A finite element model of the eye matched with in vitro experiments for the prediction of traumatic retinal detachment

This study aimed to conduct finite element(FE)analysis matched with an in vitro experiment to analyze traumatic retinal detachments(TrRD)resulting from blunt trauma and provide stress and strain thresholds to predict the occurrence of TrRD.The in vitro experiment was performed on forty-eight porcine eyes using a pendulum device.We examined dynamic mechanical responses at four energy levels.A FE model,based on experimental results and published data,was used to simulate TrRD.Fifty-one additional eyes underwent immediate pathological examination following blunt impact.A dynamic variation of velocities was observed post-impact,displaying an approximate cosine oscillation-attenuation profile.Energy absorption increased as the initial energy and differed significantly at four energy levels(p<0.001).FE simulation showed a peak strain of 0.462 in the anterior vitreous body and a peak stress of 1.408 MPa at the cornea at the high-energy level.During the energy transfer,the stress was initially observed in retinal region along the impact direction at the separation.TrRD were observed in injured eyes,where a few detachments were detected in control eyes.Correlations were performed between the proportion of pathological outcomes and FE results.In conclusion,this study suggests that stress contributes to the development of retinal detachment,providing an indicator to distinguish the occurrence of TrRD.

Clinical study on Hypotony following blunt ocular trauma

AIM: To evaluate the incidence and risk factors of hypotony in patients with blunt ocular trauma. METHODS: The medical records of 145 patients with blunt ocular trauma were reviewed. Hypotony was defined as an average intraocular pressure (IOP) of 5mmHg or less for three times. RESULTS: Among these 145 patients, hypotony was noted in 10 (6.9%) patients. The rate of hypotony in patients with ciliochoroidal detachment was 66.7% (2 out of 3 eyes), and 5.6% (8 out of 142 eyes) in patients without ciliochoroidal detachment,the difference was statistically significant (P=0.003). The rate of hypotony in patients with traumatic retinal detachment was 18.5% (5 out of 27 eyes), and 4.2% (5 out of 118 eyes) in patients without traumatic retinal detachment, the difference was statistically significant (P=0.026). The rate of hypotony in the patients with anterior proliferative vitreoretinopathy was 42.9% (3 out of 7 eyes) and 5.1% (7 out of 138 eyes) in the patients without anterior proliferative vitreoretinopathy, the difference was statistically significant(P=0.002). CONCLUSION: Ocular hypotension is a complication of blunt ocular trauma. The risk factors include ciliochoroidal detachment, traumatic retinal detachment, and anterior proliferative vitreoretinopathy.