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Silicone oil in the anterior chamber
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
Emulsified silicone oil can appear as early as 6 months, and at any time thereafter.4 It has been found that the incidence of emulsification correlates positively with the duration for which the oil is left in the eye, increasing significantly after 2 years.4 Emusified silicone oil in the anterior chamber appears on biomicroscopy as multiple bubbles in the superior quadrant. Smaller amounts may be seen only by using gonioscopy. Ultrasound biomicroscopy (UBM) studies have demonstrated silicone oil (1000 cSt viscosity) to be present in the anterior chamber in 62% of phakic eyes and in all pseudophakic and aphakic eyes containing silicone oil for 6–9 months,7 although Valone and McCarthy3 reported no such difference. Previous studies have reported rates of approximately 7%,6,9 but these studies relied on only biomicroscopy to identify silicone oil in the anterior chamber. The presence of oil in the anterior chamber has been implicated as the primary cause of secondary open-angle glaucoma and silicone oil keratopathy.
Anterior segment OCT
Published in Pablo Artal, Handbook of Visual Optics, 2017
In clinical practice, imaging of the AS has been traditionally carried out with slit-lamp biomicroscopy. However, AS imaging is currently a rapidly advancing field of ophthalmology and provides tools that supplement well-established modalities. Those modern techniques include ultrasound biomicroscopy (UBM), confocal microscopy, Scheimpflug imaging, and corneal topography (Wolffsohn and Peterson, 2006, Konstantopoulos et al., 2007, Wolffsohn and Davies, 2007, Guthoff and Stachs, 2011). Apart from instrumentation development, a tremendous effort has been made to implement image analysis techniques that allow obtaining quantitative information on the state of the cornea, anterior chamber, corneoscleral angle, and crystalline lens (Wolffsohn and Peterson, 2006, Heur and Dupps, 2009, Pinero, 2015). Consequently, application of new technologies for in vivo imaging significantly improves clinical procedures in ophthalmology.
Angle-Closure Glaucomas
Published in Neil T. Choplin, Carlo E. Traverso, Atlas of Glaucoma, 2014
Christopher C. Teng, Jeffrey M. Liebmann, Celso Tello, Robert Ritch, David S. Greenfield
With high-frequency, high-resolution, anterior segment ultrasound biomicroscopy (UBM), we can image the structures surrounding the posterior chamber, examination of which has been previously limited to histopathological examination. UBM is ideally suited to the study of the angleclosure glaucomas because of its ability to simultaneously image the ciliary body, posterior chamber, iris–lens relationship, and angle structures. The currently available commercial unit operates at 50 MHz and provides lateral and axial resolution of approximately 50 μm and 25 μm, respectively. Tissue penetration is approximately 4–5 mm. The images shown in this chapter were obtained with the standard 50-MHz transducer.
Scleritis and Episcleritis following Coronavirus Disease (COVID-19) Vaccination
Published in Ocular Immunology and Inflammation, 2023
Srinivasan Sanjay, Ashit Handa, Ankush Kawali, Rohit Shetty, Sai Bhakti Mishra, Padmamalini Mahendradas
A detailed history of current topical medication, ocular diseases, previous ocular/systemic surgeries, systemic inflammatory disease (e.g. rheumatoid arthritis/seronegative arthritis), subsequent therapy regimens, and clinical outcome of the treatment were elicited. Visual acuity, intra ocular pressure, anterior segment examination (including the evaluation of inflammation according to the SUN grading system where appropriate), and posterior segment evaluation was recorded. Ultrasound B scan was also performed in all the patients with scleritis to rule out the posterior scleritis to detect the presence of sub Tenon’s fluid, thickened sclero-choroidal complex, exudative detachment and or sub retinal fluid. Ultrasound biomicroscopy of the anterior segment was not performed on any of our patients.
Surgical Outcomes of Modified CO2 Laser-assisted Sclerectomy for Uveitic Glaucoma
Published in Ocular Immunology and Inflammation, 2022
Junyan Xiao, Chan Zhao, Yang Zhang, Anyi Liang, Yi Qu, Gangwei Cheng, Meifen Zhang
Postoperatively, the patients were treated with topical antibiotics and prednisolone eye drops, the doses of which were gradually adjusted and tapered to the preoperative maintenance dose by uveitis specialists. In addition, 2% pilocarpine was used each night for at least 4 weeks. Adjustable sutures were released transconjunctivally under a slit lamp at an early stage (<14 days) after the operation. The inner wall of the TM was assessed via gonioscopy at each visit. An experienced investigator performed ultrasound biomicroscopy (UBM) at 1 month, 3 months, and 12 months postoperatively. The probe frequency was 50 MHz, and the dB gain was adjusted to obtain the optimal image resolution and quality in the sclerectomy area. The size of the intrascleral lake at 1 month was compared with that at follow-up visits, and the morphological changes were divided into the following 4 types (Figure 1): stable (no change), mild reduction (≤30% change), moderate reduction (30% to 50% change), and severe reduction (>50% change, impending closure). If IOP exceeded 21 mm Hg and UBM revealed a severe reduction in the size of the intrascleral lake, then a needling procedure was performed, followed by a subconjunctival or subscleral injection of 5-FU (0.2 mL, 50 mg/mL). If the target IOP was not achieved, then laser goniopuncture (LGP) was performed with a Microruptor II neodymium: YAG (Nd:YAG) laser after severe PAS or iris incarceration was excluded postoperatively.
Analyzing Anatomical Factors Contributing to Angle Closure Based on Anterior Segment Optical Coherence Tomography Imaging
Published in Current Eye Research, 2022
Bingsong Wang, Kai Cao, Zhiheng Wang, Ye Zhang, Nathan Congdon, Tao Wang
This study was strengthened by the relatively large sample scale. Also, analyses were performed objectively through mathematical models. Hence, arbitrary subjectivity is mostly excluded. Furthermore, we studied relatively early stages of the disease that had no acute attacks, no peripheral anterior synechia, and no laser treatment history, therefore we investigated unaffected eyes with original anatomic configuration. Our study has several limitations. This was a cross-sectional study, which made us unable to establish causal relationship. Also, ciliary body position, iris insertion position, and choroid expansion have been reported to be associated with the mechanism of angle closure.16,35 We were unable to perform ultrasound biomicroscopy on this large scale. There are some other potential risk factors for angle closure could not be included by our study. Some eyes were excluded because of poor AS-OCT image quality or indeterminate scleral spur location, which might affect the accuracy of the results. Finally, we did not evaluate dynamic factors in our study which also have been reported to play a role in the development of angle closure.