The Discussion About Different Full-field ERGs Produced By Differently Colored Artificial IOLs

Objective: With blue light appearing more and more in our daily life, the retinaldamage caused by the blue light has gradually been realized. The patients after cataractsurgery should be paid particularly attention to the retinal damage, because of theabsence of light filtering by lens.To compare the differences between transparentmonofocal IOLs and blue-light filtering monofocal IOLs in the full-fieldelectroretinogram(F-ERG) for the evaluation of the retinal function and its protection byblue-light filtering intraocular lens.Method: The patients were divided into two groups randomly, from March2013till December2013at the Second Affiliated Hospital of Dalian Medical University, whowould undergo phacoemulsification combined with intraocular lens implantation. Thosewho implanted with Rayner SuperflexRintraocular lens(transparent monofocal IOL)were set as control group and comprised of36cases (40eyes), of which,21eyes wereof18males and19eyes of18females, II grade of nuclear type cataract had15eyes, Ⅲgrade of nuclear type cataract had18eyes, Ⅳ grade of nuclear type cataract had7eyes.Those implanted HOYA PY-60AD intraocular lens(blue-light filtering monofocal IOL)were set as the experimental group comprising of40cases(42eyes), of which,20eyeswere of20males and22eyes of20females, II grade of nuclear type cataract had16eyes, Ⅲ grade of nuclear type cataract had19eyes, Ⅳ grade of nuclear type cataracthad7eyes. All the patients were examined with the full-field electroretinogram, operated by a skilled operator, among12:00-14:00at1day before operation, at1monthand3months after operation. The aim was to observe international standardizationproject’s six indicators, and to statistical analysis.Results:(1) The control group: All the post-operative peak times of Dark-adapted0.01ERG, Dark-adapted3.0ERG, Dark-adapted10.0ERG, Light-adapted3.0ERG,and Light-adapted3.0flicker ERG as compared to pre-operative peat times, wereshorter and showed statistically significant differences(P<0.05). Only the differencebetween post-operation at1month and at3months was not significant(P>0.05). All thepost-operative amplitudes were higher than preoperative data(P<0.05). The differencebetween post-operation at1month and at3months was not significant too(P>0.05).There were no statistically significant differences among pre-operation, post-operationat1month, and post-operation at3months in Dark-adapted3.0oscillatory potentialspeak time(P>0.05).(2) The experimental group: All the post-operative peak times and amplitudescompared with preoperative data, had statistically significant differences(P<0.05).But the difference between post-operation at1month and at3months was notsignificant (P>0.05). All the post-operative peak times were shorter than preoperative(P<0.05), except for the Dark-adapted10.0ERG b-wave(P>0.05). All the postoperativeamplitudes were higher than preoperative data(P<0.05).(3) The control group: The peak time of Dark-adapted10.0ERG a–wave wasshorter than that of Dark-adapted3.0ERG(P<0.05), but the amplitude was higher(P<0.05). The difference of b-wave between Dark-adapted10.0ERG and Dark-adapted3.0ERG was no statistically significant(P>0.05).The experimental group: The peak time of Dark-adapted10.0ERG was shorterthan that of Dark-adapted3.0ERG(P<0.05), and the amplitude of a-wave was higher(P<0.05). The difference of b-wave amplitude between Dark-adapted10.0ERG andDark-adapted3.0ERG was no statistically significant(P>0.05).(4)At1month after surgery, the experimental group’s peak times of Dark-adapted3.0ERG b-wave and Dark-adapted10.0ERG b-wave were longer than that of the control group(P<0.05). The experimental group’s amplitudes of Dark-adapted10.0ERGa-wave、Dark-adapted3.0oscillatory potentials and Light-adapted3.0flicker ERG werelonger than that of the control group(P<0.05). Those differences were statisticallysignificant. The difference of the other indicators between the two groups was notstatistically significant(P>0.05).(5)At3months after surgery, the experimental group’s peak times of Dark-adapted3.0ERG b-wave and Dark-adapted10.0ERG b-wave were longer than that of thecontrol group,and showed statistically significant differences(P<0.05). The experimentalgroup’s peak time of Dark-adapted3.0oscillatory potentials was shorter than that ofcontrol group. The difference was statistically significant(P<0.05). The experimentalgroup’s amplitudes of Dark-adapted3.0oscillatory potentials and Light-adapted3.0flicker ERG were longer than that of the control group,and showed statisticallysignificant differences(P<0.05).The difference of the other indicators between the twogroups was no statistically significant(P>0.05).Conclusion: Cataract can cause extended full-field ERG peak time and reducedamplitude. The high strength light can reduce the change of F-ERG caused by cataract.It can better to accurate assessment of vision after cataract surgery. Blue-light filteringintraocular lens causes prolonged dark adaptation’s peak time, and simultaneouslyinfluenced the scotopic sensitivity, due to filtered part of blue-light. In this small sampleexperiment of three months follow-ups, we found that the macular and inner retina wereprotected by the blue-light filtering intraocular lens. We are looking forward to carry outa large sample clinical trial with long-term follow-ups which would confirm its retinalprotection in the future.