Lipemia Retinalis with Proliferative Diabetic Retinopathy: A Case Report

Dear Editor,

Lipemia retinalis is a rare manifestation of severe hyper-triglyceridemia. On fundus examination, retinal vessels develop a creamy-white discoloration that begins peripherally at triglyceride (TG) levels of approximately 2,500 to 3,499 mg/dL, extends centrally when TG exceeds 3,500 to 5,000 mg/dL, and the fundus may take on a salmon-pink appearance when TG is >5,000 mg/dL [1]. A 42-year-old male patient with 15-year type 2 diabetes and 4-year chronic pancreatitis was presented for diabetic eye screening. Best-corrected visual acuity was 20 / 20 in both eyes; anterior segments were unremarkable. Written informed consent for publication of the research details and clinical images was obtained from the patient.

Widefield fundus photography showed diffusely white retinal vessels with multiple blot hemorrhages and lipid exudates in both eyes; the left eye also had moderate pre-retinal hemorrhage (Fig. 1A, 1B).

Fig. 1

Images of the case. (A, B) Initial widefield fundus photography showing white retinal vessels, multiple blot hemorrhages, and lipid exudates in both eyes, with preretinal hemorrhage in the left eye. (C, F) Widefield intravenous fluorescein angiography showed multiple areas of focal hypofluorescence consistent with capillary nonperfusion of both eyes, while the left eye showed fluorescence leakage consistent with neovascularization elsewhere. (D, E) Widefield fundus photography taken 2 months later shows the normalized color of retinal vessels. (G) A peripheral venous sample was not grossly lipemic but showed milky-colored turbid serum, while fasting lipid profile reported a total cholesterol level of 1,595 mg/dL and triglyceride level of 7,590 mg/dL. (H) Initial optical coherence tomography (OCT) of the right eye showed hyperreflectivity of the dilated superficial retinal capillaries, which was much improved (J) 2 months later. (I) Initial OCT of the left eye showed retinal inner-layer hyperreflectivity and outer-layer shadowing consistent with preretinal hemorrhage in addition to hyperreflective materials accumulated in the dilated superficial retinal capillaries, all of which were much decreased (K) 2 months later.

The optical coherence tomography (OCT) of both eyes showed hyperreflectivity within dilated superficial retinal capillaries and intraretinal lipid exudates. The left eye additionally showed inner retinal hyperreflectivity and outer-layer shadowing compatible with preretinal hemorrhage (Fig. 1H, 1I).

Ultra-widefield fluorescein angiography (UWF-FA) revealed multiple focal hypofluorescent areas consistent with capillary nonperfusion in both eyes. The left eye showed leakage consistent with neovascularization elsewhere and blockage of underlying vessels by preretinal hemorrhage (Fig. 1C, 1F).

A peripheral venous sample appeared milky and turbid (Fig. 1G). Fasting lipid profile showed total cholesterol of 1,595 mg/dL and TGs of 7,590 mg/dL (typical adult reference ranges vary by laboratory: total cholesterol <200 mg/dL, TGs <150 mg/dL). After 4 weeks of a low-fat diet and fenofibrate 160 mg daily under endocrinology care, total cholesterol decreased to 305 mg/dL and TGs to 512 mg/dL. Panretinal photocoagulation (PRP) was performed for proliferative diabetic retinopathy (PDR) in the left eye. Two months later, fundus photographs showed vessel color normalization and improvement of the preretinal hemorrhage (Fig. 1D, 1E). Follow-up OCT also showed decreased reflectivity of the retinal vessels, consistent with the improved status of lipemia retinalis (Fig. 1J, 1K).

Lipemia retinalis itself requires no specific therapy [1]. Management targets TGs <500 mg/dL using a low-fat diet, fibrates, or n-3 polyunsaturated fatty acids [2], with evaluation for secondary causes [3]. In a prior South Korean report of lipemia retinalis with diabetic retinopathy, UWF-FA showed dilated and tortuous vessels without additional angiographic leakage attributable to lipemia retinalis, and OCT showed no macular edema [4]. Our case documents active PDR with neovascularization elsewhere and wide nonperfusion on UWF-FA, and bilateral OCT hyperreflectivity that diminished in parallel with TG lowering and PRP. Reports using swept-source OCT or OCT angiography in lipemia retinalis without clinical diabetic retinopathy described hyperreflective vessels and choriocapillaris alterations, with clinical normalization preceding tomographic resolution [5]; we add temporal coupling of biochemistry, imaging, and treatment in the setting of active PDR and propose the OCT vascular signal as a pragmatic adjunct marker of improvement.

We hypothesize that severe chylomicronemia likely increases intravascular optical backscatter, generating OCT vascular hyperreflectivity; reducing circulating particle burden should attenuate the signal. Hypertriglyceridemia may also raise plasma viscosity, impair endothelial function, and enhance lipid peroxidation, which could exacerbate ischemia, leakage, and neovascular drive in diabetes. These mechanisms remain theoretical. In our patient, TG decreased from 7,590 to 512 mg/dL over 4 weeks, followed by two-month improvements in fundus color and OCT vascular reflectivity in parallel with PRP, supporting a plausible causal chain while not proving it.