The Role of Anterior Chamber Depth on Post-operative Refractive Error After Phacovitrectomy

Abstract

To investigate the effect of phacovitrectomy on the post-operative anterior chamber depth (ACD) and refractive outcomes, and to analyze the potential differences between vitreous filling with BSS, air and gas. Methods: Patients who underwent phacovitrectomy were included in this study and invited for repeated post-operative examination including refraction and biometry at least 3 months after the surgery. Data retrieved included demographic information, indication for phacovitrectomy, surgical details, type of vitreous filling (BSS, air or gas), pre-operative and postoperative biometric data including K-readings, axial length (AL), and ACD, as well as spherical equivalent (SE) values of the target and final refraction. Results: Forty-three eyes of 43 patients were included in this study, including 10 eyes filled with BSS, 18 with air and 15 with gas. The mean difference between the final measured spherical equivalent (SE) and the SE of the intended target refraction was 0.61±0.68 D (p = 0.019). Only 58.1% of eyes had a final SE within ±0.5D of the target refraction. Following surgery, AL remained unchanged, while mean pre-operative ACD increased significantly from 3.11±0.34 mm to 4.77±0.47 mm (p < 0.001). There was no difference in refractive error between the vitreous fillings and no correlation with AL or ACD. Conclusions: Phacovitrectomy is associated with lower accuracy of post-operative refraction compared to cataract surgery. This may be attributed to a significant change in ACD, influencing the effective lens position of the IOL, and may require adjustment of the preoperative calculations.

Axial length, vitreoretinal pathology, and anterior chamber depth can predict postoperative refractive outcomes in phacovitrectomy/silicone oil removal

“…In addition, the multiple regression analysis revealed that ACD was another significant factor associated with postoperative PE. Similarly, ACD was related to the degree of refractive error in a study by Katz et al [18] . They thought ACD influenced the IOL position.…”

“…We think three primary reasons may contribute to this. First, the vitreoretinal pathology will likely make measuring preoperative ocular biometry and estimating lens position more challenging [12,[14][15][16][17][18] . Second, the formulas for calculating intraocular lens (IOL) power are designed for regular cataract surgery rather than the combined surgery.…”

Detection of Anterior Hyaloid Membrane Detachment Using Deep-Range Anterior Segment Optical Coherence Tomography

“…These results indicate that AHM detachment is associated with lower accuracy of postoperative refraction, but no apparent tendency existed as to the myopic or hyperopic shift in those eyes. In eyes undergoing combined vitrectomy and cataract surgery, postoperative refraction is reported to be less accurate compared to cataract surgery alone, in which changes in the effective lens position after combined phacovitrectomy plays an important role [ 28 , 29 ]. In our study, it seems that the effective lens position was less predictive in eyes with visible AHM due to the lack of support for the posterior lens capsule by AHM attachment.…”

Anterior Chamber Depth After Phacovitrectomy [Letter]

“…We were very interested in the paper by Katz et al 1 concerning the role of anterior chamber depth (ACD) on post-operative refractive error after phacovitrectomy, published in your journal, because in the past we published some studies concerning the ACD changes after surgery, mostly after refractive surgery. 2 …”