Proteomic analysis of vitreous biopsy techniques.

PURPOSE: To compare vitreous biopsy methods using analysis platforms used in proteomics biomarker discovery. METHODS: Vitreous biopsies from 10 eyes were collected sequentially using a 23-gauge needle and a 23-gauge vitreous cutter instrument. Paired specimens were evaluated by UV absorbance spectroscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: The total protein concentration obtained with a needle and vitrectomy instrument biopsy averaged 1.10 mg/mL (standard error of the mean = 0.35) and 1.13 mg/mL (standard error of the mean = 0.25), respectively. In eight eyes with low or medium viscidity, there was a very high correlation (R = 0.934) between the biopsy methods. When data from 2 eyes with high viscidity vitreous were included, the correlation was reduced (R = 0.704). The molecular weight protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of paired needle and vitreous cutter samples were similar, except for a minority of pairs with single band intensity variance. Using LC-MS/MS, equivalent peptides were identified with similar frequencies (R ≥ 0.90) in paired samples. CONCLUSION: Proteins and peptides collected from vitreous needle biopsies are nearly equivalent to those obtained from a vitreous cutter instrument. This study suggests both techniques may be used for most proteomic and biomarker discovery studies of vitreoretinal diseases, although a minority of proteins and peptides may differ in concentration.

The metabolic syndrome and severity of diabetic retinopathy.

BACKGROUND: While metabolic syndrome has been strongly implicated as a risk factor for macrovascular diseases, such as stroke and cardiovascular disease, its relationship with microvascular diseases, including diabetic retinopathy, has been less defined. The purpose of this pilot study was to investigate the association between metabolic syndrome and the presence and severity of diabetic retinopathy. METHODS: A retrospective case-control chart review at the University of Iowa ophthalmology and primary care clinics included 100 patients with proliferative diabetic retinopathy (PDR), 100 patients with nonproliferative diabetic retinopathy (NPDR), 100 diabetic patients without diabetic retinopathy, and 100 nondiabetic patients who were randomly selected. Using the International Diabetes Foundation definition, the prevalence of metabolic syndrome and the number of components of metabolic syndrome were compared among these groups. RESULTS: The prevalence of metabolic syndrome in patients with diabetes was 69.3%, which was significantly higher than that in patients without diabetes (27%; P<0.0001) (odds ratio [OR] =6.28; 95% confidence interval [CI]: 3.76-10.49; P=0.0004). However, there was no significant difference in the prevalence of metabolic syndrome between diabetics with and without diabetic retinopathy, with rates of 67.5% and 73%, respectively (P=0.36) (OR =0.77; 95% CI: 0.45-1.32; P=0.34). In addition, there was no significant difference between the PDR and NPDR groups, with rates of 63% and 72%, respectively (P=0.23) (OR =0.70; 95% CI: 0.38-1.30; P=0.26). CONCLUSION: The metabolic syndrome was highly prevalent in patients with diabetes, but it was not associated with the presence or severity of retinopathy.

Treatment of ocular surface squamous cell intraepithelial neoplasia with and without mitomycin C.

PURPOSE: To analyze the outcome of excisional biopsy of ocular surface (conjunctival and corneal) squamous cell intraepithelial (in situ) neoplasia with and without the adjunctive use of intraoperative and postoperative mitomycin C. METHODS: A retrospective case review was conducted on 34 consecutive patients with histopathologically proven ocular surface squamous cell intraepithelial neoplasia who were treated from January 1, 1980, to December 31, 2008, at University of Iowa Hospitals and Clinics. Eyes in which a minimum follow-up period of 3 months was available were included in the statistical analysis. RESULTS: Of 34 eyes, 32 met the inclusion criteria. Adjunctive therapy was provided with mitomycin C in 17 eyes, including 13 that had only postoperative treatment and 4 that had only intraoperative treatment. The adjunctive use of mitomycin C was associated with a significantly reduced prevalence of recurrence (5.9% vs. 66.7%; P = 0.0005). When the surgical margins were positive, the use of adjunctive mitomycin C was associated with a reduced prevalence of tumor recurrence (12.5% vs. 55.6%), but this difference was not statistically significant (P = 0.13). When surgical margins were negative, the adjunctive use of mitomycin C was significantly associated with a reduced prevalence of recurrence (0% vs. 83.3%; P = 0.002). CONCLUSIONS: The adjunctive use of mitomycin C is significantly associated with a reduction in the prevalence of postoperative recurrences of ocular surface squamous cell intraepithelial neoplasia and should be considered as an adjunctive therapy even when surgical margins are negative.

A pregnant pause.

A 23-year-old pregnant woman presented with a rapidly progressive unilateral optic neuropathy. The evaluation was complicated by her being pregnant and the issues surrounding the evaluation and management of the pregnant patient with a neuro-ophthalmic finding is discussed. Eventually an orbital apex lesion was found and proved to be an orbital schwannoma. Rapid growth of an orbital schwannoma should be included in the differential diagnosis of progressive visual loss in a pregnant patient.