Optical Coherence Tomography Angiography Findings in Post-Traumatic Purtscher Retinopathy: A Case Report

Introduction

Purtscher retinopathy (PR) is an uncommon but serious vision-threatening eye disorder that mainly occurs among middle-aged men after head injury or chest compression. In cases in which changes similar to PR occur without preceding trauma, such as in acute pancreatitis, collagenosis, lymphoproliferative disorders, systemic lupus erythematosus, breast surgeries, orthopedic surgeries, bone marrow transplantation, or intravitreal injection, the condition is referred to as Purtscher-like retinopathy [1,2].

The diagnosis is primarily clinical and is based on unilateral or bilateral sudden vision loss with fundus features, including cotton-wool spots, Purtscher flecken (polygonal retinal whitening), retinal hemorrhages, and optic disk swelling [1–4]. Although the pathophysiology of the disease is not fully understood, the main cause of PR seems to be an embolic occlusion of the precapillary arterioles that supply the superficial peripapillary capillaries [1,2].

To date, imaging studies – primarily fluorescein angiography – have been pivotal in elucidating the vascular involvement in PR [1–6]. More recently, the development of novel imaging techniques, such as optical coherence tomography angiography (OCT-A), has enabled a more detailed evaluation of retinal and choroidal microcirculation in PR without the need for contrast agents [7–18]. OCT-A, being both safer and more sensitive than fluorescein angiography, provides strong support for the ischemic pathogenesis of PR [7–18]. Moreover, the use of OCT-A shows the presence of ischemic changes that are not visible in the fluorescein angiography examination [8].

Here, we report a case of PR in which OCT-A demonstrated ischemic injury affecting both the retinal and choroidal circulation. To the best of our knowledge, this is the first reported case of post-traumatic PR in which choroidal ischemia was identified on initial OCT-A and confirmed on follow-up examination.

Case Report

A 63-year-old man with head and cervical spine injury after a fall from a height reported visual impairment in the right eye 2 days after the injury. During his initial ophthalmological examination in the acute stage, the best-corrected visual acuity (BCVA) of the right eye was counting fingers at a distance of 50 cm and 0.6 in the left eye according to the Snellen chart; intraocular pressure in both eyes was 18 mmHg. Examination of the anterior segment of the eye did not reveal any post-traumatic changes; the pupillary reaction to light was normal. The patient had cataracts in both eyes. Fundoscopic examination of the right eye revealed massive retinal edema, intraretinal hemorrhages, multiple confluent foci of cotton-wool spots, and Purtscher flecken (Figure 1A). Fundoscopic evaluation of the left eye revealed no abnormalities. The OCT (DRI-OCT Triton SS-OCT Angio, Topcon Inc, Tokyo, Japan) examination showed hyperreflectivity of the inner retinal layers, paracentral acute middle maculopathy (PAMM) (Figure 2A), presence of subretinal fluid (Figure 3A), and the detachment of the internal limiting membrane (Figure 2A). The OCT scan of the optic disc was normal (Figure 4A). Due to the patient’s general condition and the possibility of performing OCT-A, we did not perform fluorescein angiography. The OCT-A scan showed blood flow disorders in the superficial and deep retinal plexuses, with a visible area of capillary non-perfusion. At the level of the choriocapillaris, apart from a large intense dark area, which corresponded to ischemia of the inner retinal layers, there were visible single patches of hypoperfusion with sharp edges that could independently indicate ischemic injury at the choriocapillaris level (Figure 5A). A diagnosis of post-traumatic PR was made. A computed tomography (CT) scan of the head and orbits did not show any post-traumatic changes, while a CT scan of the cervical spine revealed an axial fracture with posterior displacement of the proximal fragment by approximately 3.2 mm. Systemic steroid therapy was initiated: 5 pulses of methylprednisolone at a dose of 1 g were administered, then systemic steroid therapy was continued, using prednisolone in decreasing doses. In a subsequent check-up after 2 weeks, a gradual regression of the changes present in the fundus examination was observed. OCT showed a gradual decrease in retinal thickness and internal limiting membrane apposition (Figure 2B). OCT-A revealed persistent nonperfusion in both the superficial and deep capillary plexuses; blood flow disturbances were also observed at the level of the choriocapillaris (Figure 5B). At the follow-up examination after 3 months, the BCVA of the right eye was hand movements, intraocular pressure was normal, the anterior segment did not differ from the norm, and the fundus examination showed the discreet pallor of the optic nerve head and isolated retinal hemorrhages (Figure 1B). OCT showed a decrease in retinal and choroidal thickness (Figure 3B, 3C). OCT of the optic disc showed a decrease in the retinal nerve fiber layer thickness (Figure 4B). On OCT-A, persistent nonperfusion was observed in the superficial and deep retinal capillary plexuses, with discrete nonperfusion at the level of the choriocapillaris. Observed small patches of hypointense signal represented sequelae of choroidal infarctions from the acute stage (Figure 5C).

Discussion

This case highlights that ischemic changes in PR can affect both the retinal and choroidal circulation, emphasizing that early OCT-A evaluation is essential not only for detecting microvascular involvement but also for guiding prognosis.

The diagnosis of PR is often done clinically. Cotton-wool spots have the highest prevalence, followed by retinal whitening and retinal hemorrhages. Purtscher flecken seen on fundoscopy are considered pathognomic, although they are not seen in 50% of patients [1]. In our case, apart from optic disc edema, we observed all off these signs. The signs in the course of post-traumatic PR are mostly bilateral, although they can also be unilateral [1–4], as in the present case.

The characteristic retinal findings are believed to result from occlusion of peripapillary terminal arterioles supplying the superficial peripapillary capillary network. Leukoembolization, endothelial injury, complement 5 activation, and small-arteriole occlusion leading to capillary bed infarction have been implicated in the pathogenesis of PR and Purtscher-like retinopathy [2].

Currently, OCT and OCT-A provide valuable insights into PR [7–18]. In the acute phase of PR, OCT often demonstrates increased reflectivity and thickening of the inner retinal layers corresponding to Purtscher flecken and cotton-wool spots, as was seen in our case (Figure 3A) [9,11–13]. In initial OCT, we also detected internal limiting membrane detachment (Figure 2A). Similar internal limiting membrane detachment has been reported by Xiao et al [11] and Prabhu et al [14].

PAMM has been reported in several cases of PR [9,11,12], appearing as hyperreflective bands in the inner nuclear layer that likely reflect ischemia and may correspond to Purtscher flecken on OCT [2]. PAMM was also observed in our study (Figure 3A). Hyperreflectivity of the Henle fiber layer has been proposed as a marker of deep capillary plexus ischemia in PR and Purtscher-like retinopathy [17]. Alterations of the outer retinal layers, including ellipsoid zone disruption, have also been described in PR [8,10,11]. Gediz et al reported a case of acute macular neuroretinopathy secondary to PR [19].These findings suggest that ischemia in PR may extend beyond the inner retina, potentially affecting choroidal circulation.

In PR, OCT-A reports indicate the presence of ischemia at the level of the superficial and deep retinal plexuses, which corresponds to retinal thickening and PAMM presence [7,9,11,13,15]. In the study by Xiao et al, OCT-A flow voids in both the superficial and deep capillary plexuses resulted in a markedly enlarged foveal avascular zone [11]. The literature also includes reports of PR and Purtscher-like retinopathy in which the ischemic insult was suspected at the level of the choriocapillaris [12,18,19]. In our study, similar to other studies, in the initial OCT-A examination, the swelling of the inner retinal layers prevented the reliable assessment of the choriocapillaris [12,18,19]. The intense dark area at the level of the choriocapillaris may have resulted from ischemic injury or from artifacts caused by massive retinal edema. However, the area of shadowing was more intense than in the retinal plexuses, and its boundaries did not exactly correspond to them. Additionally, single patches of hypoperfusion with sharp edges were observed, which may correspond to ischemic injury of the choroidal lobules. In the study by Li et al, in which pseudo-PR was described, OCT-A revealed an apparent reduction in the blood flow signal at the deep retinal and choriocapillaris layers, with a honeycomb-like hypointense signal pattern. After 3 months of follow-up, OCT revealed the resolution of the retinal edema, but the PAMM lesions remained visible. Based on OCT-A, the honeycomb-like pattern turned into a homogeneous reduction of blood flow, with small patches of hypointense signal areas in the choriocapillaris [12]. İpek et al reported similar findings, but only in a case of pseudo-PR. In their PR case, the initially observed retinal ischemia and suspected choriocapillaris ischemia resolved, with no perfusion abnormalities detected on follow-up OCT-A [18]. In our case, similar to previous reports [7,8,12], follow-up examinations revealed resolution of retinal edema with subsequent retinal thinning, while OCT-A demonstrated persistent areas of capillary nonperfusion in the superficial and deep retinal plexuses. Once the retinal swelling subsided, assessment of choriocapillaris perfusion was improved, revealing a homogeneous hypoperfused area at this level, consistent with the findings of Li et al [12].

The report of Li et al, as well as ours, indicate that choroidal ischemia can occur in the course of pseudo-PR and PR [12]. These findings underscore the value OCT-A for detecting and monitoring ischemic changes in PR. Moreover, these findings are supported by a case of PR reported by Gomez-Ulla et al, in which indocyanine green angiography demonstrated persistent choroidal hypofluorescence up to 5 months after trauma [6].

In the cases involving PR, the patients spontaneously recovered, although the data are not conclusive. The visual prognosis is variable, and in severe disease, the prognosis is usually poor [1,2]. Hypoperfusion of the retinal plexuses has been suggested as poor prognostic factors [2,12]. Disorder in the choroidal microcirculation could be an additional cause of the resulting poor vision observed in some patients with PR [6,7,12,19], as in our case, in which an atrophy of the retina and choroid developed and BCVA worsened to hand movements.

According to evidence-based medicine, management primarily consists of observation, owing to the self-limiting course of PR [3]. Nevertheless, certain practitioners recommend early intravenous corticosteroid pulse therapy. In our case, we also used high-dose corticosteroid therapy. Corticosteroids are intended to stabilize the microvascular channels and membranes of neurons, thereby reducing the accumulation of neutrophils and the release of pro-inflammatory factors, along with inhibiting complement system activation, which collectively contribute to retinal cell apoptosis. The literature provides limited high-quality evidence regarding their actual efficacy in PR cases [1,4]. In the treatment of PR, medications that improve eye microcirculation, such as carbonic anhydrase inhibitors or pentoxifylline, may also be beneficial. To reduce thrombotic risk, anticoagulant and antiplatelet therapies are warranted. In cases in which macular edema or delayed retinal neovascularization develops months after the initial event due to chronic ischemia, anti–vascular endothelial growth factor injections should be considered [3]. Due to the lack of uniform recommendations, each case of PR should be individually assessed and managed [1].

Conclusions

PR can affect both the retinal and choroidal circulation. OCT-A complements the diagnosis of PR and provides rapid, safe, and non-invasive assessment of microvascular changes, offering key prognostic insight. In cases of PR, the presence of ischemic changes in the retina and choroid can be associated with poor final visual acuity.