Optical Coherence Tomography Of Macular After Cataract Phacoemulsification

Cystoid macular edema is a known complication of cataract extraction, as well as a common cause of visual loss. Many factors are thought to contribute to its incidence such as the type of cataract surgery, duration of surgery, posterior capsule intaction perioperation, vitreous loss , inflammation postoperation , and some latent retinopathy like diabetes. Although phacoemulsification has the advantages of small incision, quick rehabilitation, cystoid macular edema may still happen. Optical coherence tomography (OCT) is a new diagnostic technique in recent years that can provide cross-sectional images of macular in vivo and quantify macular thickness variation with a precision of 10 u m. It appears to be more objective and reproducible which indicates that OCT may be the best choice to investigate macular changes after cataract surgery.In this study, we use Germany Zeiss-Humphery OCT to analyze macular changes at 2w, 4w, 6w, 8w, 3m after uneventful cataract phacoemulsification. 60 cases in normal group and 50 cases in PHACO group are enrolled. The results are as following:1. At 2w postoperatively, the best-corrected visual acuity is 0.65 + 0.1. While 3m postoperatively it is 0.8?.15, except one 0.1.2. 48(96%) eyes remain foveal contour, while 2 eyes appears low reflective cystoid spaces in the neural epithelium, of which one happens at 2w postoperatively with wide dimension which has not totally rehabitted recently , the other shows limited cystoid edema parafovea at 8wpostoperatively followed by 2 lines visual loss that resolved at 8w postoperatively.3. The meanD of all 60 normal measurements of central foveal thickness is 151.5+ 11.1 u m. It increases after phacoemulsification, which has significant difference only at 4~6w postoperatively that disappears at 8w postoperatively. There is no significant statistical difference in foveal center between 3.5mm incision group and 5.5mm group. Central foveal thickness was considered to be abnormal when it was greater than 185 u m. In 10 eyes, the fovea appears abnormally thickened after operation, including 8 eyes of single foveal thickening , all of which happened at 2~6w postoperatively and 90%(9 eyes) resolved till six months postoperatively.4.At all stages linear regression analysis showed a significant relationship(R=0.6~0.8) between the mean macular thickness in the central fovea and visual acuity reported on a log (MAR) scale which is much higher at 4~6w postoperatively(R=0.7, 0.8).5.Retinal map of macular preoperatively shows valley figure which is thin (blue black) at center and thick (yellow green) peripheral. After operation blue-black area at center became thin like fornical figure especially at 4~6w which resolved till 8w postoperatively. One retinal map of significant cystoid macular edema remains fornical contour all along.To sum up, macular thickness increases after phacoemulaification. Very little appears cystoid macular edema resulting in visual loss, but most of which can resolve. Optical coherence tomography can investigate macular changes perfectly after cataract surgery with high-resolution and better reproducibility to provide important evidence to early clinical diagnosis and treatment.