CLINICAL SCIENCE Visul nd Antomic Outcomes of Vitrectomy With Temporry Kertoprosthesis or Endoscopy in Oculr Trum With Opque Corne Dl W. Chun, MD; Mrcus H. Colyer, MD; Keith J. Wroblewski, MD BACKGROUND AND OBJECTIVE: To exmine the outcomes of vitrectomy in oculr trum with opque corne. PATIENTS AND METHODS: This retrospective study included 17 eyes of 16 ptients who underwent vitrectomy with temporry kertoprosthesis or endoscopy t Wlter Reed Army Medicl Center, Wshington, DC, from Mrch 2003 to October 2010. RESULTS: A temporry kertoprosthesis ws used in 8 eyes (47%) nd endoscopy in 9 eyes (53%). Overll, the number of eyes with visul cuity of 20/200 or better improved from 0 t bseline to 5 (29%) t 6 INTRODUCTION months. The number of eyes with retinl detchment lso improved from 10 (59%) t bseline to 3 (18%) t 6 months. CONCLUSION: Vitrectomy my be sfely performed in oculr trum with opque corne using temporry kertoprosthesis or endoscopy with comprble outcomes. Endoscopy llows erlier dignosis nd tretment of occult pthology nd requires less time nd fewer procedures to implement thn the temporry kertoprosthesis. [Ophthlmic Surg Lsers Imging 2012;43:302-310.] Oculr trum is often complicted by cornel opcities tht my interfere with the dignosis nd mngement of posterior segment pthology. Fulborn et l. 1 reported tht the corne ws involved in 57% of severe perforting injuries in civilin popultion. The leding cuse of blindness ws retinl detchment occurring either t the time of injury or during the postopertive period. Among From Wlter Reed Ntionl Militry Medicl Center, Bethesd, Mrylnd. Originlly submitted April 13, 2012. Accepted for publiction April 22, 2012. Presented t the Americn Society of Retin Specilists Annul Meeting, August 24, 2011, Boston, Msschusetts. The uthors hve no finncil or proprietry interest in the mterils presented herein. The views expressed in the rticle re those of the uthors nd do not refl ect the officil policy of the Deprtment of the Army, Deprtment of Defense, or United Sttes Government. Address correspondence to Dl W. Chun, MD, The Retin Group of Wshington, 7501 Greenwy Center Drive, Suite 300, Greenbelt, MD 20770. E-mil: chunretin@gmil.com doi: 10.3928/15428877-20120618-09 302 COPYRIGHT SLACK INCORPORATED
TABLE 1 Review of Vitrectomy With Temporry Kertoprosthesis for Oculr Trum Author No. of Eyes Men (Medin) Follow-Up (Mo) Cler Grft t Finl Visit Retin Attched t Finl Visit Ahmdieh 17 6 33% 67% Dong 18 107 25 75% 88% Gllemore 12 11 (9) 73% 91% Grci-Vlenzuel 19 22 59% 55% Gelender 20 7 (6) 43% 43% Roters et l. 21 34 30 15% 88% Yn 22 7 28 43% 71% the injuries sustined in militry combt treted t Wlter Reed Army Medicl Center (WRAMC) from Februry 2003 to November 2005, 46% of the 79 eyes with perforting injuries hd entrnce wounds in the corne. 2 Most cornes retin dequte clrity to perform retinl surgery, but some hve severe opcities tht preclude the dignosis nd repir of posterior segment pthology. Cornel clrity my be ffected by severe stroml edem, sutures, glue, foreign bodies, nd distortion cused by lrge oversewn defects. Computed tomogrphy nd ultrsonogrphy my yield clues to the presence of pthology such s retinl detchment, introculr foreign bodies (IOFBs), or occult rupture, 3-7 but retinl ters nd detchments my still be missed. Erly intervention my prevent some lte complictions, but n lterntive intropertive viewing system my be desirble due to the incresed risk of itrogenic injury in n eye with opque corne. 8 Options include the open-sky technique, temporry kertoprosthesis, penetrting kertoplsty without temporry kertoprosthesis, or endoscopy. 9-13 The use of temporry kertoprostheses for vitrectomy in oculr trum ws described by Lnders et l. 9 in 1981. These kertoprostheses were composed of polymethylmethcrylte cylinder with threded shft to secure it to the recipient corne nd minus optic to permit posterior segment surgery without the use of dditionl lenses. The silicone temporry kertoprosthesis, described by Eckrdt in 1987, 14 is sutured to host cornel tissue nd llows improved ccess to the periphery of the posterior segment due to its shorter shft length. In the sme yer tht Lnders et l. reported on their temporry kertoprostheses, 1.7-mm smll-dimeter rigid endoscope ws described for use in vitrectomy. 10 In 1990, Volkov et l. 15 reported using flexible ophthlmic endoscope on 23 eyes for posterior segment surgery. Lter tht yer, Eguchi et l. 13 described using 20-guge video endoscope to view the fr periphery of the posterior segment nd to exmine the subretinl spce in n eye with prolifertive vitreoretinopthy (PVR) retinl detchment. In 1994, the lser ophthlmic endoscope ws reported for the tretment of PVR. 16 Severl studies hve exmined vrious temporry kertoprostheses for vitrectomy following oculr trum (Tble 1), but the ophthlmic endoscope hs not been widely dopted for this purpose despite its introduction more thn 20 yers go. The current study reports on the functionl nd ntomic outcomes of vitrectomy with either temporry kertoprosthesis or endoscopy in oculr trum with opque corne. PATIENTS AND METHODS This retrospective interventionl cse series ws conducted under reserch protocol pproved by the Institutionl Review Bord of the WRAMC Deprtment of Clinicl Investigtion by reviewing ll of the vitrectomies performed t WRAMC from Mrch 2003 to October 2010. Inclusion criteri were ge 18 yers or older, oculr trum requiring vitrectomy, nd opque corne with no introculr view. Exclusion criteri were bseline no light perception (NLP) sttus, the use of stndrd viewing techniques for ny prt of vitrectomy, nd incomplete dt. Either 7.0-mm Eckrdt temporry kertoprosthesis (Dutch Ophthlmic USA, Exeter, NH) or the Endo Optiks E2 Endoscopy System (Endo OPHTHALMIC SURGERY, LASERS & IMAGING VOL. 43, NO. 4, 2012 303
Optiks, Little Silver, NJ) ws used s the sole mens of introculr visuliztion during vitrectomy in ll of the study eyes. All of the eyes in the kertoprosthesis group were mnged conservtively to llow for cornel clering until n urgent indiction for vitrectomy such s retinl detchment ws dignosed ultrsonogrphiclly or if vitrectomy ws required for less urgent condition in the presence of nonclering corne. The endoscopic procedures were performed when ny indiction for vitrectomy ws identified without witing for cornel clering. All of the cornel procedures were performed by one of two cornel surgeons nd ll of the retinl procedures were performed by one of three retinl surgeons. The conventionl viewing systems vilble t WRAMC tht filed to provide n introculr view in ll of the study eyes included the Oculus BIOM 2 (Oculus, Inc., Lynnwood, WA) with disposble nd utoclvble reduction lenses nd the Volk Mini Qud XL (Volk Opticl, Inc., Mentor, OH) wide-ngle indirect contct lens viewing system. Dt Collection Dt obtined from trnsfer summries, inptient nd outptient medicl records, opertive reports, nd slit-lmp photogrphs nd surgicl videos were collected in Microsoft Excel 2007 spredsheet (Microsoft Corp., Redmond, WA). Oculr trum dt included the mechnism nd type of injury clssified ccording to the Oculr Trum Clssifiction. 23,24 The Oculr Trum Score ws lso clculted for ech eye. 25 Bseline dt were collected from the lst clinicl exmintion before vitrectomy nd from intropertive findings. Snellen best-corrected visul cuity (BCVA) ws converted to logrithm of the minimum ngle of resolution (LogMAR) visul cuity scores for sttisticl nlysis. Eyes for which Snellen visul cuity could not be mesured were ssigned LogMAR scores ccording to scle dpted from Holldy in which counting fingers = 2.0, hnd motions = 3.0, nd light perception = 4.0. 26 No bseline NLP eyes were included in the study, but NLP in the postopertive setting ws ssigned score of 5.0. Overll cornel opcifiction ws sufficient to preclude conventionl introculr visuliztion in ll study eyes, but the cuses of opcifiction in the centrl 4 mm of the corne were exmined to compre the degree of injury between the two groups. Dense vitreous hemorrhge ws defined s vitreous hemorrhge obscuring the posterior pole. The mcul ws considered to be involved if ny prt of the mcul ws ffected by condition or procedure. PVR ws grded ccording to the updted Retin Society clssifiction. 27 Sttisticl Anlysis The dt collection spredsheet ws exported to the IBM Sttisticl Pckge for the Socil Sciences version 18 (IBM Corp., Chicgo, IL) for nlysis. Continuous vribles were compred using the Wilcoxon rnk sum test. The Fisher exct test ws used to compre ctegoricl vribles. All reported P vlues re two sided. RESULTS Oculr Trum Dt nd Bseline Chrcteristics From Mrch 2003 to October 2010, there were 679 cses of militry nd civilin oculr trum treted t WRAMC. A totl of 194 eyes required vitreoretinl surgery, of which 98.5% were due to combt injuries from Opertion Irqi Freedom nd Opertion Enduring Freedom. Sixty-four (33.5%) of the 191 eyes injured during Opertion Irqi Freedom nd Opertion Enduring Freedom lso hd some degree of cornel injury. Seventeen eyes of 16 ptients met the criteri for inclusion in this study. Eight eyes of eight ptients underwent vitrectomy with temporry kertoprosthesis nd nine eyes of eight ptients underwent endoscopy. All of the temporry kertoprosthesis procedures were performed from Mrch 2003 to June 2008 prior to the cquisition of the endoscope. All of the endoscopic vitrectomies were performed from June 2008 to October 2010. Fifteen ptients were Americn soldiers who sustined militry combt injuries. One soldier hd bilterl posterior segment trum with opque corne. One ptient ws civilin whose filed cornel grft dehisced fter blunt injury. There were no differences with respect to the oculr trum vribles (Tble 2). The two groups were similr with respect to the mjor bseline chrcteristics between the two study groups (Tble 3); however, more retinl detchments involved the mcul in the kertoprosthesis group thn in the endoscopy group (P =.015). All of the retinl ters in both groups were subclinicl nd were dignosed intropertively. Five of the seven retinl detchments (71%) in the kertopros- 304 COPYRIGHT SLACK INCORPORATED
TABLE 2 Ptient Chrcteristics nd Oculr Trum Dt Chrcteristic Overll (n =17) Kertoprosthesis (n = 8) Endoscopy (n = 9) P Age (y) 27 ± 10 25 ± 7 28 ± 13 Right/left eyes 8/9 5/3 3/6 Mechnism of injury Combt 16 (94%) 8 (100%) 8 (89%).58 Non-combt 1 (6%) 0 (0%) 1 (11%).99 Type of injury Penetrting 1 (6%) 1 (13%) 0 (0%).47 IOFB 10 (59%) 5 (63%) 5 (56%).99 Perforting 2 (12%) 1 (13%) 1 (11%).99 Rupture 4 (24%) 1 (13%) 3 (33%).58 Zone of injury b Zone 1 9 (53%) 5 (63%) 4 (44%).64 Zone 2 3 (18%) 1 (13%) 2 (22%).99 Zone 3 5 (29%) 2 (25%) 3 (33%).99 Lcertion > 10 mm 6 (35%) 3 (38%) 3 (33%).99 Uvel prolpse 12 (71%) 5 (63%) 7 (78%).62 Oculr trum score c 70 (37 80) 65 (47 80) 70 (37 80).82 IOFB = introculr foreign body. Men ± stndrd devition. b Zone 1: corne; Zone 2: scler up to 5 mm posterior to limbus; Zone 3: posterior to Zone 2. c thesis group were dignosed preopertively using ultrsonogrphy. The remining two retinl detchments (29%) were discovered intropertively; the indictions for vitrectomy in these eyes were trumtic ctrct nd nonclering vitreous hemorrhge in one eye nd IOFB in second eye. One eye in the kertoprosthesis group underwent vitrectomy for IOFB without retinl detchment. Only one of the three retinl detchments (33%) in the endoscopy group ws dignosed preopertively. The remining two retinl detchments (66%) were dignosed intropertively during removl of trumtic ctrct nd dense vitreous hemorrhge. The indictions for vitrectomy in the remining eyes in the endoscopy group were IOFB in two eyes nd trumtic ctrct with IOFB or dense vitreous hemorrhge in four eyes. Grde C PVR occurred t similr rtes in both groups but extended posterior to the equtor in ll of the ffected eyes in the kertoprosthesis group. In the endoscopy group, grde C PVR ws found only nterior to the equtor. Surgicl Dt Both the medin number of dys from injury to vitrectomy nd the medin surgicl time were significntly shorter in the endoscopy group (Tble 4). There were no differences in the surgicl procedures performed between the two groups except for mculr membrne stripping (P =.029) nd perfluoro-n-octne use (P <.0005), which were more common in the kertoprosthesis group. All of the eyes in the kertoprosthesis group received cornel llogrft t the conclusion of vitrectomy. 3- nd 6-Month Postopertive Outcomes The visul nd ntomic outcomes were similr for the two groups t 3 nd 6 months (Tbles 5 nd 6, respectively). Six of the 17 eyes (35%) hd 20/200 or better BCVA t 3 months. The two eyes in the kertoprosthesis group with this outcome hd worse vision t 6 months due to recurrent retinl detchment in one eye nd cornel grft filure in nother. One eye OPHTHALMIC SURGERY, LASERS & IMAGING VOL. 43, NO. 4, 2012 305
TABLE 3 Bseline Preopertive Chrcteristics Chrcteristic Overll (n =17) Kertoprosthesis (n = 8) Endoscopy (n = 9) P LogMAR 4.0 (2.0 4.0) 4.0 (2.0 4.0) 4.0 (2.0 4.0).57 20/200 or better BCVA 0 (0%) 0 (0%) 0 (0%).99 Cornel opcities b 3 4+ stroml edem 17 (100%) 8 (100%) 9 (100%).99 3 4+ blood stining 5 (29%) 2 (25%) 3 (33%).99 Hze or scrring 8 (47%) 3 (38%) 5 (56%).64 Foreign bodies 7 (41%) 1 (13%) 6 (67%).05 Totl hyphem 3 (18%) 1 (13%) 2 (22%).99 Trumtic ctrct 11 (65%) 5 (63%) 6 (67%).99 Trumtic phki 4 (24%) 2 (25%) 2 (22%).99 Dense vitreous hemorrhge 10 (59%) 4 (50%) 6 (67%).64 Vitreous foreign bodies 7 (41%) 2 (25%) 5 (56%).34 Retinl foreign body dmge 6 (35%) 3 (38%) 3 (33%).99 Trumtic mculopthy 7 (41%) 4 (50%) 3 (33%).64 Trumtic optic neuropthy 4 (24%) 1 (13%) 3 (33%).58 Retinl ters 13 (76%) 7 (88%) 6 (67%).58 Retinl detchment 10 (59%) 7 (88%) 3 (33%).15 Involving mcul 7 (41%) 6 (75%) 1 (11%).015 Grde C PVR 9 (53%) 5 (63%) 4 (44%).64 Suprchoroidl hemorrhge 5 (29%) 3 (38%) 2 (22%).62 LogMAR = logrithm of the minimum ngle of resolution; BCVA = best-corrected visul cuity; PVR = prolifertive vitreoretinopthy. b Centrl 4 mm. in the kertoprosthesis group improved from 20/400 t 3 months to 20/60 t 6 months with the removl of dense lens cpsulr membrne. All of the eyes in the endoscopy group with 20/200 or better BCVA t 3 months mintined this level of vision t 6 months. The cuses of visul cuity worse thn 20/200 t 3 months in the kertoprosthesis group were filed grft with recurrent retinl detchment in two eyes nd unrelted to the corne in four eyes (mculopthy, recurrent retinl detchment, or lens cpsule opcity). In the endoscopy group, visul cuity worse thn 20/200 t 3 months ws ccounted for by cornel opcities lone in one eye, cornel opcities with mculopthy, neuropthy, or retinl detchment in three eyes, nd mculopthy lone in one eye. At 6 months, visul cuity worse thn 20/200 in the kertoprosthesis group ws ccounted for by cornel opcities lone in two eyes, cornel opcities with mculopthy, neuropthy, or retinl detchment in three eyes, nd unrelted to the corne in two eyes (mculopthy or retinl detchment). In the endoscopy group, this level of vision ws ccounted for by cornel opcities in one eye nd cornel opcities with mculopthy or neuropthy in four eyes. Only one repet penetrting kertoplsty ws performed during the study period nd this occurred before the 3-month visit. A totl of four eyes underwent repet retinl detchment repir. In the kertoprosthesis group, this ws performed fter the 3-month visit in one eye nd shortly fter the 6-month visit in nother eye. Two eyes with recurrent retinl detchment in the kertoprosthesis group were not repired due to poor visul prognosis (NLP nd bre light perception). In the endoscopy group, repet retinl detchment repirs were performed before the 3-month visit in one eye nd before the 6-month visit in nother eye. No surgicl complictions occurred in ny of the eyes during the study period. 306 COPYRIGHT SLACK INCORPORATED
TABLE 4 Surgicl Dt Chrcteristic Overll (n =17) Kertoprosthesis (n = 8) Endoscopy (n = 9) P Dys from injury 18 (7 96) 38 (11 87) 14 (7 96).034 Surgicl time in hours 3.8 (1.8 10.5) 8.4 (5.8 10.5) 2.8 (1.8 3.8) <.0005 Prs pln lensectomy 11 (65%) 5 (63%) 6 (67%).99 Membrne stripping 9 (53%) 4 (50%) 5 (56%).99 Involving mcul 4 (24%) 4 (50%) 0 (0%).029 IOFB removl 10 (59%) 3 (38%) 7 (78%).15 Relxing retinectomy 4 (24%) 2 (25%) 2 (22%).99 Perfl uoro-n-octne 9 (53%) 8 (100%) 1 (11%) <.0005 Lser or cryoretinopexy 15 (88%) 7 (88%) 8 (89%).99 Endotmponde 15 (88%) 8 (100%) 7 (78%).47 Air 2 (12%) 1 (13%) 1 (11%).99 SF 6 2 (12%) 0 (0%) 2 (22%).47 C 3 F 8 8 (47%) 6 (75%) 2 (22%).057 Silicone oil 3 (18%) 1 (13%) 2 (22%).99 Encircling buckle 5 (29%) 3 (38%) 2 (22%).62 IOFB = introculr foreign body; SF 6 = sulfur hexfl uoride; C 3 F 8 = perfl uoropropne. TABLE 5 3 Month Postopertive Outcomes Vrible Overll (n =17) Kertoprosthesis (n = 8) Endoscopy (n = 9) P LogMAR 3.0 (0.2 4.0) 3.0 (1.0 4.0) 2.0 (0.20 4.0).34 20/200 or better BCVA 6 (35%) 2 (25%) 4 (44%).62 Cornel grft filure 2 (25%) Retinl detchment 5 (29%) 4 (50%) 1 (11%).13 Involving mcul 4 (24%) 3 (38%) 1 (11%).29 LogMAR = logrithm of the minimum ngle of resolution; BCVA = best-corrected visul cuity. TABLE 6 6-Month Postopertive Outcomes Vrible Overll (n =17) Kertoprosthesis (n = 8) Endoscopy (n = 9) P LogMAR 2.0 (0.2 5.0) 3.0 (1.0 5.0) 1.3 (0.20 3.0).093 20/200 or better BCVA 5 (29%) 1 (13%) 4 (44%).29 Cornel grft filure 3 (38%) Retinl detchment 3 (18%) 3 (38%) 0 (0%).082 Involving mcul 3 (18%) 3 (38%) 0 (0%).082 LogMAR = logrithm of the minimum ngle of resolution; BCVA = best-corrected visul cuity. OPHTHALMIC SURGERY, LASERS & IMAGING VOL. 43, NO. 4, 2012 307
DISCUSSION The results of this study suggest tht vitrectomy my be sfely performed with either temporry kertoprosthesis or endoscopy in eyes with opque corne following oculr trum with comprble visul nd ntomic outcomes. Both techniques cn be used to view introculr contents while mintining closed system, which should reduce the risks ssocited with open sky vitrectomy including introculr hemorrhge, prolpse of introculr tissues, nd difficulty of globe mnipultion. 9,11,28 The mjor differences observed between the two techniques re tht endoscopy llows erlier intervention nd shorter surgicl times thn does the temporry kertoprosthesis. Erlier vitrectomy in the endoscopy group cn be ttributed to differences in the mngement options vilble with ech technique. Although the eyes in ech group sustined similr degrees of injury nd shred similr bseline chrcteristics, the decision to perform vitrectomy in the endoscopy group ws mde t the discretion of the surgeon when n indiction for vitrectomy ws identified. The eyes in the kertoprosthesis group preceded the rrivl of the endoscope t WRAMC nd were thus mnged conservtively with seril ultrsonogrphy. The decision to perform vitrectomy ws mde only fter ultrsonogrphic evidence of retinl detchment developed or if nother indiction for vitrectomy ws present in n eye with nonclering corne. Conservtive mngement of eyes without clinicl evidence of retinl detchment is generlly preferred over explortory vitrectomy with kertoprosthesis becuse opque cornes often grdully cler with time nd the risk of cornel grft filure is incresed if penetrting kertoplsty is performed during the first 2 months of oculr trum. 21 Severely injured eyes re lso more likely to require dditionl procedures or silicone oil, which my stress the donor endothelium nd ultimtely result in decompenstion or filure of the grft. 21,29,30 In our study, cornel grft filure ws observed in two eyes (25%) t 3 months nd three eyes (38%) t 6 months. These eyes my hve been ble to retin their ntive cornes if endoscopy hd been vilble t the time of their vitrectomy. If their cornes filed to cler sufficiently with time, delyed llogrfting could hve then been performed severl months lter when the eye ws quiet nd the risk of grft filure ws lower. A mjor limittion of conservtive mngement of severe eye injuries is the difficulty of ccurtely dignosing retinl ters nd detchments ultrsonogrphiclly, prticulrly in the presence of significnt vitreous hemorrhge nd orgnizing membrnes. Ltent retinl breks nd detchments my be missed due to the presence of medi opcities nd frequent nterior loction of retinl pthology. 31,32 Mny of the eyes in the endoscopy group were found to hve occult retinl ters nd detchments tht would certinly hve progressed to more extensive pthology if the eyes hd been mnged conservtively. Conversely, the pthology in the kertoprosthesis group would hve been less extensive if prompt vitrectomy could hve been performed before retinl detchment becme evident ultrsonogrphiclly. The benefit of erly intervention is reflected in the lower rtes of mculr involvement by retinl detchments nd posterior grde C PVR in the endoscopy group. Preretinl trction nd PVR re the leding cuse of surgicl filure in penetrting nd perforting injuries nd their erly removl is known to reduce lte complictions such s retinl ters nd detchments. 33-38 There is no consensus regrding the timing of vitrectomy following oculr trum, but severl studies hve reported better outcomes when surgery is performed within the first 2 weeks. 35,38-40 In our opinion, high-risk conditions predisposing to vitreoretinl trction should undergo prompt vitrectomy even in the bsence of frnk retinl detchment. Conditions for which erly vitrectomy hs been dvocted include perforting injuries, lens disruption, ciliry body epithelil dmge, dense vitreous hemorrhge, significnt vitreous loss, trctionl complictions, nd endophthlmitis. 1,28,41 IOFBs should lso be removed promptly to reduce the risk of retinl toxicity when their composition is unknown. 36 Erly IOFB removl lso prevents encpsultion, which my otherwise complicte their sfe removl. 36,42 An indirect benefit of the erly tretment of occult pthology nd the prevention of its progression is shorter surgicl time. The mngement of more extensive retinl detchments nd PVR in the kertoprosthesis group required dditionl procedures such s mculr membrne stripping nd the instilltion nd removl of perfluorocrbon liquids for intropertive tmponde nd countertrction during membrne dissection. The shorter surgicl times in the endoscopy group re lso directly relted to differences in the pro- 308 COPYRIGHT SLACK INCORPORATED
cedures required to implement ech viewing system. Wheres endoscopy ws performed through stndrd 20-guge sclerotomies nd required no dditionl time or invsive procedures to implement, the temporry kertoprosthesis required dditionl time to remove glue, revise sutures, trephinte the corne, suture nd remove the kertoprosthesis, nd grft cornel tissue t the conclusion of vitrectomy. Although such dt were not vilble for this study, dditionl time my hve been incurred witing for the cornel nd retinl surgeons to prepre for their respective procedures. Prolonged surgery nd dditionl invsive procedures my be ssocited with higher operting costs nd incresed risk of surgicl nd nesthetic complictions. The ese of creting surgicl ccess for endoscopy nd its bility to be employed shortly fter oculr trum lso llows it to be used for dignostic purposes in cses where the vibility of the retin or optic nerve re uncertin. With endoscopy, these structures my be exmined directly nd help guide decisions for dditionl intervention. 10 Direct exmintion of nterior structures lso llows the tretment of fr peripherl pthology such s cyclitic membrnes nd nterior loop trction without requiring sclerl depression or globe mnipultion. 13,43 This is prticulrly helpful in severe oculr trum where closed but frible wounds nd suprchoroidl hemorrhge my be excerbted by excessive globe mnipultion. The smller incisions required for endoscopy should lso further reduce the risk of hemorrhgic complictions nd prolpse of introculr contents compred to those of the temporry kertoprosthesis. The limittions of endoscopy re relted to its inferior imge qulity, chnging introculr perspective, nd steep initil lerning curve. Video imges obtined through smll-guge endoscopy probes re inherently of low resolution. The bsence of stereopsis nd the dynmic introculr perspective nd field of view my be disorienting, prticulrly in n eye with dense vitreous hemorrhge or disorgnized introculr contents. Complex bimnul surgery, which my be required in cses of extensive PVR, is lso difficult to perform with endoscopy. Other fctors include the cost of the endoscopy system nd its probes, which hve limited lifespn. In summry, vitrectomy my be performed sfely in eyes with opque corne following oculr trum either with temporry kertoprosthesis or endoscopy with similr visul nd ntomic outcomes. Endoscopic vitrectomy requires less surgicl time to use nd fcilittes the erly dignosis nd tretment of occult retinl ters nd detchments. For these resons, endoscopy should be considered for use in most cses of oculr trum with opque corne nd the temporry kertoprosthesis should be reserved for use in cses requiring extensive bimnul surgery or for delyed vitrectomy when the risk of grft filure is lower in eyes t low risk of hrboring occult retinl ters or detchments. The limittions of this study re its smll smple size, its retrospective nture, nd the difficulty of controlling for the complexities of oculr trum. Additionl investigtion compring both techniques is required to vlidte the findings of this study. A rndomized, prospective, multicenter tril compring the two viewing systems my provide dditionl insight into the reltive strengths nd weknesses of ech nd whether the findings of this study cn lso be generlized to nontrumtic cses. REFERENCES 1. Fulborn J, Atkinson A, Olivier D. Primry vitrectomy s preventive surgicl procedure in the tretment of severely injured eyes. Br J Ophthlmol. 1977;61:202-208. 2. Colyer MH, Weber ED, Weichel ED, et l. Delyed introculr foreign body removl without endophthlmitis during Opertions Irqi Freedom nd Enduring Freedom. Ophthlmology. 2007;114:1439-1447. 3. Rubsmen PE, Cousins SW, Winwrd KE, Byrne SF. Dignostic ultrsound nd prs pln vitrectomy in penetrting oculr trum. Ophthlmology. 1994;101:809-814. 4. Krmer M, Hrt L, Miller JW. Ultrsonogrphy in the mngement of penetrting oculr trum. Int Ophthlmol Clin. 1995;35:181-192. 5. Joseph DP, Piermici DJ, Beuchmp NJ Jr. Computed tomogrphy in the dignosis nd prognosis of open-globe injuries. Ophthlmology. 2000;107:1899-1906. 6. Dss AB, Ferrone PJ, Chu YR, Esposito M, Gry L. Sensitivity of spirl computed tomogrphy scnning for detecting introculr foreign bodies. Ophthlmology. 2001;108:2326-2328. 7. Sevel D, Krusz H, Ponder T, Centeno R. Vlue of computed tomogrphy for the dignosis of ruptured eye. J Comput Assist Tomogr. 1983;7:870-875. 8. McCuen BW, Fung WE. The role of vitrectomy instrumenttion in the tretment of severe trumtic hyphem. Am J Ophthlmol. 1979;88:930-934. 9. Lnders MB 3rd, Foulks GN, Lnders DM, Hickingbothm D, Hmilton RC. Temporry kertoprosthesis for use during prs pln vitrectomy. Am J Ophthlmol. 1981;91:615-619. 10. Norris JL, Clesby GW, Nknishi AS, Mrtin LJ. Introculr endoscopic surgery. Am J Ophthlmol. 1981;91:603-606. 11. Hirose T, Schepens CL, Lopnsri C. Subtotl open-sky vitrectomy for severe retinl detchment occurring s lte compliction of oculr trum. Ophthlmology. 1981;88:1-9. 12. Gllemore RP, Bokosky JE. Penetrting kertoplsty with vitreoretinl surgery using the Eckrdt temporry kertoprosthesis: modified technique llowing use of lrger cornel grfts. Corne. 1995;14:33-38. 13. Eguchi S, Arie M. A new ophthlmic electronic videoendoscope system for introculr surgery. Arch Ophthlmol. 1990;108:1778-1781. OPHTHALMIC SURGERY, LASERS & IMAGING VOL. 43, NO. 4, 2012 309
14. Eckrdt C. A new temporry kertoprosthesis for prs pln vitrectomy. Retin. 1987;7:34-37. 15. Volkov VV, Dnilov AV, Vssin LN, Frolov YA. Flexible endoscopes: ophthlmoendoscopic techniques nd cse reports. Arch Ophthlmol. 1990;108:956-957. 16. Urm M. Lser endoscope in the mngement of prolifertive vitreoretinopthy. Ophthlmology. 1994;101:1404-1408. 17. Ahmdieh H, Soheilin M, Sjjdi H, Azrmin M, Abrishmi M. Vitrectomy in oculr trum. Fctors influencing finl visul outcome. Retin. 1993;13:107-113. 18. Dong X, Wng W, Xie L, Chiu AM. Long-term outcome of combined penetrting kertoplsty nd vitreoretinl surgery using temporry kertoprosthesis. Eye (Lond). 2006;20:59-63. 19. Grci-Vlenzuel E, Blir NP, Shpiro MJ et l. Outcome of vitreoretinl surgery nd penetrting kertoplsty using temporry kertoprosthesis. Retin. 1999;19:424-429. 20. Gelender H, Viser A, Snyder WB, Fuller DG, Hutton WL. Temporry kertoprosthesis for combined penetrting kertoplsty, prs pln vitrectomy, nd repir of retinl detchment. Ophthlmology. 1988;95:897-901. 21. Roters S, Szurmn P, Hermes S, Thumnn G, Brtz-Schmidt KU, Kirchhof B. Outcome of combined penetrting kertoplsty with vitreoretinl surgery for mngement of severe oculr injuries. Retin. 2003;23:48-56. 22. Yn H, Cui J, Zhng J, Chen S, Xu Y. Penetrting kertoplsty combined with vitreoretinl surgery for severe oculr injury with blood-stined corne nd no light perception. Ophthlmologic. 2006;220:186-189. 23. Kuhn F, Morris R, Witherspoon CD, Heimnn K, Jeffers JB, Treister G. A stndrdized clssifiction of oculr trum. Ophthlmology. 1996;103:240-243. 24. Piermici DJ, Sternberg P Jr, Aberg TM Sr, et l. A system for clssifying mechnicl injuries of the eye (globe). The Oculr Trum Clssifiction Group. Am J Ophthlmol. 1997;123:820-831. 25. Kuhn F, Misik R, Mnn L, Mester V, Morris R, Witherspoon CD. The Oculr Trum Score (OTS). Ophthlmol Clin North Am. 2002;15:163-165. 26. Holldy JT. Proper method for clculting verge visul cuity. J Refrct Surg. 1997;13:388-391. 27. Mchemer R, Aberg TM, Freemn HM, Irvine AR, Len JS, Michels RM. An updted clssifiction of retinl detchment with prolifertive vitreoretinopthy. Am J Ophthlmol. 1991;112:159-165. 28. Conwy BP, Michels RG. Vitrectomy techniques in the mngement of selected penetrting oculr injuries. Ophthlmology. 1978;85:560-583. 29. Spiegel D, Nsemnn J, Nwrocki J, Gbel VP. Severe oculr trum mnged with primry prs pln vitrectomy nd silicone oil. Retin. 1997;17:275-285. 30. Roters S, Hmzei P, Szurmn P, et l. Combined penetrting kertoplsty nd vitreoretinl surgery with silicone oil: 1-yer follow-up. Grefes Arch Clin Exp Ophthlmol. 2003;241:24-33. 31. Cox MS, Schepens CL, Freemn HM. Retinl detchment due to oculr contusion. Arch Ophthlmol. 1966;76:678-685. 32. Johnston PB. Trumtic retinl detchment. Br J Ophthlmol. 1991;75:18-21. 33. Abrms GW, Topping TM, Mchemer R. Vitrectomy for injury: the effect on introculr prolifertion following perfortion of the posterior segment of the rbbit eye. Arch Ophthlmol. 1979;97:743-748. 34. Benson WE, Mchemer R. Severe perforting injuries treted with prs pln vitrectomy. Am J Ophthlmol. 1976;81:728-732. 35. Brinton GS, Aberg TM, Reeser FH, Topping TM, Abrms GW. Surgicl results in oculr trum involving the posterior segment. Am J Ophthlmol. 1982;93:271-278. 36. Michels RG. Surgicl mngement of nonmgnetic introculr foreign bodies. Arch Ophthlmol. 1975;93:1003-1006. 37. Cox MS, Freemn HM. Retinl detchment due to oculr penetrtion: I. Clinicl chrcteristics nd surgicl results. Arch Ophthlmol. 1978;96:1354-1361. 38. Ryn SJ, Allen AW. Prs pln vitrectomy in oculr trum. Am J Ophthlmol. 1979;88:483-491. 39. Meredith TA, Gordon PA. Prs pln vitrectomy for severe penetrting injury with posterior segment involvement. Am J Ophthlmol. 1987;103:549-554. 40. Cupples HP, Whitmore PV, Wertz FD 3rd, Mzur DO. Oculr trum treted by vitreous surgery. Retin. 1983;3:103-107. 41. Coles WH, Hik GM. Vitrectomy in introculr trum: its rtionle nd its indictions nd limittions. Arch Ophthlmol. 1972;87:621-628. 42. Hutton WL, Snyder WB, Viser A. Surgicl removl of nonmgnetic foreign bodies. Am J Ophthlmol. 1975;80:838-843. 43. Fude F, Wiedemnn P. Vitreoretinl endoscope for the ssessment of the peripherl retin nd the ciliry body fter lrge retinectomies in severe nterior PVR. Int Ophthlmol. 2004;25:53-56. 310 COPYRIGHT SLACK INCORPORATED