[A preliminary observation of implanting a double-eyelet capsular tension ring in eyes with serious lens subluxation]

Objective: To evaluate the clinical efficiency of an iris hook combined with a modified double-eyelet capsular tension ring (MCTR) in the treatment of serious lens subluxation. Methods: Retrospective case series. A total of 16 patients (20 eyes) with serious lens subluxation were enrolled in Zhongshan Ophthalmic Center from March 2016 to December 2016. All the patients had an iris hook inserted to support the capsule during the phacoemulsification. Then an MCTR was implanted and sutured onto the sclera. Both intraoperative and postoperative complications, such as posterior capsular opacification and macular edema, were recorded. The postoperative examinations included visual acuity, intraocular pressure, slit-lamp examination, and Pentacam for evaluation of the positions of the capsule and the intraocular lens(IOL). The best corrected visual acuities before and after operation were compared with the matched t test. Results: There were 11 males(12 eyes) and 5 females (8 eyes) among the 16 patients (20 eyes) aged (36±16) years, including 5 cases of Marfan's syndrome (7 eyes), spontaneous ectopia lentis in 7 patients (9 eyes), and traumatic lens dislocation in 4 patients (4 eyes). All the MCTRs were successfully implanted into the capsule. The best corrected visual acuity ranged from 0.3 to 1.0, with 0.5 or higher accounting for 90% (18 eyes). It was 0.20±0.14 and 0.21±0.13, respectively, at 3 and 6 months, which was significantly better than the preoperative best corrected visual acuity (logarithm of the minimal angle of resolution) (0.74±0.51;t=5.302, P<0.001; t=5.131;P<0.001). One eye had macular edema 3 months after surgery, and then was treated by conservative management. Two eyes(2 case) developed mild posterior capsular opacification 6 months after operation. No intraocular hypertension was persistently observed. All IOLs and capsular bags were in the expected position without an obvious tilt or displacement. Conclusion: The surgical strategy of iris hooks combined with MCTRs in the treatment of serious lens subluxation could maintain long-term stability of the capsule. (Chin J Ophthalmol, 2018, 54: 343-348).

[Clinical characteristics and surgical effect observation of congenital aniridia combined with cataract]

Objective: To analyze the clinical manifestations, surgical approaches and postoperative prognosis for the cases of congenital aniridia combined with cataract. Methods: In this retrospective case series, 26 patients diagnosed with congenital aniridia combined with cataract were collected from Zhongshan Ophthalmic Center from February 2002 to August 2016. The Clinical data were collected to analyze the clinical features, surgical approaches and postoperative prognosis. T-test was used for statistical analysis. Results: Twenty-six bilateral congenital aniridia patients were included in the case series, with 50% male cases. The average age for the first visit was (8.72±8.06) years old. Hereditary patients constitutes 30.8% (8/26) of the total number. The proportions for bilateral and unilateral cataracts were 88.5% (23/26) and 11.5% (3/26) respectively, and 49 eyes suffering from both congenital aniridia and cataract were therefore included in the final analysis. The most common morphology cataract subtypes were lamellar cataract (24.5%, 12/49), posterior subcapsular cataract (22.4%, 11/49), and total cataract (18.4%,9/49). The observed ocular comorbidities included nystagmus (36.7%, 18/49), vitreous opacity (28.6%, 14/49), foveal hypoplasia (20.4%, 10/49), ametropia (12.2%, 6/49), exotropia (12.2%, 6/49), congenital glaucoma (12.2%, 6/49), esotropia (4.1%, 2/49), congenital ptosis (4.1%, 2/49), lens ectopia (4.1%, 2/49), scleral staphyloma (2.0%, 1/49) and pigmentary degeneration of retina (2.0%, 1/49). 30.6% (15/49) eyes were performed the cataract extraction surgery. The percentage of postoperative best corrected visual acuity (BCVA) for ≥0.1 and ≥0.3 were 93.3% (14/15) and 20.0% (3/15) respectively. Evaluated ocular pressure (33.3%, 5/15), severe posterior capsular opacification (PCO) (13.3%, 2/15) and choroidal hemorrhage combined with choroidal detachment (6.7%, 1/15) were detected as the postoperative complications. Followed by cataract extraction, 80.0% (12/15) eyes were sequentially performed the intraocular lens implantation, while, 20.0% (3/12) eyes remained aphakia due to ocular comorbidities. Conclusions: Congenital aniridia combined with cataract are rare diseases, calling for the precious retrospective researches. This disorder tended to affect both eyes and occurred hereditary. The clinical courses of the cases presented progressive features. Ocular comorbidities were the crucial factors to influence the surgical approaches and postoperative prognosis. (Chin J Ophthalmol, 2017, 53: 821-827).

Noise reduction in magnetic resonance imaging

This paper describes a noise-reduction technique applicable to multiple-measurement systems. This method, known as measurement-dependent filtering (or MDF), can be used to advantage in a number of MRI applications. We present the general theory for one of these applications, material-canceled projection imaging. We discuss and show the results of MDF for material-canceled images as well as for heavily T2-weighted spin-echo images and computed T2 images. Significant improvements in SNR are demonstrated while spatial resolution is preserved.