case_images: PMC8302396_01
case_images: Fundus photographs. (a) At the first visit, funduscopy showed an almost normal appearance in both eyes. (b) Three months after the first visit, funduscopy showed optic disc pallor in both eyes. (c) Twenty-two months after the first visit, the optic disc pallor remained unchanged.
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case_images: Funduscopy revealed no abnormal findings in the optic disc, retina, or vitreous humor in both eyes (BE) (Figure 1(a)). Funduscopy revealed optic disc pallor (Figure 1(b)), and OCT showed thinning of all layers of the macula and the neuroretinal rim of the optic nerve head in BE (Figures 3(c) and 3(d)), although there was improvement of visual acuity (from NLP to CF). At her final visit, approximately two years after the first visit, her BCVA remained 0.01 in the RE and CF 10 cm in the LE, and funduscopy showed optic disc pallor in BE (Figure 1(c)).
case_images: Visual fields. (a) At the first visit, Goldman's perimetry (GP) showed a visual-field defect of the lower nasal right eye and extensive visual-field loss in the left eye. (b) Two months after the first visit, GP showed severe visual-field defects with peripheral visual islands in both eyes.
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case_images: Haag-Streit, Bern, Switzerland) showed a visual-field defect in the lower nasal RE and extensive visual-field loss in the LE (Figure 2(a)). However, spectral-domain optical coherence tomography (OCT; Carl Zeiss Meditec AG, Two months after the first visit, GP showed severe visual-field defects but recovered peripheral visual islands in BE (Figure 2(b)).
case_images: Optical coherence tomography (OCT) imaging. At the first visit, OCT revealed no remarkable findings on the macula and optic discs in both eyes (a, b). However, the macula (c, e) and optic disc head (d, f) had thinned in both eyes during the clinical course.
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case_images: fig3
case_images: Dublin, CA, USA) revealed no remarkable findings in all retinal layers nor swelling around the optic discs in BE (Figures 3(a) and 3(b)). Dark-adapted single-flash electroretinograms (ERG; LE-4000, Tomey, Nagoya, Japan) using a strong flash (200 cd s m-2) showed normal amplitudes in BE (Figure 4(a)). Funduscopy revealed optic disc pallor (Figure 1(b)), and OCT showed thinning of all layers of the macula and the neuroretinal rim of the optic nerve head in BE (Figures 3(c) and 3(d)), although there was improvement of visual acuity (from NLP to CF). OCT revealed the thinned macula and optic nerve head (Figures 3(e) and 3(f)).
case_images: Dark-adapted single-flash electroretinograms (ERG) and pattern visual evoked potential (VEP) findings. (a) At the first visit, ERG showed normal amplitudes in both eyes (BE). (b) One month after the first visit, ERG showed slightly decreased oscillatory potentials (OPs) in BE. (c) After changing the EGFR-TKI treatment, the ERG response did not change in BE two months after the first visit. (d) Three months after the first visit, ERG showed markedly decreased OPs in BE. (e) VEP two weeks after the first visit had decreased P100 amplitudes in the midline occipital region of BE. (f) VEPs are non-recordable in BE.
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case_images: Dublin, CA, USA) revealed no remarkable findings in all retinal layers nor swelling around the optic discs in BE (Figures 3(a) and 3(b)). Dark-adapted single-flash electroretinograms (ERG; LE-4000, Tomey, Nagoya, Japan) using a strong flash (200 cd s m-2) showed normal amplitudes in BE (Figure 4(a)). Full-field pattern-reversal visual evoked potentials (VEPs) showed decreased P100 amplitudes in BE, indicating bilateral optic neuropathy (Figure 4(e)). Three weeks after the first visit, her BCVA had further decreased to 0.02 in the RE and no light perception (NLP) in the LE, and ERG showed slightly decreased oscillatory potentials (OPs) in BE (Figure 4(b)). Orbital MRI showed improvement in the enhanced left optic nerve (Figure 5(b)); however, the ERG response had not changed in BE (Figure 4(c)). The ERG showed markedly decreased OPs in BE (Figure 4(f)).
case_images: Magnetic resonance imaging (MRI). (a) One week after the first visit, T2-weighted MRI demonstrates well-marked enhancement of the left optic nerve compared to the right optic nerve. (b) Two months after the first visit, MRI showed improvement in the enhancement of the left optic nerve.
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case_images: Brain and orbital magnetic resonance imaging (MRI) revealed left optic neuritis but showed neither metastatic cancer nor the white matter lesions seen in multiple sclerosis (Figure 5(a)). Orbital MRI showed improvement in the enhanced left optic nerve (Figure 5(b)); however, the ERG response had not changed in BE (Figure 4(c)). Additional MRI scans (Figure 5(b)) performed during the course of the disease showed no evidence of optic neuropathy or optic nerve abnormalities.
case_images: Visual acuity and treatment timeline. Decimal best-corrected visual acuity (BCVA) is described from the first visit to the final visit. RE: right eye; LE: left eye; CF: counting fingers; HM: hand motion; NLP: no light perception. Gefitinib is changed to osimertinib two months after the first visit. Three courses of steroid pulse treatment are administered before changing to osimertinib.
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case_images: fig6
case_images: Visual acuity and treatment timeline were described in Figure 6.