Sympathetic Nerve-mediated Fellow Eye Pain During Sequential Cataract Surgery By Regulating CSF3

Objective:Cataract is the leading cause of blindness in the world,and the main effective treatment is surgery to restore visual function.Sequential cataract surgery is now more common in both eyes than simultaneous cataract surgery.Multiple studies have shown that patients experienced more pronounced pain during surgery in the second eye,even when both cataract surgeries were performed under the same conditions by the same ophthalmologist.This phenomenon has aroused extensive attention of ophthalmologists.However,due to the limitations of pain assessment methods,some ophthalmologists are still skeptical about the pain differences in bilateral cataract surgery.In this study,patient samples and animal models were used to verify the pain difference of bilateral staging cataract surgery,to explore the changes in the inflammatory response of the contralateral anterior chamber after the first eye surgery,and to clarify the regulation mechanism of pain difference,so as to provide reference for the clinical work.Methods:1.Cataract Surgery Pain Scoring QuestionnairePain score questionnaire was conducted to compare the difference of pain score between the first and second eye.2.Changes of cytokine expression levels in the contralateral aqueous humor after cataract surgeryA total of 80 patients who underwent cataract surgery in the second eye were included in the experimental group,and divided into 4 subgroups according to the interval between surgeries(3 days,1 week,2 weeks,or 1 month).The control group included 20 patients who underwent unilateral cataract surgery for the first time.All surgeries were performed by the same surgeon.Aqueous humor was collected during cataract surgery for mass spectrometry and PCR array.3.Study on the increased pain of the contralateral eye caused by first eye surgery in ratsSD rats were randomly divided into two groups.In the experimental group(Con＿Post),the spikes signals of left trigeminal ganglion(TG)neurons were recorded 1day after lens extraction in the right eye.The rats without any surgery were used as the control group(Con＿Pre)to record spikes of the left TG neurons.4.Study on the upregulation of CSF3 in contralateral aqueous humor induced by first lens surgery in rabbitsThe New Zealand White rabbits were randomly divided into three groups and phacoemulsification was performed on both eyes.Aqueous humor was collected as a control sample during the surgery of the first eye(Con),and the aqueous humor was collected at 3 days(3D),1 week(1W)and 1 month(1M)after the first eye surgery.The collected aqueous humor samples were detected by q PCR.5.Study on sympathetic nerve regulation of contralateral aqueous humor CSF3 in rabbitsThe New Zealand White rabbits were randomly divided into two groups.One group underwent right-side superior cervical sympathetic ganglionectomy(SCGx＿R),and the other group did not.1 week after phacoemulsification in the right eye,phacoemulsification of left eye was performed in both groups.And the aqueous humor samples of both eyes were collected for ELISA detection.6.Study on ipsilateral sympathetic nerve regulating contralateral eye pain in the first eye(1)Electrophysiological experiment: SCGx rat model was established,and the spikes signals of left TG neurons were recorded after ECLE in the right eye.(2)SD rats were randomly divided into SCGx group(left and right random)and control group(Con).Capsulorhexis in left eye was performed 1 week after right eye Capsulorhexis.Corneal sensitivity was measured before and after surgery.Aqueous humor was collected 24 hours after the surgery and quantitative analysis of inflammatory cells was performed by flow cytometry.(3)To establish neutrophil clearance model: SD rats were randomly divided into fucoidan group(Fucoidan)and control group(Con).Fucoidan was injected intravenously after Capsulorhexis in the right eye.In control group,only Capsulorhexis was performed on the right eye.The effect of neutrophil clearance was evaluated by flow cytometry and corneal sensitivity measurement.Result:1.There is difference in pain during cataract surgery between front and rear eyes(1)The results of the pain score questionnaire show that for patients who have undergone cataract surgery in both eyes by stages,there is difference in the visual analogue scale(VAS)score of pain between the two eyes.(2)The electrophysiological experiments in rats showed that the removal of lens in the first eye caused an increase in the spikes frequency of neurons in the contralateral trigeminal ganglion.2.There is difference in cytokine expression level in aqueous humor of eyes(1)cytokine-mediated inflammatory response is the main cause of hyperalgesia during surgery in the second eye,and inflammation varies with the time interval between the two eyes.Gene expression and protein levels of CSF3 in the aqueous humor of the second eye were significantly increased compared to the control group and peaked at one week after surgery in the first eye.(2)QPCR results of rabbit phaco model showed that CSF3 in contralateral aqueous humor was significantly increased 1 week after the first surgery.3.The ipsilateral sympathetic nerve with the first eye regulates the CSF3 in the aqueous humor and the pain of the contralateral eye(1)CSF3 in the aqueous humor of contralateral eye of rabbits in the SCGx group was decreased significantly.(2)In the SCGX＿r group,the ratio of neutrophils in the aqueous humor of the left and right eyes was decreased significantly.(3)The rats of SCGx＿R group showed the lowest corneal sensitivity among the three groups(Con,SCGx＿R and SCGx＿L).(4)The corneal sensitivity was significantly decreased when the Ly6 G positive cells in aqueous humor were removed by fucoidan.(5)The spikes frequency of left trigeminal ganglion neurons in SCGX＿R group was significantly lower than those in Con＿Pre and Con＿Post groups.Conclusions:1.For patients who have undergone sequential cataract surgery in bilateral eyes,there is difference in the pain of both eyes.2.After surgery in the first eye,the activity of inflammatory factors in the aqueous humor of the contralateral eye was increased,and the protein level and gene expression of granulocyte colony-stimulating factor CSF3 were significantly increased,reaching the peak 1 week after the first surgery.It was found that the expression of CSF3 in aqueous humor showed a similar trend through the verification of rabbit phacoemulsification model.3.The increase of CSF3 significantly increased the content of neutrophils in contralateral aqueous humor,and the reduction of neutrophils can effectively relieve contralateral eye pain.4.The contents of CSF3 and neutrophils in the contralateral eyes were regulated by the ipsilateral sympathetic nerve in the first eye.The removal of unilateral superior cervical ganglion can effectively reduce the corneal sensitivity and trigeminal ganglion discharge frequency of the contralateral eyes.5.CSF3 and sympathetic activity may become analgesic targets in ophthalmic surgery.