Optic neuropathy in McCune-Albright syndrome: effects of early diagnosis and treatment of growth hormone excess.

CONTEXT: GH excess is a serious complication of McCune-Albright syndrome (MAS) and has been associated with craniofacial morbidity. OBJECTIVE: The aim of the study was to determine whether early diagnosis and treatment of MAS-associated GH excess prevents optic neuropathy and hearing impairment, the major morbidities associated with GH excess. DESIGN AND SETTING: A retrospective cross-sectional analysis was conducted at a clinical research center. PATIENTS: Twenty-two subjects with MAS-associated GH excess and 21 control MAS subjects without GH excess were included in the study. INTERVENTION: Biochemical testing included random GH, nadir GH after glucose load, nadir GH on frequent sampling, and IGF-I Z-score. Subjects underwent imaging, ophthalmological, audiological, and otolaryngological assessment. Treatment included octreotide, pegvisomant, transphenoidal surgery, and/or radiotherapy as indicated. MAIN OUTCOME MEASURE: Association of optic neuropathy and hearing impairment to age at GH excess diagnosis/treatment was measured. RESULTS: Of 129 MAS subjects, 26 (20%) were diagnosed with GH excess based on elevation of two measures of GH function. Of these, 22 subjects were candidates for pharmacological intervention. Optic neuropathy was significantly correlated with intervention status, with no cases in the early intervention group (diagnosed/treated before age 18) or the control group, and four of seven (57%) in the late intervention group (diagnosed/treated after age 18) (Fisher's exact test; odds ratio, 0.027; P = 0.0058). Early diagnosis/intervention was not associated with reduction in hearing deficits (odds ratio, 1.25; P = 1.00). Mean head circumference SD score was significantly higher in the late (6.08; range, 2.70 to 22.56) than the early intervention (2.67; range, -0.65 to 6.72) or control groups (2.13; range, -2.06 to 7.79) (P = 0.003). CONCLUSIONS: Early diagnosis/treatment of GH excess in MAS is important to prevent optic neuropathy and craniofacial expansion. The relationship between hearing deficits and GH excess remains less clear and requires further study.

Lenticular meridional astigmatism secondary to iris mesectodermal leiomyoma.

A 61-year-old African American man presented with decreased vision of 2 months duration. Examination revealed a significant lenticular astigmatism and sectoral cataract as a result of an amelanotic iris lesion. Slitlamp optical coherence tomography (OCT) revealed angle crowding. An excisional biopsy was performed along with phacoemulsification in the right eye, with intraocular lens implantation for meridional lenticular astigmatism. Histopathology and histoimmunochemistry confirmed a diagnosis of uveal mesectodermal leiomyoma. Lenticular astigmatism may be a subtle sign of an anterior segment tumor. Anterior segment slitlamp OCT is an effective tool in diagnosing as well as monitoring small interval changes in these types of tumors.

Selective venous catheterization for the localization of phosphaturic mesenchymal tumors.

Tumor-induced osteomalacia (TIO) is characterized by renal phosphate wasting, hypophosphatemia, and aberrant vitamin D(3) metabolism and is caused by fibroblast growth factor 23 (FGF-23)-producing mesenchymal tumors, which are often difficult to locate. We investigated the utility of selective venous sampling in tumor localization. The primary endpoint was identification of the FGF-23 concentration ratio between the venous drainage of the tumor bed and the general circulation that was diagnostic of the location of an FGF-23-secreting tumor. Fourteen subjects underwent 15 sampling procedures after functional and anatomic imaging studies. Subjects fit into three imaging categories: no suspicious site, multiple sites, and single site (positive controls). FGF-23 levels were measured by ELISA. Suspicious tumors were resected for diagnosis, confirmation, and cure. In subjects with a positive venous sampling study and subsequent cure, a minimum ratio of 1.6 was diagnostic. In 7 of 14 subjects there was suggestive imaging, a diagnostic ratio, and an associated TIO tumor (true positive). Four of these required complicated resection procedures. In 4 of 14 subjects with no suspicious site on imaging studies, an FGF-23 diagnostic ratio was not detected (true negative). Biopsy or resection of a single lesion in 2 of 14 subjects with a diagnostic ratio failed to identify a TIO tumor (false positive). A diagnostic FGF-23 ratio was absent in 1 of 14 subjects whose tumor was a single highly suspicious lesion on imaging studies (false negative). These data yield a sensitivity of 0.87 [95% confidence interval (CI) 0.47-0.99] and a specificity of 0.71 (95% CI 0.29-0.96). Selective venous sampling for FGF-23 was particularly useful in subjects with multiple suspicious sites or an anatomically challenging planned resection but not in the absence of a suspicious lesion on imaging studies.

Toxic anterior segment syndrome: common causes.

PURPOSE: To identify the most common risk factors associated with toxic anterior segment syndrome (TASS). SETTING: Ophthalmic surgical centers in the United States, Argentina, Brazil, Italy, Mexico, Spain, and Romania. METHODS: A TASS questionnaire on instrument cleaning and reprocessing and extraocular and intraocular products used during cataract surgery was placed on the American Society of Cataract and Refractive Surgery web site. A retrospective analysis of questionnaires submitted by surgical centers reporting cases of TASS was performed between June 1, 2007, and May 31, 2009, to identify commonly held practices that could cause TASS. Members of the TASS Task Force made site visits between October 1, 2005, and May 31, 2009, and the findings were evaluated. RESULTS: Data from 77 questionnaires and 54 site visits were analyzed. The reporting centers performed 50 114 cataract surgeries and reported 909 cases of TASS. From January 1, 2006, to date, the 54 centers reported 367 cases in 143 919 procedures; 61% occurred in early 2006. Common practices associated with TASS included inadequate flushing of phaco and irrigation/aspiration handpieces, use of enzymatic cleansers, detergents at the wrong concentration, ultrasonic bath, antibiotic agents in balanced salt solution, preserved epinephrine, inappropriate agents for skin prep, and powdered gloves. Reuse of single-use products and poor instrument maintenance and processing were other risk factors. CONCLUSIONS: The survey identified commonly held practices associated with TASS. Understanding these findings and the safe alternatives will allow surgical center personnel to change their practices as needed to prevent TASS. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Scanning electron microscopy visualization of methicillin-resistant Staphylococcus aureus after contact with gatifloxacin with and without preservative.

PURPOSE: To test a visual model by looking at the differences in effect of Zymar((R)) (gatifloxacin plus benzalkonium chloride [BAK]) when compared to gatifloxacin and a normal saline (NS) control upon a methicillin and gatifloxacin-resistant Staphylococcus aureus (MRSA) species. METHODS: An ocular isolate of gatifloxacin-resistant (minimal inhibitory concentration >2 to 4 microg/mL) MRSA was grown to confluency. Chambered slides were prepared with bacterial culture smears, and then incubated with either gatifloxacin at the concentrations of 1 and 10 microg/mL, Zymar containing equivalent concentrations of gatifloxacin, or NS. Bacterial cultures were fixed after 10, 30, and 60 min. Fixed slides were coated in gold sputter for examination. Bacteria were visually evaluated with scanning electron microscopy (SEM) at 50,000x. Blinded review of SEM images compared structural changes and mitotic activity across samples. RESULTS: MRSA exposed to 10 microg Zymar for 60 min showed significantly greater pleomorphism and cell wall surface changes when compared to gatifloxacin (P < 0.0001) and NS (P = 0.001), and significantly less mitotic activity than NS (P = 0.002). CONCLUSION: Using SEM, the topical formulation of gatifloxacin 0.3% (Zymar), which contains BAK, had greater antibacterial activity than did gatifloxacin alone in gatifloxacin and methicillin-resistant S. aureus, thereby illustrating potential advantages of the preservative in the commercial formulation. We further show that these effects can be visualized and quantified.