Occlusive retinal vasculopathy with macular branch retinal artery occlusion as a leading sign of atypical hemolytic uremic syndrome - a case report

Purtscher Retinopathy Resulting from a Car Crash Accident-Multimodal Imaging Value

Purtscher retinopathy is a rare but severe sight-threatening eye condition that mostly occurs in middle-aged men after chest compression or head injury. In cases such as acute pancreatitis, connective tissue disorders, kidney failure or COVID-19 infection with similar ocular findings but no history of trauma, a diagnosis of Purtscher-like retinopathy is made. We present a case of a 72-year-old female with typical symptoms of Purtscher retinopathy in both eyes after a car crash accident. Although the pathophysiology of the disease is not fully understood, the main cause of Purtscher retinopathy seems to be an embolic occlusion of the precapillary arterioles which supply the superficial peripapillary capillaries. Activation of the C5a component of the complement predisposes the leukocytes to aggregation, which obstructs blood flow. The main symptom of Purtscher retinopathy is sudden, painless deterioration of vision which occurs up to 48 h after the injury. In most patients, the changes observed in the fundus of the eye resolve within several months, and visual acuity slowly improves, sometimes even returning to the state from before the injury. However, risk factors such as older age, high hyperopia, and late treatment implementation can make the prognosis less favorable.

Complement-mediated thrombotic microangiopathy on a background of Alport syndrome: A case report

Here we present a case of complement-mediated thrombotic microangiopathy (TMA) in a patient who has a background of Stage 5 chronic kidney disease secondary to Alport syndrome. We explain our approach to the diagnosis of TMA, especially the reliance on non-renal manifestations of TMA and the role of kidney biopsy given there was a background of advanced kidney impairment at baseline.

Bilateral Retinal Venous Occlusion in Atypical Hemolytic-Uremic Syndrome Due to Complement Factor H Mutation

PURPOSE

Atypical hemolytic uremic syndrome (aHUS) is a rare progressive thrombotic microangiopathy caused by overactivation in the alternative complement pathway. A wide spectrum of environmental triggers, such as viruses, vaccination, drugs, pregnancy, neoplasms, transplant, and autoimmune diseases can cause aHUS in genetically susceptible individuals. In this report, the diagnosis and treatment process of aHUS and bilateral retinal venous occlusion (RVO) will be presented.

METHODS

Single-case, retrospective management of ophthalmological and systemic manifestations.

RESULTS

A 28-year-old G2P2 female with acute blurred vision and history of acute renal failure. She was diagnosed with preeclampsia in her gestation history. After the laboratory work-up, the diagnosis of aHUS was confirmed. She was treated with eculizumab following 14 days of plasmapheresis. However, her visual acuity was 20/20 on the right and 20/60 on the left at the time of admission. Retinal examination revealed flame-shaped hemorrhages, exudation, and macular edema. The patient was diagnosed with branch RVO in the right eye. Subsequently, central RVO was occurred in the left eye. Intravitreal dexamethasone implant was administered for both eyes since there was no reasonable regression in retinal findings with bevacizumab treatment. She went into remission and her BCVA reached 20/25 during the 12-month follow-up period under the eculizumab therapy.

CONCLUSION

Diagnosis of aHUS is challenging especially during pregnancy and the postpartum period. Although ocular involvement is quite rare, we described bilateral RVO in aHUS case with homozygous nonsense mutation (c.2134 G > T p.G712). Dexamethasone implant should be considered for the treatment of RVO in aHUS cases.

Monoclonal gammopathies of clinical significance (MGCS): In pursuit of optimal treatment

Monoclonal gammopathy of clinical significance (MGCS) represents a new clinical entity referring to a myriad of pathological conditions associated with the monoclonal gammopathy of undetermined significance (MGUS). The establishment of MGCS expands our current understanding of the pathophysiology of a range of diseases, in which the M protein is often found. Aside from the kidney, the three main organ systems most affected by monoclonal gammopathy include the peripheral nervous system, skin, and eye. The optimal management of these MGUS-related conditions is not known yet due to the paucity of clinical data, the rarity of some syndromes, and limited awareness among healthcare professionals. Currently, two main treatment approaches exist. The first one resembles the now-established therapeutic strategy for monoclonal gammopathy of renal significance (MGRS), in which chemotherapy with anti-myeloma agents is used to target clonal lesion that is thought to be the culprit of the complex clinical presentation. The second approach includes various systemic immunomodulatory or immunosuppressive options, including intravenous immunoglobulins, corticosteroids, or biological agents. Although some conditions of the MGCS spectrum can be effectively managed with therapies aiming at the etiology or pathogenesis of the disease, evidence regarding other pathologies is severely limited to individual patient data from case reports or series. Future research should pursue filling the gap in knowledge and finding the optimal treatment for this novel clinical category.

Retinal findings in glomerulonephritis

The complement system is part of the innate immune system activated by three distinct pathways: classical, lectin and alternative. It is also involved in retinal development and homoeostasis. Dense deposit disease is a rare renal disease associated with mutations in Complement factor H and overactivity of the alternative complement pathway. As well as glomerulonephritis, many affected individuals have retinal drusen and may be at risk of vision loss due to macular atrophy or choroidal neovascularisation. We discuss the reclassification of dense deposit disease as a type of C3 glomerulonephropathy, and hypothesise on the mechanisms of retinal abnormalities. Drusen have also been described in individuals with other types of glomerulonephritis involving abnormalities of the classical (membranoproliferative glomerulonephritis type 1) or lectin (IgA nephropathy, lupus nephritis) complement pathways. Although drusen are found in abnormalities of all three complement pathways, the age at onset, aetiology, and the threat to vision differs. This review describes drusen and other retinal abnormalities associated with the glomerulonephritides due to abnormal activation in each of the three complement activation pathways, and provides the first report of drusen occurring in a patient with the recently reclassified C3 glomerulonephritis with homozygous variant V62I in complement factor H. Optometric management of young patients presenting with retinal drusen is discussed, and complement-based therapies for visual loss are reviewed.

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.