We report a case of fibrinoid reaction after diabetic vitrectomy surgery. Our case report describes a male patient with severe fibrinoid reaction with both intravitreal fibrin bands and subretinal fibrin and fluid following vitrectomy for diabetic retinopathy. He was managed initially with posterior subtenon and suprachoroidal injection of triamcinolone as well as intravitreal injection of tissue plasminogen activator (TPA). Fluid-air exchange and air-fluid exchange were also performed to remove the fibrin degradation product. 1 millimeter of air tamponade was placed in the vitreous cavity to displace the remaining subretinal fibrin. During this patient’s follow-up, the patient’s OCT including ultrawide-field OCT showed transvitreal fibrin bands, subretinal fibrin, as well as subretinal fluid in the right eye. The degradation of intravitreal fibrin bands as well as decrease in subretinal fluid were noted 2 days after intravitreal TPA and suprachoroidal injection of triamcinolone acetonide. The subretinal fibrin was partially reabsorbed and displaced after repeated injection of TPA and air tamponade placement 1 week later. Subsequent follow-up showed complete resolution of the subretinal fibrin and subretinal fluid as well as improved visual acuity. In summary, we describe a case of fibrinoid reaction after vitrectomy for diabetic retinopathy which was successfully treated. Wide-field OCT may also be used to assist in the recognition of this phenomenon.

© 2023 The Author(s). Published by S. Karger AG, Basel

Fibrinoid syndrome is a rare post-operative ophthalmic condition that varies in severity ranging from fibrin strands to being a dense pupillary membrane in the vitreous chamber [1]. It typically presents within 1 to 2 weeks after ophthalmic surgery [1]. No consensus on the treatment currently exists. However, treatment with tPA agents and steroids have been reported previously. We therefore report a case of a patient with fibrinoid syndrome following diabetic vitrectomy procedure that was managed with administration of triamcinolone acetonide (TA), intravitreal injections of tissue plasminogen activator (TPA), and gas-fluid exchange.

A 57-year-old male presented to our ophthalmologist outpatient clinic at the China Medical University Hospital (CMUH) with decreased visual acuity (VA) in both eyes for 6 months. Past history was significant for diabetes mellitus type 2. There was also history of cataracts and uncomplicated phacoemulsification with in-the-bag intraocular lens implantation 6 months ago. At the initial visit, VA was counting fingers at 10 cm bilaterally and intraocular pressure was 19 mm Hg for the right eye and 38 mm Hg for the left eye. Vitreous hemorrhage secondary to diabetic retinopathy was noted in the right eye and neovascular glaucoma in the left eye. Pars plana vitrectomy, endolaser, and membrane delamination were then performed in the right eye. Filtering procedure was also arranged for the left eye.

At post-operation day (POD) 1 of vitrectomy, intraocular pressure was noted to be 19 mm Hg for the right eye. The best-corrected visual acuity improved to 20/2,000. Partially obscured fundus of the right eye was also noted with faint vitreous hemorrhage and transvitreal fibrin strands. Fibrinoid syndrome was therefore suspected. The patient then received posterior subtenon injection of 40 mg TA. 5 days later, optical coherence tomography (OCT) and ultrawide-field OCT of the right eye showed subretinal fluid, subretinal fibrin, and transvitreal fibrin (shown in Fig. 1, 2a). From the ultrawide-field OCT image, transvitreal fibrin was noted to have a fish-net-like mixed with knots configuration (shown in Fig. 2a). His vision was also reduced to hand motions. TPA (50 μg) via intravitreal injection with suprachoroidal injection of TA (4 mg) was then given. Two days later (POD 8), there was complete reabsorption of the transvitreal fibrin bands that was seen on follow-up ultrawide-field OCT (see Fig. 2b). OCT of the right eye also showed significant reduction of the subretinal fluid but with persistent subretinal fibrin (shown in Fig. 1b). VA at POD 8 improved to counting finger at 30 cm. To remove any remaining fibrin degradation products, air-fluid exchange was performed followed by fluid-air exchange with balanced salt solution. 1 cc of air was also left inside the eye after these exchanges and prone position was maintained. Another 25 microgram tPA was also injected intravitreally. At POD 15, color fundus photography (see Fig. 3) and OCT was obtained. Color fundus imaging showed clear fundus with easily seen retinal vasculature and optic disc. On OCT, complete resolution of the subretinal fluid and reduced subretinal fibrin were noted (shown in Fig. 1c). VA also improved to 20/400. On POD 43, there was complete resolution of the subretinal fibrin (shown in Fig. 1d). His final VA improved to 20/150. Overall clinical course was summarized in Figure 4. The CARE checklist has been completed by the authors of this case report and attached as online supplementary material at www.karger.com/doi/10.1159/000529912.

Optical coherence tomography (OCT) of the right eye during follow-up. a Post-operative day (POD) 6 demonstrated transvitreal fibrin. b POD 8 demonstrated resolution of the transvitreal fibrin bands and reduction of the subretinal fluid. Additionally, persistence of the subretinal fibrin was also seen. c POD 14 demonstrated resolution of the subretinal fluid and fibrin with some remnant subretinal fibrin. d POD 40 days revealed complete resolution of subretinal fibrin and fluid.

Ultrawide-field optical coherence tomography (OCT) of the right eye on POD 6 (a) showing subretinal fluid with transvitreal fibrin strandings as well as retinal pigment epithelial detachment and POD 8 (b) showing reduction of the intraretinal fluid and retinal pigment epithelial detachment and significant resolution of the transvitreal fibrin strandings.

Color fundus image of the right eye on POD 15 demonstrated clear fundus with easily seen retinal vasculature and optic disc. No vitreous opacity caused by fibrinoid syndrome was otherwise seen.

Clinical timeline: a 57-year-old male who was diagnosed with fibrinoid syndrome. BCVA, best-corrected visual acuity; OCT, optical coherence tomography; TA, triamcinolone acetonide; TPA, tissue plasminogen activator.

We report a case of transvitreal fibrinoid material following diabetic vitrectomy in the right eye which was managed successfully with TA, TPA injections, and intravitreal air combined with prone positioning. We further documented the vitreal fibrin strands with ultrawide-field OCT.

Fibrinoid syndrome is a rare post-vitrectomy complication, with incidence varying between 8% and 22% [2]. The pathophysiology is poorly understood. It has been hypothesized that vitrectomy and endolaser may promote inflammatory processes secondary to compromised blood retinal barrier which may result in the exudation of plasma proteins into the vitreous cavity. This would lead to the activation of fibrin and therefore fibrinoid syndrome. Furthermore, laboratory studies have shown TPA activity to be significantly decreased in the first days following ophthalmic surgery. This reduction in tPA could again predispose patients toward fibrinoid reaction [3]. Risk factors for this reaction include combination surgery [1].

There are very few reports on fibrinoid syndrome in literature and those that exist have discussed TPA and steroid injection to be the therapies of choice [4]. Some examples include Nelson et al. [4] and Dotan et al. [5]. The article by Nelson et al. [4] is a case of fibrinoid syndrome which involved a 58-year-old woman with proliferative diabetic retinopathy and vitreous hemorrhage who underwent vitrectomy in both eyes. The early post-operative course for each eye in Nelson et al. [4] was complicated by choroidal effusion and submacular fibrinoid material noted on OCT. The left eye also developed transvitreal fibrinoid bands. Nelson et al. [4] treated their patient with intravitreal TA and showed near resolution of submacular fluid and fibrinoid material 2 weeks later for both eyes. However, this stands in contrast with our study as we did not demonstrate resolution after TA injection [4]. The article by Dotan et al. [5] was another prospective cohort study of which 40 patients of 40 eyes with anterior chamber fibrin reaction developing after cataract surgery were recruited. However, they only included patients that failed to respond to steroids treatment. The purpose of their study was to assess response toward tPA injections. Their result showed that 32 (80%) of their fibrinoid syndrome with steroid-resistant patients had complete clearance and 8 (20%) had partial clearance at day 1 after TPA injections. Furthermore, at 1-month follow-up, they showed complete resolution in 95% of their patients [5]. These results from literature showed that fibrinoid syndrome would ordinarily be responsive to either tPA or steroid injections. Our patient – despite having received posterior-subtenon injection of 40 mg triamcinolone after initial presentation – still experienced deterioration in terms of his fibrinoid syndrome. It was only after additional intravitreal tPA and suprachoroidal injection of triamcinolone before any improvement in the fibrinoid reaction was seen for our patient. Our case thus highlighted the fact that for a specific subgroup of patients with more severe fibrinoid reaction, larger doses of anti-inflammatory agents may be necessary. TPA is an example of a therapeutic agent that can potentially offer rapid resolution of intravitreal fibrin strands and may prevent further complications brought on by the fibrin. As part of our case, we also demonstrated the potential utility of removing vitreous fluid and utilizing air tamponade agent in certain fibrinoid syndromes. As we wanted to prevent the reaggregation of fibrin from the remaining fibrin degradation product, our patient also underwent the additional preventative step of removing the vitreous fluid after the resolution of fibrin. Furthermore, as there was some residual subretinal fibrin noted after tPA injection on POD 9, 1.0 cc of air tamponade agent was also used to displace the subretinal fibrin.

There is no consensus on the optimal evaluation protocol for fibrinoid syndrome. However, any diagnosis is usually made clinically and based on detailed history taking as well as the use of more commonly seen diagnostic modalities like slit-lamp exam and standard OCT imaging. There are instances where fibrinoid syndrome can be difficult to diagnose. For example, it can be difficult to elucidate fibrin strands when clear fundus view is obscured by the presence of faint vitreous hemorrhage (which is a common occurrence among vitrectomized eyes). During these situations, having an additional diagnostic modality like ultrawide OCT may further assist the clinician in arriving at the correct diagnosis. Our case showed that through documentations by ultrawide OCT, one was able to better appreciate the fish-net configuration of transvitreal fibrin that was originally obscured by faint vitreous hemorrhage. Ultrawide-field OCT therefore has helped us in arriving at the correct diagnosis of fibrinoid syndrome for our patient. This was important as it allowed for the timely and appropriate subsequent therapeutic interventions that was just described in our case.

We report the multimodal imaging and clinical course from a patient with fibrinoid syndrome in the right eye after vitrectomy for diabetic retinopathy including ultrawide-field OCT. A fish-net configuration of transvitreal fibrin strand was appreciated as a part of our imaging workup. Our patient was then successfully managed with TA and intravitreal TPA therapy with good anatomical and visual outcome.

Ethical approval is not required for this study in accordance with national guidelines. The treatment followed the tenets of the Declaration of Helsinki. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

The authors declare no conflict of interest.

This research received no external funding.

San-Ni Chen contributed to the conception and design of the case report. Alan Yun-Hsuan Hsu and San-Ni Chen drafted the manuscript, supervised and revised the manuscript to meet academic standards, and have approved the final manuscript and take responsibility for the integrity and accuracy of this study.

All data generated or analyzed during this study are included in this article and its online supplementary material. Further inquiries can be directed to the corresponding author San-Ni Chen or co-author Alan Yun-Hsuan Hsu.

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