Evaluation of the characteristics of primary iridociliary cysts using ultrasound biomicroscopy at a tertiary care centre.

OBJECTIVE: To evaluate the ultrasound biomicroscopic characteristics of primary iridociliary cysts presenting to a Canadian tertiary care centre. DESIGN: Retrospective study. PARTICIPANTS: A total of 189 patients (212 eyes) referred to the Sinai Health System (Toronto) for suspected iris abnormalities. METHODS: Clinical records of patients referred between March 2016 and October 2019 were reviewed. All patients were evaluated and received a diagnosis of an iridociliary cyst using ultrasound biomicroscopy (UBM). Data were collected for age, sex, involvement (iris vs ciliary body), laterality, size, and location on initial examination and subsequent follow-up. RESULTS: Of the 189 patients (212 eyes) with iridociliary cysts, more were female (65.1%) versus male (34.9%). The highest incidence occurred in females aged 21-30 years (13.2%). The iris pigment epithelium was involved in 84.4%, and only the ciliary body was involved in 3.8%. Both the iris pigment epithelium and the ciliary body were involved in 10.8%. The size of the cysts ranged between 0.5 and 4.41 mm in diameter. Cysts greater than 1 mm in diameter occurred in 78.7%, and 86.8% of cysts occurred unilaterally. Twelve percent were multicystic, and 8.5% were multiloculated, with 1% exhibiting both features. Twenty-three eyes (12.2%) were reviewed at 1 year of follow-up with UBM. Stable iridociliary cysts with no appreciable change in size were seen in 73.9% (n = 17). Iridociliary cyst growth was noted at 4 months in 1 patient. CONCLUSION: Information regarding iridociliary cysts is not easily available in the literature. UBM is a helpful clinical tool in the evaluation of iris abnormalities. Iridociliary cysts tend to be stable and compatible with a low rate of complications.

Lower ocular pulse amplitude with dynamic contour tonometry is associated with biopsy-proven giant cell arteritis.

OBJECTIVES: To determine the role of the ocular pulse amplitude (OPA) from Pascal dynamic contour tonometry in predicting the temporal artery biopsy (TABx) result in patients with suspected giant cell arteritis (GCA). DESIGN: Prospective validation study. PARTICIPANTS: Adults aged 50 years or older who underwent TABx from March 2015 to April 2017. METHODS: Subjects on high-dose glucocorticoids more than 14 days or without serology before glucocorticoid initiation were excluded. The OPA from both eyes was obtained and averaged just before TABx of the predominantly symptomatic side. The variables chosen for the a priori prediction model were age, average OPA, and C-reactive protein (CRP). Erythrocyte sedimentation rate (ESR), platelets, jaw claudication, and eye findings were also recorded. In this study, subjects with a negative biopsy were considered not to have GCA, and contralateral biopsy was performed if the clinical suspicion for GCA remained high. An external validation set (XVAL) was obtained. RESULTS: Of 109 TABx, 19 were positive and 90 were negative. On univariate logistic regression, the average OPA had 0.60 odds for positive TABx (p = 0.03), with no statistically significant difference in age, sex, CRP, ESR, or jaw claudication. In suspected GCA, an OPA of 1 mm Hg had positive likelihood ratio 4.74 and negative likelihood ratio 0.87 for positive TABx. Multivariate regression of the prediction model using optimal mathematical transforms (inverse OPA, log CRP, age >65 years) had area under the receiver operating characteristic curve (AUROC) = 0.85 and AUROCXVAL = 0.81. CONCLUSIONS: OPA is lower in subjects with biopsy-proven GCA and is a statistically significant predictor of GCA.

Comparison of tensile strength of slip knots with that of 3-1-1 knots using 10-0 nylon sutures.

PURPOSE: The aim of this study was to compare the tensile strength of slip knots with that of 3-1-1 knots using 10-0 nylon sutures. METHODS: In vitro, destructive materials testing was used. By adhering to the American Standard for Testing and Materials standards for testing of suture materials, slip knots were compared with 3-1-1 knots using 10-0 nylon suture material. Tensile testing was performed on each knot type using the Instron Microtester (Model 5848 Norwood, MA). Scanning electron microscopy was used to analyze all sutures tested to failure. The main outcome measure was the maximum load (newtons) or ultimate tensile strength before which each knot failed by breakage or by unraveling. RESULTS: The mean force resulting in failure by breakage of the 3-1-1 knot and slip knot was 0.71 and 0.64 N, respectively (P = 0.048). The mean force resulting in failure by the unraveling of the 3-1-1 knot and slip knot was 0.48 and 0.37 N, respectively (P = 0.022). CONCLUSIONS: In 10-0 nylon sutures, the 3-1-1 knot has a statistically significant greater tensile strength than the slip knot has in conditions wherein they fail by either breakage or unraveling.