lamellar corneal transplantation surgery allows for selective replacement of the diseased corneal endothelium [ 14 ] . descemet 's stripping endothelial keratoplasty ( dsek ) and descemet 's membrane endothelial keratoplasty ( dmek ) have been shown to have superior outcomes compared to penetrating keratoplasty in terms of postoperative astigmatism and visual function [ 5 , 6 ] . cataract surgery has been successfully combined with penetrating keratoplasty since the 1970s and became popular as the  triple procedure .  more recently , the combination of endothelial keratoplasty with cataract surgery was named the  new triple procedure  . advantages of the triple procedure include faster visual rehabilitation and no further endothelial damage induced by sequential cataract surgery . in the classic triple procedure , penetrating keratoplasty induces changes in the anterior and posterior corneal curvature with reduced predictability because of an alteration in the keratometric readings needed for intraocular lens power calculation . dsek on the other hand induces no significant changes in corneal topography and therefore the refractive outcomes after triple dsek are more predictable , although a mild postoperative hyperopic shift may be observed . in the present study , we describe a novel surgical approach of combined descemet 's stripping endothelial keratoplasty and medium incision cataract surgery ( mics ) . all surgeries were performed under retrobulbar anesthesia using a 1  :  1 mixture of 2% lignocaine and 0.5% bupivacaine . a temporal approach was used . conjunctival limbal peritomy was started with two 3  mm oblique relaxation cuts at the 7- and 11-o'clock positions ( for the right eye ) . this was followed by a 10 to 12  mm limbal peritomy ( figure 1(a ) ) . an 8  mm long , straight , partial thickness scleral incision with its center 2  mm from the limbus was made with a 2.5  mm crescent knife ( alcon surgicals , fort worth , tx , usa ) . using the crescent knife , a 4  mm long sclerocorneal tunnel was dissected from the scleral incision , extending approximately 2  mm into clear cornea ( figure 1(b ) ) . three paracentesis sites were created with a 15  slit knife at the 3- , 6- , and 12-o'clock positions ( for the right eye ) . 0.1  ml of trypan blue ( 0.6  mg / ml ) ( visionblue ; dutch ophthalmic research center , amsterdam , netherlands ) was used to stain the anterior capsule under air . a dispersive viscoelastic agent ( viscoat , alcon laboratories inc . ) a 3  mm keratome ( alcon surgicals , fort worth , tx , usa ) was introduced into the center of the tunnel , and the anterior chamber was entered . anterior capsulorhexis was performed using a pair of capsulorhexis forceps or a bent 27-gauge needle ( figure 1(c ) ) . a gentle hydrodissection was performed to loosen the attachments of the nucleus to the capsular bag . two sinskey hooks were used to dislocate the nucleus from the bag as described previously . the internal entry across the entire length of the sclerocorneal tunnel was completed with a keratome . subsequently , irrigation and aspiration were performed using a 23-gauge aspiration cannula ( duckworth & kent ltd . , the anterior chamber was filled with a cohesive viscoelastic agent ( provisc , alcon laboratories inc . ) . an intraocular lens was inserted in the capsular bag . with the ac maintainer infusion on descemet 's membrane was stripped with a reverse sinskey hook utilizing the epithelial mark as a guide ( figure 1(e ) ) . donor lenticules were prepared either manually in dsek or by microkeratome in descemet 's stripping automated endothelial keratoplasty ( dsaek ) . in dsek , the donor 's cornea was mounted in a pressurized artificial anterior chamber filled with optisol . manual dissection was initiated in the periphery with a diamond knife , which was calibrated to a desired depth . the donor lenticule was then placed endothelial side up and trephination was performed from the endothelial side . the anterior stromal cap was carefully separated from the underlying donor lenticule . for dsaek , a 5  mm sheet glide was inserted into the anterior chamber through the scleral wound ( figure 1(f ) ) . viscoelastic agent ( healon , advanced medical optics , santa ana , ca ) was placed on the surface of the glide . the donor lenticule was transferred endothelial side down onto the viscoelastic - coated sheet glide ( figure 1(g ) ) . in seven out of the eight cases , a pair of tan 's forceps ( asico , westmont , usa ) was utilized to draw the donor lenticule into the anterior chamber through the nasal paracentesis ( figure 1(h ) ) . during this maneuver , anterior chamber was maintained via the infusion line . the infusion line was removed after the graft was pulled into the anterior chamber . in one case , the donor lenticule was inserted after being taco - folded and was then unfolded inside the anterior chamber with the injection of filtered air . at the end of the surgery , the anterior chamber was filled with air for 810 minutes ( figure 1(i ) ) . the side ports were hydrated , and the main wound was sutured with interrupted 10 - 0 nylon sutures when needed . combined ek and mics surgery was performed in 8 eyes of 7 patients ( 5 females , 2 males ) with fuchs ' endothelial dystrophy and cataract . the mean age of the patients was 75.5  3.64 years ( table 1 ) . graft dislocation was seen in 1 eye requiring repositioning with intracameral sulfur hexafluoride ( 18% ) gas on the first postoperative day . quick resolution of graft rejection was achieved with intensive corticosteroids . the mean decimal best - corrected visual acuity ( snellen ) six out of 8 cases ( 75% ) achieved a best - corrected visual acuity of 0.3 at the end of 1 year . suboptimal visual acuity in 2 cases was due to radiotherapy - related optic neuropathy ( n = 1 ) and myopic maculopathy ( n = 1 ) . kraff / theoretical ( srk / t ) formula was employed for the calculation of intraocular lens power before the surgery . the mean target spherical refraction was 1.11  0.17 diopters ( myopic ) and the mean achieved spherical refraction was 1.18  0.87 diopters ( hyperopic ) resulting in a mean hyperopic shift of 2.2 diopters . consequently , the definition of a triple procedure has been expanded to include ek with cataract surgery . however , it may not be feasible to perform phacoemulsification in all cases undergoing a triple procedure due to the lack of resources ( especially in developing economies ) or expertise ( very dense mature cataracts ) or both . both phacoemulsification and small - incision cataract surgery have been shown to be safe and effective for visual rehabilitation of cataract patients . one prospective , comparative study found that although the effectiveness of mics and phacoemulsification was not significantly different , phacoemulsification was associated with higher costs . it is often difficult to perform phacoemulsification in cases with severe corneal edema , which impairs adequate intraoperative visualization . our novel approach of combined ek and mics provides an effective solution to these issues , since the approach and surgical steps are inherently complementary to each other . the highlight of this surgical technique includes the use of a large scleral tunnel fashioned temporally in order to provide easy access during the surgery . this is pertinent in chinese eyes with small palpebral fissures and shallow anterior chamber depth . in our study after cataract extraction and intraocular lens implantation , we used the same scleral tunnel to insert the donor lenticule . the use of a large scleral tunnel and an anterior chamber glide does not require folding of the graft thereby minimizing the risk of endothelial trauma . successful use of scleral tunnel during ek has been described previously using busin 's glide . however , we feel that it is challenging to introduce busin 's glide into the anterior chamber in chinese eyes that are characteristically small and have a shallow anterior chamber . hence , we have adopted the use of pull - through technique and anterior chamber sheet glide for graft insertion at our center . in the present study , this may be related to retained viscoelastic agent in the donor - host interface . although we tried to minimize the use of viscoelastic agent during the donor insertion , it is not possible to entirely eliminate the use of viscoelastic agents during ek using a sheet glide . graft dislocations after ek triple procedure have been reported to occur in 1.77% of the cases by terry et al . reported the results of ek in 118 eyes of which a combination of phacoemulsification and ek was performed in 41 eyes . overall , graft detachment was the most commonly observed complication ( 23% of eyes ) in their study . however , the authors did not specify the proportion of graft dislocations after triple procedure . although it is believed that the risk of graft dislocations is low with the use of anterior chamber maintainer thereby avoiding viscoelastic during ek surgery , a large , randomized , prospective study of ek surgery with or without the use of viscoelastic agent can verify the relative rates of tissue dislocation resulting from this single factor . in our study , bcva of 0.3 or better was achieved in 6 out of 8 cases . visual outcomes were suboptimal in 2 cases due to associated problems in the posterior segment . terry et al . reported a best spectacle corrected visual acuity of 0.5 or higher in 97% of the patients at the end of 12 months , while another study reported excellent visual outcomes ( average 20/34 ) after ek triple procedure . one of the unresolved issues is the preoperative detection of posterior segment problems especially cystoid macular edema that might affect the visual acuity outcomes in these patients . similar to conventional triple procedure , careful preoperative retinal screening ( if the corneal clarity permits an adequate view of the posterior segment ) should be performed . in the present study , the mean target preoperative spherical refraction was 1.1  diopters ( myopic ) . because early experience with ek had demonstrated a trend towards postoperative hyperopic shift in refraction of approximately 1 diopter , eyes undergoing a triple procedure in our series were actually targeted between 0.89 and 1.34 diopters preoperatively . however , only two out of eight eyes included in this study achieved plano refraction . our findings match the earlier report by covert and koenig   who reported a mean hyperopic shift of 1.13 diopters in their cases . however did not observe any significant hyperopic shift in their cases that underwent triple procedure . the hyperopic shift observed in our study may be attributed to the learning curve in terms of intraocular lens power selection during ek triple procedure at our centre . the graft thickness would be variable in our cases that underwent dsek with manual preparation of the donor lenticule . another possibility is inaccurate preoperative keratometry values in these cases due to irregular corneal surface . overall , our novel approach of combined ek and mics can be performed for patients with fuchs ' corneal dystrophy and dense cataract . further studies with large sample size , a comparative group , and long - term outcomes are desirable .
purpose . to describe the surgical technique and outcomes of combined descemet 's stripping endothelial keratoplasty and medium incision manual cataract surgery ( mics ) in chinese eyes 
 . methods . 
 surgery was performed in 8 eyes of 7 patients ( 5 females , 2 males ) . 
 primary outcomes included success of the surgery and final outcomes . results . 
 surgery was performed in patients with fuchs ' endothelial dystrophy and cataract ( mean age 75.5  3.64 years ) . 
 mics tunnel was used to insert the donor lenticule into the anterior chamber . 
 all surgeries were performed successfully . 
 graft dislocation was seen in 1 eye requiring repositioning with intracameral sulfur hexafluoride gas on the first postoperative day . 
 graft rejection was noted in one patient at the end of one year . 
 the mean decimal best - corrected visual acuity improved from 0.1  0.07 to 0.3  0.15 . 
 suboptimal visual acuity in 2 cases was due to radiotherapy - related optic neuropathy ( n = 1 ) and myopic maculopathy ( n = 1 ) . 
 the mean target spherical refraction was 1.11  0.17 diopters ( myopic ) and the mean achieved spherical refraction was 1.18  0.87 diopters ( hyperopic ) resulting in a mean hyperopic shift of 2.2 diopters . 
 conclusions . 
 the approach of combined descemet 's stripping endothelial keratoplasty and mics is a viable surgical technique for cases with endothelial dysfunction and cataract .