Background: Measuring pharmacodynamic biomarkers near the therapeutic site of action presents considerable challenges for sites with limited matrix volume or difficult access. Bioanalytical method qualification requires the use of numerous matrix samples, which is problematic for rare matrices. The aim of this study was to design and implement a streamlined, fit-for-purpose strategy for qualification of biomarker assays in rare matrices. Materials & methods: A multiplexed biomarker immunoassay was developed in human aqueous humor. Results: Our strategy was successfully implemented, providing characterization of assay performance while reducing number of samples in assay qualification. Our assay was used in clinical trial support for an ophthalmic drug candidate. Conclusion: Our results indicate this approach can be applied to other early stage drug development programs facing similar challenges.
Bioanalytical assay development and qualification requires the use of numerous matrix samples, which is problematic for rare matrices. We designed and successfully implemented a streamlined strategy for qualification of biomarker assays in rare matrices.

This is a case report of Epstein-Barr virus (EBV) uveitis confirmed via aqueous humor polymerase chain reaction (PCR) and metagenomics. This 72-year-old male with a history of diabetes and herpes zoster complained of redness and blurred vision in his right eye for eight months. Mild conjunctival injection, anterior chamber cells, mutton-fat keratic precipitates, and vitreous haze were noted. Fluorescein angiography revealed dye leakage from retinal vessels without retinal ischemic changes. Only the serum anti-cytomegalovirus (CMV) IgG was positive while the aqueous humor PCR for VZV (Varicella-zoster virus), HSV (Herpes simplex viruses), CMV, and EBV was initially negative. Inflammation recurred and vitreous haze worsened after discontinuing nine-month topical ganciclovir and oral prednisolone. the aqueous humor PCR was repeated due to persistent low-grade inflammation. The EBV PCR turned out to be positive. Shotgun metagenomics revealed 1459 classified sequences (1.62%) and confirmed the EBV infection. Topical ganciclovir and methylprednisolone treatment was resumed. Conjunctival injection improved while pigmented keratic precipitates lessened. Elderly patients with diabetes or under immunosuppression may be susceptible to chronic uveitis associated with subsequent EBV infection. Repeated aqueous humor PCR and shotgun metagenomics are important tools in the diagnosis of this case of chronic indolent panuveitis.

BACKGROUND: Generally, there is no lipoprotein in aqueous humor, and chyle usually exists transiently in the body. Therefore, persistent chylous aqueous humor is rare.
METHODS: We report a case of a 39-year-old man with persistent milky white appearance over the right eye.
METHODS: The patient had a history of poorly controlled diabetes for the past 2 years and central retinal vein occlusion of the same eye for the past 2 weeks. The patient\'s right eye had a uniform milky appearance in the anterior chamber, transparent cornea, and no keratic precipitate in the posterior cornea. Color Doppler ultrasound of the affected eye showed no obvious inflammation in the vitreous cavity. Laboratory tests revealed severe chylemia. The patient was finally diagnosed as chylous aqueous humor.
RESULTS: After conventional hypolipidemia and hypoglycemia treatment and locally glucocorticoid treatment. The milky white changes in the anterior chamber improved considerably and finally disappeared.
CONCLUSIONS: Although the impact of hyperlipidemia on the cardiovascular system and digestive system is well known, its impact on the eyes is often overlooked. We report a rare case of unilateral chylous aqueous humor caused by hyperlipidemia. Through the analysis of this special case, we recommend that ophthalmologists should pay attention to the impact of blood lipid change on eyes.

BACKGROUND: Pseudorabies virus (PRV) was thought to only infect animals. Recent studies have shown that it can also infect human.
METHODS: We report a case of pseudorabies virus encephalitis and endophthalmitis, diagnosed 89 days after onset, confirmed with intraocular fluid metagenomic next generation sequencing (mNGS) after the result of two cerebrospinal fluid (CSF) mNGS tests were negative. Although treatment with intravenous acyclovir, foscarnet sodium, and methylprednisolone improved the symptoms of encephalitis, significant diagnostic delay resulted in permanent visual loss.
CONCLUSIONS: This case suggests that pseudorabies virus (PRV) DNA in the intraocular fluid may have a higher positivity than that in the CSF. PRV may persist in the intraocular fluid for an extended period and may thus require extended antiviral therapy. Patients with severe encephalitis and PRV should be examined with the focus on pupil reactivity and light reflex. A fundus examination should be performed in patients with a central nervous system infection, specifically, those in a comatose state, to help reduce eye disability.

OBJECTIVE: The purpose of this study was to describe a case of a 64-year-old man presenting with cytomegalovirus and herpes simplex virus retinitis coinfection in the setting of Burkitt lymphoma.
METHODS: A case report including multimodal imaging and anterior chamber polymerase chain reaction results was used.
RESULTS: This case highlights the importance of the clinical examination and maintaining high diagnostic suspicion for viral retinitis in immunocompromised patients.
CONCLUSIONS: Aqueous fluid PCR can be a useful adjunctive test to distinguish and confirm a diagnosis of viral retinitis. Given the limited sample volume of aqueous biopsy, it is important to prioritize the order of PCR testing based on clinical suspicion of the causative agent.

BACKGROUND: Previously, diagnosis of ocular toxoplasmosis is based on clinical symptoms and Toxoplasma serology. Checking serological indicators often cannot reflect the real intraocular situation, and may even mislead clinicians to make wrong judgments.
METHODS: A 38-year-old male patient visited our ophthalmology clinic with a chief complaint of decreased vision for about 5 days in his right eye.
METHODS: Aqueous humor sample analysis found Toxoplasma DNA detectable, and Toxoplasma immunoglobulin G (IgG) and immunoglobulin M (IgM) to be positive. His serum Toxoplasma IgG was also positive (10.04 IU/mL; reference range: 0 to 7.2 IU/mL). Therefore, the final diagnose was ocular toxoplasmosis involving his right eye.
METHODS: Oral prednisone 60 mg/day and azithromycin 0.25 g/day were started. Oral antibiotic treatment for toxoplasma was continued for 4 weeks, and prednisone followed by weekly stepwise tapering in steps of 10 mg/day.
RESULTS: The BCVA and fundus of right eye remained stable after treatment at follow-up.
CONCLUSIONS: This article reported a case of ocular Toxoplasma gondii infection diagnosis by serum and aqueous humor antibody tests. We provide some additional information on the T gondii infection diagnosis.

UNASSIGNED: Herpetic anterior uveitis (AU) is usually caused by the herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Herein, we report a case of herpetic AU associated with human herpesvirus 7 (HHV-7) infection.
UNASSIGNED: A case report.
UNASSIGNED: A 49-year-old female patient presented with complaints of blurred vision and hyperemia in the right eye. Slit-lamp examination revealed bilateral fine and a few small white keratic precipitates (KPs), Descemet membrane folds in the right eye, and severe and mild cellular infiltration in the anterior chamber of the right and left eye, respectively. HHV-7 viral DNA was detected by a polymerase chain reaction assay of an aqueous humor sample. The AU improved significantly with topical steroids.
UNASSIGNED: We report a rare case of herpetic AU characterized by fine and small white KPs in which only HHV-7 DNA was detected in the aqueous humor.

The current pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become a global threat to the human population. Infection with SARS-CoV-2 leads to a wide spectrum of clinical manifestations. Ocular abnormalities have been reported in association with COVID-19, but the nature of the impairments was not specified. Here, we report a case of a female patient diagnosed with glaucoma on re-hospitalization for ocular complications two months after being discharged from the hospital upon recovery from COVID-19. Meanwhile, the patient was found re-positive for SARS-CoV-2 in the upper respiratory tract. The infection was also diagnosed in the aqueous humor through immunostaining with antibodies against the N protein and S protein of SARS-CoV-2. Considering the eye is an immune-privileged site, we speculate that SARS-CoV-2 survived in the eye and resulted in the patient testing re-positive for SARS-CoV-2.

BACKGROUND: The amount of aqueous humor that is constantly produced by the ciliary processes and the equal amount that flows out through the trabecular meshwork via the drainage angle or through the uveoscleral route is very small (2-3 μg/min each), representing approximately 1% of the content of the anterior chamber; therefore, it is challenging to visualize its flow.
METHODS: A 69-year-old man who had high intraocular pressure (IOP) (>20 mm Hg) with the maximum glaucoma eyedrop dose and presented with severe visual field loss (Humphrey Field Analyzer 30-2: -26.32 dB) had been implanted with a 350-mm2 Baerveldt tube of the aqueous chamber type for refractory open-angle glaucoma. The IOP ultimately decreased (<15 mm Hg) with no need for glaucoma eyedrops.
METHODS: After the procedures, a fibrin membrane repeatedly formed on the anterior surface of the intraocular lens.
METHODS: This issue was resolved by two rounds of neodymium-doped yttrium aluminum granet (Nd:YAG) laser surgery and prescription steroidal eyedrops.
RESULTS: During the laser surgery, an unusual and unintended fibrin flap appeared at the opening of the Baerveldt tube; this flap moved synchronously with the heartbeat, as verified by checking the pulse at the radial artery of the wrist. The fibrin flap mimicked the behavior of a cardiac valve, and the aqueous humor and stray fibrin particles mimicked the blood in the chambers of the heart. Although the Baerveldt tube itself is an artificial instrument that is not present in normal human eyes, we hypothesize that our observation shows the fundamental mechanism of aqueous humor drainage.
CONCLUSIONS: This novel, vividly descriptive observation highlights the important role of the heartbeat as a drainage pump in aqueous humor flow dynamics and IOP homeostasis, which are treatment targets for glaucoma, the leading cause of blindness.

BACKGROUND: We report a case of chronic retinal necrosis (CRN) combined with cytomegalovirus (CMV) corneal endotheliitis.
METHODS: An 80-year old man was diagnosed with CRN that developed after tube shunt surgery with vitrectomy for secondary glaucoma associated with CMV corneal endotheliitis. After the use of oral valganciclovir and panretinal photocoagulation, the retinal lesion resolved rapidly and he has maintained visual acuity better than before the onset of CRN.
CONCLUSIONS: Use of oral valganciclovir, prophylactic panretinal photocoagulation for the non- perfusion area and vitrectomy were effective in maintaining the visual acuity for the patient with CRN.