Indian Journal of Ophthalmology

CASE REPORT
Year
: 2019  |  Volume : 67  |  Issue : 3  |  Page : 417--419

OCT angiography features of paracentral acute middle maculopathy


Amravi Shah, Pukhraj Rishi, Charanya Chendilnathan, Soni Kumari 
 Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, 18 College Road, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Pukhraj Rishi
Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, 18 College Road, Chennai - 600 006, Tamil Nadu
India

Abstract

Paracentral acute middle maculopathy (PAMM) refers to retinal lesions with changes in the inner nuclear layer on spectral domain optical coherence tomography (OCT). PAMM is associated with retinal vascular pathology involving the deep capillary plexus. We report two cases of PAMM in Indian subjects using multimodal imaging highlighting the OCT angiography (OCTA) findings. The first case is of a middle-aged female with a paracentral scotoma with SS-OCT (swept-source optical coherence tomography) and OCTA findings suggestive of “chronic” PAMM. The second case presented with sudden decreased vision, and multiple creamy white lesions suggestive of “acute” PAMM, imaging features depicting a possible venular obstruction. These cases demonstrate the importance of considering PAMM as a differential diagnosis in patient presenting with nonspecific visual complains and apparently normal ophthalmic examination. The recognition of PAMM should prompt an appropriate evaluation and investigation.



How to cite this article:
Shah A, Rishi P, Chendilnathan C, Kumari S. OCT angiography features of paracentral acute middle maculopathy.Indian J Ophthalmol 2019;67:417-419


How to cite this URL:
Shah A, Rishi P, Chendilnathan C, Kumari S. OCT angiography features of paracentral acute middle maculopathy. Indian J Ophthalmol [serial online] 2019 [cited 2024 Mar 28 ];67:417-419
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?2019/67/3/417/252403


Full Text



Paracentral acute middle maculopathy (PAMM) is a recently recognized entity, as a variant of acute macular neuroretinopathy (AMN), manifesting as hyperreflective band-like lesion at inner nuclear layer (INL) and outer-plexiform layer (OPL) on spectral domain optical coherence tomography (SD-OCT).[1] With advent of OCT-A (optical coherence tomography-angiography), PAMM has emerged as vascular pathology resulting from ischemia of deep retinal layers.[2],[3] Herein, we report a case each of “acute” and “chronic” PAMM and highlight the differences between the two.

 Case Reports



Case 1

A 40-year-old lady presented with a complaint of dark spot obscuring her central vision of 7-month duration. Best-corrected visual acuity (BCVA) was 20/20 bilaterally. Fundus examination of right eye was normal; left eye revealed whitish-gray intraretinal lesion nasal to fovea [Figure 1]a and [Figure 1]b. Fundus autofluorescence [FAF; [Figure 1]c] showed normal foveal hypo-reflectivity. Swept-source OCT (SS-OCT, Atlantis, Topcon Corporation, Tokyo, Japan) revealed an altered foveal contour along nasal foveal slope [[Figure 1]d, arrowhead] with hyperreflectivity at OPL [[Figure 1]d, arrow]. Fluorescein angiography (FA) did not reveal any abnormal pattern [Figure 1]e. OCT-A (Cirrus HD-OCT 5000 Carl Zeiss Meditec, Dublin, USA) revealed an area of capillary dropout in deep retinal capillary plexus indicating an arteriolar pattern of ischemia [Figure 2]a,[Figure 2]b,[Figure 2]c,[Figure 2]d. Multifocal electroretinogram showed blunting of foveal and parafoveal responses with normal perifoveal ring responses [Figure 2]e. Humphrey visual field testing (10-2) revealed a paracentral scotoma [Figure 2]f.{Figure 1}{Figure 2}

Case 2

A 40-year-old healthy male came with complaint of diminution of vision in left eye of 2 years duration. BCVA was 20/20 bilaterally. Fundus examination of left eye revealed creamy-white, subretinal lesion superotemporal to fovea [Figure 3]a and [Figure 3]b. FAF showed normal foveal pattern with hypoautofluorescence at superotemporal lesion [Figure 3]c. SS-OCT showed hyperreflectivity in the inner retinal layers [Figure 3]d and [Figure 3]e. FA showed blocked choroidal fluorescence at supero-temporal lesion area [Figure 3]f. OCTA revealed area of capillary abnormalities in deep capillary plexus nasal to foveal avascular zone (FAZ) showing a fern-like pattern [Figure 4]a,[Figure 4]b,[Figure 4]c,[Figure 4]d,[Figure 4]e,[Figure 4]f.{Figure 3}{Figure 4}

 Discussion



Recently, two forms of AMN have been defined by Sarraf et al. Type 1 AMN, or PAMM, is characterized by SD-OCT findings at the level of INL, whereas type 2 AMN is associated with abnormalities of outer-retinal layers at macula.[1] PAMM and AMN are distinct disorders with some overlapping features. First, the average age of patients with PAMM was 59 years and they were predominantly male, whereas the patients with traditional AMN lesions were on an average 33 years of age and tended to be of female gender. Second, PAMM is thus an OCT finding associated with various retinal vascular diseases, whereas AMN is an independent disease entity.

The primary etiology in PAMM may be ischemia of the intermediate and deep capillary systems, which are responsible for blood supply to middle retina.[4],[5] Patients typically present with recent onset of one or multiple paracentral scotoma(s) in one or both eyes. Complaints can range from generalized blurring of central vision and difficulty focusing to more specific shapes of paracentral scotomas, such as a fixed “gray spot.” Visual acuity may be mildly reduced in affected eye, although patients can have 6/6 vision. Amsler grid testing may be useful in such cases to help document the scotoma.[1] Compared to cotton wool spots, the retinal whitening associated with PAMM lesions is noticeably distinct, appearing duller gray-white in color, less opaque, deeper in the retina, and not following the distribution of the nerve fiber layer.[1],[6],[7] Moreover, these lesions are evanescent and may already have resolved before clinical examination. PAMM lesions may resolve with thinning of INL, resulting in persistent paracentral scotomas for the patient (as seen in Case 1).[4] OCTA features of PAMM include abnormal vasculature at the level of deep capillary plexus at the site corresponding to the lesion on SD-OCT. Three patterns are described: arteriolar, globular, and fern-like. A combination of patterns is also possible.[6] 10-2 automated Humphrey visual field testing and Amsler chart recordings can help documentation and monitoring progression of scotoma.

Our first patient presented with small fleck-like lesion superotemporal to fovea [Figure 1]a,[Figure 1]b,[Figure 1]c. On SS-OCT, the band-like lesion at OPL shows some undulations at its margins signifying reperfusion and subsequent resolution of the infarct of OPL and INL [Figure 1]d. An arteriolar pattern of capillaries on the deep capillary plexus segment of OCT-A further denotes ischemia of inner retinal layers possibly following an arteriolar obstruction [Figure 2]a,[Figure 2]b,[Figure 2]c,[Figure 2]d. As the arterioles reperfuse, the band-shaped hyperreflectivity on OCT slowly resolves along with reduction in the area of capillary loss on OCT-A, nevertheless leaving behind a scotoma close to fixation. PAMM typically occurs in elderly males. However, our case is atypical for her gender and age at presentation. Our second case presented with multiple hyperreflective areas, the largest superotemporal to fovea [Figure 3]a,[Figure 3]b,[Figure 3]c. The hyperreflective band-like lesions on SS-OCT are limited to inner plexiform layer (IPL) in smaller areas near fovea. However, the large superotemporal lesion shows involvement of all inner retinal layers from OPL to RNFL indicating the extent of ischemia [Figure 3]d and [Figure 3]e. These multiple lesions are all associated with fern-like capillary pattern on OCTA [Figure 4]a,[Figure 4]b,[Figure 4]c,[Figure 4]d,[Figure 4]e,[Figure 4]f. AMN typically occurs in younger females. However, our case is atypical for his gender and age at presentation.

PAMM generally presents as a focal area of hyperreflectivity; only a single case report has noted multiple PAMM lesions.[7] There is currently no treatment available for PAMM. Management is aimed at the identification and treatment of underlying vascular risk factors, if present.

 Conclusion



In conclusion, our report adds to the growing knowledge on PAMM and its features on multimodal imaging.

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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