Characteristics of Silicone Oil Emulsification After Vitrectomy for Rhegmatogenous Retinal Detachment: An Ultrasound Biomicroscopy Study

Purpose: To investigate the characteristics of silicone oil (SO) emulsification after vitrectomy for rhegmatogenous retinal detachment (RRD) and possible correlations with clinical factors.Methods: Patients who underwent primary pars plana vitrectomy with SO injection for RRD followed by SO removal at the Eye and ENT Hospital of Fudan University between January 2016 and January 2020 were included. Ultrasound biomicroscopy (UBM) images of the anterior segment were taken before SO removal. Eight signs of SO emulsification in the UBM images were graded as 1 (present) or 0 (not present) and the grades for all signs in each eye were summed. Correlations between SO emulsification grade and clinical factors were determined.Results: A total of 118 patients (118 eyes) were enrolled in this study. Emulsified SO particles were found in all 118 eyes (100%). The eight signs were more frequently detected in the superior part of the eye. The mean total SO emulsification grade was 19.99 ± 12.98 (range: 1–36). Younger age and male (both P < 0.05) were associated with higher total SO emulsification grade. Patients with intraocular pressure (IOP) > 21 mmHg or the use of antiglaucoma medications at the time of SO removal had a higher total SO emulsification grade, were younger, and were more frequently male (all P < 0.05) than patients without ocular hypertension.Conclusions: UBM could play an important role in the diagnosis and grading of SO emulsification. Younger patients and males are more prone to SO emulsification, which may lead to elevated IOP.

Assessment of the Capsular Tension Ring Implantation Effect on the IOL Position in the Long Term Period after Uncomplicated Phacoemulsification

Purpose: To assess the capsular tension ring implantation effect on the IOL position according to different devices in the long term period after uncomplicated phacoemulsification.Patients and methods. The study enrolled 234 patients (273 eyes) with cataract without zonular weakness. A standard examination, optical biometry and Sheimpflug imaging were performed preoperatively. In all cases phacoemulsification with IOL implantation, supported by CTR in 11 % of cases (30 eyes) was performed in 1, 3, and 6 months after surgery autorefractometry, visual acuity, biometry, OCT of anterior segment and ultrasound biomicroscopy were provided.Results. By the 3rd month a small shift of IOL towards the retina was revealed without any refraction changes. In cases with CTR implantation the anterior chamber depth was stable. According to OCT data the angle of IOL tilt in the horizontal meridian gradually decreased, the dynamics was significant from 3 months (p = 0.032). There were no changes in the vertical direction. After CTR implantation IOL position did not significantly change. There was no difference between the groups (p > 0.05) by 6 month. The phenomenon of IOL “deflection” according to OCT data was observed in 20.87 % of cases was in 1 month after operation. In the presence of CTR its frequency decreased to 15.00 %, and in the absence, it increased to 21.63 %. In every fifth case of deformation the measurements did not give us a definite reason to further consider it a “deflection” by 6 months after the operation. In 4.24 % of cases fact of IOL “deflection” was absent at the first month but appeared by the 6 month. There was not any case of CTR implantation among described cases of IOL position change.Conclusion. Fluctuation of anterior chamber depth is observed up to 3 months after uncomplicated phacoemulsification. Changes in IOL tilt angle occur throughout the observation period with a significant decrease in the horizontal plane by 6 month. Implantation of the CTR should stabilize anterior chamber depth, block the IOL tilt and also reduce the percentage of IOL deflection cases in the defined group.

The role of anterior segment optical coherence tomography in uveitis-glaucoma-hyphema syndrome

Purpose To describe features of uveitis-glaucoma-hyphema (UGH) syndrome, using Anterior Segment-Optical Coherence Tomography (AS-OCT) and Ultrasound Biomicroscopy (UBM) and to evaluate the diagnostic role of AS-OCT as an imaging technique alternative to UBM. Design Retrospective case series. Methods Four eyes of 4 patients with UGH syndrome were analyzed. All patients reported previous uncomplicated cataract surgery with in-the-bag implantation of single-piece-intraocular lens (IOL). They underwent at presentation complete ophthalmological examination and imaging with slit-lamp anterior segment photographs, UBM and AS-OCT. Results Although AS-OCT did not allow to visualize the structures behind the iris, it displayed a contact between IOL (plate and/or haptics) and iris and IOL tilting in 3 out of 4 eyes. AS-OCT directly detected the cause of UGH syndrome in one eye, 2 eyes required some expedients to display the iris chafing, like scans in mydriasis and/or patient's gaze direction change. AS-OCT did not allow to appreciate the IOL-iris contact (showed by UBM technique) only in one eye, probably due to the change of patient position from supine to sitting, and consequent anteriorization of iris diaphragm. Furthermore AS-OCT showed fine details, as capsular bag collapse and indirect signs of haptic malposition in 3 out of 4 eyes. Conclusion AS-OCT is a non-invasive technique that allows to determine IOL position and IOL-uveal contact in selected cases of UGH syndrome. Considering AS-OCT and UBM advantages and limitations, AS-OCT should be used as first imaging modality when clinical diagnosis is uncertain. When UGH diagnosis cannot be verified using AS-OCT, UBM should be performed.

Comperative analysis of accuracy between low-frequency ultrasound biomicroscopy and 14-MHz ultrasonography with tissue harmonic imaging for the evaluation of the posterior lens capsule in traumatic cataracts

Background To compare the accuracy of low-frequency ultrasound biomicroscopy (LFUBM) and 14-MHz ultrasonography with tissue harmonic imaging (14-MHz + THI) in the assessment of posterior capsule (PC) integrity in patients with traumatic cataracts (TCs). Methods From January 2019 to October 2020, 51 patients (51 eyes) with TCs who were scheduled for cataract extraction and for whom the PC of the lens could not be observed by the slit lamp visited Tianjin Eye Hospital, including 47 patients (47 eyes) with a penetrating injury of the eyeball and 4 patients (4 eyes) with a blunt injury of the eyeball. All eyes underwent LFUBM and 14-MHz + THI examinations before cataract extraction to determine the integrity of the PC. The integrity of the PC observed in surgery was the actual findings, and the consistency between the 2 methods was assessed in terms of the preoperative examination and intraoperative findings. Fisher’s exact test was used for consistency analysis, and P < 0.05 was considered statistically significant. Results Thirty-two eyes with ruptured PCs and 19 eyes with intact PCs were actual findings in surgery. Thirty eyes with ruptured PCs and 21 eyes with intact PCs were examined by LFUBM. Thirty-two eyes with ruptured PCs and 19 eyes with intact PCs were examined by 14-MHz + THI. There were no significant differences between the 2 methods and the intraoperative findings (P = 0.293 LFUBM, P = 0.623 14-MHz + THI). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of LFUBM and 14-MHz + THI were 91 and 94%, 95 and 89%, 97 and 94%, 86 and 89% and 92 and 92%, respectively. Conclusions Both LFUBM and 14-MHz + THI were proved to have high levels sensitivity and specificity in diagnosing the status of the PC in TC and they can be used as accurate diagnostic tool in these cases.

Comparative analysis of ultrasound biomicroscopy between femto-assisted and ultrasound cataract removal in case of lens subluxation

Purpose of the study to carry out a comparative analysis of the state of the zonular fibers before and after surgery on UBM between femtolaser assisted and classical ultrasound cataract removal. Material and methods. 19 patients (38 eyes) with age-related cataracts. 22 eyes were with pseudo-exfoliative syndrome. All patients were examined with grade 1 lens subluxation. The first group of 19 eyes underwent cataract femto-phacoemulsification. The second group included 19 eyes without using a femtolaser. The state of the fibers was determined on the UBM on the fifth day after the operation at the end of antibiotic therapy. Results. The data showed the presence of a statistically significant difference between the group with femto-assistance and the group without it. In the first group, UBM analysis showed that the state of the zonular fibers remained in the same state in 16 of 19 eyes. In the second group, 11 of 19 eyes required ring implantation with suturing to the sclera and 3 required IOL implantation with seamless fixation to the sclera and vitrectomy. Conclusions. The appropriate path to surgery depends on the most accurate objective assessment of the condition of the lens ligaments, since the position of the IOL is one of the main factors for a good result expected by the patient after surgery. Reducing the «trauma» of the eye with lens surgery has been a key success factor and femtolaser guidance provides valuable assistance in obtaining it. Key words: lens subluxation, femtosecond laser, UBM.