Spectral-domain Optical Coherence Tomography For Diagnosis Of Posterior Vitreous Detachment In Myopia Patients

Posterior vitreous detachment (PVD) is defined as a separation between the posterior vitreous cortex and the internal limiting membrane of the retina.It is more common in myopia patients. Laser in situ keratomileusis (LASIK) is the most popular refractive surgical procedure for correction of myopia.The effect of LASIK on vitreoretinal structure is of increasing interest. Spectral-domain optical coherence tomography (OCT) can provide ultrahigh-resolution information on disease morphology. So we use spectral-domain OCT to study the prevalence of PVD and the incidence of LASIK associated PVD in mypia patients.This paper studied in two aspects:Part 1 OCT for diagnosis of posterior vitreous detachment in myopia patientsObjective: To evaluate the presence of initial stages of PVD in myopia patients.The incidence and risk factors associated with PVD were investigated.Methods:Thirty-seven patients (73 eyes) with myopia or myopic-astigmatic were prospectively evaluated for the presence of PVD using OCT and kinetic B-scan ultrasound.Results:Thirty-five eyes (47.9%) were found to have perifoveal PVD using OCT while none were found using B-scan ultrasound. Logistic regression analysis indicated that female was a significant risk factor associated with perifoveal PVD.Conclusions:There is a high prevalence of perifoveal PVD in these myopia or myopic-astigmatic patients while most occurred in nasalsuperior quadrant. Female may be a significant risk factor associated with perifoveal PVD. OCT is the most effective tool for diagnosis of initial stages of PVD.Part 2 Incidence of PVD following LASIKObjective: To determine the presence of posterior vitreous detachment (PVD) in myopia patients after laser in situ keratomileusis (LASIK).Methods:Thirty-seven patients (73 eyes) with myopia or myopic-astigmatic had LASIK surgery. The vitreoretinal interfaces were evaluated preoperatively and postoperatively for the presence of PVD using OCT and kinetic B-scan ultrasound.Results:Thirty-five eyes (47.9%) had previously existing perifoveal PVD before surgery. No new occurrence of PVD or extension of a previously existing partial PVD and no serious posterior segment complications such as vitreomacular traction syndrome or retinal breaks were found during the postoperative 3-month follow-up period.Conclusions:LASIK may not be the cause of new occurrence of PVD or extension of a previously existing partial PVD. A cause—effect relationship between LASIK and PVD has not been proven. Evaluating the vitreoretinal interface before and after LASIK using OCT would be an effective method in finding the occurance and the development of PVD and other vitreoretinal changes.