Nodular Posterior Scleritis Mimicking Choroidal Tumor in a Patient With Systemic Lupus Erythematous: A Case Report and Literature Review.

PURPOSE: Posterior scleritis is a potentially blinding ocular disorder that is often difficult to diagnose because of the low incidence and varied clinical presentation. Nodular posterior scleritis can mimic a choroidal mass and pose diagnostic difficulties to clinicians. This case report and literature review aimed to evaluate the clinical presentation of nodular posterior scleritis that mimics choroidal tumor, along with the etiologies, treatment modalities, and outcomes. DESIGN: Case report and literature review. METHODS: We describe a case of nodular posterior scleritis that presented as a choroidal mass in a patient with systemic lupus erythematous. Previous reports on nodular posterior scleritis presenting as choroidal mass were reviewed. RESULTS: Including this case, there were 14 cases of nodular posterior scleritis presenting as a choroidal mass in the past 20 years. The mean age was 50 years, with women being predominant (79%). All cases had unilateral eye involvement. Most patients presented with a drop in vision (ranging from counting fingers to visual acuity of 20/30). The cause was mostly idiopathic in 79% of reported cases. Most patients (71%) were treated with a course of systemic steroids. Two patients required systemic steroids together with immunosuppressive agents. Most patients responded to treatment with visual recovery and resolution of the choroidal mass. CONCLUSIONS: Nodular posterior scleritis is a rare disease that can easily be confused with choroidal tumor. Associated ocular pain is a useful feature for differentiating nodular posterior scleritis from other forms of choroidal masses. Early diagnosis and prompt treatment usually can deliver a good outcome.

Quantification and structure elucidation of in vivo bevacizumab modification in rabbit vitreous humor after intravitreal injection.

Off-label and intravitreal use of bevacizumab, a recombinant immunoglobulin against VEGF, has been practiced widely for ophthalmic treatments. However, longitudinal data of its intravitreal status is unavailable due to a lack of reliable methods for bevacizumab determination. Thus its pharmacokinetics and pharmacodynamics are uncertain. We developed and validated a high performance liquid chromatographic method to determine bevacizumab in vitreous humor and utilized a novel strategy to assess in vivo temporal binding changes by affinity chromatography. Mass spectrometry and tandem mass spectrometry detection were used for structural evaluation. The coefficient of variation (CV) for intrabatch imprecision varied from 0.5 to 14.3% and for interbatch imprecision from 1.9 to 11.6%. The linearity was over 0.9982, lower limit of quantification 1.95 µg, recoveries over 95%, and accuracy between 90 and 112% over the range of 1.95-250 µg of bevacizumab in 100 µL of vitreous humor. Blank vitreous humor showed no interference peak. It was stable at room temperature for 5 h. Bevacizumab elimination in the vitreous followed first order kinetics with half-life as 5.7 days and elimination rate as 0.1221 day(-1). Peptide mapping and tandem mass spectrometry revealed structural modifications of the in vivo bevacizumab mainly on the heavy chain in both variable and constant regions 7 days after intravitreal injection. Minor changes were also discovered on the light chain. Affinity chromatography showed significant affinity changes in samples 21 days after intravitreal injection. The changes were consistent with structural modifications as found in endothelial cell migration assays results. In conclusion, we have established a robust chromatographic method for determination of bevacizumab and strategies with affinity chromatography and molecular mass detection that revealed bevacizumab structural and possible functional changes in vitreous.