The Occurrence And Progression Of Posterior Vitreous Detachment In Patients With High Myopia In Peri-cataract-operation Period

Background The posterior vitreous detachment(PVD) means the separation of the inner limiting membrane(ILM) and posterior vitreous cortex(PVC). The detachment will lead to the traction that destroys some structures of retina, which is the potential reason of many retinal diseases. So the study of PVD is critical to the prevention and treatment of retinal diseases.Objective1. To compare the incidence of PVD between highly myopic cataract eyes after the phacoemulsification and emmetropic cataract eyes.2. To compare the incidence of PVD before and after the phacoemulsification in highly myopic cataract eyes.3. To compare the incidence of PVD before and after the phacoemulsification in n emmetropic cataract eyes.4. To investigate the incidence and progression of PVD after the phacoemulsification in highly myopic cataract eyes and emmetropic cataract eyes.Methods1. Patients were admitted to the department of ophthalmology of Tianjin General Hospital between 8/2014 and 12/2015. All patients received the cataract surgery of single eye. The prospective cohort was used. All patients were divided into two groups according to the eye axis length(?26mm were experimental group A1 and the other side of eyes were control group A2;?24mm were experimental group B1 and the other side of eyes were control group B2).2. 125 patients were enrolled, 42 highly myopic patients and 83 emmetropic patients.Clinical data were collected, such as biochemical index, intraocular pressure, and corneal thickness. B-scan and OCT(optical coherence tomography) of both eyes were exerted before and after the surgery. About the incidence and progression of PVD, statistical analysis was taken between experimental group A1 and A2, B1 and B2, as well as A1 and B1.Result1. In A1group+A2 group(84 eyes totally), 30eyes(35.71%) had PVD before the surgery; and in B1gourp+B2 group(166 eyes totally), 31eyes(18.67%) had PVD before the surgery. The difference had statistical significance.(?2=4.11 P=0.04)2. In A1 group, 10 eyes(10/42, 23.81%) with occurred PVD or progressed PVD were found one month after the surgery. In A2 group, however, the same thing only occurred in 3 eyes(7.14%) The difference had statistical significance.(?2=6.40 P=0.01)3. In B1 group, 7 eyes(7/83, 8.43%) with occurred PVD or progressed PVD were found one month after the surgery. In B2 group, the same thing occurred in 6 eyes(7.23%). The difference had no statistical significance.(?2=0.44 P=0.26)4. The statistical difference of the incidence of PVD one month after the surgery also happened between A1 group and B1 group.(?2=5.33 P=0.01)Conclusion1. The incidence of PVD is higher in highly myopic cataract patients than that in emmetropic cataract patients.2. The phacoemulsification can lead to or deteriorate PVD in highly myopic cataract patients in 1 month.3. The phacoemulsification does not lead to or deteriorate PVD in emmetropic cataract patients in 1 month.4. The incidence of PVD is higher in highly myopic cataract patients after the cataract surgery than that in emmetropic cataract patients in 1 month.