Bilateral paracentral acute middle maculopathy associated with open mitral valve repair

Abstract

Purpose

To disseminate a case study of Paracentral Acute Middle Maculopathy (PAMM) occurring bilaterally following open mitral valve repair.

Observations

The patient reported to the clinic initially with severe vision loss in both eyes and abnormal findings on retinal imaging indicative of PAMM. After a follow-up of 4 weeks, the patient showed mild improvement in visual acuity. After a follow-up of 16 weeks, the patient showed significant improvement in visual acuity.

Conclusions and Importance

There is currently no treatment for PAMM. This report provides an important case of PAMM occurring after a surgery that is the first bilateral case of its kind. It is crucial to continue researching this topic to further understand PAMM and its possible causes and indications.

1. Introduction

First reported in 2013, Paracentral Acute Middle Maculopathy (PAMM) is characterized by band-like lesions in the inner nuclear layer (INL) of the retina in patients experiencing scotomas. Anatomical changes are visible in the middle layer of the retina using optical coherence tomography (OCT) and OCT Angiography (OCTA). PAMM has been seen in both elderly populations and young, otherwise healthy, individuals. The condition has also presented in patients with underlying neurologic and cardiovascular diseases, and sometimes as a complication of a surgery.¹ One instance where PAMM has been reported following a vascular procedure was after a coronary angiography; however, it did not present bilaterally. The following case describes the rare occurrence of bilateral retinal changes correlating with PAMM immediately after an open mitral valve repair.

2. Case report

A 67-year-old woman with a history of mitral valve repair was referred to the retina clinic due to decreased vision in both eyes. She reported that she exhibited severe blurred vision concurrently in both eyes following the procedure. The patient presented to the retina clinic and had a complete exam done, including slit lamp biomicroscopy, dilated fundus examination, optical coherence tomography (OCT), fundus photography, fluorescein angiography (FA), and OCT angiography (OCTA). She complained of severe decreased vision in both eyes following the surgery and was not evaluated for her symptoms prior to her visit. Upon chart review of the patient's recent hospitalization, the patient underwent an uncomplicated open mitral valve repair. The patient did experience multiple episodes of hypotension intraoperatively and postoperatively, with blood pressure reaching a low of 71/49, necessitating the use of vasopressors. Following the procedure, the patient was transferred to the ICU for further monitoring where she remained intubated and on vasopressors. The patient required a prolonged intubation due to persistent acidosis and hypercapnia. She was extubated approximately 24 hours following the procedure, at which point she immediately reported decreased vision. Upon presenting to the clinic for evaluation, intraocular pressures were normal. Slit lamp biomicroscopy of the anterior segment, including the anterior chamber, cornea, iris, ciliary body, and lens, was performed and within normal limits. At the initial visit, the patient's best corrected visual acuity (BCVA) was 20/Count Fingers at 6 feet in the right eye and 20/400 in the left eye. OCT imaging of both eyes showed bilateral intra-retinal edema consistent with retinal ischemia (Fig. 1). The central subfoveal thickness (CST) in the right eye and left eye was 288 μm and 329 μm respectively. The dilated fundus examination and the fundus photography showed areas of retinal whitening corresponding to the areas of the PAMM lesions (Fig. 2). The FA revealed bilateral central non-perfusion (Fig. 3). OCTA imaging of the retinal vessels revealed significant capillary dropout bilaterally (Fig. 4).

Fig. 1.

Optical coherence tomography (OCT) of the right and left eyes from the initial visit. A, B: OCT scans of the right (A) and left (B) maculas, respectively, showing hyperreflective bands in the inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and retinal thickening bilaterally.

Fig. 2.

Initial fundus imaging of the right and left eyes. A, B: Color fundus photo of the right (A) and left (B) eyes, respectively, showing whitening of the retina bilaterally, and apparent PAMM lesions in the left eye.

Fig. 3.

Initial Fluorescein Angiography of the right and left eyes. A, B: Late stage fluorescein Angiogram of the right (A) and left (B) eyes, respectively, showing central non-perfusion bilaterally.

Fig. 4.

Optical coherence tomography-angiography (OCTA) of the right and left eyes from the initial visit. A, B: OCTA scans of the right (A) and left (B) maculas, respectively, showing capillary dropout in the superficial vascular complex, deep vascular complex, and avascular complex bilaterally, with major capillary dropout apparent in the left eye.

The purpose of this report is to provide a unique case of a patient with bilateral PAMM presenting immediately following an open mitral valve repair surgery.

The findings from the images and scans were consistent with Paracentral Acute Middle Maculopathy. The patient was prescribed prednisolone acetate 1 % ophthalmic solution four times a day. Despite limited evidence regarding the efficacy of topical steroids in treating retinal edema associated PAMM, the patient was prescribed prednisolone acetate 1 % due to its effects in reducing intraretinal inflammation.² At the four week follow up the patient reported slightly improved vision in the left eye. The BCVA at that visit was 20/Count Fingers at 2 feet in the right eye, and 20/250 in the left eye. No apparent improvement of the bilateral retinal edema was observed, and the patient was directed to taper off the prednisolone acetate 1 % ophthalmic solution. At the sixteen-week follow-up the patient reported significant improvement for vision in both eyes. The BCVA at that visit was 20/60 in the right eye and 20/30 in the left eye. At that visit, the patient presented with significant improvement of inner nuclear layer (INL) edema in both eyes on OCT imaging (Fig. 5). OCT imaging also showed improvements in retinal thickening with CST values of 256 μm and 263 μm for the right and left eye, respectively. OCTA imaging showed no improvement in capillary dropout for either eye (Fig. 6). The patient did not receive any additional treatments for the condition but has been scheduled to return for routine observation.

Fig. 5.

Optical coherence tomography (OCT) of the right and left eyes from the sixteen-week follow-up visit. A, B: OCT scans of the right (A) and left (B) maculas, respectively, showing improvement of hyperreflective bands in the inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and retinal thickening bilaterally.

Fig. 6.

Optical coherence tomography-angiography (OCTA) of the right and left eyes from the sixteen-week follow-up visit. A, B: OCTA scans of the right (A) and left (B) maculas, respectively, showing capillary dropout in the superficial vascular complex, deep vascular complex, and avascular complex bilaterally, with major capillary dropout apparent in the left eye.

3. Discussion

Bilateral presentation of Paracentral Acute Middle Maculopathy associated with mitral valve repair has not been previously documented. However, there has been a reported case of PAMM occurring after coronary angiography as documented by.³ Initially, PAMM was described as a version of acute macular neuroretinopathy (AMN) due to the characteristic central vision loss and lesions that are identified using various forms of imaging.⁴ It often involves paracentral lesions and associated scotomas, which are typically permanent. In recent times, the disease has been characterized by hyperreflectivity and thickening of the INL. The condition has also been associated with ischemic changes in the retina due to underlying cardiovascular diseases, complications from procedures, or use of vasopressors.⁵ There have been a limited number of cases reported showing PAMM arising from coronary angiography or other vascular procedures, but there is no documented case of the condition presenting itself bilaterally, or after a mitral valve repair procedure.

Finding and diagnosing PAMM requires imaging, particularly Optical Coherence Tomography. The scan provides visualization of the various retinal layers and demonstrates hyperreflective bands in the inner nuclear layer, inner plexiform layer, outer plexiform layer, and retinal thickening. The disease may be difficult to diagnose due to its similarities with other retinal diseases on OCT scans; however, OCT-A may provide better visualization of perfusion abnormalities in various retinal layers, specifically in the superficial vascular complex, deep vascular complex, and avascular complex which cannot be illustrated by fluorescein angiography. The condition itself does not have any treatments or cure; however, a growing understanding of the condition may lead to evidence-based interventions. Diagnosing a patient with PAMM should encourage a deeper look into systemic issues, particularly those related to the cardiovascular system. In this case, the exact etiology of PAMM is unknown; however possible mechanisms include: micro emboli secondary to the procedure, vasopressor exposure during and after the procedure, intraoperative and postoperative hypotension, or potential hypoperfusion intraoperatively.⁶ Given the bilateral presentation of PAMM in this patient, a systemic etiology such as vasopressor exposure or hypotension is more likely than an embolic source. Future research is needed to characterize the exact pathogenesis of PAMM in patients following cardiac surgery and to further elucidate the best intervention for this condition. Additionally, the possibility of PAMM following a cardiac procedure may warrant increased monitoring of visual symptoms following the procedure and should be considered for all patients presenting with decreased vision following invasive cardiac interventions.

4. Conclusions

Paracentral Acute Middle Maculopathy is a potential complication of mitral valve repair. Diagnosis is made by fundoscopy and imaging of the retina. The eye condition has been linked with cardiovascular diseases. No treatment has been established for this condition yet, but observation and treatment of underlying cardiovascular disease is recommended.

CRediT authorship contribution statement

Humza Sulahria: Writing – original draft, Methodology. Ohidul Mojumder: Writing – review & editing, Methodology, Conceptualization. Greggory M. Gahn: Writing – review & editing, Methodology, Conceptualization. Arshad M. Khanani: Writing – review & editing, Supervision, Conceptualization.

Patient consent

Written consent to publish this case has not been obtained. This report does not contain any personal identifying information.

Acknowledgements and disclosures

No funding or grant support

Authorship

All authors attest that they meet the current ICMJE criteria for Authorship.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.