially in her right eye.

Tamoxifen maculopathy: The importance of screening and long follow-up

We report a case of a patient treated with tamoxifen 20mg daily as hormone therapy for breast cancer. On regular ophthalmological follow-up, tamoxifen maculopathy was detected on SD-OCT (Spectral Domain Optic Coherence Tomography, Carl Zeiss Meditec®), so the medication was discontinued. Despite discontinuation of the medication, the maculopathy progressed over time. We have been following our patient for seven years. Tamoxifen may produce a toxic maculopathy which may progress despite discontinuation of the medication. We consider our case interesting, given the lengthy follow-up of the patient with sequential SD-OCT images. To the best of our knowledge, our case represents the longest follow-up period for a patient with tamoxifen maculopathy. Moreover, we would like to stress the importance of screening in asymptomatic patients on this medication, in order to detect early pathological signs.

Combined cSLO-OCT imaging as a tool in preclinical ocular toxicity testing: A comparison to standard in-vivo and pathology methods

INTRODUCTION

Confocal scanning laser ophthalmoscopy and optical coherence tomography (cSLO-OCT) became available for human and animal ophthalmic examinations in recent years. The purpose of this study was to evaluate lesion detection and localization with cSLO-OCT imaging in an experimental outer retinal toxicity model and to compare cSLO-OCT to standard examination methods (indirect ophthalmoscopy (IO), fundus photography (FP) and central section histopathology).

METHODS

A test compound was orally administered to albino rats (n = 4) for four weeks (part A) and to albino (n = 2) and pigmented (n = 2) rats for eight weeks (part B). Control animals received vehicle only. Retinal changes were documented using cSLO-OCT, IO, FP, angiography and histopathology. Retinal thicknesses were compared between groups using a mixed effects model.

RESULTS

All compound-treated animals developed progressive multifocal hyperreflective spot changes mostly confined to the retinal pigment epithelium. In study parts A and B, cSLO identified fundus lesions earlier than IO/FP in albino rats. In study part B, cSLO quantified fundus lesions more accurately than IO/FP in albino rats but no difference was seen in pigmented rats. Central section histopathology revealed no abnormalities in three out of four compound-treated animals in part B. Altogether, without cSLO-OCT, present fundus changes would have remained undetected in one of four compound-treated animals in both parts A and B.

DISCUSSION

Integration of combined cSLO-OCT imaging into toxicology study design can improve toxicity study readouts and facilitate longitudinal examination of single animals at multiple time points, leading to a reduction of experimental animal numbers.

Retinal structural changes in patients receiving tamoxifen therapy by spectral-domain optical coherence tomography

Purpose: To evaluate choroidal thickness, ganglion cell complex (GCC) and photoreceptor outer segment (PROS) length were measured in patients with breast cancer undergoing tamoxifen therapy, using spectral-domain optical coherence tomography (SD-OCT); results were compared with those for normal eyes.Materials and methods: Forty-four patients with breast cancer, undergoing tamoxifen therapy, and 41 healthy controls were included in this prospective, comparative study. All participants underwent a complete ophthalmologic evaluation and SD-OCT. Subfoveal, nasal (nasal distance to fovea 500, 1000, 1500 μm), and temporal (temporal distance to fovea 500, 1000, 1500 μm) choroidal thickness measurements were performed using the enhanced depth imaging mode of SD-OCT. Using an Early Treatment Diagnostic Retinopathy Study (ETDRS) circle at the macular level, the automated retinal segmentation software was applied to determine the thickness of the GCC. PROS length was determined manually, as the distance from the inner surface of the ellipsoid zone to the inner surface of retina pigment epithelium.Results: The mean choroidal thickness was statistically greater in the tamoxifen group than controls in all quadrants (p < 0.001 for all quadrants). Of all tamoxifen users (44 eyes of 44 patients), 33 eyes (75%) had uncomplicated pachychoroid (UCP). Pachychoroid pigment epitheliopathy (PPE) was detected in five tamoxifen-group patients (11.3%). Patients with PPE in one eye had UCP in the fellow eye. Central serous chorioretinopathy findings were observed in one patient. Tamoxifen users had statistically lower GCC thickness in all inner rings of the ETDRS inlay and in the nasal outer ring only (p = 0.027, 0.002, 0.002, 0.001, and 0.030, respectively). No statistically significant difference in mean subfoveal PROS length was found between the groups.Conclusions: SD-OCT provides valuable information for identifying structural changes and evaluating ocular findings in patients receiving tamoxifen therapy. Increased choroidal thickness, PPE and thinning GCC were detected in tamoxifen users. These OCT findings may be an early indicator of retinal toxicity for patients undergoing tamoxifen therapy in the follow-up period.

Optical coherence tomography-based consensus definition for lamellar macular hole

BACKGROUND

A consensus on an optical coherence tomography definition of lamellar macular hole (LMH) and similar conditions is needed.

METHODS

The panel reviewed relevant peer-reviewed literature to reach an accord on LMH definition and to differentiate LMH from other similar conditions.

RESULTS

The panel reached a consensus on the definition of three clinical entities: LMH, epiretinal membrane (ERM) foveoschisis and macular pseudohole (MPH). LMH definition is based on three mandatory criteria and three optional anatomical features. The three mandatory criteria are the presence of irregular foveal contour, the presence of a foveal cavity with undermined edges and the apparent loss of foveal tissue. Optional anatomical features include the presence of epiretinal proliferation, the presence of a central foveal bump and the disruption of the ellipsoid zone. ERM foveoschisis definition is based on two mandatory criteria: the presence of ERM and the presence of schisis at the level of Henle's fibre layer. Three optional anatomical features can also be present: the presence of microcystoid spaces in the inner nuclear layer (INL), an increase of retinal thickness and the presence of retinal wrinkling. MPH definition is based on three mandatory criteria and two optional anatomical features. Mandatory criteria include the presence of a foveal sparing ERM, the presence of a steepened foveal profile and an increased central retinal thickness. Optional anatomical features are the presence of microcystoid spaces in the INL and a normal retinal thickness.

CONCLUSIONS

The use of the proposed definitions may provide uniform language for clinicians and future research.

Wide field retinal imaging and the detection of drug associated retinal toxicity

Background

To describe the peripheral retinal findings associated with systemic medication toxicity and to outline the importance of ultra-widefield imaging in the detection, analysis and monitoring of these abnormalities.

Main text

This review highlights the retinal manifestations associated with the more common drug toxicities, with emphasis on the peripheral features and the indications for wide field imaging. The presenting findings, underlying pathophysiology, and retinal alterations in hydroxychloroquine, thioridazine, didanosine, tamoxifen, MEK-inhibitor, and immune checkpoint inhibitor associated drug toxicity will be described and the importance of wide field imaging in the evaluation of these abnormalities will be emphasized.

Conclusions

Wide field retinal imaging can improve the detection of peripheral retinal abnormalities associated with drug toxicity and may be an important tool in the diagnosis and management of these disorders.

Improvements in visual acuity and macular morphology following cessation of anti-estrogen drugs in a patient with anti-estrogen maculopathy resembling macular telangiectasia type 2: a pathogenic hypothesis

Background

The relationship between anti-estrogen drugs and macular telangiectasia type 2 (MacTel-2) remains unknown. Here we report a case with anti-estrogen maculopathy resembling MacTel-2 with improved visual function and macular morphology following cessation of anti-estrogen drugs.

Case presentation

A 53-year-old woman presented with a 5-month history of central vision loss and anorthopia in both eyes. She had received oral tamoxifen followed by toremifene for 69 months. Funduscopy, fluorescein angiography, and optical coherence tomography (OCT) revealed MacTel-2-like findings OU. Fundus autofluorescence (FAF) showed hyper-autofluorescence at the fovea OU. Visual acuity, macular morphology on OCT, and FAF findings gradually improved after cessation of anti-estrogen drugs.

Conclusions

In the present case, visual acuity, macular morphology, and impairment of the retinal pigment epithelium (RPE) improved following cessation of anti-estrogen drugs, suggesting the relationship between retinal toxicity of anti-estrogen drugs and the development of MacTel-2-like findings. From these results and the previous observations, toxicity of both photoreceptor and RPE cells caused by anti-estrogen drugs may contribute to the development of anti-estrogen maculopathy similar to MacTel-2.

OCT Angiography Findings of Tamoxifen Retinopathy: Similarity with Macular Telangiectasia Type 2

PURPOSE

We aimed to describe the vascular changes in eyes associated with tamoxifen retinopathy using OCT angiography (OCTA) and to compare these changes with abnormalities in macular telangiectasia type 2 (MacTel 2) previously reported in the literature.

DESIGN

Retrospective, observational study.

PARTICIPANTS

Seventeen eyes with tamoxifen retinopathy and 17 eyes of age-matched healthy control participants.

METHODS

The medical records of patients who visited the ophthalmology department with a history of taking tamoxifen were reviewed. Tamoxifen retinopathy was diagnosed based on typical spectral-domain (SD) OCT findings, such as intraretinal cavitation, photoreceptor disruption, or both. Multimodal imaging, particularly focused on OCTA, was analyzed. To compare vessel density in OCTA, age-matched normal control participants also were enrolled.

MAIN OUTCOME MEASURES

Descriptive appraisal of the vascular abnormalities and objective quantification of vessel density associated with tamoxifen retinopathy.

RESULTS

Among 292 patients who were screened, 26 were diagnosed with tamoxifen retinopathy. Of these, 17 eyes of 10 patients who were evaluated using OCTA were included. All patients were women, with a median patient age of 65.0 years. They were treated with tamoxifen as adjuvant endocrine therapy for breast cancer. All eyes showed intraretinal cavitation, and 8 eyes showed focal photoreceptor disruption as well, on OCT. On OCTA imaging, 14 eyes (82.4%) showed saccular capillary telangiectasia at the deep capillary plexus and 6 eyes (35.3%) showed right-angled vessels. Foveal vessel density of the superficial plexus was significantly lower in eyes with tamoxifen retinopathy than in control participants (P = 0.003). Crystalline deposits on fundus photographs (12 eyes [70.6%]) and increased autofluorescence on fundus autofluorescence (16 eyes [94.1%]) also were noted as characteristic findings of tamoxifen retinopathy.

CONCLUSIONS

In addition to morphologic changes of tamoxifen retinopathy in SD OCT, its vascular changes on OCTA, such as telangiectatic vascular change at the deep capillary plexus and right-angled vessels, are similar to those observed in the early stages of MacTel 2.

Late-Stage Sjögren-Larsson Syndrome Maculopathy Imaged With OCT Angiography

Three adult siblings with Sjögren-Larsson syndrome (SLS) demonstrated signs of late-stage SLS maculopathy, including intraretinal crystals, atrophic changes, and lipofuscin deposition. This first report of SLS maculopathy imaged with optical coherence tomography angiography revealed decreased retinal capillary density, vessel dilation, and increased flow voids in the superficial and deep capillary plexuses. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e78-e82.].

SEX STEROIDS AND MACULAR TELANGIECTASIA TYPE 2

PURPOSE

To investigate the relationship between macular telangiectasia Type 2 and systemic levels of sex steroids or their antagonization.

METHODS

In a prospective single-center study, 90 patients with macular telangiectasia Type 2 were investigated. Female patients were evaluated for previous surgical (e.g., ovariectomy) and/or pharmacological (e.g., aromatase inhibitors, tamoxifen) therapy resulting in reduced action of sex steroids. In males, free serum testosterone levels were assessed in patients and controls.

RESULTS

Fourteen of 49 (29%) female patients had a history of pharmacological suppression of sex steroids and/or ovariectomy. These patients were younger at disease onset when compared with those without such medical history (mean ± SD: 47.1 ± 7.8, range: 38-59, versus 60.1 ± 7.6, range: 45-76; P < 0.0001). Male patients showed significantly lower free serum testosterone levels compared with controls at younger age (P < 0.0001 and 0.04 in the first and second age quartiles, respectively), as opposed to nonsignificant differences in older patients. In men ≤ 60 years of age, a biochemical hypogonadism (free serum testosterone < 0.05 ng/mL) was present in 53% (8/15) and 4% (2/49) of patients and controls, respectively (P < 0.0001).

CONCLUSION

The results indicate that steroidal sex hormones might be involved in the presumably multifactorial pathophysiology of macular telangiectasia Type 2.

Uveoretinal Adverse Effects Presented during Systemic Anticancer Chemotherapy: a 10-Year Single Center Experience

BACKGROUND

The present study describes our 10-year experience with uveoretinal adverse events that manifest because of chemotherapy.

METHODS

A retrospective chart review was performed for all patients who presented to the ophthalmologic department while undergoing systemic chemotherapy between July 2005 and June 2015.

RESULTS

A total of 55 patients (mean age, 51.2 years, 38 women [69.1%]) suspected of having uveoretinal disease owing to the use of chemotherapeutic agents alone were enrolled. Breast cancer was the predominant disease (36.4%); noninfectious anterior uveitis (21.8%) was the most common condition. Bilateral involvement was observed in 16 patients (29.1%). Although cisplatin (21.8%) was the most commonly used drug, daunorubicin, cytarabine, tamoxifen, toremifene, and imatinib were also frequently used. The median duration until ophthalmologic diagnosis was 208.5 days (range, 19-5,945 days). The proportion of patients with final visual acuity (VA) < 20/40 Snellen VA (0.5 decimal VA) was 32.7%. However, no relationship was observed between final VA < 20/40 and age, sex, therapeutic agents, and metastasis.

CONCLUSION

Uveoretinal complications were mostly mild to moderate and exhibited a favorable response to conservative therapy. A considerable number of patients exhibited significant irreversible loss of vision after cessation of the causative chemotherapeutic agent. Ophthalmological monitoring is required during chemotherapy.

Tamoxifen Use in a Patient with Idiopathic Macular Telangiectasia Type 2

Crystalline deposits and neurosensory retinal cavitary changes can develop in both tamoxifen retinopathy and nonproliferative idiopathic macular telangiectasia type 2 (MacTel2). MacTel2 is typically differentiated from tamoxifen retinopathy based on the presence of late leakage and mid-phase telangiectatic vessels on fluorescein angiography (FA) and the presence of hyperautofluorescence. Unlike MacTel2, tamoxifen retinopathy is known to be a progressive disease and the cessation of tamoxifen results in resolution of retinopathy. We report a unique case of nonproliferative MacTel2 in a 36-year-old Hispanic woman with tamoxifen use and the vision outcome 30 months after cessation of tamoxifen. The FA and optical coherence tomography angiography findings of this patient support the diagnosis of MacTel2, but her cessation of tamoxifen led to partial reversal of the topographic findings and improvement in visual acuity. This patient is also unique in the unusually young age of presentation for MacTel2. Our case supports that there are common pathways in the pathogenesis of tamoxifen retinopathy and MacTel2, and tamoxifen use could potentially accelerate foveal atrophy in patients with MacTel2.

Docetaxel Retinopathy: A Case Report

Background

To report the use of En-face optical coherence tomography (OCT) in a patient treated with docetaxel and tamoxifen for breast cancer for the detection of macular edema (ME) without evidence of leakage on fluorescein angiography (FA).

Case Presentation

A 52-year-old woman treated for breast cancer presented with bilateral visual loss for 2 months. FA showed no significant leakage while spectral-domain OCT scans of both eyes showed foveolar and parafoveolar cystic spaces in a moderately thickened macula. En-face OCT segmented at the inner retina showed the petaloid arrangement of cystic cavities, comparable to a cystoid ME.

Conclusions

The combined use of tamoxifen could have potentiated the toxic effect of docetaxel on the macula. En-face OCT images may reveal a petaloid aspect of the macula due to cysts in the inner retina segmentation, when FA shows no leakage.

Multimodal imaging of foveal cavitation in retinal dystrophies

PURPOSE

Inherited retinal dystrophies and cone dysfunction syndromes may show a sharp hyporeflective interruption in the outermost retinal layers on optical coherence tomography (OCT), known as foveal cavitation (FC). The aim of the study was to describe the morpho-functional features of FC in patients affected by retinal dystrophies by means of multimodal imaging.

METHODS

A consecutive series of patients affected by FC were prospectively recruited for the study. Patients underwent short-wavelength (SW) and near-infraRed (NIR) fundus autofluorescence (FAF), spectral domain OCT (SD-OCT), microperimetry (MP), and multifocal electroretinogram (mfERG). Mean size of FC on OCT was correlated with best-corrected visual acuity (BCVA).

RESULTS

Overall, 15 patients (30 eyes) were enrolled. Mean age was 38.2 ± 14.5 years (range: 10-60), with nine females (60 %). Mean BCVA was 0.5 ± 0.4 LogMAR. SD-OCT revealed focal loss of outer retinal layers and disruption of inner segment ellipsoid zone. Vertical height of FC (mean 27.77 ± 18.77 μm) was indirectly related to BCVA; complete forms of FC, with total loss of outer OCT bands, showed a poorer visual outcome. The FC size on NIR-FAF turned out to be larger with respect to SD-OCT and SW-FAF.

CONCLUSION

Our data indicate that the presence of FC worsens functional outcome in patients affected by retinal disorders; complete and higher lesions are associated with a worse morpho-functional prognosis in these eyes.

The tipping point: Tamoxifen toxicity, central serous chorioretinopathy, and the role of estrogen and its receptors

Purpose

To describe a case of tamoxifen toxicity superimposed on central serous chorioretinopathy (CSCR). We review the role of estrogen and the effect of tamoxifen on ocular tissues.

Observations

A 32-year-old Hispanic female with infiltrating ductal carcinoma of the left breast (T2N1M0, triple-positive), status post chemotherapy and bilateral mastectomy, presented with complaint of a floater and decreased central vision of the right eye (OD). Symptoms began three weeks after initiating tamoxifen and five months after the last cycle of chemotherapy and dexamethasone. Visual acuity (VA) was 20/30 OD at presentation. Clinical examination and multimodal imaging revealed subretinal fluid (SRF) and pigment epithelial detachment (PED) suggestive of CSCR. After one month of monitoring, VA improved to 20/20; there was SRF resolution, small PED, and focal ellipsoid zone (EZ) band loss. Two weeks later, after undergoing surgery and starting a topical steroid, she returned with count fingers (CF) VA and large SRF OD. Steroid cessation improved SRF after one month, but VA was unchanged. Tamoxifen was discontinued, and VA improved to 20/100 with near-complete resolution of SRF at three weeks, and significant reduction in choroidal thickness at two months. At final follow-up, VA was 20/200, and there was focal EZ band loss sub-foveally, minimal SRF, and small PED.

Conclusions and Importance

Treatment with tamoxifen may lead to ocular toxicity and can complicate the recovery course of patients affected with CSCR. Variations in levels of the estrogen receptor-alpha (ER-α) and treatment with tamoxifen (ER-α partial agonist) may lead to loss of the protective effect of estrogen in the retinal pigment epithelial cells in premenopausal women. Furthermore, tamoxifen toxicity can lead to focal photoreceptor loss. Treatment in these cases should be coordinated together with the oncologist.

Tamoxifen retinopathy: a case report

Purpose

To present a case of tamoxifen retinopathy on a 57-year-old woman.

Design

An observational case.

Methods

A review of history, clinical examination, and findings on Spectral-domain Optical Coherence Tomography (SD-OCT), fluorescein angiogram (FA) and electro-oculogram (EOG) was conducted.

Results

A 57-year old female patient, who had been treated with oral tamoxifen after mastectomy due to breast cancer, had profound visual impairment in both eyes. Disruption of the ellipsoid zone and interdigitation zone which represent photoreceptor damage as well as macular thinning was revealed on SD-OCT in both eyes. Bilateral retinal pigmented epithelium (RPE) function compromised was indicated by reduced Arden ratio in EOG.

Conclusion

Tamoxifen-induced retinopathy could be detected by SD-OCT and EOG. As it is irreversible, patients who are given tamoxifen need regular ophthalmic consultation, including SD-OCT and EOG before and during the treatment in order to early detect and avoid further retinal damage.