***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: Laser photocoagulation treatment of occult choroidal neovascularization ( CNV ) in age related macular degeneration has been up to now discouraging . We report a r and omized clinical trial comparing ‘ grid ’ laser treatment versus the natural course in 24 eyes with this kind of neovascularization . In 12 eyes a low energy scatter photocoagulation was applied to the areas of presumed CNV and abnormal retinal pigment epithelium , sparing the fovea . The follow-up ranged from 1 to 3 years . At the three months follow-up visit , the subretinal exudation appeared reduced in 40 % of the treated eyes and in none of the control eyes . During the period of follow-up the occult CNV turned to classic CNV in 4 treated and in 4 untreated eyes . At the last examination ( average follow-up 18 months ) , anatomical and functional conditions were not significantly different in the two groups . Our data fail to show a beneficial long-term effect of grid laser treatment for occult CNV ; no iatrogenic complications were seen in our series PURPOSE To investigate the correlation between reading speed and scotoma size in patients with subfoveal occult with no classic choroidal neovascularization ( CNV ) in age-related macular degeneration ( AMD ) participating at 2 of 28 centers in the Verteporfin in Photodynamic Therapy trial . DESIGN Prospect i ve , observational case series . PARTICIPANTS Twenty-two eyes of 22 patients with occult with no classic CNV in AMD . METHODS Patients '  reading speed was examined using a German- language reading test ( Radner Lesetest ) . Scotoma size was measured using the microperimetry program 2.01 of the Rodenstock Scanning Laser Ophthalmoscope . MAIN OUTCOME MEASURES Reading acuity , reading speed , size of absolute ( AS ) and relative scotoma ( RS ) . RESULTS There was a significant correlation between the size of AS and reading speed ( r = -0.48 , P = 0.023 ) , as well as AS and reading acuity ( r = 0.52 , P = 0.013 ) . No correlation was seen between RS and reading speed or reading capacity . CONCLUSION The size of absolute scotoma correlated significantly with reading capacity and reading speed and may influence these measures A prospect i ve r and omised trial of argon laser photocoagulation of vascular disciform lesions in the elderly is presented . The results based on 2 years ' follow-up show that patients within the treatment group fared better than those in the nontreatment group , although the difference between the 2 groups was not significant at a level ofp=001 in any single analysis . It is clear that in a large majority of vascular disciform lesions the neovascular tissue can be obliterated by photocoagulation , but recurrence of new vessel formation soon after treatment represents a risk to such patients after successful treatment OBJECTIVE To determine the prevalence and causes of low vision and blindness in a Japanese adult population . DESIGN Population -based cross-sectional study . PARTICIPANTS R and omly selected residents ( n = 3870 ) of Tajimi City , Japan , who were 40 years of age or older . METHODS Of the 3021 study participants ( 78.1 % of 3870 eligible persons ) , 2977 ( 76.9 % ) underwent a complete ophthalmologic examination including measurement of the best-corrected visual acuity ( BCVA ) with full subjective refraction using a L and olt ring chart at 5 m. Age- and gender-specific prevalence rates of low vision and blindness were estimated and causes were identified . MAIN OUTCOME MEASURES Low vision and blindness were defined as BCVA in the better eye worse than 20/60 to a lower limit of 20/400 and worse than 20/400 , respectively ( World Health Organization [ WHO ] criteria ) and worse than 20/40 but better than 20/200 and 20/200 or worse , respectively ( United States criteria ) . RESULTS The overall prevalence of blindness according to the WHO or U.S. criteria was 0.14 % ( n = 4 ; 95 % confidence interval [ CI ] , 0.06 - 0.32 ) . The primary causes were optic atrophy , myopic macular degeneration , retinitis pigmentosa , and uveitis . The overall prevalence of low vision according to the WHO criteria was 0.39 % ( 95 % CI , 0.18%-0.60 % ) and according to the U.S. criteria was 0.98 % ( 95 % CI , 0.66%-1.30 % ) , which was significantly greater in women and in the older half of the participants than in the younger half ( P = 0.0079 and < 0.0001 , respectively ) . The leading causes of low vision in descending order were cataract followed by glaucoma , and those of monocular blindness were myopic macular degeneration , glaucoma , and trauma . CONCLUSIONS The prevalence of  low vision  and  blindness in Japanese adults was one of the lowest among those reported . The major causes of low vision were cataract and glaucoma , and the leading cause of monocular blindness was myopic macular degeneration PURPOSE To evaluate the 1-year effect of transpupillary thermotherapy ( TTT ) on occult choroidal neovascularization membranes ( CNV ) . METHODS In this prospect i ve , r and omized , controlled pilot study of 28 patients with occult or minimally classic ( < 10 % ) neovascularization membranes with a diameter less than 4500 microm , 19 patients were treated with TTT , while nine received sham treatment .  Outcome measures were membrane diameter , visual acuity and reading ability . RESULTS The median age of patients r and omized to TTT was 78 years ( range 24 years ) ; that of patients r and omized to sham was 79 years ( range 9 years ) . There was no difference regarding membrane diameter at baseline between the two groups ; the median membrane diameters were 3400 microm ( range 2400 microm ) in the TTT group and 3200 microm ( range 2300 microm ) in the sham group ( p = 0.639 ) . Visual acuity ( VA ) was similar , with a median of 0.2 ( minimum-maximum 0.08 - 0.5 ) in the TTT group and a median of 0.16 ( min-max 0.10 - 0.32 ) in the sham group . A total of 21 patients were followed for 1 year , 13 in the TTT group ( 2.7 treatments/patient ) and eight in the sham group . Membrane diameter increased in both groups , by a median of 350 microm ( range 1600 microm ) in the TTT group and 800 microm ( range 1700 microm ) in the sham group ( p = 0.414 ) , respectively , and there was a loss in VA of > or = 15 letters in 5/13 patients ( 38 % ) in the TTT group compared with 2/8 patients ( 25 % ) in the sham group ( p = 0.266 ) . Reading ability deteriorated equally over time in both groups . Seven patients were lost to follow-up due to reluctance to continue in the study ( n = 4 ) or development of a classical component > 50 % ( n = 3 ) requiring photodynamic therapy ( PDT ) . CONCLUSION The results from this r and omized , prospect i ve pilot study of TTT for occult CNV did not indicate that TTT has a beneficial effect on visual outcome 1 year after treatment compared with the visual outcome that results from the natural course of the disease . The small study size limits statistical power and results from large control studies are needed PURPOSE To present best-corrected visual acuity ( BCVA ) findings and other clinical outcomes from eyes of patients enrolled in one of the Submacular Surgery Trials ( SST ) evaluating  surgical removal versus observation of predominantly hemorrhagic subfoveal choroidal neovascularization ( CNV ) associated with age-related macular degeneration . DESIGN R and omized clinical trial ( SST Group B Trial ) . PARTICIPANTS Eligible patients had subfoveal choroidal neovascular lesions greater than 3.5 disk areas ( 8.9 mm2 ) composed of at least 50 % blood ( either blood or CNV underlying the center of the foveal avascular zone ) and BCVA of 20/100 to light perception in the study eye . INTERVENTION Patients were assigned r and omly at time of enrollment to observation or surgical removal of blood and any associated CNV . MAIN OUTCOME MEASURE A successful outcome was defined a priori as either improvement in visual acuity ( VA ) , no change in VA , or a decline in VA of no more than 1 line ( 7 letters ) from baseline to the 24-month examination based on an intent-to-treat analysis . RESULTS Of 336 patients enrolled , 168 were assigned to each treatment arm ; treatment arms were balanced by baseline characteristics . Of 1501 expected examinations 3 months through 36 months after baseline , 1370 ( 91 % ) were performed . Loss of > or = 2 lines ( > or = 8 letters ) of VA occurred in 56 % of surgery eyes , versus 59 % of observation eyes examined at 24 months . Although severe loss of VA was not the primary outcome of interest , surgery more often prevented such loss : 36 % in the observation arm versus 21 % in the surgery arm at the 24-month examination ( chi2 P = 0.004 ) . Of initially phakic eyes , the cumulative percentage that had undergone cataract surgery by 24 months was 44 % in the surgery arm , compared with 6 % in the observation arm . Twenty-seven eyes ( 16 % ) in the surgical arm , compared with 3 eyes ( 2 % ) in the observation arm , had a rhegmatogenous retinal detachment ( RD ) . CONCLUSIONS Submacular surgery as performed in the SST Group B Trial did not increase the chance of stable or improved VA ( the primary outcome of interest ) and was associated with a high risk of rhegmatogenous RD , but did reduce the risk of severe VA loss in comparison with observation . This article contains additional online-only material available at http://www.oph source .com/periodicals/ophtha BACKGROUND Pegaptanib , an anti-vascular endothelial growth factor therapy , was evaluated in the treatment of neovascular age-related macular degeneration . METHODS We conducted two concurrent , prospect i ve , r and omized , double-blind , multicenter , dose-ranging , controlled clinical trials using broad entry criteria . Intravitreous injection into one eye per patient of pegaptanib ( at a dose of 0.3 mg , 1.0 mg , or 3.0 mg ) or sham injections were administered every 6 weeks over a period of 48 weeks . The primary end point was the proportion of patients who had lost fewer than 15 letters of visual acuity  at 54 weeks . RESULTS In the combined analysis of the primary end point ( for a total of 1186 patients ) , efficacy was demonstrated , without a dose-response relationship , for all three doses of pegaptanib ( P<0.001 for the comparison of 0.3 mg with sham injection ; P<0.001 for the comparison of 1.0 mg with sham injection ; and P=0.03 for the comparison of 3.0 mg with sham injection ) . In the group given pegaptanib at 0.3 mg , 70 percent of patients lost fewer than 15 letters of visual acuity , as compared with 55 percent among the controls ( P<0.001 ) . The risk of severe loss of visual acuity ( loss of 30 letters or more ) was reduced from 22 percent in the sham-injection group to 10 percent in the group receiving 0.3 mg of pegaptanib ( P<0.001 ) . More patients receiving pegaptanib ( 0.3 mg ) , as compared with sham injection , maintained their visual acuity or gained acuity ( 33 percent vs. 23 percent ; P=0.003 ) . As early as six weeks after beginning therapy with the study drug , and at all subsequent points , the mean visual acuity among patients receiving 0.3 mg of pegaptanib was better than in those receiving sham injections ( P<0.002 ) . Among the adverse events that occurred , endophthalmitis ( in 1.3 percent of patients ) , traumatic injury to the lens ( in 0.7 percent ) , and retinal detachment ( in 0.6 percent ) were the most serious and required vigilance . These events were associated with a severe loss of visual acuity in 0.1 percent of patients . CONCLUSIONS Pegaptanib appears to be an effective therapy for neovascular age-related macular degeneration . Its long-term safety is not known BACKGROUND Ranibizumab -- a recombinant , humanized , monoclonal antibody Fab that neutralizes all active forms of vascular endothelial growth factor A -- has been evaluated for the treatment of neovascular age-related macular degeneration . METHODS In this multicenter , 2-year , double-blind , sham-controlled study , we r and omly assigned patients with age-related macular degeneration with either minimally classic or occult ( with no classic lesions ) choroidal neovascularization to receive 24 monthly intravitreal in 
    Output:
    
In the medium to long term laser photocoagulation of CNV slows the progression of visual loss in people with neovascular AMD .
However , it is associated with an increased risk of visual loss immediately after treatment and this period may be longer in people with subfoveal AMD .
No studies have compared photocoagulation with modern pharmacological agents for AMD for non-subfoveal CNV