the complexities associated with inferior retinal detachment ( rd ) complicated by inferior proliferative vitreoretinopathy ( pvr ) are well recognized . in attempts to reduce the postoperative burden for patients ,
fluorinated so and perfluorocarbon liquids ( pfcls ) have been used as alternative internal tamponades but are not well tolerated as long - term internal tamponades [ 14 ] . in the early 2000s partially fluorinated alkanes ( falks ) were introduced as long - term heavy tamponades .
although its tolerability and biocompatibility have been demonstrated in the experimental animal and in human eyes , early f6h8 dispersion and emulsification with consequent inflammatory responses have frequently been reported [ 58 ] .
the use of so in combination with falks ( heavy silicone oil , hso ) , thereby increasing the viscosity of falks , has been suggested to reduce emulsification [ 9 , 10 ] .
four different prefabricated mixtures of falks and so of varying specific gravities and viscosities are now available : oxane hd , densiron 68 , hws 463000 , and hws 453000 .
all these mixtures include high viscosity so , ranging from 5000 to 100000  cst [ 1 , 1117 ] .
while encouraging results have been published , difficulties associated with the intraoperative handling of the substance ( e.g. , air - heavy tamponade exchange , heavy liquid - heavy tamponade exchange , or heavy tamponade removal ) , as well as postoperative side effects , have also been reported [ 1821 ] . before prefabricated mixtures were available , dual filling with f6h8 and so 1000  cst was carried out in two selected series of patients with inferior pvr by tognetto et al .   and rizzo et al . , with excellent results .
injected a mixture of 3 ml f6h8 and 7 ml of 1000  cst so , while rizzo et al .   performed a sequential injection of 70% f6h8 and 30% so 1000  cst
when either prefabricated mixture or dual fillings were used , almost all vitreoretinal surgeons chose to inject the heavy tamponade after heavy liquid - air exchange , obtaining intraoperative flattening of the retina with the heavy liquid . in the present series we , retrospectively ,
analyze the outcomes of patients with inferior rd complicated by inferior pvr , who were operated on using f6h8 as an intraoperative tool to flatten the retina and in whom a direct partial exchange between f6h8 and so 1000  cst was performed .
the eyes were tamponed with different quantitative ratios of f6h8 and so ( 70/30 , 60/40 , 50/50 , 40/30 , and 30/70 ) .
we performed a retrospective evaluation of 22 patients with inferior retinal detachment and inferior retinal breaks complicated by severe inferior pvr , who were operated on between 2007 and 2011 by means of pars plana vitrectomy ( ppv ) .
f6h8 was used as an intraoperative tool to flatten the retina , and at the end of the surgery f6h8 was partially replaced with so 1000  cst .
this procedure was chosen because all the patients of the series declared to be unable to maintain an appropriate postoperative face - down positioning which would have been required with conventional tamponade . in all eyes pvr had a grade greater than cp-6 and greater than ca-6 ( updated pvr classification ) .
perfluorohexyloctane ( fluoron , germany ) has the following physical properties : density of 1.3  g / cm , viscosity of 2.5  mpa  s , and an interface tension against water of 49.1  mn / m .
initial clinical examination included a detailed history of ophthalmic surgery , a complete ophthalmologic examination with measurement of best - corrected visual acuity ( va ) using the early treatment diabetic retinopathy study tables , measurement of intraocular pressure ( iop ) , and detailed fundus examination .
the rd was described , noting the grade of pvr , using the updated classification of the retina society .
the same examinations were carried out at all follow - up visits throughout the study .
our patients comprised 10 women and 12 men , whose ages ranged from 34 to 84 years ( mean : 69 years ) .
ten patients were not operated on for retinal detachment before undergoing ppv surgery with f6h8 .
of the 12 patients who had previous vitreoretinal surgery , 8 ( nos . 4 , 5 , 6 , 8 , 10 , 12 , 14 , and 22 ) underwent ppv with scleral buckle ( sb ) , 2 ( nos .
all patients underwent ppv using the millennium vitrectomy system ( bausch & lomb inc . , st .
a scleral buckling procedure was performed using a silicone encircling band in 11 ( nos . 1 , 3 , 11 , 13 , 15 , 16 , 17 , 18 , 19 , 20 , and 21 ) of the 12 patients without prior buckling surgery and
patient ( no . 9 ) placement of an encircling band was not possible due to extensive adherences under the lateral rectus muscle as a consequence of previous glaucoma surgery ( trabeculectomy with mitomycin ) . in this case
2 , 4 , 5 , 6 , 7 , 8 , 10 , 12 , 14 , and 22 ) underwent a scleral buckling procedure before ppv with f6h8 . in these cases , we decided not to revise the sb to save time ( much work had to be done on the vitreous , epiretinal , and subretinal membranes ) . in the 3 phakic patients ( nos . 1 , 17 , and 21 )
the lens was removed by performing phacoemulsification through a clear corneal tunnel at the time of vitrectomy .
this was followed by implantation of an intraocular lens ( iol ) in 1 patient ( no .
1 ) , while 2 patients ( no . 17 and 21 ) were left aphakic ( although the capsular support was intact ) to enhance visualization during ppv . in all patients , the vitreous base was shaved using the vitrector , and all epiretinal membranes were removed .
subretinal membranes were removed when deemed necessary to achieve retinal flattening . in 3 patients ( nos . 3 , 4 , and 7 ) it was not possible to achieve inferior retinal mobility due to severe contraction , so a peripheral retinectomy was performed . in another patient ( no .
17 ) inferior retinectomy was associated with the removal of a wooden epiretinal foreign body .
the operation was concluded with a direct partial exchange between f6h8 and so 1000  cst .
in particular , when the light fiber had been inserted into the 2 o'clock sclerotomy and a passive unprotected charles flute cannula was inserted into the 10 o'clock sclerotomy , so 1000  cst was actively injected through the infusion line .
the exchange was stopped at 70% of the vitreous cavity in 3 patients ( nos . 1 , 2 , and 3 ) , at 60% in 7 patients ( nos . 3 , 4 , 5 , 6 , 7 , 8 , and 9 ) , at 50% in 3 other patients ( nos . 9 , 10 , and 11 ) , at 40% in 2 patients ( nos . 12 and 13 ) , and at 30% in 9 patients ( nos . 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , and 22 )
( patients 3 and 9 were operated on twice ) . to obtain the desired quantitative ratio of f6h8 to
so , the volume of the vitreous cavity was calculated in cubic millimeters by measuring the length of the vitreous cavity , using standardized a scan ultrasonography , and multiplying it by a coefficient of 315 .
filled with so , the vitreous cavity length was measured using a sound speed of 980  m / s for so 1000  cst or 1040  m / s for so 5000  cst .
the ratio of f6h8 to so was changed over time according to our observations during the postoperative period in the first patients of the series ( see section 3 ) . in 21 patients
the tamponade was removed via the pars plana between the third and the fifth month after surgery . in 1 patient
16 ) the tamponade has not yet been removed due to her compromised general health conditions , which have not allowed her to undergo surgery .
the follow - up period was between 12 and 48 months ( mean 22.63 months ) .
we observed the efficacy and safety of f6h8 as an intraoperative tool for retinal flattening during ppv , the best ratio of f6h8 to so in the postoperative period , the duration of presence of the f6h8/so tamponade , the technical difficulties encountered in f6h8/so removal , and the final anatomical and functional outcome , including any complications .
f6h8 was efficacious as an intraoperative agent used to flatten the retina in all cases .
the interface of the f6h8 bubble inside the eye was not as visible as that of conventional perfluorocarbon liquid .
in the first 9 patients ( nos . 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , and 9 ) of the series
the exchange was stopped when there was still more f6h8 than so inside the eye , to be sure of an effective inferior retinal tamponade postoperatively ( ratios of 70/30 , 60/40 ) . in these cases at fundus examination on postoperative day 1 , with the patient in a seated position , we observed two phases ( f6h8 and so , not mixed together ) , with an interface above the superior arcades when the ratio was 70/30 and at the level of the superior arcades when the ratio was 60/40 . in all of these 9 patients ( 3 ( nos . 1 , 2 , and 3 ) with a ratio of 70/30 and 7 ( nos . 3 , 4 , 5 , 6 , 7 , 8 , and 9 ) with 60/40 ( patient no .
3 was operated on twice with f6h8 ) ) few days after surgery and throughout the entire follow - up period with the tamponade in the eye , at the beginning of fundus visualization , the two substances appeared amalgamated with a clear fundus visualization but after a few seconds we observed a cloudiness of the tamponade in the posterior pole and in the inferior quadrants .
based on the above mentioned results , we lowered the ratio of f6h8 to so to 50/50 in 3 patients , to 40/60 in 2 patients , and to 30/70 in 9 patients . in these cases ( ratio : 50/50 to 30/70 ) on postoperative day 1 there was a visible interface just below the optic nerve ( ratio : 50/50 ) ( patients nos .
9 , 10 , and 11 ) , below the inferior arcade ( ratio : 40/60 ) ( patients nos . 12 and 13 ) , or further down ( ratio : 30/70 ) ( patients nos .
14 , 17 , 19 , 20 , and 21 ) . in the other 4 patients ( nos .
15 , 16 , 18 , and 22 ) with a 30/70 ratio no interface was visible and the two substances were perfectly amalgamated on the first day after surgery . in the course of followup with the tamponade inside , just a few days after surgery ,
only one phase was observed in the eyes of patients with ratios of 50/50 , 40/60 , and 30/70 who had shown two phases on postoperative day 1 .
no further changes were observed in these patients during the rest of the follow - up period . in all these patients , including those with a 30/70 ratio who showed a single phase from postoperative day 1 , the phase remained single throughout followup and no cloudiness was observed during fundus examination , allowing the physician to follow up the eye very carefully and perform laser if necessary . during the followup 1 patient ( no .
1 ) with a f6h8/so ratio of 70/30 showed increased iop the day after surgery , which was controlled with medications for the next 20 days , until it returned to be within normal limits .
five patients , with ratios of 60/40 ( 3 ( nos . 6 , 8 , and 9 ) ) , 50/50 ( 2 ( nos . 9 and 10 ) ) , and 30/70 ( 1 ( no .
9 was operated on twice with f6h8 ) , showed low iop , which remained in the low range throughout the follow - up period , without any clinical signs of hypotony . during the follow - up period posterior synechiae were observed in 5 patients : 1 ( no . 1 ) with a f6h8/so ratio of 70/30 , 1 ( no . 8) with 60/40 , 1 ( no .
9 ) with 60/40 in the first operation and 50/50 in the second operation , and 2 ( nos . 16 and 21 ) with 30/70 .
in 1 patient ( no . 13 ) inferior retinal hemorrhages were observed but were resolved one month after surgery ( 40/60 ratio ) .
two patients ( nos . 18 and 19 ) , both with a ratio of 30/70 , developed cystoid macular edema , as determined by oct examination . finally , in 1 patient ( no .
11 ) with 50/50 ratio a migration of the tamponade into the anterior chamber occurred through a partial inferior zonular dehiscence , forming bubbles of the f6h8/so mixture in the anterior chamber but not causing corneal damage . no patient showed emulsification or signs of vasculitis or uveitis .
regarding retinal behavior during the presence of the f6h8/so tamponade , we observed retinal attachment without progression of pvr in 16 out of 22 patients ( 72% ) . among the remaining patients , we observed recurrent inferior pvr in 2 ( nos .
3 and 9 ) ( ratios of 70/30 and 60/40 , resp . ) and recurrent tractional rd with superior pvr in 3 ( nos . 14 , 17 , and 22 ) ( all with 30/70 ratio ) . due to her compromised general conditions 1 patient ( no .
16 ) was followed up for 14 months without f6h8/so removal : no signs of inflammation or uveitis were observed , except for the formation of mild posterior synechiae ; the retina remained attached although a pucker was observed . except for
the f6h8/so mixture was removed very easily via the pars plana , by means of manual active aspiration through a cannula , three - to - five months after surgery .
the resistance of the tamponade to aspiration was very low . at the end of the active aspiration of the mixture we left a small bubble of f6h8/so on the surface of the posterior retina , which was removed with an unprotected charles flute cannula .
no adhesion of the mixture to the surface of the retina was observed and no dispersion was noted in either the vitreous cavity or the anterior chamber . during tamponade removal in all the patients with 70/30 and 60/40 ratios
the f6h8/so was very cloudy , while in those with lower ratios it remained transparent . in 1 patient ( no .
7 ) removal of the f6h8/so mixture was associated with residual membrane peeling and gas tamponade . in 2 patients ( nos . 6 and 8) with low iop , removal of f6h8/so
was followed in the same procedure by so 1000  cst tamponade . in these 2 patients
so was not removed ; no signs of emulsification were observed after 28 and 36 months , respectively , and iop remains in the low range without clinical signs of hypotony .
2 ) with high myopia , who presented with recurrent inferior rd with inferior pvr after two sb procedures , underwent ppv with a f6h8/so tamponade ( 70/30 ratio ) . in the followup
the patient was not seen for followup in the subsequent six months ; then , 12 months after removal , he returned to us showing a significant inflammatory reaction of the eye and recurrent shallow rd with retinal ischemia .
recurrent inferior pvr underwent f6h8/so removal and ppv with pvr removal and were resubjected to tamponade with f6h8/so after flattening the retina intraoperatively with pure f6h8 ( as in the first operation with f6h8 ) . at the end of the operation a direct partial exchange with
so  cst was performed , obtaining f6h8/so ratios of 60/40 and 50/50 , respectively . in these 2 patients ,
the behavior of f6h8/so in the postoperative period was the same as described in the first procedure in terms of temporary cloudiness .
the mixture was efficacious in flattening the retina in both patients and no recurrence of pvr was observed in the follow - up period .
one ( no . 9 ) of these 2 patients with low iop after the first operation with f6h8/so showed low iop after the second operation with f6h8/so , but without clinical signs of hypotony .
3 ) and after four months in the other ( no . 9 ) ; at the end of the surgery the eye with normal preoperative iop ( no .
3 ) was left without a tamponade , while the eye with low preoperative iop ( no .
14 , 17 , and 22 ) with recurrent rd and superior pvr underwent f6h8/so removal , ppv , pvr removal , and intraoperative flattening of the retina with conventional perfluorocarbon liquid and direct complete exchange between perfluorocarbon liquid and so 1000  cst .
all of these 3 patients showed a flat retina in the followup without recurrence of pvr .
two of them ( nos . 14 and 22 ) with normal iop underwent so removal , while the other ( no . 17 ) did not undergo so removal due to low iop . in the latter patient
so is still in the eye after 12 months , without signs of emulsification and iop remains in the low range without signs of hypotony . in summary , at the end of the follow - up period the retina was attached in 21 out of 22 patients ( 17 without a tamponade , 3 with a so 1000  cst tamponade , and 1 with a f6h8/so tamponade ) .
sixteen patients ( 72% ) had va better than 20/400 . before entering the study 20 patients ( 90% ) had va below 20/400 and 2 patients ( 9% ) had va of 20/400 .
comparing preoperative to postoperative data , va was unchanged in 2 patients ( 9% ) , worse in 1 patient ( 4.5% ) , and better in 19 patients ( 86% ) .
four prefabricated mixtures of falks and so , differing in specific gravities and viscosities , are now available : oxane hd , densiron 68 , hws 463000 , and hws 453000 [ 1 , 1117 ] .
all mixtures are composed of high viscosity so , ranging from 5000 to 100000  cst [ 1 , 1117 ] .
encouraging results have been shown using all of them , although many authors have observed postoperative complications including dispersion or emulsification and intraocular inflammation [ 20 , 21 ] .
in fact , most vitreoretinal surgeons inject heavy tamponade after heavy liquid / air exchange , thus running the risk of slippage of the retinotomy edge in the case of large retinotomies . in order to avoid retinotomy slippage ,
a direct heavy liquid / heavy tamponade exchange can be performed ; however , this procedure may lead to a  contamination  of the heavy tamponade , thus increasing the risk of emulsification ,  sticky  so , and inflammatory response . due to the high viscosity ,
difficulties in heavy tamponade removal have also been reported , including the need to enlarge the sclerotomy , risk of posterior retinal damage , and collapse of the eye .
this has stimulated vitreoretinal surgeons to seek alternative and safer methods for heavy tamponade removal [ 2527 ] . before prefabricated mixtures became available , dual filling with f6h8 and
so 1000  cst was used in two selected series of patients with inferior pvr , by tognetto et al .   and rizzo et al . .
injected a mixture prepared in a syringe of 3  ml f6h8 and 7  ml polydimethylsiloxane 1000 ( the syringe was shaken for a few seconds ) , while rizzo et al .   used a sequential injection of 70% f6h8 and 30% so 1000  cst
moreover , rizzo et al .   reported the outcome of another series of patients with severe rd , including cases with inferior rd and inferior pvr , who were tamponed with a dual filling of f6h8 ( 70% ) and so 1000  cst ( 30% ) and showed good intraocular tolerance of the mixture . both tognetto et al .   and rizzo et al .
[ 23 , 28 ] chose to inject the heavy tamponade after heavy liquid - air exchange , obtaining intraoperative flattening of the retina with heavy liquid .
f6h8 was initially used as an intraoperative agent to flatten the retina and was left in the eye without so as a long - term heavy tamponade in several clinical trials .
although f6h8 has been reported as being efficacious and without side effects in intraoperative flattening of the retina , its postoperative use not combined with so has been discontinued due to the postoperative development of intraocular inflammation and emulsification in an elevated percentage of cases [ 58 ] . in the present series , as also reported by kirchhof et al .   and by roider et al .
, f6h8 was easy to inject and efficacious in all cases as an intraoperative agent to flatten the retina .
although we could not perform a direct comparison with conventional perfluorocarbon liquid , as f6h8 has a lower specific gravity than conventional perfluorocarbon liquid , it seems to require a more few minutes to obtain an appropriate flattening of the retina .
we suggest that injecting the intraoperative tamponade only after pvr removal has been completed and/or retinotomy has been performed , to avoid the risk of tamponade migration under the retina .
we did not experience any f6h8 migration under the retina and succeeded in flattening the retina in every patient .
the interface of the f6h8 bubble inside the eye is not as visible as that of conventional perfluorocarbon liquid and consequently the surgeon has to exercise caution , especially during the exchange with so . in all our patients
the f6h8/so mixture was removed very easily via the pars plana , between the third and the fifth month after surgery .
the resistance of the tamponade to aspiration was very mild , probably due to the low viscosity of the mixture .
our results are in agreement with those of tognetto et al . , who showed that a 30/70 ratio is the optimal ratio to obtain an optically clear single - bubble mixture and maintain a good tamponade effect on the inferior retina . in our series 4 of the 9 eyes with
a f6h8/so ratio of 30/70 showed a single bubble from day 1 after surgery ( no visible interface ) , no cloudiness during fundus examination , and good inferior retinal tamponing .
in almost all cases of their series with a ratio of 30/70 tognetto et al .   noted a superior meniscus between the heavy oil bubble and water .
none of the patients in our series with a 30/70 ratio showed a superior meniscus ; they showed excellent fundus visualization even in the extreme superior periphery of the retina and good inferior retinal tamponing .
safety and efficacy of the mixture were also observed in the eyes tamponed with higher ratios of f6h8/so : no inflammation / emulsification or negative effects on postoperative retinal flattening were observed .
in particular , with ratios of 70/30 and 60/40 we experienced a clouding effect after a few seconds of fundus visualization , making the followup challenging but not impossible .
the cloudiness with these quantitative ratios might be explained by micelle formation of f6h8 as a function of surfactant concentration and is possibly related to eye movements or to the patients ' exposure to cold [ 1 , 29 ] ; in our series this phenomenon seemed to be induced by light during ophthalmoscopy , perhaps due to its heating effect . in our opinion
this two - phase phenomenon , which may occur under different circumstances , is transitory , thus preventing pvr formation at the interphase . with the 50/50 and 40/60 ratios the surgeon has to wait for between two to three days and a week to visualize a single mixture during fundus examination ,
the preoperative method of vitreous volume measurement adopted in the present series to obtain the desired f6h8/so ratio is less precise if compared to the use of prefabricated mixtures with known f6h8/so ratios .
although the amount of f6h8 injected intraoperatively to fill the vitreous cavity in order to obtain retinal flattening confirmed our preoperative calculations , we believe that a small percentage of error still exists .
however , this small percentage of error ( 810% maximum ) is unlikely to have a jeopardizing effect on the final outcome . in our series ,
pvr recurrence during followup with a tamponade in the eye was observed with different quantitative ratios of f6h8 to so ( 1 with 70/30 , 1 with 60/40 , and 4 with 30/70 ) . in our opinion
this may be related to the underlying retinal disease , although it is difficult or often impossible to distinguish between problems caused by the tamponade and those associated with the complicated underlying retinal disease . with the mixture in the eye we experienced a percentage of recurrence of pvr of 27.2% , which is within the 6%35% range reported for so filled eyes [ 22 , 30 , 31 ] .
however , we may assume that an analysis limited to the subgroup of patients who underwent surgery with so for inferior rd with inferior pvr , and who were unable to maintain a face - down position in the postoperative period , would have shown a recurrence rate of more than 35% .
we experienced a final retinal reattachment rate of 95% after at least one year of followup . during the follow - up period 1 patient with a f6h8/so ratio of 70/30 developed a transient iop increase : this corresponds to 4.5% of the cases , which is lower than the 12%70% incidence reported in the literature .
five patients ( 1 of these 5 was operated on twice with f6h8 ) , 3 with ratio of 60/40 , 2 with 50/50 , and 1 with 30/70 , showed low iop , which remained low throughout followup without any clinical signs of hypotony . in 2 of these patients
three patients with a followup of 28 months , 36 months , and 12 months , respectively , still have so inside the eye .
the 5 patients with low iop represent 22.7% of our cases ; this incidence is slightly higher than the 15% hypotony rate reported in complicated rd with conventional tamponades .
it has been postulated that hypotony development might be exacerbated by a biological reaction to the heavy tamponade . as mentioned above ,
although it can not be affirmed with certainty , hypotony ( which was present in 1 of the 5 patients before entering the study ) , as well as the pvr recurrence rate observed , the transient increase in iop , the formation of posterior synechiae , and cystoid macular edema occurrence , might be related to the underlying severe retinal disease .
we did not clinically observe any obvious emulsification or dispersion in any of the cases .
our results are in substantial agreement with those of tognetto et al .   and rizzo et al .   and
might be explained by the absorption of oil bubbles into f6h8 and of f6h8 bubbles into so .
the f6h8/so removal time of between 3 and 5 months without signs of emulsification / inflammation further testifies to the intraoperative and postoperative safety of the procedure adopted .
even the patient with compromised general conditions who was followed for 14 months without f6h8/so removal did not present any signs of inflammation , uveitis , or other problems , except for the formation of a pucker .
moreover , no signs of emulsification / inflammation were observed in the 2 patients who were also subjected to f6h8/so tamponade in their second operations .
our attention has been focused on the final anatomical results ; however , if we consider the critical preoperative conditions of the eyes analyzed in our series , we can also express satisfaction with the final functional results , as 16 out of 22 patients ( 72% ) reached va better than 20/400 .
to our knowledge this sequence of surgical steps renders our technique different from the others and efficacious in avoiding possible side effects related to the intraoperative handling of the substance ( e.g. , air - heavy tamponade exchange , heavy liquid - heavy tamponade exchange , or heavy tamponade removal ) , as well as postoperative side effects .
moreover , the outcomes in the eyes of our series treated with different quantitative ratios of f6h8/silicone oil ( 70/30 , 60/40 , 50/50 , 40/30 , and 30/70 ) are presented : to the best of our knowledge , this has never previously been reported in vivo . in our opinion f6h8/pdms is a good alternative in the treatment of inferior rd with inferior pvr , especially for patients , as those of the present series , who are not able to maintain a face - down position in the postoperative period . with a mean followup of 22.63 months , our series , although limited by the relatively small number of patients and by the retrospective nature of the analysis , seems to indicate that the f6h8/so 1000  cst mixture is a safe agent for retinal flattening .
we can also say that the surgical technique adopted in our case series was found to be very simple and safe .
 
 purpose . to evaluate the effectiveness and safety of perfluorohexyloctane ( f6h8 ) for intraoperative flattening of the retina and of f6h8/silicone oil ( so ) 1000  cst as a postoperative tamponade for inferior retinal detachment with inferior proliferative vitreoretinopathy . methods . 
 this is a retrospective review of 22 patients who underwent pars plana vitrectomy using f6h8 as an intraoperative tool to flatten the retina . at the end of the surgery a direct partial exchange between f6h8 and 
 so 1000  cst was performed , tamponing the eye with different ratios of f6h8/so ( 70/30 , 60/40 , 50/50 , 40/30 , and 30/70 ) . anatomical and functional results and complications were evaluated over the follow - up period ( mean 22.63 months ) . results . 
 f6h8 was efficacious for intraoperative flattening of the retina . 
 twenty - one of the 22 patients achieved a complete retinal reattachment . 
 postoperative visual acuity ( va ) ranged from light perception to 20/70 , with 72% of patients obtaining va better than 20/400 . 
 no emulsification / inflammation was observed whatever the ratio of f6h8/so used . with higher ratios of f6h8/so ( 70/30 and 60/40 ) cloudiness of the tamponade was observed . 
 a transparent mixture was present with all the other ratios . 
 conclusions . 
 the surgical technique adopted is very simple and safe . 
 the optimal f6h8/so ratio seems to be between 50/50 and 30/70 . 
1. Introduction
2. Materials and Methods
3. Results
4. Discussion