Outcomes of and barriers to cataract surgery in Sao Paulo State, Brazil

Transcription

1 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 DOI /s RESEARCH ARTICLE Open Access Outcomes of nd brriers to ctrct surgery in So Pulo Stte, Brzil Gbriel de Almeid Ferreir, Luis Fiorvnti Schl, Mrcel Ddmos Ferro, Antonio Crlos Lottelli Rodrigues, Rjiv Khndekr nd Silvn Artioli Schellini * Abstrct Bckground: Ctrct is the leding cuse of blindness in developing countries nd identifiction of the brriers to ccessing tretment is essentil for developing pproprite public helthcre interventions. To evlute the brriers to ctrct surgery fter dignosis nd ssess the postopertive outcomes in So Polo Stte, Brzil. Methods: This prospective study evluted ctrct ptients from 13 counties in São Pulo Stte in Ctrct ws dignosed in the community by mobile ophthlmic unit nd ptients were referred to hospitl for mngement. Gender, ge, distnce to the hospitl nd locl municipl helth structure were evluted s possible brriers. Dt were nlyzed for postopertive outcomes nd the impct on blindness nd visul impirment. Results: Six hundred ptients were dignosed with ctrct with men ge of 68.8±10.3 yers nd 374 (62.3%) were femles. Two hundred nd fifty-four (42.3%) ptients presented to the referrl hospitl. One hundred fortyfour (56.7%) underwent surgery, 56 (22.0%) decided not to undergo surgery, 40 (15.7%) required only YAG-Lser nd 14 (5.5%) required spectcle prescription only. Visul cuity incresed sttisticlly significntly from 1.07±0. 73 logmar t presenttion to 0.25±0.41 logmar t the finl visit fter introculr lens implnttion (p=0.000). There ws sttisticlly significntly decrese from 17 (11.8%) blind ptients nd 55 (38.2%) visully impired ptients t presenttion to 2 (1.4%) nd 5 (3.5%) ptients respectively fter tretment (p=0.000). Conclusion: Less thn hlf of the individuls with ctrct presented to the hospitl for surgery. Among the ptients who underwent tretment, there ws n overll decrese in the number of blind individuls nd visully impired individuls. The brriers to ctrct surgery were older ge, greter distnce to the hospitl, municiplities with fewer inhbitnts nd less ophthlmic services. Keywords: Ctrct, Blindness, Tretment Outcome, Helth services ccessibility Bckground Ctrct surgery is leding cuse of blindness in developing countries [1]. In 2010, there were n estimted 39 million blind individuls nd 285 million visully impired individuls globlly. Ctrct ws considered the primry cuse of blindness, responsible for 51% of these cses [2]. In 1990, the World Helth Orgniztion (WHO) creted Vision 2020 the right for sight inititive, which ims to eliminte voidble blindness by 2020 worldwide. Despite * Correspondence: sschellini@gmil.com Universidde Estdul Pulist Julio de Mesquit Filho Fculdde de Medicin Cmpus de Botuctu Botuctu, So Pulo, Brzil improvement in ccess to surgery, mny regions worldwide do hve dequte coverge for ctrct surgery [3]. Brriers to ccess ctrct surgery differ by regions nd include, gender, fer of surgery, sttus of visul disbility, eductionl level, visul needs, distnce from the cre provider, cost nd lck of n escort/cretker [4]. Brzil hs universl public helth system (Sistem Único de Súde SUS) tht provides surgery without cost to those in need [5]. Despite universl helthcre, ctrct remins the mjor cuse of blindness in Brzil [6, 7]. Approprite public helthcre strtegies cn be developed to eliminte ctrct s source of blindness using dt from studies of brriers to ctrct surgery in The Author(s) Open Access This rticle is distributed under the terms of the Cretive Commons Attribution 4.0 Interntionl License ( which permits unrestricted use, distribution, nd reproduction in ny medium, provided you give pproprite credit to the originl uthor(s) nd the source, provide link to the Cretive Commons license, nd indicte if chnges were mde. The Cretive Commons Public Domin Dediction wiver ( pplies to the dt mde vilble in this rticle, unless otherwise stted.

2 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 2 of 7 regions of Brzil. Currently there re no published studies of brriers to ctrct surgery in Brzilin popultion. The present study evlutes the brriers to ctrct surgery nd presents some suggestions to increse the uptke of ctrct surgery. Methods A cross-sectionl prospective survey ws performed in the southwest region of São Pulo Stte, Brzil, involving ptients who were screened t Ophthlmic Mobile Unit (OMU) in SUS covered ll the costs for tretment. Ptients were screened in 13 municiplities (Tble 1). The tertiry helth reference center for the 13 municiplities ws the Clinicl Hospitl of Botuctu Medicl School (Hospitl ds Clínics d Fculdde de Medicin de Botuctu HCFMB). This study ws pproved by the Ethics Committee of the Fculdde de Medicin de Botuctu UNESP, So Pulo, Brzil nd dhered to the tenets of the Declrtion of Helsinki. All study subjects signed consent form. The UMO tem ws composed of ophthlmologists nd locl helth workers from ech municiplity. Subjects underwent comprehensive oculr exm. Visul cuity (VA) ws evluted using n illuminted Snellen E chrt nd the vlues were converted to the logrithm of the minimum ngle of resolution (logmar) for sttisticl nlysis. The Snellen to logmar conversion ws s follows: counting fingers, hnd movement, light perception nd without light perception corresponded to 2.10, 2.40, 2.70 nd 3.00, respectively [8]. The WHO definitions were used to clssify vision s follows: blindness ws defined s VA<20/400 nd visul impirment ws 20/ 400<VA<20/60 in the better eye with the best opticl correction [9]. All prticipnts underwent n objective nd subjective refrction with n utorefrctor (Accuref-K; Shinn Nippon, Tokyo, Jpn) nd mnul refrctor (RT 6000; Nidek Co. Ltd., Gmgori, Jpn). Slit lmp biomicroscopy (Shinn Nippon, Tokyo, Jpn) ws performed to evlute the nterior segment nd the posterior segment using 90 D Volk lens. For ptients who did not chieve good vision with refrction, dilted exmintion ws performed (Mydricyl; Alcon Inc., Fort Worth, TX, USA) for comprehensive evlution of the lens nd fundus. Introculr pressure (IOP) ws mesured with ir-puff tonometer (CT-60; Topcon Corp., Tokyo, Jpn). For ptients with IOP over 20 mmhg, Goldmnn tonometry ws performed to confirm the ir-puff tonometry redings (Hg-Streit AG, Köniz, Switzerlnd). To ensure consistency, survey stff were trined, periodiclly monitored nd the equipment ws clibrted regulrly. All dt collection sheets were pretested. After the ophthlmic exm, ptients dignosed with ctrct or pseudophki with posterior cpsule opcifiction (PCO) were referred to the HCFMB for further exmintion, YAG (yttrium luminum grnet) lser or surgery nd n ppointment ws scheduled. The municiplities provided trnsporttion to the hospitl on the dy of the ppointment. At the hospitl, the ptient underwent nother ophthlmic exmintion. Biometry ws performed using the IOLMster 500 (Crl Zeiss Meditec, Jen, Germny) nd IOL clcultions trgeted emmetropi in ll eyes. In eyes with dense ctrcts tht precluded opticl biometry, the Tble 1 Chrcteristics of the municiplities served by the Ophthlmic Mobile Unit in 2014 Totl ptient referred n (%) Inhbitnts n Per cpit income (R$) M-HDI Distnce to the Hospitl (km) Agudos 42 (7.0) Brr Bonit 99 (16.5) Borcéi 41 (6.8) Brots 57 (9.5) Conchs 27 (4.5) Dois Córregos 13 (2.2) Icng 30 (5.0) Igrçu do Tietê 81 (13.5) Mctub 50 (8.3) Óleo 19 (3.2) Pirmboi 19 (3.2) Promissão 102 (17.0) Tquritub 20 (3.3) Informtion not provided by municiplities n=number Number of ophthlmologists n

3 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 3 of 7 xil length ws mesured with n ultrsonic biometer (SP-1000AP; Sonoptek, Beijing, Chin) nd the IOL power ws clculted with the IOLMster. Ptients underwent phcoemulsifiction or extrcpsulr ctrct extrction (ECCE) bsed on surgeon preference. All ptients underwent IOL implnttion. Sttisticl nlysis To nlyze demogrphics nd outcomes fter tretment, the dt obtined t the OMU visit were trnsferred to n Excel spredsheet (Microsoft Corp., Redmond, WA, USA). The electronic medicl records from the hospitl were used to collect dt on the dignosis, surgicl procedure nd postopertive outcome nd trnsferred to n Excel spredsheet. Ntionl dt were consulted to determine possible brriers for evlution in this study relting to ptient dherence to the proposed tretment. The socioeconomic nd demogrphic dt of the ssisted municiplities, such s Humn Development Index (HDI), per cpit income nd number of inhbitnts, were obtined from the Instituto Brsileiro de Geogrfi e Esttístic 2010 (IBGE) [10]. Dt on the infrstructure of the ophthlmic service of the prticipting municiplities were collected using stndrdized questionnire, nswered by the officil representtive of Public Helth Cre for the municiplity. Dt nlysis ws performed with SPSS 22.0 softwre (IBM Corp., Armonk, NY, USA). The frequency, men nd stndrd devition were clculted. Normlly distributed dt were nlyzed by the Kolmogorov-Smirnov nd Shpiro-Wilk tests. Sttisticl significnce ws indicted by p<0.05. Results During the study period, 600 ptients from 13 prticipting municiplities were dignosed with ctrct or PCO nd referred to the HCFMB. The men ge of the ptients ws 68.8 ± 10.3 yers, of which 374 (62.3%) were femle, 46 (7.7%) were blind nd 202 (33.7%) were visully impired (Tble 2). Tble 2 Generl chrcteristics of the six hundred individuls referred to the reference hospitl in 2014 Age (yers) 68.8±10.3 Best Corrected Visul Acuity (logmar) 0.60±0.53 Gender Femle 374 (62.3) Mle 226 (37.7) Blindness 46 (7.7) Visul Impirment 202 (33.7) Attended to the reference center 254 (42.3) men± stndrd devition n (%) Two hundred nd fifty-four (42.3%) ptients presented for scheduled cre. Presenttion to the referrl hospitl vried between 16% to 63% mong the municiplities. Younger ptients hd sttisticlly greter tendency to present to the referrl hospitl (67.4±11.3 yers vs. 70.0±9.1 yers, p=0.004) (Fig. 1), with no sttisticl influence of gender (p>0.05). Attendnce ws sttisticlly ssocited with visul impirment (p=0.000) but not blindness (p>0.05) (Tble 3). Of the 254 ptients who ttended the hospitl, 144 (56.7%) underwent surgery in t lest one eye, 56 (22.0%) did not undergo surgery due other ophthlmic comorbidities or becuse the ptient refused surgery, 40 (15.7%) were pseudophkic with PCO tht required YAG cpsulotomy, nd 14 (5.5%) hd milder lens opcities nd resonble VA with spectcle correction nd remined under observtion. YAG cpsulotomy ws performed in 65 eyes of 40 ptients, resulting in sttisticlly significnt improvement in VA from 0.93±0.73 logmar before cpsulotomy vs 0.25 ±0.46 logmar fter cpsulotomy, p<0.000). Prior to YAG lser tretment there were four (10.0%) blind ptients nd 11 (27.5%) visully impired ptients. After YAG cpsulotomy there ws sttisticlly significnt reduction in the number of blind ptients to zero nd visully impired ptients to 2 (2.0%) (p<0.000, both comprisons). Of the 56 ptients who did not undergo surgery, 27 (48.2% of those who did not undergo surgery nd 10.7% of ll ptients) hd surgery postponed due to mild lens opcity, 17 (30.4) were lost to follow-up before surgery nd 9 (16.1%) refused surgery. A totl of 253 surgeries were performed, of which 245 were phcoemulsifiction nd 8 were extrcpsulr ctrct extrction (ECCE), ll with IOL implnttion. There ws sttisticlly significnt increse in VA from 1.07±0.73 log- MAR (20/225 Snellen cuity) preopertively to 0.25±0.41 logmar (20/32 Snellen cuity) t lst postopertive visit (p=0.000). The men improvement is VA ws log- MAR, which is equivlent to 8 lines on n erly tretment of dibetic retinopthy study (ETDRS) chrt. Of the ptients who underwent surgery, 37 (14.6%) hd n ssocited oculr comorbidity nd, in 32 (12.6%) of these ptients the comorbidity cused the low VA. The most common comorbidity ws, ge-relted mculr degenertion (AMD) in 11 (33.4%) cses. Comprison of groups with nd without comorbidities justifying the low VA indicted, sttisticlly significnt differences in the preopertive VA (1.40±0.80 logmar vs 0.83±0.70 logmar; p=0.000) nd the postopertive VA (1.05±0.82 logmar vs 0.21±0.40 logmar; p=0.000). Preopertively 17 (11.8%) ptients who underwent phcoemulsifiction in t lest one eye were clssified s blind nd 55 (38.2%) were considered visully impired. There ws sttisticlly significnt decrese fter phcoemulsifiction to 2 (1.4%) blind ptients nd 5 (3.5%)

4 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 4 of 7 Fig. 1 Comprison between ge groups who ttended or did not ttend the scheduled visit to the referrl hospitl ptients who were visully impirment (p=0.000). Of those who remined blind or visully impired fter phcoemulsifiction, 4 (57.1%) the low VA could be explined by n oculr comorbidity. The finl postopertive refrction ws vilble for 154 (60.9%) eyes. At the finl postopertive visit the men sphericl ws ± 1.13 D (rnge, D to D), the men cylindricl ws ± 1.02 D (rnge D to 0.00 D) nd the men sphericl equivlent ws -0.83±1.11 D (rnge -3.88±2.13). There were 209 ptients who underwent ctrct surgery nd YAG cpsulotomy, of whom 21 (10.0%) were blind nd 16 (7.6%) were visully impired prior to tretment. After tretment, there ws sttisticlly significnt decrese in the number of blind ptients to 2 (0.9%) nd 7 (3.3%) remined visully impired (p<0.000). Dt on locl demogrphics nd municipl helth services ws provided by 9 of the 13 municiplities covered in the study. Hence dt on 396 ptients could be nlyzed for ttendnce nd determintion of possible brriers (Tble 4). For ptients who did not present for their scheduled visits, the municipl HDI ws sttisticlly significntly higher (0.772±0.029 versus 0.763±0.034, p=0.034), there ws sttisticlly greter distnce to the hospitl (83.2±32.9 km vs 73.6±28.9 km, p=0.00), sttisticlly higher per cpit income (R$890.6±156.1 vs R$836.6±164.1, p=0.000) nd sttisticlly lower popultion (21,923.7±9,642.4 inhbitnts vs 24,287.9± 8,349.1 inhbitnts, p=0.000). Regrding the municiplity helth structure, 84.2% of ptients who did not present for the scheduled visit hd ophthlmologists in their municiplity of origin, compred to 92.3% of those who ttended (p=0.016). Additionlly, ptients who did not ttend hd sttisticlly significntly more blindness prevention progrms (18.4% vs 4.8%, p=0.000), sttisticlly better locl coverge by ophthlmic surgeons (18.4% vs 4.8%, p=0.000), sttisticlly greter vilbility of ophthlmic equipment t municipl primry helthcre fcilities (50.9% vs 39.3%, p=0.022) nd sttisticlly better municipl hospitl services nd infrstructure to perform phcoemulsifiction (23.7% vs 9.5%, p=0.000). Tble 3 Comprison of individuls who ttended or did not present to the reference hospitl in 2014 Attended (n=254) - n(%) Did not present (n=346) - n (%) Age (yers) 67.4± ± Best Visul Acuity (logmar) 0.62± ± Gender Femle 155 (61.0) 219 (63.3) Mle 99 (39.0) 127 (36.7) Blindness 24 (9.4) 22 (6.4) Visul Impirment 106 (41.7) 96 (27.7) <0.001 men ± stndrd devition n=number; p<0.05 is sttisticlly significnt (bold vlues) p Discussion The outcomes of this cross-sectionl study of ctrct ptients indicted tht those who presented to the referrl hospitl were younger nd minly femles. This observtion is similr to other Brzilin studies [11 13] nd is likely due to the chrcteristics of the Brzilin popultion which hs greter number of elderly women (IBGE 2010) [10]. Although the current study reported greter femle presenttion to the referrl hospitl, there ws no sttisticl difference between genders (p>0.05). In the current study, reltively low number of ptients (42.3%) dignosed with ctrct (bsed on the OMU screening) presented to the specilized hospitl for phcoemulsifiction or YAG cpsulotomy.

5 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 5 of 7 Tble 4 Demogrphic dt of 396 individuls nd the municiplities of origin bsed on ttendnce in 2014 Attended (n=168); (%) Did not ttend (n=228); n (%) p Age (yers) 69.3± ± Best Visul Acuity (logmar) 101 (60.1) 151 (66.2) Gender Femle 67 (39.9) 77 (33.8) Mle 9 (5.4) 21 (9.2) Blindness 46 (27.4) 59 (25.9) HDI 0.763± ± Distnce to the specilized hospitl (km) 73.6± ± Per cpit income (R$) 836.6± ± Inhbitnts ± ± Ptients with blindness prevention progrm 8 (4.8) 42 (18.4) Ptients with ophthlmologist in county of origin 155 (92.3) 192 (84.2) Hospitl with structure for fcectomy 16 (9.5) 54 (23.7) Ophthlmic Apprtus in the bsic helth 66 (39.3) 116 (50.9) Ctrct cmpign in the lst five yers 154 (91.7) 209 (91.7) Totl 168 (%) 228 (%) men±stndrd devition n=number; p<0.05 is sttisticlly significnt (bold vlues) In the entire study smple, 10.0% of ptients were blind nd 7.6% were visully impired t presenttion. After tretment, there ws sttisticlly significnt decrese in blindness to 0.9% of ptients nd 3.3% of the ptients were visully impired (p<0.000). Hence, despite the low ptient presenttion rte for referrl, the tretment ws effective nd chieved the WHO criteri. The WHO recommends mximum of 5.0% of ptients with best corrected visul cuity less thn 20/400 (blindness) fter ctrct surgery. A British study of 127,658 ptients reported n improvement in VA from 0.63 logmar t bseline to 0.16 ±0.30 logmar fter ctrct surgery [8]. The VA outcomes of the current study re lower thn the British study [8]. The differences in outcomes between studies re like becuse the British study ws performed in developed country, on lrger smple size nd with erlier dignosis. In the current study, mny ptients hd ssocited oculr comorbidity tht resulted in the low VA t finl visit. However, the postopertive VA in ptients without comorbidities in the current study ws similr to the British study [8]. A recent study from São Pulo, Brzil reported decrese from 17.6% blind ptients nd 23.5% visully impired t bseline, to 5.9% nd 11.8% respectively, fter ctrct surgery [14]. The VA outcomes from the current study re well within or exceed the rnge reported from other developing countries. For exmple, study of ctrct surgery in rurl province in Los reported 9.5% blind nd 44.3% visully impired postopertively [15]. In Nigeri, 58.5% remined blind nd 16.1% remined visully impired fter surgery [16]. In Nepl, 8.0% of ptients remined blind nd 22.0% remined visully impired fter surgery [17]. In Pkistn, 36.8% remined blind nd 22.0% remined visully impired [18]. The poorer VA outcomes t finl postopertive visit from some of the other developing countries re likely due to the uncertin surgicl conditions, often treting cses where biometry ws difficult to perform, or ptients were phkic. Additionlly, in some of the other developing countries stndrd ctrct surgery techniques my not be possible the surgeons my need to improvise bsed on the surgicl environment [19, 20]. However, in the current study ctrct surgery ws performed in specilized tertiry hospitl with good infrstructure with the option of IOL implnttion in ll ptients which explins the good postopertive outcomes. The number of surgeries, the qulity of surgery nd the finl VA re ll fctors for chieving the gol of Vision Access to helthcre services is nother brrier despite the strtegy of pproching ptients in their hometown using n OMU nd detecting individuls who require surgery. For exmple, despite these inititives, only 42.3% of the screened ptients presented to the specilized hospitl in the current study. Our nlysis of the socil, economic nd demogrphic chrcteristics nd the helth structure of the municiplities indicted tht greter distnce from the hospitl, with higher HDI, higher per cpit income ndlowermuniciplpopultion were most unlikely to present to the referrl hospitl. These chrcteristics cn be considered the brriers to

6 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 6 of 7 tretment of ctrcts in So Polo Stte, Brzil. Interestingly the sme brriers were reported in rurl region of Chin [21] nd in centrl Ethiopi [22]. The fctors higher per cpit income nd higher HDI differ from other studies, which described insufficient fmily income nd n underdeveloped popultion s importnt brriers [21 23]. Perhps ptients with higher per cpit income re ble to undergo tretment in their hometown or elsewhere, bering the expenses of the procedure. This observtion my explin the lck of presenttion to the referrl hospitl. Other fctors tht contribute to the low presenttion rte for ophthlmic surgeries re, comorbidities, fer of the opertion or of becoming blind postopertively [4, 14]. There re n verge 62 ophthlmologists per 1 million inhbitnts in Ltin Americ nd this number is incresing. Therefore, there re n dequte number of ophthlmologists for coverge of ctrct surgery [24]. However, the number of ophthlmologists tht perform ctrct surgery nd how mny surgeries ech ophthlmologist performs remins unknown. Unlike previous study [24], we found tht the mjority of ptients who did not present to the referrl hospitl hd higher number of ophthlmologists in their hometown. Despite the unfvorble presenttion, ptients who did not ttend cn hve their ctrcts ddressed in their own municiplities. These municiplities my hve n dequte number of ophthlmologists, surgeons nd hospitl infrstructure for ctrct surgery. There re some limittions to the present study, including the lck of dt on the best-corrected VA for ll ptients nd tht the brriers were not nlyzed individully. Seprte nlyses of the brriers were not performed becuse we collected generlized dt regrding the study popultion. However, there is reltive pucity of dt from studies evluting Brzilin smple with n OMU. Hence, the outcomes of the current study provide dt tht cn be used to llocte dequte resources nd develop public helthcre inititives. The outcomes of the current study indicte tht the elimintion of ctrct s cuse of blindness nd/or visul impirment in Brzil requires greter coordintion between the municiplity nd the regionl tertiry hospitl to ensure greter uptke of surgery. Conclusion Less thn hlf of the ptients dignosed with ctrct in municiplities using n OMU ctully presented to specilized hospitl for tretment despite referrl. However, the outcome of phcoemulsifiction ws encourging, resulting in significnt reduction of blind nd visully impired ptients. The min brrier to ttendnce were dvnced ge, greter distnce to the specilized hospitl nd municiplities with lower popultions. However, the presence of blindness prevention progrms, ophthlmic surgeons, vilble ophthlmic equipment t helthcre centers nd hospitl with the resources to perform phcoemulsifiction my be fctors tht reduce dherence to ppointments t specilized hospitl. Abbrevitions AMD: Age-relted mculr degenertion; ECCE: Extrcpsulr ctrct extrction; ETDRS: Erly tretment of dibetic retinopthy study; HCFMB: Hospitl ds Clínics d Fculdde de Medicin de Botuctu; HDI: Humn Development Index; IBGE: Instituto Brsileiro de Geogrfi e Esttístic; IOL: Introculr lens; IOP: Introculr pressure; logmar: logrithm of the minimum ngle of resolution; OMU: Ophthlmic Mobile Unit; PCO: Posterior cpsule opcifiction; SUS: Sistem Único de Súde; VA: Visul cuity; WHO: World Helth Orgniztion; YAG: Yttrium luminum grnet Acknowledgements None. Funding None. Avilbility of dt nd mterils Dt were nlyzed in ophthlmology deprtment, fculty of medicine, universidde estudul pulist UNESP, Brzil. The dtsets used nd/or nlyzed during the current study re vilble from the corresponding uthor on resonble request. Authors contributions GAF ws the min writer nd dt nlyzer. LFC nd MFR relized the dt collection. ACLR nd SAS concepted nd corrected the pper nd suggested chnges. RK collborted with the dt nlysis nd english spelling. All uthors red nd pproved the finl mnuscript. Ethics pprovl nd consent to prticipte The study ws pproved by fculty of medicine ethicl committee, Universidde Estudul Pulist UNESP, Brzil. We obtined written informed consent from ll prticipnts. Consent for publiction Not pplicble Competing interests The uthors declre tht they hve no competing interests. Publisher s Note Springer Nture remins neutrl with regrd to jurisdictionl clims in published mps nd institutionl ffilitions. Received: 4 July 2017 Accepted: 28 November 2017 References 1. Allen D, Vsvd A. Ctrct nd surgery for ctrct. Br J Ophthlmol. 2006;333(7559): Pscolini D, Mriotti SP. Globl estimtes of visul impirment: Br J Ophthlmol. 2012;96(5): Foster A. Ctrct nd "Vision 2020-the right to sight" inititive. Br J Ophthlmol. 2001;85(6): Lewllen S, Courtright P. Recognising nd reducing brriers to ctrct surgery. Community Eye Helth. 2000;13(34): Kr-Júnior N, Dellpi R Jr. Espíndol RFd. Dificulddes de cesso o trtmento de pcientes com indicção de cirurgi de ctrt nos Sistems de Súde Público e Privdo. Arq Brs Oftlmol. 2011;74: Arújo Filho A, Slomão SR, Berezovsky A, Cinoto RW, Morles PHÁ, Sntos FRG, et l. Prevlence of visul impirment, blindness, oculr disorders nd ctrct surgery outcomes in low-income elderly from metropolitn region of São Pulo - Brzil. Arq Brs Oftlmol. 2008;71:

7 de Almeid Ferreir et l. BMC Ophthlmology (2017) 17:259 Pge 7 of 7 7. Slomão SR, Mitsuhiro MRKH, Belfort R Jr. Visul impirment nd blindness: n overview of prevlence nd cuses in Brzil. An Acd Brs Ciênc. 2009;81: Dy AC, Donchie PH, Sprrow JM, Johnston RL, Royl College of Ophthlmologists' Ntionl Ophthlmology D. The Royl College of Ophthlmologists' Ntionl Ophthlmology Dtbse study of ctrct surgery: report 1, visul outcomes nd complictions. Eye (Lond). 2015;29(4): Tbin G, Chen M, Espndr L. Ctrct surgery for the developing world. Curr Opin Ophthlmol. 2008;19(1): Instituto Brsileiro de Geogrfi e Esttístic. Censo Demográfico Avlible from: censo2010/. [Lst ccessed on: 29 dez 2016] 11. Gomes BAF, Bincrdi AL, Fonsec Netto C, FFP G, HVD MJ. Perfil socioeconômico e epidemiológico dos pcientes submetidos à cirurgi de ctrt em um hospitl universitário. Rev Brs Oftlm. 2008;67: LMPD S, Muccioli C, Belfort R Jr. Perfil socioeconômico e stisfção dos pcientes tendidos no mutirão de ctrt do Instituto d Visão - UNIFESP. Arq Brs Oftlmol. 2004;67: Ventur LO, Brndt CT. Projeto Mutirão de Ctrt em centro de referênci oftlmológico, em Pernmbuco: perfil, gru de stisfção e benefício visul do usuário. Arq Brs Oftlmol. 2004;67: Mitsuhiro MH, Berezovsky A, Belfort R Jr, Ellwein LB, Slomo SR. Uptke, Brriers nd Outcomes in the Follow-up of Ptients Referred for Free-of- Cost Ctrct Surgery in the So Pulo Eye Study. Ophthlmic Epidemiol. 2015;22(4): Shields MK, Csson RJ, Muecke J, Losern S, Loungsouks P, Vnnvong S, et l. Intermedite-Term Ctrct Surgery Outcomes from Rurl Provinces in Lo People's Democrtic Republic. Ophthlmic Epidemiol. 2015;22(4): Odugbo OP, Mpyet CD, Chirom MR, Aboje AO. Ctrct blindness, surgicl coverge, outcome, nd brriers to uptke of ctrct services in Plteu Stte. Nigeri. Middle Est Afr J Ophthlmol. 2012;19(3): Thp SS, Khnl S, Pudyl I, Twyn SN, Ruit S, vn Rens GH. Outcomes of ctrct surgery: popultion-bsed developing world study in the Bhktpur district. Nepl. Clin Experiment Ophthlmol. 2011;39(9): Bourne R, Dineen B, Jdoon Z, Lee PS, Khn A, Johnson GJ, et l. Outcomes of ctrct surgery in Pkistn: results from The Pkistn Ntionl Blindness nd Visul Impirment Survey. Br J Ophthlmol. 2007;91(4): Venktesh R, Murlikrishnn R, Blent LC, Prksh SK, Prjn NV. Outcomes of high volume ctrct surgeries in developing country. Br J Ophthlmol. 2005;89(9): Lindfield R, Vishwnth K, Ngounou F, Khnn RC. The chllenges in improving outcome of ctrct surgery in low nd middle income countries. Indin J Ophthlmol. 2012;60(5): Zhng XJ, Jhnji V, Leung CK, Li EY, Liu Y, Zheng C, et l. Brriers for poor ctrct surgery uptke mong ptients with operble ctrct in progrm of outrech screening nd low-cost surgery in rurl Chin. Ophthlmic Epidemiol. 2014;21(3): Mehri ZA, Zewedu RT, Gulilt FB. Brriers to ctrct surgicl uptke in centrl ethiopi. Middle Est Afr J Ophthlmol. 2013;20(3): Dhliwl U, Gupt SK. Brriers to the uptke of ctrct surgery in ptients presenting to hospitl. Indin J Ophthlmol. 2007;55(2): Btlle JF, Lnsingh VC, Silv JC, Eckert KA, Resnikoff S. The ctrct sitution in Ltin Americ: brriers to ctrct surgery. Am J Ophthlmol. 2014;158(2): e1. Submit your next mnuscript to BioMed Centrl nd we will help you t every step: We ccept pre-submission inquiries Our selector tool helps you to find the most relevnt journl We provide round the clock customer support Convenient online submission Thorough peer review Inclusion in PubMed nd ll mjor indexing services Mximum visibility for your reserch Submit your mnuscript t