Evaluation of Anterior Chamber Depth and Anterior Chamber Angle Changing After Phacoemulsification in the Primary Angle Close Suspect Eyes

Effect of Cycloplegia on Anterior Segment Structures and Scleral Thickness in Emmetropic Eyes

Purpose: To evaluate the effects of topical cyclopentolate hydrochloride-induced cycloplegia on anterior segment biomechanics in emmetropic eyes using anterior segment-optical coherence tomography (AS-OCT). Methods: Twenty-five emmetropic eyes of 25 volunteers were included. All underwent central corneal thickness (CCT) and anterior chamber depth (ACD) measurements. Anterior scleral thickness (AST) was measured at the level of the scleral spur (SS)(AST-0), 1,000 μm posterior of the SS (AST-1), and 2,000 μm posterior of the SS (AST-2) in the nasal and temporal quadrants using AS-OCT. All measurements were repeated after cycloplegia. Results: The mean age was 30.6 ± 12.4 (8-45) years. The mean CCT did not significantly change after cycloplegia (P = 0.7). The mean ACD was significantly increased [3.3 ± 0.2 (2.7-3.9) to 3.7 ± 0.3 (3-4.2) μm; P = 0.001]. In the nasal quadrant, the mean AST-1 and AST-2 were 512.3 ± 34.4 (433-570) and 529.6 ± 34.2 (449-599); decreased to 478 ± 26.8 (423-530) and 486.2 ± 28.3 (422-544) μm, respectively, after cycloplegia (P = 0.00; P = 0.00). In the temporal quadrant, the mean AST-1 and AST-2 were 522.5 ± 24.7 (473-578) and 527.2 ± 39.9 (450-604); decreased to 481.1 ± 33.7 (421-550) and 484.6 ± 26.6 (433-528) μm, respectively (P = 0.00; P = 0.00). There was no significant difference in AST-0 after cycloplegia in both quadrants [from 697.5 ± 46 (605-785) to 709.5 ± 64.7 (565-785) for nasal and from 718.4 ± 40.1 (632-796) to 722.9 ± 60.6 (596-838) for temporal; P = 0.2; P = 0.3, respectively]. Conclusion: After cycloplegia, there was a significant thinning of ASTs posterior to SS and a slight increase in AST in the SS level. ACD deepened after cycloplegia, and there was no significant change in CCT. Cycloplegic agents temporarily inhibit ciliary muscle contraction and may affect anterior segment parameters and sclera. Inhibition of forward-inward movement of the ciliary body by cycloplegia affects ASTs and ACD by causing a change in the mechanical force of the ciliary muscle on the sclera.

Assessment of anterior chamber angle changes after phacoemulsification with swept-source OCT

AIM

To assess the changes of anterior chamber angle in patients with shallow anterior chamber after phacoemulsification combined with intraocular lens (IOL) implantation, based on anterior segment swept-source optical coherence tomography (AS-SS-OCT) measurements.

METHODS

This was a prospective case control study; sixty eyes of sixty case were scheduled for cataract surgery with normal intraocular pressure (IOP). Based on anterior chamber depth (ACD) and gonioscopy findings, the eyes were divided into two groups: group of shallow anterior chamber and narrow angle (SAC group, 30 eyes); and group of normal anterior chamber group with wide angle (NAC group, 30 eyes). Measurements of ACD, anterior chamber volume (ACV), iris volume (IV), lens vault (LV), angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), and trabecular iris angle (TIA) were conducted in each group before and 3mo after surgery.

RESULTS

There was no significant difference in age, axial length (AL), corneal curvature, corneal diameter, intraocular pressure, and IV between two groups before surgery, except for the LV (P=0.000). ACD and ACV were prominently larger in the NAC group than the SAC group 3mo after operation (3.69±0.38 vs 3.85±0.39 mm, P=0.025; 161.37±19.47 vs 178.26±20.30 mm³, P=0.002). AOD750, ARA750 in nasal and inferior quadrants, TISA750 in all quadrants except temporal, and TIA750 in all quadrants in SAC group were significantly smaller than those in NAC group after operation (all P<0.05).

CONCLUSION

Cataract surgery can deepen anterior chamber and increase the width of anterior chamber angle in Chinese subjects, but the angle related parameters including AOD750, ARA750, TISA750, TIA, TISA750, and ACV in patients with shallow anterior chamber and narrow angle do not reach the normal level.

The change of anterior chamber angle parameters after cataract surgery in diabetic patients

Purpose:

The purpose of this study is to investigate the change of anterior chamber angle morphology after cataract surgery in patients with type 2 diabetes mellitus (DM2) using anterior segment optical coherence tomography (AS-OCT).

Methods:

In this prospective and comparative study, 57 eyes of the patients with cataract were investigated. The patients were divided into two groups. The DM2 group included cataractous type 2 diabetic patients without diabetic retinopathy (n = 30) and the non-DM2 group included nondiabetic participants with cataract (n = 27). The AS-OCT examinations were performed at baseline and 1 month after the cataract surgery. The corrected distance visual acuity (CDVA), intraocular pressure (IOP), angle-opening distance at 500 µm (AOD-500) and trabecular iris space area at 500 µm (TISA-500), and scleral spur angle (SSA) in temporal quadrant were analyzed.

Results:

The mean age, sex, and axial length values were similar in both groups (p > 0.05 for all). The CDVA was significantly improved in both groups (p < 0.001). The mean AOD-500, TISA-500, and SSA were increased and the mean IOP was decreased after cataract surgery in both groups (p < 0.001 for all). There were not any statistically significant intergroup differences in CDVA, IOP, and AS-OCT measurements between the DM2 and non-DM2 groups (p > 0.05 for all).

Conclusion:

Cataract surgery showed significant increases in mean anterior chamber angle parameters and reductions in IOP values in both diabetic and nondiabetic patients without intergroup significant differences. These results suggested the safety and effectiveness of cataract surgery, especially regarding anterior chamber angle parameters and so IOP changes.

Temporary changes of visual outcomes and anterior chamber parameters after phacoemulsification and low-add-power segmented intraocular lens implantation for primary angle closure disease

PURPOSE

To evaluate the temporary changes in visual outcomes and anterior segment parameters after cataract surgery plus low-add bifocal intraocular lens (IOL) implantation for primary angle closure disease (PACD).

METHODS

This retrospective comparative case-control study included two groups: low-add-power segmented IOL and monofocal IOL. Postoperative examination involved evaluation of uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), uncorrected intermediate visual acuity (UIVA), and spherical equivalent (SE). Anterior segment examination was performed using anterior segment optical coherence tomography.

RESULTS

This study included 19 eyes of 11 consecutive patients who underwent cataract surgery. The low-add group had better UDVA than the monofocal group at 3 months postoperatively, better UIVA at 1 month postoperatively, better UNVA at 1 week postoperatively. In the low-add group, SE increased at 1 and 3 months postoperatively compared with 1 week postoperatively. In the monofocal group, objective SE decreased at 1 and 3 months postoperatively compared with 1 week postoperatively. In the low-add group, the anterior chamber depth (ACD) became significantly deep gradually at 1 and 3 months compared with at 1 week postoperatively. In the monofocal group, the ACD became significantly shallow gradually at 1 and 3 months than at 1 week postoperatively.

CONCLUSION

The low-add-power segmented IOL achieved better far and intermediate distance visual acuity after cataract surgery in PACD patients than did the monofocal IOL. The ACD became deeper and SE showed a hyperopic shift with the low-add-power segmented IOL at 1 and 3 months after cataract surgery compared with at 1 week after cataract surgery.