Anterior Segment Changes in Patients With Glaucoma Following Cataract Surgery.

This prospective observational study investigates the impact of cataract surgery on anterior segment parameters in nonglaucomatous and primary open-angle glaucoma (POAG) eyes, utilizing anterior segment optical coherence tomography (AS-OCT). The study involved 42 Caucasian patients, divided into a control group and a POAG group. Comprehensive ophthalmic examinations were performed along with AS-OCT imaging and biometry preoperatively, as well as on one day, one week, and one month following cataract surgery. The results showed significant post-operative changes in anterior chamber depth (ACD) and angle width in both groups, suggesting that cataract surgery may influence the structural parameters associated with glaucoma risk and management. Specifically, a marked increase in ACD and improvement in angle-opening distances were observed, highlighting the potential of cataract extraction to alter intraocular fluid dynamics favorably. Despite these changes, the study noted an initial spike in increased intraocular pressure (IOP) in POAG patients immediately post-operative, which stabilized during follow-up. For the control group, IOP showed gradually reducing IOP values in the follow-up visits. The findings underscore the role of advanced imaging technologies in understanding glaucoma's pathophysiology and the potential benefits of cataract surgery in glaucoma patients. The study advocates for further research with a larger, more diverse patient population and extended follow-up to explore the long-term implications of cataract surgery on glaucoma dynamics, emphasizing the importance of personalized management and treatment strategies particularly for glaucoma patients.

Comparison of central corneal thickness in healthy eyes using ultrasound pachymetry, non-contact specular microscopy and a high-resolution Scheimpflug camera.

PURPOSE: To compare and analyze the interchangeability in measuring central corneal thickness (CCT) using ultrasonic pachymetry (USP, PACHMATE 2, DGH, Inc, Exton, PA, USA), non-contact specular microscopy (NCSM, CEM-530, Nidek CO, LTD, Gamagori, Japan) and a high-resolution Scheimpflug Camera (Pentacam HR, OCULUS, Wetzlar, Germany). METHODS: An observational, cross-sectional study was performed recruiting 216 volunteers, for a sample size of 216 eyes with no ocular abnormalities other than refractive errors. All subjects underwent pachymetric measurements obtained by USP, NCSM and Pentacam HR. Examinations were performed by the same examiner with USP always following the noncontact examinations. RESULTS: The mean CCT (± SD) was 560.30 ± 38.80 µm, 556.76 ± 36.83 µm and 547.31 ± 35.28 µm for USP, NCSM and Pentacam HR, respectively. The Bland-Altman analysis showed that the highest concordance was found between USP and NCSM, with differences between - 13.18 µm and 20.26 µm. For the differences between measurements obtained with Pentacam HR and USP, the differences at Bland-Altman plot were between - 28.25 and 13.57 µm. The lowest concordance was found for the CCT values measured with Pentacam HR and NCSM, with differences between - 25.67 and 6.86 µm. The intraclass correlation coefficient (ICC) between all pairs of measurements was between 0.979 and 0.987, suggesting that the mean measurements were strongly correlated. CONCLUSION: Measurements obtained with all three devices had high correlation. USP and NCSM were found in good agreement and high concordance, too. The above results indicate that these two devices are interchangeable in clinical practice. Pentacam HR may be a useful alternative for measuring CCT; however, it significantly underestimates CCT and cannot be used interchangeably with the other devices that we studied.

Corneal biomechanical properties measured with the Ocular Response Analyser in a myopic population.

PURPOSE: To explore the possible association between myopia and corneal biomechanical properties in a Caucasian population, and the correlations between the properties of right and left eyes. METHODS: Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using the Ocular Response Analyser (ORA) in both eyes of 95 normal adult subjects aged between 19 and 48 years. The spherical equivalent refractive errors of the participants ranged from 0.25 to -14.00 D. The mean CH and CRF values for the right and left eyes were recorded for each subject. CH and CRF data were compared between different refractive groups. RESULTS: CH was found to be slightly lower in high myopes (>-6.00 D, mean CH 10.0 ± 1.2 mmHg) in comparison to moderate myopes (>-3.00 to -6.00 D, 10.1 ± 1.4 mmHg) and emmetropes and low myopes (+0.25 to -2.75 D, 10.9 ± 1.5 mmHg). The decrease in CH with the degree of myopia was about 0.13 mmHg per D or roughly 1% per D (r(2) = 0.084, p < 0.001). Inter-subject variations were much greater than any systematic changes. CRF was not correlated with refractive error (r(2) = 0.001, p = 0.66). Although the refractive error was highly correlated between the two eyes (r(2) = 0.89, p < 0.001), CH and CRF showed a lower inter-ocular correlation (r(2) = 0.68, p < 0.001 and r(2) = 0.77, p < 0.001 respectively). CONCLUSIONS: These findings may indicate that the viscoelastic properties of the cornea are altered to a minor extent in myopia. However, in this normal population, any overall systematic changes in CH and CRF with refractive error were small in comparison with the considerable inter-subject scatter at any level of refraction.