Purpose: We assessed changes in ocular biometrics following Ahmed valve implantation. Methods: We conducted a retrospective analysis involving 76 eyes of 76 glaucoma patients who underwent Ahmed valve implantation; these patients were followed up for 6 months. Preoperative data, including age, intraocular pressure (IOP), refractive status, axial length, central corneal thickness, anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior and posterior keratometry, were evaluated preoperatively and at 1 week, 1 month, and 6 months postoperatively. Results: The mean IOP exhibited a significant reduction from 39.17 ± 14.06 mmHg preoperatively to 11.43 ± 3.25 mmHg (p < 0.001), 13.18 ± 4.64 mmHg (p < 0.001), and 12.95 ± 4.37 mmHg (p < 0.001) at 1 week, 1 month, and 6 months postoperatively, respectively. Furthermore, the axial length exhibited a significant post-surgery reduction, measuring 23.74 ± 2.01 mm preoperatively and 23.48 ± 1.86 mm (p < 0.001), 23.57 ± 1.94 mm (p < 0.001), and 23.61 ± 1.98 mm (p = 0.002) at 1 week, 1 month, and 6 months postoperatively, respectively. However, no significant changes were observed in various other parameters, such as anterior and posterior keratometry, refractive status, ACA, ACD, or ACV, at 6 months post-surgery (p > 0.05). Conclusions Ahmed valve implantation resulted in a significant reduction in axial length. Furthermore, it had transient but non-significant effects on keratometry, refractive status, ACA, ACD, and ACV at 6 months after surgery.