Comparison between open-angle glaucoma and angle-closure glaucoma regarding the short-term optic disc vessel density changes after trabeculectomy

Abstract

To compare the microvasculature of the optic disc in open-angle glaucoma (OAG) and angle-closure glaucoma (ACG) after trabeculectomy. This study included 34 patients divided into two groups based on the angle: (1) the OAG Group, which included 24 eyes from 24 patients, and (2) the ACG Group, which included ten eyes from 10 patients. All patients were subjected to comprehensive ophthalmic examinations. It included best-corrected visual acuity (BCVA), Goldmann applanation tonometry, gonioscopy, slit-lamp biomicroscopy, dilated fundus examination, and stereoscopic examination of the optic disc. The central corneal thickness was measured using a Nidek AL scan optical biometer. The visual field was evaluated by standard automated perimetry using Humphrey Field Analyzer (24–2 Swedish interactive threshold algorithm; Carl-Zeiss Meditec, Dublin, CA). Moreover, optical coherence tomography angiography (OCT-A) was performed utilizing the RTVue XR Avanti scanner (Optovue Inc., Fremont, CA, USA) preoperatively as well as 1 month after surgery. There was a statistically significant increase in optic disc vessel density (VD) in the whole image, radial peripapillary, inferior, superior, temporal, and nasal quadrant in OAG after surgery. Regarding the change in VD after surgery in ACG patients, there was a statistically significant increase in optic disc VD in the whole image, radial peripapillary, inferior, superior, temporal, and nasal quadrant in ACG after surgery.Regarding the percentage of VD change following trabeculectomy surgery, there were highly significant differences between the two groups for the whole image, radial peripapillary, inferior quadrant, and temporal quadrant VD. Statistically significant changes were also observed in the superior and nasal quadrants of VD. However, no significant change in VD was detected within the disc. In conclusion, the optic disc VD improved after the reduction of intraocular pressure (IOP) by surgery in both OAG and ACG. However, ACG demonstrated a significant improvement than the OAG.

Variations in Lens Thickness Affecting the Anterior Chamber Length and Their Potential Measurement Using a Biometer

“…Currently, devices based on optical low-coherence reflectometry (OLCR) are available, including the Lenstar LS900 (Haag-Streit Köniz), Aladdin (Topcon), AL-Scan (Nidek), and OA-2000 (Tomey) [13][14][15][16]. The accuracy and repeatability of measurements with these instruments are excellent and have been verified in various studies, where the values were similar to the values obtained from these instruments [9,11,17,18].…”

“…This advanced technique uses the principles of light wave interference to provide highly accurate measurements of the eye's structure, which is essential for tailoring treatments in ophthalmology (Figure 1). This method is critical to several aspects of ophthalmology, most notably the calculation of intraocular lens (IOL) power for cataract surgery and the assessment of refractive errors [4,8,12,13]. It is based on the principle of superimposing two or more sources of coherent light (typically lasers) to create an interference pattern.…”

“…Three parameters are essential for the calculation of IOL power: axial length, anterior chamber depth, and lens thickness. With the development of fourth-and fifth-generation IOL calculation formulas, lens This method is critical to several aspects of ophthalmology, most notably the calculation of intraocular lens (IOL) power for cataract surgery and the assessment of refractive errors [4,8,12,13]. It is based on the principle of superimposing two or more sources of coherent light (typically lasers) to create an interference pattern.…”

Retinal Ganglion Cell Function and Perfusion following Intraocular Pressure Reduction with Preservative-Free Latanoprost in Patients with Glaucoma and Ocular Hypertension

“…Several studies have used OCTA to assess the changes in VD after lowering IOP [ 17 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Hollo [ 31 ] was the first to report a significant increase in peripapillary angioflow density at 2–4 weeks in six eyes of four young subjects after a large (more than 50%) decrease in IOP with topical medication.…”

“…These changes were independent of IOP, but the intensity of the signal strength had an effect on VD. After trabeculectomy, some studies [ 17 , 34 , 35 , 36 ] reported a significant increase in peripapillary and macular VD in open-angle and angle-closure glaucoma [ 37 ], which was associated with higher pre-operative IOP and greater IOP reduction [ 36 ], suggesting that ocular perfusion impairment may be improved via IOP reduction. The improvement in NFL-plexus capillary density occurred in areas with minimal RNFL thinning, in eyes with early glaucoma, which may have greater potential to restore perfusion [ 18 ], while eyes with advanced visual field loss after successful trabeculectomy had reduced peripapillary and macular VD, which may be relevant to the experience of deterioration after surgery [ 38 , 39 ].…”