Anterior dislocation of a Morcher capsular tension ring

Capsular tension ring explant complication rate comparison using Miyake-Apple video analysis

PURPOSE

To compare the complication rate and time required to explant standard capsular tension rings (CTRs) vs suture-guided CTRs (SGCTRs).

SETTING

Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

DESIGN

Experimental study.

METHODS

Eight cadaver eyes were prepared using standard Miyake-Apple protocol with digital video recording. A 4 clock-hour zonular dialysis was created, followed by a capsulorhexis, hydrodissection, and CTR (n = 4) or SGCTR (n = 4) implantation. With the CTR hidden from view by the overlying iris, ophthalmic surgical instruments were used to remove the CTRs. Time required to remove the CTR and any complications were recorded. A limit of 180 seconds was imposed to determine inability to remove the CTR.

RESULTS

In the standard CTR group (n = 4), removal was associated with high rates of complication (100%). Complications included capsular tears (n = 2), dialysis extension (n = 1), and inadvertent intracapsular cataract extraction (n = 1). The SGCTR group had no complications associated with removal (n = 4). Time required to explant a CTR was significantly reduced from 164.5 seconds with standard CTRs to 6.9 seconds with SGCTRs (P = .001).

CONCLUSIONS

Attempts to remove a standard CTR from the capsular bag was met with a high complication rate. The addition of suture to the leading eyelet of the CTR prior to implantation significantly reduced the time and effort required to remove the CTR and was associated with a significant reduction in complication rates.

Misplaced capsule tension ring in anterior chamber: A unique way of explantation

We report a patient who presented with endocapsular capsule tension ring (CTR) in iridocorneal angle leading to secondary angle closure glaucoma (ACG) and subsequent removal of the CTR from trabeculectomy ostium. Secondary ACG was diagnosed 2 years and 6 months after cataract surgery in which a CTR was used for zonular instability. CTR removal with trabeculectomy was performed, after which there was the resolution of symptoms. To the best of our knowledge, this is the first case report in which CTR was removed from trabeculectomy ostium. We describe a surgical technique to explant CTR and combining with trabeculectomy.

Research on calculation of the IOL tilt and decentration based on surface fitting

The tilt and decentration of intraocular lens (IOL) result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentration) and the scanned angle, at which a piece of AS-OCT image was taken by the instrument, the IOL tilt and decentration were calculated. IOL tilt angle and decentration of each subject were given. Moreover, the horizontal and vertical tilt was also obtained. Accordingly, the possible errors of IOL tilt and decentration existed in the method employed by AS-OCT instrument. Based on 6–12 pieces of AS-OCT images at different directions, the tilt angle and decentration values were shown, respectively. The method of the surface fitting to the IOL surface can accurately analyze the IOL's location, and six pieces of AS-OCT images at three pairs symmetrical directions are enough to get tilt angle and decentration value of IOL more precisely.