Effect of Nd:YAG Laser Capsulotomy on Anterior Segment Parameters in Patients with Posterior Capsular Opacification after Phacovitrectomy

Influence of the "Inverted U Method" Nd: YAG Laser Posterior Capsulotomy on Anterior Segment Parameters, Decentration and Tilt of Intraocular Lens in Patients after Phaco-vitrectomy

PURPOSE

To investigate the effects of the "inverted U method" Nd:YAG laser posterior capsulotomy on anterior segment parameters, decentration and tilt of intraocular lens (IOLs) and visual acuity in posterior capsular opacification (PCO) patients after combined phaco-vitrectomy.

METHODS

Seventy-six patients (76 eyes) were enrolled in this study, who were diagnosed as PCO and underwent "inverted U method" Nd:YAG laser posterior capsulotomy. All patients had undergone previous combined phaco-vitrectomy for rhegmatogenous retinal detachment. The parameters including IOL decentration, angle of IOL tilt, anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), keratometry, pupil size, axial length (AL), intraocular pressure (IOP), refractive status, corrected distance visual acuity (CDVA), objective scattering index (OSI) and Chinese version of Visual Function 14 (VF-14) index were obtained before and 3 months after capsulotomy.

RESULTS

After capsulotomy, the tilt angle and decentration of the IOLs at both vertical (tilt: p = .004, decentration: p = .029) and horizontal meridian (tilt: p = .001, decentration: p = .017) were significantly decreased, ACA increased (p = .015), CDVA (p = .000), VF-14 score (p = .000) and OSI (p = .000) were significantly improved. There were a significant decrease in cylindrical error (p = .001) and a myopic shift in spherical error (p = .001) after the capsulotomy. No significant differences in ACD, ACV, CCT, keratometry, pupil size, AL and IOP were detected (p > .05 for all).

CONCLUSION

The "inverted U method" Nd: YAG laser posterior capsulotomy decreases tilt and decentration of the IOL, increases ACA and causes no change in ACD, ACV, CCT and IOP in patients after phaco-vitrectomy. These changes make a decrease in cylindrical error and a myopic shift in spherical error. Laser capsulotomy significantly improves visual acuity.

Utility of the optical quality analysis system for decision-making in Nd: YAG laser posterior capsulotomy in patients with light posterior capsule opacity

Background

A prospective cohort study was performed to evaluate whether the Optical Quality Analysis System (OQAS) can serve as a valuable additional indicator for appropriate posterior capsulotomy referral.

Methods

One hundred and five eyes from 96 patients undergoing capsulotomy were divided into precapsulotomy logMAR CDVA ≤0.1 group and logMAR CDVA > 0.1 group. CDVA, and the Visual Function 14 index (VF-14) score were estimated before and 1 month after capsulotomy. The objective scattering index (OSI) value was measured by using the OQAS. Posterior capsule opacification (PCO) severity was assessed with Evaluation of PCO 2000 (EPCO 2000) software.

Results

In logMAR CDVA > 0.1 group, the correlations of OSI, logMAR CDVA, EPCO score and VF-14 score were very strong preoperatively. In logMAR CDVA ≤0.1 group, preoperatively, OSI was correlated with logMAR CDVA (r = 0.451), EPCO score (r = 0.789), and VF-14 score (r = 0.852). LogMAR CDVA has weak correlation with VF-14 score (r = − 0.384) and EPCO score (r = 0.566). VF-14 score was correlated with EPCO score (r = − 0.669). In the logMAR CDVA ≤0.1 group, there was no significant difference in logMAR CDVA between precapsulotomy and postcapsulotomy (P > 0.05). In the two groups, all the other optical quality parameters were significantly improved after capsulotomy (P < 0.05). In logMAR CDVA > 0.1 group, the area under the curve of the ROC of the OSI was 0.996 (P = 0.000). In logMAR CDVA ≤0.1 group, the area under the curve of the ROC of the OSI was 0.943 (P = 0.000).

Conclusions

The OSI was useful for evaluating of PCO and prediction of beneficial capsulotomy. Especially for patients with slight PCO and better visual acuity, OSI is more valuable than CDVA and completely objective examination.

Trial registration

The study protocol was registered at the Chinese Clinical Trial Registry. Register: ChiCTR1800018842 (Registered Date: October 13th, 2018).

Application of capsular bag relaxation for capsular contraction syndrome

The present study analyzed the surgical method and clinical effects of capsular bag relaxation surgery (CBRS) for the treatment of capsular contraction syndrome (CCS), which usually occurs post-phacoemulsification. The retrospective case study comprised of a total of 25 patients (25 eyes) who developed CCS after phacoemulsification and subsequently underwent CBRS. Among these patients, 15 patients (15 eyes) received actinoid relaxing incisions and 10 patients (10 eyes) underwent a second continuous curvilinear capsulorhexis. Postoperative naked-eye visual acuity was determined and compared with preoperative naked-eye visual acuity. Size changes of the transparent zone of the anterior capsule opening were observed under a slit lamp, as well as the anterior and posterior capsular membrane conditions and position of the intraocular lens (IOL). In addition, the presence of any subjective symptom, including glare or monocular diplopia, was investigated. A final 6-month postoperative follow-up was conducted for each patient. Visual acuity of all operated eyes improved to various extents. Notably, glare and monocular diplopia were no longer evident and patients could observe things clearly. Visual differences pre- and post-surgery were statistically significant (u=5.143, P<0.01). In addition, capsular bag shrinkage and relaxation were revealed under a slit lamp, the area of the transparent zone of the anterior capsule opening was expanded and the IOL remained centered. To conclude, CBRS is an effective treatment method for patients with CCS who are not suitable to receive laser treatment.