***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose : To study the association between chronic intake of aspirin and intraoperative bleeding during cataract surgery and the effect of discontinuing the medication before surgery . Setting : Department of Ophthalmology , Meir Hospital , Sapir Medical Center , KfarSaba , Israel . Methods : Sixty‐one patients having cataract surgery and receiving aspirin to prevent thromboembolic events were divided into 3 groups : Group A , continuation of the medication ; Group B , cessation of aspirin intake for 2 to 5 days before surgery ; Group C , cessation of medication for 7 to 10 days before surgery .  Blood tests of coagulation parameters , a detailed question naire , and 1 day and 1 week follow‐up were evaluated . Results : There were no significant differences in blood tests and the amount and incidence of intraoperative bleeding among the 3 groups . Diathermy was used somewhat more in Group A ; however , there was no difficulty stopping the bleeding in any case and discontinuation of the medication had no effect on the intraoperative course or postoperative outcome . Conclusions : Aspirin intake was not associated with significant intraoperative bleeding ; thus , discontinuation of aspirin is usually not indicated . Clear corneal phacoemulsification is advantageous in patients receiving antiplatelet therapy OBJECTIVES To compare ranibizumab with focal/grid laser or a combination of both in diabetic macular edema ( DME ) . DESIGN Prospect i ve , r and omized , interventional , multicenter clinical trial . PARTICIPANTS A total of 126 patients with DME . METHODS Subjects were r and omized 1:1:1 to receive 0.5 mg of ranibizumab at baseline and months 1 , 3 , and 5 ( group 1 , 42 patients ) , focal/grid laser photocoagulation at baseline and month 3 if needed ( group 2 , 42 patients ) , or a combination of 0.5 mg of ranibizumab and focal/grid laser at baseline and month 3 ( group 3 , 42 patients ) . MAIN OUTCOME MEASURES The primary end point was the change from baseline in best-corrected visual acuity ( BCVA ) at month 6 . RESULTS At month 6 , the mean gain in BCVA was significantly greater in group 1 ( + 7.24 letters , P = 0.01 , analysis of variance ) compared with group 2 ( -0.43 letters ) , and group 3 ( + 3.80 letters ) was not statistically different from groups 1 or 2 . For patients with data available at 6 months , improvement of 3 lines or more occurred in 8 of 37 ( 22 % ) in group 1 compared with 0 of 38 ( 0 % ) in group 2 ( P = 0.002 , Fisher exact test ) and 3 of 40 ( 8 % ) in group 3 . Excess foveal thickness was reduced by 50 % , 33 % , and 45 % in groups 1 , 2 , and 3 , respectively . CONCLUSIONS During a span of 6 months , ranibizumab injections by the current protocol had a significantly better visual outcome than focal/grid laser treatment in patients with DME PURPOSE To evaluate the efficacy and safety of ranibizumab administered monthly for three months and then quarterly in patients with subfoveal choroidal neovascularization ( CNV ) secondary to age-related macular degeneration ( AMD ) . DESIGN Phase IIIb , multicenter , r and omized , double-masked , sham injection-controlled trial in patients with predominantly or minimally classic or occult with no classic CNV lesions . METHODS Patients were r and omized 1:1:1 to 0.3 mg ranibizumab ( n = 60 ) , 0.5 mg ranibizumab ( n = 61 ) , or sham ( n = 63 ) treatment groups . The primary efficacy endpoint was mean change from baseline visual acuity ( VA ) at month 12 . RESULTS Mean changes from baseline VA at 12 months were -16.3 , -1.6 , and -0.2 letters for the sham , 0.3 mg , and 0.5 mg groups , respectively ( P < or = .0001 , each ranibizumab dose vs sham ) . Ranibizumab arrested CNV growth and reduced leakage from CNV . However , the treatment effect declined in the ranibizumab groups during quarterly dosing ( e.g. , at three months the mean changes from baseline VA had been gains of 2.9 and 4.3 letters for the 0.3 mg and 0.5 mg doses , respectively ) . Results of subgroups analyses of mean change from baseline VA at 12 months by baseline age , VA , and lesion characteristics were consistent with the overall results . Few serious ocular or nonocular adverse events occurred in any group . CONCLUSIONS Ranibizumab administered monthly for three months and then quarterly provided significant VA benefit to patients with AMD-related subfoveal CNV and was well tolerated . The incidence of serious ocular or nonocular adverse events was low OBJECTIVE The 2-year , phase III trial design ated Anti-vascular endothelial growth factor ( VEGF ) Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization ( CNV ) in Age-related Macular Degeneration ( ANCHOR ) compared ranibizumab with verteporfin photodynamic therapy ( PDT ) in treating predominantly classic CNV . DESIGN Multicenter , international , r and omized , double-masked , active-treatment-controlled clinical trial . PARTICIPANTS Patients with predominantly classic , subfoveal CNV not previously treated with PDT or antiangiogenic drugs .  INTERVENTION Patients were r and omized 1:1:1 to verteporfin PDT plus monthly sham intraocular injection or to sham verteporfin PDT plus monthly intravitreal ranibizumab ( 0.3 mg or 0.5 mg ) injection . The need for PDT ( active or sham ) retreatment was evaluated every 3 months using fluorescein angiography ( FA ) . MAIN OUTCOME MEASURES The primary , intent-to-treat efficacy analysis was at 12 months , with continued measurements to month 24 . Key measures included the percentage losing < 15 letters from baseline visual acuity ( VA ) score ( month 12 primary efficacy outcome measure ) , percentage gaining > or=15 letters from baseline , and mean change over time in VA score and FA-assessed lesion characteristics . Adverse events were monitored . RESULTS Of 423 patients ( 143 PDT , 140 each in the 2 ranibizumab groups ) , the majority ( > or=77 % in each group ) completed the 2-year study . Consistent with results at month 12 , at month 24 the VA benefit from ranibizumab was statistically significant ( P<0.0001 vs. PDT ) and clinical ly meaningful : 89.9 % to 90.0 % of ranibizumab-treated patients had lost < 15 letters from baseline ( vs. 65.7 % of PDT patients ) ; 34 % to 41.0 % had gained > or=15 letters ( vs. 6.3 % of PDT group ) ; and , on average , VA was improved from baseline by 8.1 to 10.7 letters ( vs. a mean decline of 9.8 letters in PDT group ) . Changes in lesion anatomic characteristics on FA also favored ranibizumab ( all comparisons P<0.0001 vs. PDT ) . Overall , there was no imbalance among groups in rates of serious ocular and nonocular adverse events . In the pooled ranibizumab groups , 3 of 277 ( 1.1 % ) patients developed presumed endophthalmitis in the study eye ( rate per injection = 3/5921 [ 0.05 % ] ) . CONCLUSIONS In this 2-year study , ranibizumab provided greater clinical benefit than verteporfin PDT  in patients with age-related macular degeneration with new-onset , predominantly classic CNV . Rates of serious adverse events were low . FINANCIAL DISCLOSURE(S ) Proprietary or commercial disclosure may be found after the references OBJECTIVE The objective of this study was to investigate whether routine medical testing before cataract surgery reduces the rate of complications during the perioperative period in adults . METHODS The study was carried out in an academic medical center in Brazil , between 10 February 2000 and 10 January 2001 . The scheduled cataract operations were r and omly assigned to one of two groups : 1 ) to be preceded by routine testing ( the " routine-testing group " ) or 2 ) not to be preceded by routine medical testing ( the " selective-testing group " ) . If the patient was assigned to the selective-testing group , it was requested that no preoperative testing be performed unless the patient presented with a new or worsening medical problem that would warrant medical evaluation with testing . In the case of patients assigned to the routine-testing group , three tests were requested : a  12-lead electrocardiogram , a complete blood count , and measurements of serum glucose .  RESULTS The sample of 1,025 patients scheduled to undergo cataract surgery was comprised of 512 assigned to the routine-testing group and of 513 assigned to the selective-testing group . The two groups had similar proportions of operations canceled and not subsequently rescheduled , 2 % in each group . The cumulative rate of medical events was similar in the two groups , 9.6 % in the routine-testing group and 9.7 % in the selective-testing group ( P = 0.923 ) . The types of medical events were also similar in both groups . DISCUSSION The results of this study suggest that routine medical testing before cataract surgery does not reduce the rate of complications during the perioperative period . The results also suggest it would be more efficient not to request routine preoperative tests unless indicated by patient history or physical examination The ability of intravitreal bovine thrombin to control intraoperative bleeding was investigated by a prospect i ve double blind study of 28 consecutive patients with vascularized preretinal membranes undergoing vitrectomy for diabetic retinopathy . Addition of thrombin ( 100 units/ml ) to the vitrectomy infusate was associated with a significantly reduced intraocular bleeding time after cutting vascularized membranes . The mean bleeding time without thrombin was 111.5 seconds , compared to 12.3 seconds with intravitreal thrombin ( P less than 0.0001 ) . Patients receiving thrombin had less overall bleeding during surgery and less vitreous hemorrhage on the second postoperative day . Intravitreal bovine thrombin was associated with increased postoperative intraocular inflammation in 20 % of patients receiving thrombin . This inflammation could be controlled by use of frequent topical steroids PURPOSE To examine the effect of proton beam irradiation on subfoveal choroidal neovascular membranes ( CNVM ) associated with age-related macular degeneration (AMD).R and omized , prospect i ve , sham-controlled , double-masked treatment trial . METHODS Thirty-seven subjects with subfoveal CNVM due to AMD were r and omly assigned to 16-Gy proton irradiation delivered in two fractions 24 hours apart or to sham control treatment . Recruitment was halted at 37 subjects for ethical reasons regarding r and omization to sham treatment when Food and Drug Administration approval of Visudyne was anticipated . RESULTS Proton irradiation was associated with a trend toward stabilization of visual acuity , but this association did not reach statistical significance . No correlations were found within the fluorescein angiography data , including greatest linear dimension of CNVM total size , area of active leakage , area of associated subretinal hemorrhage , and intensity . CONCLUSIONS With the acceptance of photodynamic therapy , future studies will require more complex design and larger sample size to determine whether radiation can play either a primary or adjunctive role in treating these lesions Background : Visual impairment and blindness are common in older people in Britain . It is important to know the causes of visual impairment to develop health service and research priorities . The authors aim ed to identify the causes of visual impairment in people aged 75 years and older in Britain . Methods : In the MRC Trial of the Assessment and Management of Older People in the Community , trial nurses tested visual acuity in everyone aged 75 years and older in 53 general practice s. For all visually impaired patients in 49 of the 53 medical practice s , data regarding the cause of vision loss were extracted from the general practice medical notes . Additional follow up question naires were also sent to the hospital ophthalmologist to confirm the cause of vision loss . Visual impairment was defined as a binocular acuity of less than 6/18 . Results : There were 1742 ( 12.5 % ) people visually impaired in the 49 participating practice s. Of these , 450 ( 26 % ) achieved a pinhole visual acuity in either eye of 6/18 or better . In these people , the principal reason for visual loss was considered to be refractive error . The cause of visual loss was available for 976 ( 76 % ) of the remaining 1292 visually impaired people identified . The main cause of visual loss was age related macular degeneration ( AMD ) ; 52.9 % ( 95 % confidence interval 49.2 to 56.5 ) of people had AMD as a main or contributory cause . This was followed by cataract ( 35.9 % ) , gla 
    Output:
    
Evidence relating to the management of patients ( from the general population ) with age-related visual problems is available from other Cochrane review s and is likely to be the best evidence available for making treatment decisions about individual patients .