Effect of primary iris and ciliary body cyst on anterior chamber angle in patients with shallow anterior chamber

Abstract

Abstract:Objective: To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle. Methods: Among the general physical check-up population, subjects with shallow anterior chambers, as judged by van Herick technique, were recruited for further investigation. Ultrasound biomicroscope (UBM) was used to detect and measure the cysts located in the iris and/or ciliary body, the anterior chamber depth (ACD), the angle opening distance at 500 µm (AOD500), and the trabecular-iris angle (TIA). A-scan ultrasonography was used to measure the ocular biometry, including lens thickness, axial length, lens/axial length factor (LAF), and relative lens position (RLP). The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images, ocular biometry, and gonioscopic grading. The eye with unilateral cyst was compared with the eye without the cyst for further analysis. Results: Among the 727 subjects with shallow anterior chamber, primary iris and ciliary body cysts were detected in 250 (34.4%) patients; among them 96 (38.4%) patients showed unilateral single cyst, 21 (8.4%) patients had unilateral double cysts, and 42 (16.8%) patients manifested unilateral multiple and multi-quadrants cysts. Plateau iris configuration was found in 140 of 361 (38.8%) eyes with cysts. The mean size of total cysts was (0.6547±0.2319) mm. In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position, the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm (113/121, 93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm (373/801, 46.6%), and a significant higher proportion was also found in the cysts located at iridociliary sulcus (354/437, 81.0%) than in that at the pars plicata (131/484, 27.1%). In evaluating the effect of the cyst on the entire anterior chamber angle, the eyes with multiple and multi-quadrants cysts manifested significant narrowing of the entire anterior chamber angle as compared with the eyes without cysts, based on the data analysis in comparison of TIA, AOD500, and gonioscopic grading evaluation. The unilateral single or double cysts in the eyes had no significant effect on narrowing of anterior chamber angle as compared with eyes without cysts. The iris and/or ciliary body cysts did not seem to affect the axial length, ACD, lens thickness, RLP, LAF. Conclusions: The prevalence of primary iris and ciliary body cyst was 34.4% in the subjects with shallow anterior chamber. The cysts larger than 0.8 mm, locating at iridociliary sulcus, or multiple and extensive cysts were inclined to cause the angle narrowing or closure.

Ciliary body cysts associated with glaucoma in a Great Dane

“…It has been reported that only an angle closure greater than 180° may lead to glaucoma (Ispa-Callen et al, 2009). Moreover, cysts larger than 0.8 mm located at the iridociliary sulcus may also be responsible for angle closure (Wang and Yao, 2012), and among eyes with angle closure, cyst size in patients with multiple cysts was significantly smaller than in patients with a single cyst (Maraone et al, 2014). To the authors' knowledge, there is no data regarding the extent of closure necessary to affect the IOP in dogs.…”

“…However, high-resolution ocular ultrasound presents higher sensitivity and sensibility (Hendrix, 2013). Ultrasound biomicroscopy has been reported as effective in the diagnosis, size evaluation and localisation of ciliary body cysts in humans (Maraone et al, 2014) and more effective than standard ocular ultrasonography (7 to 12 MHz) in the detection of canine uveal cysts (Taylor et al, 2015); thus, it may consist the method-of-choice for early diagnosis of cyst formation or detection of small-size cysts on the contralateral eye, especially in human patients that usually present smaller-size cysts [0.6547 ± 0.2319 mm (Wang and Yao, 2012), 0.81 ± 0.35 mm (Maraone et al, 2014)]. However, its use may be impractical for animal patients, as heavy sedation or general anaesthesia may be required.…”

Ciliary Sulcus Microcysts as the Source of a White-to-White Sizing Mismatch With the Implantable Collamer Lens

“…5 These cysts are almost impossible to detect with slit-lamp examination or gonioscopy, but can be more easily visualized with the UBM. 6 There are a few features that make this case unique. First, due to their size, the microcysts were only found after the ICL implantation, and only after careful segmental evaluation with the UBM.…”

“…Previous research by Wang and Yao found that multiple cysts and multiple quadrant cysts have a significant effect on angle narrowing compared to a single cyst in phakic eyes. 6 Therefore, despite the patient's good visual acuity and normal intraocular pressure, explantation was performed. Third, the white-to-white and sulcus-to-sulcus measurements had considerable discrepancy (12.2 and 10.39 mm, respectively, in the right eye), and should have been a warning sign for the use of the white-to-white measurements in sizing the ICL in this patient.…”

Altering equine corneal fibroblast differentiation through Smad gene transfer

“…Multiple studies have been performed on this group of genes examining the fibrotic effects after altering Smad7 expression . These studies have shown that downregulation of Smad2 and Smad3 occurs when Smad7 is artificially expressed.…”