ABSTRACT
In recent years, the incidence of high myopia complicated with cataract shows a gradual upward trend. Due to the special anatomical structure and lesion nature of high myopia, the difficulty and various complications of such patients are much higher than those of ordinary cataract surgery. With the continuous advancement of design and materials, the indications for capsular tension ring(CTR)have gradually expanded. Especially for patients with high myopia,it can maintain the stability of intraocular lens position, assist the relaxation of the suspensory ligament, inhibit the migration and proliferation of residual lens epithelial cells after surgery, improve the visual quality of patients and reduce the incidence of retinal detachment. This paper reviewed the history of CTR, its clinical application, and the effect of CTR on high myopia complicated with cataract.
ABSTRACT
Objective:To observe the effects of polishing the anterior and posterior capsule with irrigation/aspiration (I/A) injection needle and capsular tension ring (CTR) implantation on intraocular lens (IOL) capsular stability after phacoemulsification for ultra-high myopia with 2.0 mm coaxial micro incision.Methods:This is a prospective randomized controlled study. There were 40 patients(80 eyes) aged 46-72 years old with ultra-high myopia cataract. The grade of lens opacity was grade II-IV, and the diopter was -10 D - -24 D. During 2.0 mm coaxial micro incision phacoemulsification, adopt coin tossing method randomly, 1 eye was operated using the anterior and posterior capsule polishing 360° with I/A injection needle combined with CTR implantation as the experimental group(40 eyes), the other eye was neither polished nor CTR implantated as the control group(40 eyes). The operation interval of both eyes was less than 1 week. The size of anterior capsular orifice, effective intraocular lens position(ELP), IOL eccentricity and posterior capsular opacification(PCO) were recorded at 1 week, 1, 3 and 6 months after operation in outpatient clinic. Two independent sample t-test and Fisher exact probability test were used to compare the differences between the 2 groups. P<0.05 was defined significant difference. Results:During the follow-up period, there were no significant change in the anterior capsule area, IOL eccentricity and ELP in the experimental group. However in the control group, the anterior capsular area decreased gradually with time, and gradually IOL eccentricity increased and ELP decreased. There was no significant difference between the 2 groups in each observation index at 1 week after operation, but it was ELP that first showed the difference tendency( P<0.01). The ELP of the control group was significantly lower than that of the experimental group at 1, 3 and 6 months after operation( P<0.05). There was no significant difference in anterior capsule area and IOL eccentricity between the 2 groups at 1 and 3 months after operation( P>0.05), but there was a significant difference at 6 months( P<0.05). In terms of PCO, the incidence of PCO was 0%, 2.5% and 7.5% in the experimental group and 5.0%, 17.5% and 32.5% in the control group respectively at 1, 3 and 6 months after operation. The incidence of PCO in the experimental group was significantly lower than that in the control group( P<0.05). Conclusion:Ultra-high myopia with cataract are prone to have capsular contraction after operation, which is characterized by IOL instability and anterior capsular orifice narrowing gradually. Combined 360° anterior and posterior capsular polishing with tension ring implantation in operation can effectively maintain the stability of ELP, reduce the degree of contraction of anterior capsular orifice, reduce the eccentricity of IOL and the incidence of PCO. Polishing the anterior and posterior capsule with I/A injection needle combined with CTR implantation, is safe and effective for patients with ultra-high myopia cataract.
ABSTRACT
OBJECTIVE: To develop the accelerated release test method of docetaxel capsule tension ring and optimize its formulation. METHODS: The effects of ethanol concentration in the medium (0%, 5%, 10%) and temperature (37 and 45 ℃) on the release rate of docetaxel capsule tension ring were investigated, and the correlation regression equation between the accelerated release rate and the long-term release was established. Then, the best prescription was screened out with the accelerated release test method. RESULTS: The drug release rate of these preparations could be increased by four times under the accelerated conditions, i.e., using pH 7.4 phosphate buffer solution containing 5% ethanol as the release medium and operating at (45±0.5)℃. The accelerated release and long-term release were fitted the best using binomial model (y=0.004 6x2+0.437 4x+9.683 7, r2=0.998 4). The preparation using PLGA5050 (60K-100K=1:1, W/W) with drug-loading of 30% released drug stably and sustainedly for 30 d, and its release behavior was consistent with Peppas equation drug release model. CONCLUSION: Accelerated release testing can be employed as a rapid screening test to facilitate the formulation optimization of docetaxel capsule tension ring. This preparation has been proven to have sustained-release characteristics, suggesting a good clinical application prospect.