Paracentral Acute Middle Maculopathy following Vitrectomy for Proliferative Diabetic Retinopathy

Paracentral acute middle maculopathy in a patient with Myelin Oligodendrocyte glycoprotein antibody associated optic neuritis

Purpose

There is insufficient literature reporting the concurrent occurrence of retinal ischemic lesions with optic neuritis. In this case report, we present a distinctive instance of Optic Neuritis with a positive Myelin Oligodendrocyte glycoprotein (MOG) antibody, accompanied by retinal ischemia manifesting as paracentral acute middle maculopathy (PAMM) lesions.

Observations

Our patient is a 25-year-old female who tested positive for MOG antibodies and exhibited retinal PAMM lesions without any apparent underlying ischemic cause. She received intravenous pulse steroid therapy, and her symptoms and signs completely resolved one month later.

Conclusion

PAMM can serve as an initial manifestation of Myelin Oligodendrocyte glycoprotein Antibody Associated Disease (MOGAD). This case has the potential to contribute to the existing literature, facilitating a deeper exploration of the pathophysiology of retinal ischemia in MOG associated optic neuritis.

Recent advances in the treatment and delivery system of diabetic retinopathy

Diabetic retinopathy (DR) is a highly tissue-specific neurovascular complication of type 1 and type 2 diabetes mellitus and is among the leading causes of blindness worldwide. Pathophysiological changes in DR encompass neurodegeneration, inflammation, and oxidative stress. Current treatments for DR, including anti-vascular endothelial growth factor, steroids, laser photocoagulation, and vitrectomy have limitations and adverse reactions, necessitating the exploration of novel treatment strategies. This review aims to summarize the current pathophysiology, therapeutic approaches, and available drug-delivery methods for treating DR, and discuss their respective development potentials. Recent research indicates the efficacy of novel receptor inhibitors and agonists, such as aldose reductase inhibitors, angiotensin-converting enzyme inhibitors, peroxisome proliferator-activated receptor alpha agonists, and novel drugs in delaying DR. Furthermore, with continuous advancements in nanotechnology, a new form of drug delivery has been developed that can address certain limitations of clinical drug therapy, such as low solubility and poor penetration. This review serves as a theoretical foundation for future research on DR treatment. While highlighting promising therapeutic targets, it underscores the need for continuous exploration to enhance our understanding of DR pathogenesis. The limitations of current treatments and the potential for future advancements emphasize the importance of ongoing research in this field.

Paracentral Acute Middle Maculopathy Following Acute Primary Angle Closure and Acute Primary Angle Closure Glaucoma

Purpose

To report the prevalence, clinical characteristics and risk factors for paracentral acute middle maculopathy (PAMM) following acute primary angle closure (APAC) and acute primary angle closure glaucoma (APACG).

Methods

This retrospective study consecutively recruited patients diagnosed with APAC or APACG. Based on the spectral domain optical coherence tomography characteristics, PAMM eyes were divided into three stages. Characteristics of different stages such as the time from symptoms to treatment (TST), retinal thickness and BCVA improvement were analyzed. The risk factors of PAMM were evaluated by binary logistic regression models.

Results

A total of 781 eyes of 781 APAC or APACG patients were included, and PAMM was found in 22 (2.9%) of them. Stage III eyes had a significantly longer TST than stage I eyes (P = 0.008) while exhibiting significantly thinner retinal thicknesses (P < 0.0001). The BCVA improvement was significantly worse in the eyes treated in stage III than in those treated in stage I (P = 0.008). Older age, longer axial length and without type 2 diabetes were associated with a lower risk of incident PAMM (OR = 0.95, P = 0.028; OR = 0.52, P = 0.019; OR = 3.92, P = 0.022).

Conclusion

PAMM can be secondary to APAC or APACG at a rate of 2.9%. Different visual outcomes were observed in patients who received the intervention at different stages of PAMM. Younger patients with a shorter axial length and type 2 diabetes were found to be more susceptible to PAMM.

Clinical and Diagnostic Findings of Acute Macular Neuroretinopathy and Paracentral Acute Middle Maculopathy in the COVID-19 Era

BACKGROUND

Growing evidence suggests an association between the infection from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and eye disorders. The aim of this review was to analyze the clinical presentation and diagnostic features of acute macular neuroretinopathy (AMN) and paracentral acute middle maculopathy (PAMM) associated with COVID-19 infection. The features are then compared with previous reports regarding these retinal disorders, to recognize possible specific characteristics and to assess the role of multimodal ophthalmic imaging.

SUMMARY

A literature search was performed by consulting PubMed, Scopus, and Embase. The following terms were searched: "(COVID-19 OR SARS-CoV-2 OR coronavirus) AND ([acute macular neuroretinopathy] OR [paracentral acute middle maculopathy])." Inclusion criteria were as follows: (1) publication date from January 31, 2020 to January 31, 2022; (2) English language; (3) original research or case report; (4) free full-text availability.Optical coherence tomography (OCT) findings in AMN patients were hyper-reflectivity (HR) of the outer plexiform layer, of the outer nuclear layer, and ellipsoid or interdigitation zones (EZ and IZ, respectively) disruption. In most cases, the presence of HR and EZ/IZ abnormalities resulted combined. When performed, OCT angiography (OCTA) identified attenuation of signal of the deep capillary plexus (DCP). The most common OCT finding in PAMM was an alteration of the inner nuclear layer, associated with other areas of HR, while no signs of EZ/IZ disruption were detected. When performed, OCTA showed the attenuation of signal of both the DCP and the superficial capillary plexus.

KEY MESSAGES

In this review, we reported a case series of AMN and PAMM in patients with a previous or concomitant infection from SARS-CoV-2. The microvascular changes in these cases are highlighted by the OCTA scans. Even if we are far from the determination of a direct link between COVID-19 and these retinal disorders, we could hypothesize that the vascular alterations associated with SARS-CoV-2 infection could be a possible risk factor for both AMN and PAMM.

Retinal ischemic cascade: New insights into the pathophysiology and imaging findings

Retinal ischemia gives rise to a complex spectrum in which the cumulative profile of ischemia of the middle and inner retina can be highly variable. We reviewed the current knowledge on paracentral acute middle maculopathy (PAMM) pathophysiology and accompanying risk factors, the middle and inner retinal vasculature and blood flow, and the vulnerability of the middle retina in vaso-occlusive disorders. The inner nuclear layer (INL) is easily affected by slight degrees of retinal hypoperfusion and ischemia. INL infarction starts at perivenular sites, manifesting as skip PAMM lesions and a fern-like appearance in cross-sectional and en face views, respectively. With horizontal progression, INL infarction may develop into diffuse globular PAMM. If vertical progression occurs, the entire middle and inner portions of the retina can be affected. Transmural infarction of the middle and inner retina would be at the end of this spectrum. This gradient of ischemic progression resembles an ischemic cascade. We review the evidence supporting the term "retinal ischemic cascade," which encompasses a broad continuum of manifestations with roots in middle retinal infarction. With this terminology, variations in spatial and temporal progression and resolution of ischemia can also be delivered; it further enables addressing the possible associations between the middle and inner retinal ischemic patterns.

Association of Resolved Paracentral Acute Middle Maculopathy Lesions with Diabetic Retinopathy

Purpose

To evaluate the association between paracentral acute middle maculopathy (PAMM) lesions and diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA).

Methods

Thirteen diabetic patients without DR, 13 patients with mild nonproliferative DR (NPDR), 18 patients with moderate-to-severe NPDR, and 20 patients with proliferative DR (PDR) were included in this retrospective study. For each patient, 6 mm × 6 mm macular OCTA scans of both eyes were reviewed for the presence of acute and resolved PAMM lesions.

Results

Among diabetic patients with and without DR, 49 (94.9%) and 7 (53.8%) patients demonstrated small resolved PAMM lesions, respectively. The odds ratio for the presence of resolved PAMM lesions in the eye with DR compared to the eye of diabetic patient without DR was 21.8 (P < 0.001, 95% confidence interval 7.0-67.8). In the mild NPDR group, moderate-to-severe NPDR group, and the PDR group, 11 (84.6%), 18 (100.0%), and 20 (100.0%) patients demonstrated resolved PAMM lesions, respectively. There was a statistically significant increasing prevalence of PAMM lesions as the severity of DR increased (P < 0.001).

Conclusion

Small resolved PAMM lesions are a common form of ischemic retinal lesions in DR.

PARACENTRAL ACUTE MIDDLE MACULOPATHY ASSOCIATED WITH BRANCH RETINAL ARTERY OCCLUSION DUE TO POLYCYTHEMIA IN A PATIENT WITH TETRALOGY OF FALLOT

PURPOSE

To describe the occurrence of paracentral acute middle maculopathy (PAMM) associated with branch retinal artery occlusion secondary to polycythemia in a patient with tetralogy of Fallot.

METHODS

Case report.

RESULTS

A 30-year-old man presented with acute vision loss and superior visual deficit in his left eye for two days. His medical record had a tetralogy of Fallot. Complete blood count showed an erythrocyte count of 9.88 million/µL (4.4-5.6), hemoglobin of 17.7 g/dL (13.5-16.9), and hematocrit of 65.4% (40-49). The best-corrected visual acuity was 20/25 in the left eye, and a diagnosis of left inferotemporal branch retinal artery occlusion was made. Spectral-domain optical coherence tomography revealed a characteristic hyperreflective band-like lesion on the inner nuclear layer consistent with PAMM.

CONLUSION

Polycythemia may be a trigger for branch retinal artery occlusion-associated PAMM. We suggest a new precursor cause of PAMM that is previously undescribed.

Association of Paracentral Acute Middle Maculopathy with Visual Prognosis in Retinal Artery Occlusion: A Retrospective Cohort Study

Background

The association between paracentral acute middle maculopathy (PAMM) and visual acuity in patients with retinal artery occlusion (RAO) is unknown. This study explored the clinical features and prognostic factors for visual acuity of RAO accompanied by PAMM.

Methods

This retrospective study included patients with RAO who underwent FFA and OCT examinations at Shenzhen Eye Hospital from July 2015 to June 2019. The changes in vision and macular structure were observed.

Results

Eighty-eight patients were included. There were 58 patients (65.9%) with central RAO (CRAO) and 30 (34.1%) with branch RAO (BRAO). Fifty-two eyes were diagnosed with PAMM, of which 33 eyes (63.5%) were from CRAO patients and 19 (36.5%) were from BRAO patients. At diagnosis, the PAMM group had significantly better logMAR BCVA values than the no-PAMM group (median (IQR), 1.35 (0.725–2) vs. 2.15 (1.47–2.3), P=0.002). In addition, the PAMM group had significantly better logMAR BCVA values during follow-up than the no-PAMM group (median (IQR), 1 (0.05–2) vs. 2 (1.15–2.3), P=0.001). After adjustment for age, gender, CRAO/BRAO, comorbidities, and symptom duration, PAMM was associated with good visual acuity improvement (RR = 3.29, 95% CI: 1.29–8.37, P=0.013).

Conclusion

PAMM was associated with good visual acuity improvement during follow-up in patients with RAO.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.

Nitroglycerin as a Treatment Modality for Recurrent Isolated Paracentral Acute Middle Maculopathy: A Case Report

Paracentral acute middle maculopathy (PAMM) is a condition characterized by ischemia affecting the deep capillary plexus layer of the macula, often resulting in a paracentral visual scotoma. PAMM has been reported in association with retinal vascular diseases or as an isolated phenomenon in young and healthy individuals. There is currently no treatment for PAMM. We report a case in which sublingual nitroglycerin reversed developing visual scotomas, or blind spots, in a patient with known recurrent episodes of PAMM. 

This case describes a male patient with previously documented evidence of PAMM in both eyes following episodes of extreme physical activity or dehydration. These episodes would often last days without ultimate resolution. After one such occurrence in his right eye, the patient was treated with a sublingual nitroglycerin tablet immediately after the development of new visual scotomas. 

The patient’s visual symptoms improved within minutes of administering sublingual nitroglycerin, and completely resolved within hours.

PARACENTRAL ACUTE MIDDLE MACULOPATHY AFTER EPIRETINAL MEMBRANE REMOVAL

PURPOSE

To describe a patient with newly developed paracentral acute middle maculopathy after uncomplicated epiretinal membrane removal.

METHODS

Retrospective chart review.

RESULTS

A 74-year-old white man underwent uncomplicated vitrectomy and epiretinal membrane removal in his left eye. One week later, the patient complained of a small paracentral visual field deficit and decreased visual acuity. Spectral domain optical coherence tomography revealed a characteristic hyperreflective band-like lesion at the level of the inner nuclear layer, consistent with paracentral acute middle maculopathy. The patient was closely followed and endorsed subjective improvement of his paracentral visual deficit at 3 months postoperatively.

CONCLUSION

Paracentral acute middle maculopathy, although rare, may be encountered after epiretinal membrane removal.

DIMINUTIVE PARACENTRAL ACUTE MIDDLE MACULOPATHY LESION

PURPOSE

To describe a transient positive scotoma and corresponding optical coherence tomography (OCT) structural and angiographic findings.

METHODS

The patient was evaluated with a comprehensive ophthalmic examination to include OCT structural and angiographic imaging with two different instruments, the Zeiss Plex Elite and the Optovue RTVue XR Avanti.

RESULTS

A 45-year-old man had a sudden onset of a positive scotoma in the visual field of the left eye. No abnormalities were noted by ophthalmoscopy or fundus photography. Optical coherence tomography angiography was performed to evaluate the macular perfusion status. With each instrument, a small hyperreflective area, 175 μm in diameter, was imaged in the inner nuclear layer. The OCT angiographic images suggested a small area of decreased perfusion in the deep capillary plexus. Except for the diminutive size, the lesion had an appearance suggestive of paracentral acute middle maculopathy. The symptoms lessened rapidly, and when examined 4 days later, the lesion was less hyperreflective. Two weeks after presentation, the positive scotoma was not present and there was no longer any hyperreflectivity in the inner nuclear layer.

CONCLUSION

Detection of the lesion was aided by using OCT angiographic scans, which have a much higher scan density than conventional OCT evaluations. The diminutive abnormality was consistent with a paracentral acute middle maculopathy lesion, although smaller than those previously reported. Micro-paracentral acute middle maculopathy lesions should be considered in the differential diagnosis of positive scotomas.

Current and novel multi-imaging modalities to assess retinal oxygenation and blood flow

Retinal ischemia characterizes the underlying pathology in a multitude of retinal diseases that can ultimately lead to vision loss. A variety of novel imaging modalities have been developed to characterize retinal ischemia by measuring retinal oxygenation and blood flow in-vivo. These technologies offer valuable insight into the earliest pathophysiologic changes within the retina and provide physicians and researchers with new diagnostic and monitoring capabilities. Future retinal imaging technologies with the capability to provide affordable, noninvasive, and comprehensive data on oxygen saturation, vasculature, and blood flow mechanics are needed. This review will highlight current and future trends in multimodal imaging to assess retinal blood flow and oxygenation.

Transient vision loss associated with paracentral acute middle maculopathy detected on multi-modal imaging

Purpose

To report two patients with transient decreased vision and associated paracentral acute middle maculopathy (PAMM) lesions identified with multi-modal imaging, including what we believe to be the first documented patient of PAMM associated with iron deficiency anemia.

Observations

Case 1 is a 56-year-old man who experienced transient blurred vision one week following cardiac ablation for atrial fibrillation. Symptoms resolved by the time of presentation and visual acuity was 20/20 in each eye. Ocular examination was unremarkable aside from subtle discoloration within the papillomacular bundle in the right eye. Spectral domain optical coherence tomography (SD-OCT) revealed thickening of the middle retinal layers with a corresponding area of hyporeflectivity on the en face infrared image. This area of hyporeflectivity was confirmed on “structural” SD-OCT angiography, although no flow voids were identified. Fluorescein angiography was normal. Case 2 is a 25-year-old man with no past medical history who noted decreased central vision in his right eye upon awakening. Visual acuity was light perception in the right eye and 20/20 in the left eye. Posterior segment examination in the right eye showed tortuous retinal vessels and subtle pallor involving the superior part of the macula. SD-OCT showed thickening of the middle retinal layers of the superior macula with a corresponding area of hyporeflectivity on the en face infrared image. Systemic work-up was completed and identified severe iron deficiency anemia as the most likely inciting factor. In both cases, visual acuity was 20/20 in each eye at follow-up.

Conclusions

Small arterial occlusions of the retina remain difficult to diagnose and may represent a sequela of systemic disease. Multi-modal imaging is helpful in equivocal cases with subtle clinical findings.

Importance

The present case report illustrates the utility of multi-modal imaging in diagnosing transient ischemic events of the retina, and reports what we believe to be the first association of PAMM with iron deficiency anemia.

Long-term outcome of a Chinese cohort idiopathic retinitis, vasculitis, aneurysms, and neuroretinits (IRVAN) patients

PURPOSE

To evaluate the clinical characteristics and treatment outcomes of idiopathic retinitis, vasculitis, aneurysms, and neuroretinitis (IRVAN) in a cohort of Chinese patients.

MATERIALS

The clinical history, imaging evaluation, treatment and outcomes of 42 eyes in 21 patients diagnosed with IRVAN in a 15-year period were reviewed.

RESULTS

Most patients were females (90%) ranged from 15 to 58 years old. The initial decimal best corrected visual acuity (BCVA) of the patients ranged from light perception (LP) to 1.5 (0.55 ± 0.38). Eighteen eyes were in stage 2; 21 eyes in stage 3; and 1 in stage 5 at the initial visits according to the present staging system. Two eyes had vitreoretinal fibrovascular proliferation (FVP) and tractional retinal detachment (RD) at the initial visit. Intra-retinal microvascular abnormality (IRMA) was found in 7 eyes. Thirty-four eyes received retinal photocoagulation, 27 of which were pan-retinal photocoagulation (PRP). Total of 8 PPV were performed for VH, vitreoretinal FVP and RD, and macular epimembrane. Aneurysms on the head of optic nerve and artery bifurcations disappeared in 8 eyes and decreased in number in 2 eyes 1 year after photocoagulation. However, the BCVA of the patients did not have significant difference from that at the initial visits (P = 0.534). Seven eyes suffered severe visual impairment (BCVA ≤ 0.1) due to vitreoretinal FVP and tractional RD (3), exudative maculopathy (2), paracentral acute middle maculopathy (PAMM)(1), and neovascular glaucoma (NVG) (1).

CONCLUSIONS

We found that IRVAN have a predilection to female gender. Vitreoretinal FVP and tractional RD and exudative maculopathy are major causes of severe visual impairment in IRVAN patients. We propose to revise the present staging system to include vitreoretinal FVP and RD in the staging of IRVAN patients.

Clinical Characteristics of Paracentral Acute Middle Maculopathy in Eyes with Retinal Vascular Occlusion Diseases in Chinese Patients

Aim

To investigate the incidence and clinical characteristics of paracentral acute middle maculopathy (PAMM) and its relationship with prominent middle limiting membrane (p-MLM) sign in eyes with retinal artery occlusion (RAO) or retinal vein occlusion (RVO) in a Chinese clinical setting.

Methods

In this retrospective observational study from January 2015 to May 2020, multimodal imaging data of 807 eyes including 555 consecutive patients with RVO or 252 consecutive patients with RAO were reviewed. All patients were scanned using the spectrum-domain optical coherence tomography (OCT), and some of them underwent color fundus photography, fundus fluorescence angiography, en face OCT, and OCT angiography.

Results

PAMM was detected in 49 eyes of 49 RAO patients and 29 eyes of 29 RVO patients. The mean ages at presentation were 64.49 ± 13.90 years and 54.00 ± 18.48 years in RAO and RVO patients (P=0.006), respectively. Eyes with RAO were more prone to develop PAMM (19.44% [49/252] vs. 5.23% [29/555]; P < 0.001). Of the 78 eyes with PAMM, 24 eyes (7 eyes with RVO and 17 eyes with RAO) were found with p-MLM sign. An interesting phenomenon that had been overlooked before was that the hyperreflective line of the p-MLM sign was usually continuous, regardless of the type of PAMM lesion.

Conclusions

This series is the largest to date to describe the clinical characteristics of PAMM and p-MLM sign in Chinese patients. The incidence of PAMM and p-MLM sign in patients with RAO was relatively higher than that in patients with RVO. These signs alone probably represent milder ischemia and prompt us to carry out a comprehensive and meticulous examination to prevent the further development of the disease. In addition, the hyperreflective line of the p-MLM sign was usually continuous, which could support the totally venous nature of the retinal deep capillary plexus to some extent.

Paracentral Acute Middle Maculopathy following Surgically Induced Branch Retinal Artery Occlusion During Vitrectomy

Paracentral acute middle maculopathy (PAMM) is a spectral-domain OCT finding of a thickened hyperreflective band at the level of the intermediate layers of the inner retina, attributed to the acute phase of intermediate capillary ischemia. The purpose of this paper is to report a case of PAMM deriving from a surgically induced branch retinal artery occlusion (BRAO) during vitrectomy for vitreous hemorrhage. A 70-year-old female referred to the posterior segment office with a 1-month history of visual loss in her right eye. Best-corrected visual acuity (BCVA) was "counting-fingers" (CF) due to a dense vitreous hemorrhage. She underwent a standard 23-gauge vitrectomy with a relatively close to the optic disc endodiathermy application to an avulsed vessel. Follow-up examination revealed a well-demarcated retinal whitening involving the inferior macula. SD OCT showed a surgically induced branch retinal artery occlusion exhibiting both a cotton wool spot and a PAMM lesion. Our case affords an insight into those pathological processes involved with PAMM, providing angiographic evidence of the retinal ischemic changes responsible for its development, by angiographically proving that branch retinal artery occlusion leads to a prompt formation of both a cotton wool spot and a PAMM lesion. Our aim is to raise awareness of this potential complication of vitrectomy surgery, especially when involving multiple traumatic manipulations onto the retinal surface.

Paracentral acute middle maculopathy: from diagnosis toward clinical perspectives

In this review of literature, we reviewed the current state of knowledge on paracentral acute middle maculopathy (PAMM). The diversity of clinical manifestations, a variety of related cardiovascular and ocular conditions, as well as reported idiopathic cases, allow considering PAMM as a distinct clinical phenomenon or a syndrome. Taking into account already described and potential associations with systemic and ocular morbidity, PAMM may apply for a place of an important clinical biomarker not only for ocular but for systemic disorders in a broad cohort of patients. However, the understanding of the pathophysiology of PAMM and of its actual clinical significance is far from complete, and further studies are warranted.

Paracentral acute middle maculopathy and the organization of the retinal capillary plexuses

The retinal capillary vasculature serves the formidable role of supplying the metabolically active inner and middle retina. In the parafoveal region, the retinal capillary plexuses (RCP) are organized in a system of three capillary layers of varying retinal depths: the superficial capillary plexus (SCP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). While the dynamic flow through these plexuses is complex and not completely understood, current research points to a hybrid model that includes both parallel and in series components in which blood flows in a predominantly serial direction between the superficial vascular complex (SVC) and deep vascular complex (DVC). Each capillary plexus autoregulates independently, so that under most conditions the retinal vasculature supplies adequate blood flow and oxygen saturation at varying depths despite diverse environmental stressors. When the flow in the deep vascular complex (i.e. ICP and DCP) fails, an ischemic lesion referred to as Paracentral Acute Middle Maculopathy (PAMM) can be identified. PAMM is an optical coherence tomography (OCT) finding defined by the presence of a hyperreflective band at the level of the inner nuclear layer (INL) that indicates INL infarction caused by globally impaired perfusion through the retinal capillary system leading to hypoperfusion of the DVC or specifically the DCP. Patients present with an acute onset paracentral scotoma and typically experience a permanent visual defect. Lesions can be caused by a diverse set of local retinal vascular diseases and systemic disorders. PAMM is a manifestation of the retinal ischemic cascade in which the mildest forms of ischemia develop at the venular end of the DCP, i.e. perivenular PAMM, while more severe forms progress horizontally to diffusely involve the INL, and the most severe forms progress vertically to infarct the inner retina. Management is targeted toward the identification and treatment of related vasculopathic and systemic risk factors.

Inner retinal layers' alterations and microvasculature changes after vitrectomy for rhegmatogenous retinal detachment

PURPOSE

To examine the retinal layers' changes and alterations in retinal microvasculature in patients with rhegmatogenous retinal detachment (RRD) treated with pars plana vitrectomy (PPV).

METHODS

Participants in this study were 103 patients with RRD, 85 macula off and 18 macula on, who were treated with PPV and gas tamponade without internal limiting membrane peeling, in two centers. All participants underwent best corrected visual acuity measurement, slit-lamp examination, fundoscopy, spectral domain-optical coherence tomography and optical coherence tomography angiography at week 5 and at month 6 postoperatively. The fellow untreated eyes were also examined and served as control data.

RESULTS

A statistically significant enlargement in foveal avascular zone (FAZ) in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) was noticed 5 weeks postoperatively in patients with RRD treated with PPV compared to the fellow eyes and remained 6 months after surgery. The FAZ enlargement in the operated eyes was accompanied with a statistically significant thinning of the inner retinal layer. In addition, there was a significant decrease in foveal and parafoveal vessel density (VD) in both SCP and DCP in the operated eyes compared to control eyes at week 5 postoperatively, which also remained at postoperative month 6.

CONCLUSIONS

The study demonstrated that patients with RRD treated with PPV presented changes in the retinal microvasculature in both SCP and DCP, including enlargement of FAZ and decrease in VD. These changes seemed to be associated with inner retinal layer thinning.

Paracentral acute middle maculopathy-review of the literature

Paracentral acute middle maculopathy (PAMM) is a recently identified spectral-domain optical coherence tomography (SD-OCT) finding characterized by a hyper-reflective band spanning the inner nuclear layer (INL), which typically evolves to INL atrophy in later stages. Typical clinical features include the sudden onset of one or multiple paracentral scotomas, normal or mild reduction in visual acuity, and a normal fundus appearance or a fundus with a deep grayish lesion. Although its pathophysiology is not yet fully understood, ischemia at the level of the intermediate and deep capillary plexa has been demonstrated to play a major role. Since its first description, an increasing number of publications on PAMM have been published in ophthalmology scientific journals. The purpose of this study is to provide a review of the current literature on PAMM.

[Spectrum of diseases associated with paracentral acute middle maculopathy]

Paracentral acute middle maculopathy (PAMM) is a rare disease affecting middle layers of the central retina that is seen as a focal hyperreflective band-like lesion on optical coherence tomography. Paracentral acute middle maculopathy is associated mainly with vascular diseases. Optical coherence tomography angiography (OCTA) findings confirm the ischemic nature of paracentral acute middle maculopathy.

Purtscher-like retinopathy presented a honeycomb-like pattern in optical coherence topography angiography

Background

To report a case of Purtscher-like retinopathy (PUR) and the optical coherence tomography (OCT) and OCT angiography (OCT-A) findings before and after treatment.

Case presentation

A 65-year-old male presented with acute onset of vision loss for 2 weeks. Fundus examination revealed cotton-wool spots, retinal haemorrhage, and Purtscher flecken spread around the optic disc in the right eye. He was diagnosed with Purtscher-like retinopathy because he lacked any traumatic medical history. OCT presented some band-like hyperreflective lesions at the inner nuclear layer, which are indicative of paracentral acute middle maculopathy (PAMM). OCT-A revealed apparent reduction in blood flow signal at the deep retina and choriocapillaris layers with a honeycomb-like hypointense signal pattern. After 3 months of follow-up, OCT revealed resolution of retinal oedema, but PAMM lesions remained visible. Based on OCT-A, the honeycomb-like pattern turned into a homogeneous reduction in blood flow with small patches of hypointense signal areas in the choriocapillaris.

Conclusion

This case presented a new OCT-A sign in PUR with a honeycomb-like hypointense signal at the choriocapillaris layer, indicating the involvement and ischaemia of the choroid during the pathological process.

Management of Deep Retinal Capillary Ischemia by Electromagnetic Stimulation and Platelet-Rich Plasma: Preliminary Clinical Results

INTRODUCTION

To investigate the efficacy of retinal electromagnetic stimulation and sub-tenon autologous platelet-rich plasma in the treatment of deep retinal capillary ischemia.

METHODS

The study included 28 eyes of 17 patients aged 15-76 years (mean 37.9 years) who had deep retinal capillary ischemia. Patients who had acute-onset paracentral scotoma in the last 1 month were included in the study between January 2018 and January 2019. The diagnosis of deep retinal capillary ischemia was based on clinical history and typical findings of optical coherence tomography angiography. The eyes were divided into three groups: group 1 (n = 7 eyes) received electromagnetic stimulation alone; group 2 (n = 7 eyes) received electromagnetic stimulation and sub-tenon autologous platelet-rich plasma injection; group 3 had no intervention and served as a control group (n = 14 eyes). The patients underwent ten sessions of electromagnetic stimulation in groups 1 and 2. Sub-tenon autologous platelet-rich plasma injection was performed immediately after the first, fifth, and tenth sessions of electromagnetic stimulation in group 2. The deep retinal capillary density and best corrected visual acuity changes were investigated before and after treatment at the first month.

RESULTS

The mean deep retinal capillary density was 52.0% before electromagnetic stimulation and 56.1% after ten sessions of application in group 1; this improvement was statistically significant (p = 0.01). In the combined treatment group (group 2), the mean deep retinal capillary density was 46.9% before the treatment and 56.5% after the treatment; this increase was also statistically significant (p = 0.01). Statistically significant best corrected visual acuity improvement (p = 0.01) could be achieved only in group 2. The combined treatment was significantly superior (p < 0.01) to treatment with only electromagnetic stimulation regarding best corrected visual acuity and deep retinal capillary density. In the control group (group 3), there was no statistically significant change (p = 0.09) in the mean deep retinal capillary density and best corrected visual acuity.

CONCLUSION

Treatment of the underlying cause is a priority in the treatment of deep retinal capillary ischemia. However, in the acute period, local ischemia treatment is necessary to prevent permanent retinal damage and scotomas. In mild cases, only electromagnetic stimulation, which is non-invasive and easy to use, might have a beneficial effect on deep retinal capillary density. In more severe cases, sub-tenon fresh autologous platelet-rich plasma injection together with electromagnetic stimulation may be more effective in the treatment of local ischemia of the retina in order to augment the response.

FUNDING

The Rapid Service Fees were funded by the Ankara University Tecnopolis Institute.

CLINICAL TRIAL REGISTRATION

titck.gov.tr identifier, 2018-136.