***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: We investigated whether canalicular occlusion with a lacrimal plug could increase objective and /or subjective comfort in contact lens ( CL ) wearers ( n = 9 ) with both a history of lens intolerance and relative tear fluid deficiency . A modified Schirmer test ( MST ) was performed with the lids closed and under topical anaesthesia .  Patients with values of < 10 mm/5 min were included . The plugs were inserted into the inferior canaliculus of the eye with the lower MST result ; the contralateral eye served as a control . Conjunctival hyperaemia , Rose-Bengal and fluorescein scores , as well as subjective irritation , decreased significantly in plugged eyes at the 1 month follow-up visit but had returned to the pre-operative level at the 3 month visit . Tear fluid plasmin activity was elevated prior to plug insertion . Plasmin activity of the plugged eye was significantly lower at the 1 month visit but neither tear fluid flow ( in the collection capillary ) nor plasmin release showed any changes . The mean MST value improved insignificantly , whereas conjunctival chemosis and limbal hyperaemia showed no improvement at the 1 or 3 month follow-up visits after inferior punctal occlusion . Occlusion of the lower canaliculus with a lacrimal plug seems to induce a relatively short-lasting subjective and objective benefit for CL wearers . Plug escape or adaptive changes in lacrimal fluid secretion/ elimination rate probably took place during the follow-up . The association of increased plasmin activity with tear deficiency might lead to enhanced tissue proteolysis , and thus contribute to CL-related ocular surface changes Purpose : To evaluate the clinical efficacy , retention rates , and complications of SmartPlug insertion compared with silicone punctal plugs in patients with dry eye . Methods : Thirty-six eyes with subjective symptoms of dry eye in addition to a tear film breakup time ( TBUT ) < 5 seconds and evidence of ocular surface damage on rose Bengal or fluorescein staining were included . Treated eyes were r and omized to either a silicone plug or SmartPlug inferior punctal occlusion . Pre- and posttreatment evaluations included subjective symptom scoring , tear meniscus height , TBUT , Schirmer test , fluorescein and rose Bengal staining , and artificial tear use . Results : After a mean follow-up period of 11.2 weeks , both the silicone plug- and SmartPlug-treated eyes showed significant improvement in symptom scoring ( P = 0.002 and P = 0.005 , respectively ) , TBUT ( P = 0.035 and P = 0.009 , respectively ) , and fluorescein ( P = 0.024 and P = 0.016 , respectively ) and rose Bengal ( P = 0.008 and P = 0.046 , respectively ) staining . There was no significant difference in these parameters between the 2 plugs . SmartPlug- , but not the silicone plug-treated eyes showed significant improvement in mean tear meniscus height ( P = 0.037 ) . The use of artificial tear supplements was reduced in 10 ( 55.6 % ) silicone- and 11 ( 61.1 % ) SmartPlug-treated eyes . Minor complications related to plug insertion were experienced in 4 ( 22 % ) silicone- and 2 ( 11 % ) SmartPlug-treated eyes . Spontaneous plug loss occurred with 6 ( 33 % ) silicone plugs . Conclusions : This prospect i ve r and omized trial shows that SmartPlug insertion has equivalent clinical efficacy to the use of conventional silicone plugs . Both SmartPlug and silicone plug use can reduce dependency on tear supplements in > 55 % of patients with dry eye PURPOSE To determine the incidence of dry eye and its risk factors after myopic laser-assisted in situ keratomileusis ( LASIK ) .  DESIGN Single-center , prospect i ve r and omized clinical trial of 35 adult patients , aged 24 to 54 years , with myopia undergoing LASIK .  METHODS setting and study population : Participants were r and omized to undergo LASIK with a superior or a nasal hinge flap . They were evaluated at 1 week and 1 , 3 , and 6 months after surgery . intervention : Bilateral LASIK with either a superior-hinge Hansatome microkeratome ( n = 17 ) or a nasal-hinge Amadeus microkeratome ( n = 18 ) . main outcome measures : The criterion for dry eye was a total corneal fluorescein staining score > or =3 . Visual acuity , ocular surface parameters , and corneal sensitivity were also analyzed . Cox proportional-hazard regression was used to assess rate ratios ( RRs ) with 95 % confidence intervals . RESULTS The incidence of dry eye in the nasal- and superior-hinge group was eight ( 47.06 % ) of 17 and nine ( 52.94 % ) of 17 at 1 week , seven ( 38.89 % ) of 18 and seven ( 41.18 % ) of 17 at 1 month , four ( 25 % ) of 16 and three ( 17.65 % ) of 17 at 3 months , and two ( 12.50 % ) of 16 and six ( 35.29 % ) of 17 at 6 months , respectively . Dry eye was associated with level of preoperative myopia ( RR 0.88/each diopter , P = .04 ) , laser-calculated ablation depth ( RR 1.01/microm , P = 0.01 ) , and combined ablation depth and flap thickness ( RR 1.01/microm , P = 0.01 ) . CONCLUSIONS Dry eye occurs commonly after  LASIK surgery in patients with no history of dry eye . The risk of developing dry eye is correlated with the degree of preoperative myopia and the depth of laser treatment PURPOSE Punctal occlusion using punctal plugs is very effective for the treatment of tear-deficient dry eye . We compared the newly marketed Flex Plug ( FP , Eagle Vision Co. , Ltd. ) and the Eagle Plug ( EP , Eagle Vision Co. , Ltd. ) . SUBJECTS AND METHODS The subjects were patients with severe tear-deficient dry eye who were treated in our dry eye clinic .  FP plugs in 8 patients ( 9 eyes ) and EP plugs in 29 patients ( 35 eyes ) were compared during over 4 months of observation with regard to the time until extrusion and the possibility for re-insertion of the plugs . RESULTS During the 4 months after insertion of the plugs , the EP plugs were extruded from 35 of 51 puncta ( 68.6 % ) and the FP plugs were extruded from 4 of 13 puncta ( 30.8 % ) . In the 35 EP extrusions and in the 4 FP extrusions , re-insertion was possible . The time period until extrusion was longer for FP than for EP . In all cases , for both EP and FP , pyogenic granuloma was not observed . DISCUSSION The extrusion rate for EP plugs was much greater than for FP plugs ( 68.6 % to 30.8 % ) . Pyogenic granuloma was not observed in any instance for both types of punctal plugs PURPOSE To study the prevalence of dry eye in a hospital-based population and to evaluate the various risk factors attributable to dry eye . MATERIAL S AND METHODS In this cross-sectional study , 500 patients above 20 years of age were screened r and omly for dry eye . A 13-point question naire , Lissamine Green test , Tear film break-up time ( TBUT ) , Schirmer 's test and presence of str and s/filaments were used to diagnose dry eye . The diagnosis was made when at least three of the tests were positive . The role of  air pollution , sunlight , excessive winds  , smoking , drugs and refractive status as dry eye risk factors was assessed . RESULTS Ninety-two ( 18.4 % ) patients had dry eye .  Dry eye prevalence was maximum in those above 70 years of age ( 36.1 % ) followed by the age group 31 - 40 years ( 20 % ) . It was significantly higher ( P = 0.024 ) in females ( 22.8 % ) than in males ( 14.9 % ) , more common in rural residents ( 19.6 % ) than in urban ( 17.5 % ) and highest among farmers/labourers ( 25.3 % ) . A 2.15 fold increase was found in the odds for dry eye in those exposed to excessive wind , 1.91 fold to sunlight exposure , 1.42 to smoking , 1.38 to air pollution and 2.04 for persons on drugs . Dry eye prevalence was 14 % in emmetropes , 16.8 % in myopes and 22.9 % in hypermetropes . It was 15.6 % in those with corrected and 25.3 % in those with uncorrected refractive errors . CONCLUSION Dry eye is an under-diagnosed ocular disorder . Reduction in the modifiable risk factors of dry eye is essential to reduce its prevalence PURPOSE To evaluate the efficacy of a thermosensitive atelocollagen punctal plug in the treatment of dry eye disease . DESIGN Prospect i ve observational case series . METHODS The thermosensitive atelocollagen punctal plug was warmed at 37 C , 39 C , 41 C , and 43 C to evaluate the appropriate temperature and time for solidification . Dry eye patients were divided into 2 groups according to the preparation method of the atelocollagen punctal plug . In the conventional implantation group , atelocollagen gel was kept at room temperature for 15 minutes before implantation ( 27 eyes of 14 patients ) . In the preheating group , atelocollagen was warmed at 41 C for 8 minutes before implantation ( 23 eyes of 13 dry eye patients ) . Strip meniscometry , vital stainings , tear film break-up time ( BUT ) , and symptom scores were evaluated before and 1 month after plug implantation . RESULTS In vitro experiments revealed that heating at 41 C for 8 minutes was sufficient to solidify the gel . The mean fluorescein score in the conventional implantation group significantly improved after treatment ( before , 3.5 ± 2.3 points ; after , 2.5 ± 0.9 points , P < .05 ) . In the preheating group , the mean fluorescein score ( before , 3.7 ± 1.7 points ; after , 1.5 ± 1.2 points ) , strip meniscometry ( before , 0.6 ± 0.7 mm ; after , 1.1 ± 0.3 mm ) , BUT ( before , 3.2 ± 0.7 seconds ; after , 4.8 ± 1.0 seconds ) , and visual analog scale scores ( before , 6.6 ± 1.5 points ; after , 4.1 ± 0.9 points ) significantly improved after treatment ( P < .05 ) . CONCLUSION The thermosensitive atelocollagen punctal plug was effective for dry eye treatment . The preheating method was found to be useful to strengthen the efficacy of the thermosensitive atelocollagen punctal plug OBJECTIVE To compare the efficacy and safety of cyclosporin A ( [ CsA ] 0.05 % and 0.1 % ophthalmic emulsions ) to vehicle in patients with moderate to severe dry eye disease . DESIGN Multicenter , r and omized , double-masked , parallel-group , 6-month , vehicle-controlled . PARTICIPANTS A total of 877 patients with defined moderate to severe dry eye disease ( 292 to 293 in each treatment group ) . METHODS Two identical clinical trials ; patients were treated twice daily with either CsA , 0.05 % or 0.1 % , or vehicle . The results of these two trials were combined for analysis . MAIN OUTCOME MEASURES EFFICACY corneal and interpalpebral dye staining , Schirmer tear test ( with and without anesthesia ) , tear break-up time , Ocular Surface Disease Index ( OSDI ) , facial expression , patient subjective rating scale , symptoms of dry eye , investigator 's evaluation of global response to treatment , treatment success , and daily use of artificial tears . SAFETY occurrence of adverse events , best-corrected visual acuity , intraocular pressure , biomicroscopy , and blood trough CsA concentrations . RESULTS Treatment with CsA , 0.05 % or 0.1 % , gave significantly ( P < or = 0.05 ) greater improvements than vehicle in two objective signs of dry eye disease ( corneal staining and categorized Schirmer values ) . CsA 0.05 % treatment also gave significantly greater improvements ( P < 0.05 ) in three subjective measures of dry eye disease ( blurred vision , need for concomitant artificial tears , and the physician 's evaluation of global response to treatment ) . There was no dose-response effect . Both CsA treatments exhibited an excellent safety profile , and there were no significant topical or systemic adverse safety findings . CONCLUSIONS The novel ophthalmic formulations CsA 0.05 % and 0.1 % were safe and effective in the treatment of moderate to severe dry eye disease yielding improvements in both objective and subjective measures . Topical CsA represents a new pharmacologically based treatment for dry eye disease that may provide significant patient benefits Purpose . To determine whether canalicular occlusion with collagen and silicone pl 
    Output:
    
Although the investigators of the individual trials concluded that punctal plugs are an effective means for treating dry eye signs and symptoms , the evidence in this systematic review suggests that improvements in symptoms and commonly tested dry eye signs are inconclusive .
Although punctal plugs are believed to be relatively safe , their use is commonly associated with epiphora and , less commonly , with inflammatory conditions such as dacryocystitis