Clinical Aspects of Transient Myopia after Blunt Eye Trauma

Purpose: To investigate the clinical aspects of transient myopia after blunt eye trauma.Methods: The medical records of 32 patients treated at our hospital for from 2020 to 2022 traumatic microhyphema were analyzed retrospectively. The visual acuity, intraocular pressure, anterior chamber cells, anterior chamber depth, axial length, lens thickness, and refractive index were analyzed immediately after injury and after treatment. Patients with additional diseases such as vitreous and retinal hemorrhage, traumatic retinal detachment, iridodialysis, or orbital fracture were excluded. Correlations between the myopic changes and the amount of myopic refractive change caused by trauma were analyzed.Results: The 32 patients included 24 (75%) males and 8 (25%) females. The average myopic change was -3.03 ± 0.92 (range -1.00 to -5.25) diopters (D). The average change in anterior chamber depth due to trauma was -0.22 ± 0.11 mm, the change in lens diameter was 0.20 ± 0.09 mm, and the change in axial length was -0.07 ± 0.05 mm. The average change in refractive index due to ciliary spasm was -1.63 ± 0.65 D. The correlations between the change in refractive index and anterior chamber depth (r = 0.475, p = 0.008), traumatic ciliary spasm (r = 0.649, p < 0.001), and lens thickness (r = -0.184, p = 0.330) were determined.Conclusions: Factors such as ciliary spasm, change in the anterior chamber depth, anterior shift of the lens-iris diaphragm, and increased lens thickness affect the myopic changes caused by trauma. Of these, a shallower anterior chamber depth and ciliary spasm are highly correlated with the transient myopic changes.