Anterior chamber parameters measured by the Pentacam CES after uneventful phacoemulsification in normotensive eyes

Abstract

. Purpose: We set out to quantify changes in the anterior chamber volume (ACV), anterior chamber depth (ACD) and anterior chamber angle (ACA) measurements obtained by the Pentacam rotating Scheimpflug camera following uneventful phacoemulsification surgery in normotensive eyes with open iridocorneal angles. Methods: We enrolled 44 eyes of 44 consecutive patients undergoing cataract extraction in this prospective study. Patients with a history of glaucoma, angle‐closure glaucoma or any other concurrent ocular disease were excluded. A detailed eye examination including intraocular pressure (IOP) measurement was performed and ACV, ACD and inferior, superior, temporal and nasal ACA measurements were obtained in each patient eye using the Pentacam Comprehensive Eye Scanner (Pentacam CES) before and 3 months after phacoemulsification and intraocular lens (IOL) implantation with temporal clear corneal incision. Data were compared using paired t‐test and one‐way anova. Results: Mean preoperative ACV, ACD, ACA and IOP measurements were 164.7 ± 49.8 mm3, 3.0 ± 0.8 mm, 35.7 ± 10.2 ° and 15.8 ± 3.7 mmHg, respectively. Three months postoperatively, mean ACV, ACD, ACA and IOP measurements were 200.9 ± 33.3 mm3, 3.9 ± 0.9 mm, 41.5 ± 6.5 ° and 13.2 ± 3.9 mmHg, respectively. Postoperative mean ACV, ACD and ACA values in all four quadrants were significantly increased (p < 0.0001, p < 0.0001, p < 0.0001, respectively), whereas IOP was significantly reduced (p < 0.0001). Conclusions: The Pentacam CES allowed very easy, fast, automatic and non‐contact quantification of the anterior chamber parameters pre‐ and postoperatively in all patient eyes. Measurements obtained confirm that in normotensive eyes with open iridocorneal angles, the ACV and ACD increase and the ACA widens in all quadrants 3 months after uneventful phacoemulsification and IOL implantation. These changes are accompanied by a significant fall in IOP in the short term.

Changes in intraocular pressure and anterior segment morphometry after uneventful phacoemulsification cataract surgery

“…[17][18][19] Another important, but possibly related, difference between our study and that of Doganay et al 10 Six weeks after uneventful phacoemulsification cataract surgery, mean CCT had not changed significantly, and this is in keeping with the work of previous investigators. 1,10,16 Our study confirms the predictive value of the PD ratio for IOP reduction after uneventful cataract surgery, even when IOP is corrected for CCT.…”

“…However, increases in ACV and ACA observed in this study were somewhat greater than those reported by previous investigators, and this may be attributable to the fact that our patients had a tendency towards hypermetropia preoperatively (median preoperative SE: þ 0.50 D), as it has been shown that hypermetropes exhibit more dramatic changes in anterior segment parameters after cataract surgery. 14 The refractive state of the patients is not commented on in the study by Doganay et al 10 or by Ucakhan et al, 16 both of which also used the Pentacam but on slightly younger patients (and therefore with potentially thinner crystalline lenses preoperatively), than in our study (65.37 10 and 65.8 years 16 vs 69.2 years in the current study). It is noteworthy that excellent reproducibility and test-retest variability of anterior segment parameters measured using the Pentacam has been previously reported.…”

“…21 This latter mechanism is considered to be mediated by a backward shift of the iris (with a consequential mean opening of the ACA by 101) after removal of the crystalline lens. 16 The two former postulated mechanisms are unlikely to be related to the changes that we recorded in anterior segment parameters after cataract surgery, whereas the latter would, intuitively, seem to be related to the changes that we observed. Interestingly, Fraser and Wormald 22 reported a reduction in the need for management of angle closure glaucoma and narrow angle glaucoma in conjunction with the reducing threshold (and consequential increase in volume) of cataract surgery in the United Kingdom, reflected in a 30% reduction in laser iridotomies synchronous with a 52% increase in cataract operations in 300 NHS (National Health Service) trusts over a 6-year study period.…”

Changes in Anterior Chamber Depth after Phacoemulsification in Pseudoexfoliative Eyes and their Effect on Accuracy of Intraocular Lens Power Calculation

“…15,16,17 However, this is the first report comparing ACD changes after phacoemulsification surgery in (PEX) patients and normal patients.…”

Refraction and eye anterior segment parameters in schizophrenic patients

“…The Pentacam system measures ACD from the endothelium to the anterior lens surface without including the corneal thickness, whereas ACV is measured from the posterior cornea to the anterior lens surface (10) . The axial length (Alx) measurements and lens thickness (LT) were determined by optic biometry (Lenstar LS 900; Haag Streit Köniz, Switzerland).…”