Anterior chamber depth — a predictor of refractive outcomes after age-related cataract surgery

Abstract

Background Anterior chamber depth (ACD) is becoming a hot topic and plays an important role in correcting the refractive errors (REs) after cataract surgery. The aim of this study was to assess the ACD changes and their relationship with the REs after phacoemulsification and intraocular lens (IOL) implantation in patients with age-related cataracts. Methods One hundred forty-five eyes of 125 age-related cataract patients from the Department of Ophthalmology, Tangdu Hospital, China, were recruited. IOL Master was used for axial length (AL) and the IOL power calculation measurements, and the Pentacam HR device was used for the ACD and lens thickness (LT) measurements. Every patient underwent uncomplicated phacoemulsification by a single surgeon using a single technique. Postoperative refraction results were obtained at 1 month. The appropriate formula used for the IOL power calculation was chosen depending on the AL, specifically the Hoffer Q (AL < 22.0 mm), SRK/T (22.0 mm ≤ AL ≤ 30.0 mm), and Haigis (AL > 30.0 mm) formulas. Results The postoperative ACD was deepened and tended to stabilize gradually after 2 weeks. A concurrent hyperopic shift (0.57 ± 0.47 D) was observed when the change in the ACD was less than 1.65 mm, whereas a myopic shift (− 0.18 ± 0.62 D) occurred contrarily, and the difference between the two groups was statistically significant ( P < 0.0001). The change in ACD was significantly larger in the shallow anterior chamber (1.92 ± 0.40 mm) than in the deep chamber (1.33 ± 0.42 mm) ( P < 0.0001). Similarly, the change in ACD was larger in the short AL (2.12 ± 0.37 mm) than in the long AL (1.32 ± 0.49 mm). The postoperative ACD and refractive changes were correlated with the preoperative ACD and AL ( P < 0.0001), respectively. Two regression formulas were proposed: postoperative ACD = 3.524 + 0.294 × preoperative ACD and postoperative ACD = 3.361 + 0.228× (preoperative ACD + 1/2 LT). Conclusions The results of this study showed that the ACD deepened and was associated with a concurrent RE after cataract surgery. Postoperative changes in the ACD were related to the preoperative ACD and AL, which determined the refraction status and visual quality. The regression formula of the postoperative ACD could provide a theoretical basis for predicting refractive errors in the clinic.

Measurement of Force Required for Anterior Displacement of Intraocular Lenses and Its Defining Parameters

“…In previous studies, acrylic IOLs are characterized by less anterior capsule contraction and less or the same decentration compared with PMMA and silicone IOLs [ 25 , 26 , 27 , 28 , 29 ]. Although some studies have investigated anterior chamber depth in eyes before and after IOL implantation [ 30 , 31 , 32 , 33 ], the measurements of the biomechanical characteristics of the IOLs based on the anterior displacement force of the IOL are unique in the literature.…”

Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

“…Multiple studies [8][9][10][11][12] reported on the positive correlation of binocular RE after sequential cataract surgery and effectiveness of adjusting the target RE in the second eyes by correcting 50% of the errors from the first eyes for improving visual quality. The authors [10,13] speculated that this finding may be attributed to the revision of predictive errors from post-operative ACD. However, in China there are few reports on the calculation methods of IOL power for the second eyes of patients who underwent bilateral sequential cataract surgery.…”

“…With the increasing expectation for post-operative visual quality, the focus of the operation is not only safety, but also the best possible visual recovery. Many studies [13,24,25] suggested that refractive status was stable one month after operation, and refractive status shorter than this term should not be used as the basis for correcting the corresponding eye. Based on these clinical observations, bilateral surgery should be performed over 4 weeks, rather than simultaneously or in a short time span [26].…”

Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

“…Multiple studies [8][9][10][11][12] reported on the positive correlation of binocular REs after sequential cataract surgery and effectiveness of adjusting the target RE in the second eyes by correcting 50% of the errors from the first eyes for improving visual quality. Scholars [10,13] speculated that this finding may be attributed to the revision of predictive errors from postoperative ACD. However, in China there are few reports focused on this.…”

“…With the increasing expectation for post-operative visual quality, the focus of the operation is not only safety, but also the best possible visual recovery. Many studies [13,25,26] suggested that refractive status was stable one month after operation. Thus, bilateral surgery should be performed over 4 weeks, rather than simultaneously or in a short time span [27].…”