| BACKGROUND: Cataract is the opacification of the optical lens induced by multiple causes, which results in visual disorder, even blindness. Incidence of cataract is increasing due to the aging population and a rise in the number of younger patients. Cararact is becoming the leading cause of treatable blindness worldwide. Surgical removal of the cataract and implantation of the artificial lens is the only effective treatment for this disease. The development and application of phacoemulsification and intraocular lens implantation was a milestone in the history of ophthalmologic operation. Compared with previous surgical techniques, phacoemulsification produced a tiny surgical incision, the procedure was relatively speedy, and the wound healed fast. In addition, the patients who underwent phacoemulsification suffered less during the surgery time and recovered rapidly after operation. Furthermore, owing to innovation of synthesized material and craftsmanship in prosthetic lens, patients acquired better postoperative visual quality. However, operative complications are always obstructions in the recovery of visual acuity. There are varied descriptions of possible complications related to cataract surgery, and these complications differ at occurrence time and site in the eyeball. Cystoid macular edema and Irvine-Gass syndrome, which are associated with fundus oculi and retina, usually occur in the late stage after surgical treatment. The incidence rate of cystoid macular edema has decreased greatly along with advances in surgical technique, from intracapsular cataract extraction to extracapsular cataract extraction and now, to phacoemulsification. This new treatment for cataract replacement is propitious to maintain the integrity of posterior capsule for surgeon, which abates disturbance of the vitreous humor and reduces the risk of cystoid macular edema and Irvine-Gass syndrome after cataract operation. Nevertheless, pseudophakic cystoid macular edema is still one of the major problems that hinder patients from getting good visual quality after surgery. Macular edema is not an exact independent oculopathy. It is a generic term for a series of pathological changes on the retina and choroid, which is usually secondary to other eye diseases or to intraocular surgery. Fluid inflows in and accumulates in the retinal layers of patients who have cystoid macular edema as a consequence of macular capillary wall damage and vascular hyperpermeability. In most instances, uneventful phacoemulsification has little influence on the macroscopic funduscopic appearance of the retina in patients without any former history of retinal disease. However, novel noninvasive imaging techniques have shown that macular thickness may increase subclinically with no morphological changes after surgery. As the most vascular tissue in the eye, the choroid supplies blood and nutrition to the outer retinal layers. In consideration of the relationship between retina and chorioid, investigators examine whether the thickness of choroid increases after surgery, and whether the thickness changes relate to the incidence of cystoid macular edema.PURPOSE: To observe and compare central retinal thickness and subfoveal choroidal thickness(SFCT) before and after uncomplicated phacoemulsification and intracapsular lens implantation. To evaluate the influence of cataract surgery on subfoveal choroidal thickness.METHODS: The research was prospectively conducted on 91 eyes of 53 patients who underwent uneventful cataract surgery and finished all the postoperative examnations during the time between February, 2015 and December, 2015. Central retinal thickness and subfoveal choroidal thickness was measured at 1 day before the operation, 1 day, 1 week, 1 month and 3 months postoperatively using optical coherence tomography(OCT).RESULTS: The 53 patients had a mean age of 62.0±10.9 years. The mean preoperative subfoveal choroidal thickness was 262±76μm as baseline. It revealed negative related to age and axial length。The mean subfoveal choroidal thickness was 266±76μm,271±75μm,269±75, 263±76μmμm at postoperative 1 week, 1 month, 3 months and 6 months respectively. In 43 eyes(47.3%), subfoveal choroidal thickness remained high even 6 months postoperatively. The mean central retinal thickness was 226±20μm at baseline, and 226±17μm, 233±17μm, 225±17μm, 226±16μm at 1 week, 1 month, 3 months and 6 months after cataract surgery.CONCLUSIONS: 1. Enthanced depth imaging spectral domain optical coherence tomography is the first choice of retinal and choroidal thickness measurement. 2. Subfoveal choroidal thickness shows negative correlation with age. 3. Subfoveal choroidal thickness shows negative correlation with axial length. 4. Central retinal thickness increases significantly 1 month after cataract surgery, and restores to the basic level 3 months postoperatively. 5. Subfoveal choroidal thickness increase significantly 1 week after phacoemulsification and intraocular lens implantation, and in some cases the increase remains till 6 months postoperatively. |
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