Figure 1: Optical coherence tomography OS just above fovea
A 56-year-old woman presented with a chief complaint of seeing a spot in front of her left eye that she had first noticed suddenly the day before. She reported that the spot moves to the same area with her gaze. She had undergone successful cataract surgery in her left eye 6 weeks earlier, and was being treated for cystoid macular edema (CME). Her medical history was significant for metastatic breast cancer. Her prescription medications included fulvestrant (taken by injection) and abemaciclib (taken orally), both for breast cancer, as well as ketorolac and pred forte for the postoperative CME. Her best-corrected visual acuities were-20/25 OD and -20/40 OS. Pupils reacted normally. Slit lamp exam showed a 1+ PSC cataract in the right eye. The left eye had the PSC cataract removed, and a PSC remnant was still present on the posterior capsule. Her intraocular pressures (IOP) were 10 mm Hg OU. Dilated fundus exam appeared normal, but the central macula was difficult to evaluate. A spectral domain optical coherence tomography (OCT) scan of the right eye was normal OD, but the left eye scan showed a well defined bright hyper-reflective plaque-like lesion in the middle retinal layers, at the level of the inner nuclear layer (INL). The slightly darker area seen below the hyper reflective band, was part of the outer plexiform layer (OPL).
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The retinal capillary plexuses are generally organized into 3 trilaminar capillary layers. The superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and the deep capillary plexus (DCP).1 The blood flows in a predominately serial pathway, which is not yet completely understood, from the superficial to deep layers. Retinal vascular insufficiency leading to hypoperfusion of the deep vascular complex causes infarction of the INL and paracentral acute middle maculopathy (PAMM). PAMM is a manifestation of the ischemic cascade.1 Intraretinal hyper-reflective lines could occur in various inflammatory, degenerative, or tractional conditions. They could reflect a previously unrecognized condition of various photoreceptors, Müller cell, or retinal pigment epithelial damage.2
PAMM can be both detected and differentiated from acute macular neuroretinopathy using spectral domain OCT.3 The clinical appearance of PAMM can be subtle or absent when relying on fundus examination alone.4 Currently, no treatment exists for PAMM. These patients’ hyperreflective bands, identified by spectral domain OCT, may resolve on their own or they may evolve into atrophy with attenuation of the INL and OPL accounting for the persistent scotomas seen by some patients during long-term follow-up.5
PAMM may be present alone or may be a complication of other retinal vascular diseases.4 Reports of PAMM associated with cataract surgery, where the scotoma increased or resolved on its own, also exist.5-7 Other reports show the condition can be associated with diabetic retinopathy, hypertensive retinopathy, sickle cell retinopathy, Purtscher retinopathy, central retinal vein occlusion, and retinal artery occlusion.4
PAMM is now thought to be an OCT finding and not a disease unto itself.6,8
1. Scharf J, Freund K, Saddade S, Sarrafaef D. Paracentral acute middle maculopathy and the organization of the retinal capillary plexuses. Prog Ret Eye Res. 2021;81(3):100884. doi:j.preteyeres.2020.100884.
2. Amoroso F, Mrejen S, Pedinielli A, et al. Intraretinal hyperreflective lines. Retina. 2021;41(1):82-92. doi:10.1097/IAE.0000000000002806
3. Sarraf D, Rahimy E, Fawzi A, et al. Paracentral acute middle maculopathy. JAMA Ophthalmol. 2013;131(10):1275-1287. doi:10.1001/jamaophthalmol.2013.4056
4. Rahimy E, Kuehlewein L, Sadda S, Sarraf D. Paracentral acute middle maculopathy what we knew then and what we know now. Retina. 2015;35(10):1921-1930. doi:10.1097/IAE.0000000000000785
5. Creese K, Ong D, Sandhu S, et al. Paracentral acute middle maculopathy as a finding in patients with severe vision loss following phacoemulsification cataract surgery. Clin Exp Ophthalmol. 2017.45(6):598-605. doi:10.1111/ceo.12945.
6. Bennet TJ, Etzel J, Weber S, Sundstorm J. A case of self-documented paracentral acute middle maculopathy after cataract surgery. J Ophthalmic Photogr. 2019;41(1):27-31.
7. Chen X, Rahimy E, Sergott R, et al. Spectrum of retinal vascular diseases associated with paracentral acute middle maculopathy. Am J Ophthalmol. 2015;160(1):26-34. doi:10.1016/j.ajo.2015.04.0048
8. Coady P, Cunningham E, Vora R, et al. Spectral domain optical coherence tomography findings in eyes with acute ischemic retinal whitening Br J Ophthalmol. 2015;99(5):586-92. doi:10.1136/bjophthalmol-2014-304900.