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CASE REPORT
Year : 2023 | Volume
: 37
| Issue : 1 | Page : 63-65
Multimodal imaging of torpedo maculopathy with optical coherence tomography angiography
Leila Knani1, Slim Werda2, Mohamed Ghachem2, Anis Mahjoub2
1 University of Sousse, Ibn Jazzar Medical School; Department of Ophthalmology, Farhat Hached University Hospital, Sousse, Tunisia
2 Department of Ophthalmology, Farhat Hached University Hospital, Sousse, Tunisia
Correspondence Address:
Leila Knani
16, Rue Ennozha, Hergla 4012, Sousse
Tunisia
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/sjopt.sjopt_9_21
A 24-year-old woman presented for routine clinical evaluation. Her best-corrected visual acuity was 20/20 and slit-lamp examination of the anterior segment was normal in both eyes. Fundus examination of the left eye revealed a hypopigmented lesion, one disc diameter temporal to the fovea, with a hyperpigmented tail extending temporally from the main lesion, consistent with a torpedo maculopathy. Fundus autofluorescence showed an hypoautofluorescence with hyperautofluorescent border. Swept-source optical coherence tomography (OCT) showed a normal inner retina and a degeneration of the outer retina without retinal cavitation. OCT angiography (OCT-A) of the choriocapillaris layer revealed reverse shadowing caused by the increased transmission from the atrophied outer retina and RPE within the torpedo lesion and attenuation of signal in the area of the temporal hyperpigmentation. The superficial capillary plexus was normal. This case includes a multimodal imaging with OCT-A of torpedo maculopathy in a Tunisian woman. Further reports are required to provide a better understanding of this rare condition.
Keywords: Fundus autofluorescence, optical coherence tomography, optical coherence tomography angiography, torpedo maculopathy
Torpedo maculopathy is a rare unilateral congenital condition affecting the retinal pigment epithelium (RPE), presenting typically as a “torpedo-shaped” lesion located temporal to the fovea.[1] It was first reported by Roseman and Gass in 1992 as a solitary “hypopigmented nevus of the RPE.”[2] Patients are often asymptomatic and the lesion is detected on routine clinical evaluation. Only few series describing optical coherence tomography angiography (OCT-A) findings in Torpedo maculopathy have been reported. We report a case of torpedo maculopathy using multimodal imaging and demonstrating OCT-A features. To the best of our knowledge, this is the first case reported from Tunisia, North Africa.
Case ReportA 24-year-old woman presented in our ophthalmology department for routine clinical evaluation. She had no history of systemic disease, ocular trauma, ocular infection or inherited retinal disease. Her best-corrected visual acuity was 20/20 and slit-lamp examination of the anterior segment was normal in both eyes. Fundus examination was unremarkable in the right eye but revealed in the left eye an oval hypopigmented lesion, one disc diameter temporal to the fovea, with a hyperpigmented tail extending temporally from the main lesion, consistent with a torpedo maculopathy [Figure 1]a. The peripheral fundus examination was normal in both eyes. Fundus autofluorescence imaging of the left eye showed a hypoautofluorescence, with a hyperautofluorescent border surrounding the main lesion and hypoautofluoresence in the satellite temporal lesion [Figure 1]b. The infrared photograph showed the lesion contour and was consistent with the color fundus photograph [Figure 1]c. The swept-source OCT (SS-OCT) showed significant thinning of the outer nuclear layer and the RPE-Bruch Membrane complex as well and irregular disruptions of the ellipsoid and interdigitation zones temporal to the foveal area [Figure 2]a. The SS-OCT also showed choroidal thinning beneath the torpedo lesion and a forward movement of the larger choroidal vessels (both Sattler and Haller layers) towards the RPE. No retinal cavitation or choroidal excavation was noted. Inner retina structures and central foveal thickness in the left eye were normal.
Figure 1: Fundus imaging of the left eye showing an oval hypopigmented lesion, temporal to the fovea, with a hyperpigmented tail extending temporally from the main lesion, consistent with a torpedo maculopathy (a). The lesion shows hypoautofluorescence with hyperautofluorescent border (b). The contours are highlighted on the red-free photograph (c)
Figure 2: Swept-source optical coherence tomography of the left macula showing significant thinning of the outer nuclear layer and the retinal pigment epithelium-Bruch Membrane complex as well and irregular disruptions of the ellipsoid and interdigitation zones in the temporal foveal area. The Swept-source optical coherence tomography also shows choroidal thinning beneath the torpedo lesion and a forward movement of the larger choroidal vessels (both Sattler and Haller layers) towards the retinal pigment epithelium (a). On optical coherence tomography angiography, normal superficial capillary plexus (b). Decrease signal in the deep capillary plexus was noted in the lesion area (c, yellow arrow). Optical coherence tomography angiography of the choriocapillaris layer revealed reverse shadowing caused by the increased transmission form the atrophied outer retina and retinal pigment epithelium within the torpedo lesion, and attenuation of signal in the area of the temporal hyperpigmentation (e). En face optical coherence tomography angiography of the left macula shows decreased reflectivity (d-i)On OCT-A, superficial capillary plexus was normal [Figure 2]b. A decrease signal in the deep capillary plexus was noted in the lesion area [Figure 2]c. OCT-A of the choriocapillaris layer revealed reverse shadowing caused by the increased transmission from the atrophied outer retina and RPE within the torpedo lesion, and attenuation of signal in the area of the temporal hyperpigmentation [Figure 2]e. En face OCT-A of the left macula showed decreased reflectivity [Figure 2]d, [Figure 2]e, [Figure 2]f, [Figure 2]g, [Figure 2]h, [Figure 2]i. OCT and OCT-A of the contralateral eye were normal. The observation was recommended with a follow-up evaluation every 6 months.
DiscussionTorpedo maculopathy was first described in 1992.[2] It is a rare congenital maculopathy. Patients are often asymptomatic and the lesion is usually found during routine fundus examination. Clinical presentation is typical with a unilateral and solitary hypopigmented torpedo-shaped lesion in the temporal macula, with the tip pointing to the fovea and a variably pigmented tail.[1],[2],[3],[4] The lesion is usually away from the fovea. Satellite lesions have been described.[3] Atypical presentations have been reported in the literature such as bilateral lesions or double torpedoes.[5],[6] Recently, Venkatesh et al. described a nine-case series with the variable location of the torpedo lesion: Adjacent to the fovea, adjacent to the macula but away from the fovea, immediately within the retinal arcade or outside the retinal arcade.[3] The authors even proposed to change the nomenclature to “torpedo retinopathy” instead of “torpedo maculopathy.” The differential diagnosis includes other RPE conditions like congenital hypertrophy of the RPE and RPE lesions in Gardner Syndrom.[3] The exact etiology is still unknown. Based on recent OCT-A findings, the hypothesis of abnormal choroidal vasculature is probable.[3],[7],[8] Fundus autofluorescence imaging of torpedo maculopathy shows typically a hypoautoflurescence of the lesion and a hyperautofluorescence of the tail.[4] Ding et al. reported a normal autofluorescence possibly due to attenuation of the RPE and the outer nuclear layer at the same time.[7] Based on OCT, Wong et al. described two types of torpedo maculopathy: Type 1 showing attenuation of the outer retinal structures without outer retinal cavitation and type 2 showing both attenuation of the outer retinal structures and outer retinal cavitation.[9] In 2018, Tripathy et al. described a type 3 phenotype with choroidal excavation and degeneration of the outer retina and a subretinal cleft.[10] More recently, Light et al. proposed a type 4 phenotype with preservation of the ellipsoid zone, lack of subretinal fluid, and choroidal excavation.[11] Different subtypes can co-exist in the same lesion.[11] Our case is consistent with type 1 extrafoveal OCT morphology. This type is typically observed in younger patients. Some recent studies have reported OCT-A findings in torpedo maculopathy.[3],[7],[8] These authors reported abnormalities in the choriocapillaris layer with a diffuse attenuation of signal from the choriocapillaris. This finding is consistent with the hypothesis of abnormal choroidal vasculature. Similarly, in our case, all authors reported normal superficial capillary plexus perfusion. Some authors noted decrease signal in the deep capillary plexus in the area of torpedo lesion.[11] Grimaldi et al. supposed these abnormalities to be related to the patient's age.[8] However, we noted the same features in our young patient (24-year-old).
In conclusion, OCT-A shows diffuse attenuation of signal from the choriocapillaris, supporting choroidal implication in the development of torpedo maculopathy. Further reports are required to provide a better understanding of this rare condition.
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
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Conflicts of interest
There are no conflicts of interest.
References
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