Chylous aqueous humor caused by hyperlipidemia: A case report and literature review

**Background:** Chylous aqueous humor is a rare condition where the aqueous humor appears milky due to the presence of chylomicrons, which are normally absent in the eye. Hyperlipidemia, particularly hyperchylomicronemia, can lead to this phenomenon when the blood-aqueous barrier is compromised. This case report and literature review aim to describe a unique presentation and emphasize the ocular impact of hyperlipidemia.

**Methods:** The authors present a single case report of a 39-year-old man with a 2-year history of poorly controlled diabetes and a recent diagnosis of central retinal vein occlusion (CRVO) in the right eye. The patient presented with a 3-day history of a milky white appearance in the right eye. Clinical examination, laboratory tests (including serum triglycerides and fasting blood glucose), and imaging (slit lamp, fundus photography, optical coherence tomography, fluorescein angiography, color Doppler ultrasound) were performed. The patient was treated with systemic acipimox (lipid-lowering) and insulin, along with topical tobramycin dexamethasone, tropicamide, and carteolol eye drops. Anti-VEGF therapy and panretinal laser photocoagulation were administered for neovascularization. The authors also reviewed three previously reported cases of chylous aqueous humor from the literature.

**Key Results:** The patient's serum triglyceride level was 1603.42 mg/dL, and fasting blood glucose was 12.8 mmol/L. The right eye showed a uniform milky anterior chamber with no keratic precipitates or inflammation. The left eye had retinal lipemia. After treatment, the milky appearance resolved within 3 days. However, iris neovascularization developed on day 2, requiring anti-VEGF and laser therapy. At 1-month follow-up, visual acuity in the right eye was 20/250, intraocular pressure was normal, and the anterior chamber remained clear. The literature review identified three similar cases (all middle-aged men with diabetes and hypertriglyceridemia), all of whom had resolution of chylous aqueous humor within about 3 days with systemic and topical treatment.

**Clinical Implications:** This case underscores that hyperlipidemia, often overlooked in ophthalmology, can cause rare but reversible ocular conditions like chylous aqueous humor and lipemia retinalis. The condition may be triggered by damage to the blood-aqueous barrier from conditions like CRVO or diabetes, combined with severe hyperchylomicronemia. Prompt diagnosis and management of hyperlipidemia can reverse ocular symptoms and prevent systemic complications such as cardiovascular events. Ophthalmologists should consider lipid panel testing in patients with unexplained milky anterior chamber or retinal lipemia, especially those with diabetes or vascular occlusions.