The Clinical Value And Detective Of Macular Foveal Thickness After Phacoemulsification

Objective To detect the changes of foveal thickness following uncomplicatedphacoemulsification of senile cataract by optical coherence tomography(OCT), and detectthe changes of foveal thickness following phacoemulsification of cataract with diabeticand high myopia. Analysis the some factors that induced the increase of foveal thicknessand macular edema. To investigate the mechanism of macular edema and the influence onthe subjective and objective visual function with increase of foveal thickness afteruncomplicated phacoemulsification.Methods 60 eyes of the senile cataract following uncomplicatedphacoemulsification and IOL implantation were detected the changes of foveal thicknessby OCT. The results were analyzed the influence on the changes of postoperative fovealthickness according to the degree of inflammation and posterior Vitreous detachment(PVD). Cataracts of 22 eyes with diabetics and 24 eyes with high myopia followingphacoemulsification were detected the changes of foveal thickness and morphologicalcharacters of macular edema by OCT. Influence on foveal thickness with diabetics, highmyopia or phacoemulsification procedure was studied. Analyzed the correlation of forvealthickness with visual function. 15 patients with increase of foveal thickness at 1 monthafter phacoemulsification were examined the subjective visual function with Ocular staticvisual field and objective visual function with Veris multifocal electroretinograms.Results 60 patients were examined the changes of foveal thickness afteruncomplicated phacoemusification for senile cataract by OCT, 148.6±11.5umpreoperatively, 152.8±13.5um at 1 week after operation, 159.7±18.9um at 1 month after operation and 155.2±16.2um at 3 months after operation. There were no significantdifference at difference time postoperative comparing to preoperative (F=0.87, P＜0.05).The postoperative foveal thickness of mild inflammation group at 1 week or 1 monthfollowing uncomplicated phacoemulsification was increased obviously to preoperativeand had significant difference(F=4.31, 6.17, P＜0.05 ), but had no difference at 3 monthsfollowing phacoemulsification (P＞0.05) . There were no difference of foveal thicknessafter phacoemulsification in moderate inflammation group (P＞0.05) . There wereno changes of foveal thickness for complete PVD, and had no statistical significant(P＞0.05) .The correlation between the best corrective visual acuity and foveal thicknessat 1 week, 1 month and 3 months following phacoemulsification was -0.78,-0.72 and-0.81, and had statistical significant (P＜0.05) .The foveal thickness at 1 week or 1 monthafter phacoemulsification in diabetics had been increased obviously to preoperative andhad significant difference(F=5.62 and 4.19, P＜0.05), but had no significant difference at3 months (P＞0.05) . Morphological analysis of OCT showed that 4 patients had hadmacular edema at 1 month after phacoemulsification, 3 patients were spongy-like retinaledema, and 1 patient was retinal cystoid edema. The correlation between the bestcorrective visual acuity and foveal thickness at 1 week, 1 month and 3 months afterphacoemulsification in diabetics was-0.73,-0.82 and -0.67 , and had statisticalsignificant (P＜0.05) . the foveal thickness of high myopia preoperatively was thinnerthan that of control group and had significant difference (F=3.89, P＜0.05) . The fovealthickness at 1 week or 1 month after phacoemulsification in high myopia was increasedobviously comparing to preoperative and had significant difference (F=4.97 and 6.17,P＜0.05 ).Morphological analysis of OCT showed that 3 patients had had macular edema at1 months after phacoemulsification, 1 patients had spongy-like retinal edema, and 1patient had serious detachment of neural epithelium and 1 patient had coexist of thespongy-like retinal edema, cystoid retinal edema and serious detachment of neuralepithelium. The correlation between the best corrective visual acuity and foveal thickness at 1 week, 1 month and 3 months after phacoemulsification in high myopiawas-0.21,-0.12,-0.18, and had no statistical significant (P＞0.05). 0⁰ light stimulatingthresholds of increased foveal thickness group was 14.82±7.99dB by static visual fieldexamination of subject visual function, but the control group was 21.17±6.13dB, and hadsignificant difference(t=2.07, p＜0.05). It had significant difference of 0⁰ retinal N₁ and Pwave response densities of objective visual function by multifocal electroretiongrams(t=3.42 and 3.67, p＜0.05).Conclusions The foveal thickness was increased in mild inflammation group afteruncomplicated phacoemulsification with OCT and recovered normal at 3 monthspostoperatively. It might be related to long time operation, high phaco power, injure of irisin surgery and anterior chamber instability, etc. It suggested that this patients hadtemporary and reversely blood-retinal barrier disorder. There had no changes of fovealthickness in senile cataract with complete PVD after phacoemulsification. The visualconsequences were proportional to the degree of foveal thickness. The foveal thicknesswas increased significant at early stage after phacoemulsifucation in diabetics comparingto control group, it indicated that increase of blood sugar would induce the disorder ofretinal and micro-circulation.The phacoemulsification procedure might aggressive thedisorder of blood-retinal barrier, and induce the increase of foveal thickness or evenlymacular edema, but recover normal at 3 months after phacoemusificaion. The disorder ofblood-retinal barrier was temporary and reversely. The visual consequences afterphacoemusification in diabetics were proportional to the degree of foveal thickness. Thedecrease of foveal thickness in high myopia was related to expanding of eye, thin retinalnerve epithelial, thin choroidal and retinal malnutrition . The foveal thickness wasincreased significant and induced macular edema after phacoemusification in high myopia,it suggested that the fovea in high myopia had had low resistance to injury and neededlong time to recover. The regression analysis of best corrective visual acuity and fovealthickness after phacoemulsification in high myopia showed that it had had complex non-linear relationship, it suggested that many factors might influence on foveal thicknessand visual function. Subjective visual functional evaluation showed that the lightstimulating thresholds at central were low in the increased foveal thickness group, andindicated that the stronger light stimulation could induce the response of macular fovea.Objective visual functional evaluation showed that the response densities of N₁ and Pwave in the increased foveal thickness group were lower than control group and illustratedthat increased foveal thickness had a low reaction to stimulation, and suggested thatincreased foveal thickness had induced changes of subjective and objective visualfunction.