Advances In Vitreoretinal Surgery

JOURNAL REVIEW ADVANCES IN VITREORETINAL SURGERY DR.BHARTI AHUJA

VITRECTOMY 

Microsurgical procedure to remove some or all of the vitreous humour from the eye.

TYPES 

OPEN SKY VITRECTOMY(KASNER,1960S)-excision of damaged or diseased vitreous through a large limbal incision or a corneal wound.



CLOSED SYSTEM(MACHEMER,1970s)-Trans pars plana vitrectomy.-two port vitrectomy three port vitrectomy(current technique in use) four port vitrectomy

OCULAR ANATOMY FOR PARS PLANA

INDICATIONS OF VITRECTOMY Vitreous haemorrhage(diabetic and other causes)

 

Vitreous inflammation-noninfectious infectious(endophthalmitis)



Vitreous floaters (significant&nonsignificant)



Retinal detachment repair



Macular holes repair



Retinal scar tissue- removal(idiopathic,diabeticrelated,associated with RD)



Retained cataract fragments aftercataract surgery-removal



Dislocated lens implants –retrieval



Retinopathy of prematurity-repair



Refractory diabetic macular edema-membrane peeling and vitrectomy



Severe ocular trauma-repair and removal of intraocular foreign bodies



Indeterminate diagnosis (obtain intravitreal specimen)

PRINCIPLE OF VITRECTOMY(CLOSED ) The operation is performed through water tight incisions,so that the IOP is maintained in a suitable normal range throughout the procedure and needed amount of instruments is not restricted.  Minimum levels of suction force are used throughout the operation to avoid creating retinal breaks. 

PROCEDURE OF VITRECTOMY(CLOSED) Anaesthesia –local -peribulbar(occasionally general)  Site of incision –pars plana i.e. 3-4 mm posterior to the anterior margin of limbus(optimal location)  Size of incision-3.5 mm,(1 mm with 20 guage instruments)  Three incisions-sclerotomies/ports inferotemporal,superotemporal and superonasal ( infusion,vitreous probe and endoilluminator) 

THREE PORT CLOSED SYSTEM PARS PLANA VITRECTOMY

VITREOUS PROBES(2 TYPES) Full function(tip dia-2.2-2.5 mm )-VISC-not in use(combined infusion ,cutting and suction)-larger incision.A fiberoptic illuminationsleeve around the tip.  Divided function probes(tip dia-0.9-1.5 mm)-currently in use(smaller incision)  Modern vitreous probes-suction and cutting. pneumatic/electronic cutters QUALITIES  Higher cut rates (100-2500 cuts/min)  Lower flow rate 

ENDOSCOPES FOR VITREORETINAL SURGERY CORNEAL CONTACT LENSES  Plano concave  Self retaining  Lenses attached with infusion system  Prismatic /angulated (mainster) ILLUMINATION  19/20guage light pipe ,halogen monofilament source

ADVANTAGES OF THREE PORT VITRECTOMY(20 GUAGE) Reduced size of the instrument  Reduced weight of the instrument  Smaller incision  Better visualization 

DISADVANTAGES    

Sutured wound Ocular surface inflammation Postoperative discomfort Postoperative retinal tears(5-10%cases)

COMPLICATIONS OF VITRECTOMY        

Cataract progression Infection (endophthalmitis) Retinal tear Retinal detachment Hypotony Glaucoma Vitreous cavity hemorrhage Suprachoroidalhemorrhage

MIVS(MICROINCISIONAL VITRECTOMY SURGERY)-

EVOLUTION OF MIVS Dr,STANLEY CHANG(1993)-23 guage system.  EUGENE DE JAUN(2001)-transconjunctival 25 guage sutureless vitrectomy system  CLAUS ECKHARDT ETAL(2005)-23 guage sutureless vitrectomy system. 

CURRENT THREEPORT TECNIQUE IN MODERN VITERORETINAL SURGERY Divided system of instrumentation(1st complete divided system-ocutome ,a set of 20 guage instruments-CARL WANG,mid 1970s)  Three separate sclerotomies(ports)< 1 mm incision,i.e.23 &25 guage instruments.  Xenon light source(Cold light,near normal colour to tissues) 

ENDOSCOPES  19gaugewith 110° field  20gauge with 50° field

OPHTHALMIC ENDOSCOPIC SYSTEM UNIT

PHOTOGRAPH OF AN EYE DREPPED AND UNDERGOING A 3-PORT VITRECTOMY PROCEDURE

XENON LIGHT COMPARED WITH HALOGEN LIGHT

WIDE ANGLE FUNDUS OBSERVATION SYSTEM The BIOM noncontact system with a field of view of 70°, 90° or 110°  The EIBOS noncontact system with a field of view of 100° for 90 – diopter and 125° for 60 – diopter.  The VOLK reinverting operating lens system (ROLS); can be used to visualise upto vitreous base and ora serrata.  The AVI inverter.  The iris medical contact wide-angle system 

BIOM3

ADDITIONAL SURGICAL STEPS AS A PART OF MODERN VITREORETINAL SURGERY       

Membranectomy Fluid air exchange Air-gas exchange Silicon oil injection Photocoagulation Scleral buckling Lensectomy

THE JOURNAL OF RETINA AND VITREOUS,FEB 2009,VOL29,ISSUE2,PG225-231 NAGPAL, MANISH MS, DO, FRCS; WARTIKAR, SHARANG MS; NAGPAL, KAMAL MS Comparison of Clinical Outcomes and Wound Dynamics of Sclerotomy Ports of 20, 25, and 23 Gauge Vitrectomy Purpose: To compare the benefits, the risks and the dynamics of port closure in different gauge vitrectomy systems. Results: Vision improved from 0.048 (3/60) to 0.206 (6/24) (p = 0.0021), from 0.069 (4/60) to 0.389 (6/18) (p < 0.0001) and from 0.055 (3/60) to 0.286 (6/24) (p = 0.0010) with 20, 23, and 25-G systems, respectively. Re-bleeds occurred in 4, 1 and 4 eyes of 20, 23 and 25-G systems respectively and post-operative retinal detachment was seen in 2 cases of 20-G system. There were no cases of post-operative hypotony or endophthalmitis seen. With 23 and 25 gauge systems, significant amount of vitreous was seen blocking the inner lip of the sclerotomy ports.

CONCLUSION The small guage systems are equally and efective as 20 guage systems for noncomplicated cases of vitreous haemorrhage with faster recovery and more comfort of the patient.

Indian journal of ophthalmology,2007(vol.55 ,issue3,page 203-206) Vandana jain,dharmesh kar,s.natrajan,debraj shome,hitendra mehta,hijab mehta,Chaitra jaydev,nishikant borse . PHACOEMULSIFICATION AND PARS PLANA VITRECTOMY:A COMBINED PROCEDURE To describe the results of a combined procedure including phacoemulsification,Insertion of PCIOL,and pars plana vitrectomyin eyes with vitreoretinal pathology and coexisting cataract.

Results: In all, 65 eyes of 64 patients were included. The mean age of the patients was 50.9 years ± 17.1 (range, five to 82 years). Vitreous hemorrhage with or without retinal detachment (19 eyes, 29.2%) was the most common indication for the vitreoretinal procedure. Primary anatomical success of retina was achieved in 59 eyes (90.7%). Visual acuity improved in 48 eyes (73.8%), was unchanged in 12 eyes (18.5%) and deteriorated in five eyes (7.7%). Postoperative inflammation was significantly more in the subgroup of previously vitrectomized eyes (42%) ( P =0.014, Fisher exact test) compared to those which underwent primary vitrectomy.. CONCLUSION Combined surgery is a feasible option for patients with cataract and vitreoretinal diseases.

COMPLICATIONS WITH MIVS HIGHER INCIDENCE OF RETINAL TEARS/DETACHMENTS  ENDOPHTHALMITIS  WOUND LEAKAGE &HYPOTONY  CHOROIDAL HAEMORRHAGE &DETACHMENTS  CONJUNCTIVAL BLEBS FORMATION 

OPH SOURCE OPHTHALMOLOGY,VOL.116,ISSUE 7,PAGE 1360-65,JULY 2009, ENDOOPHTHALMITIS AFTER PARS PLANA VITRECTOMY: 25 G AND 20G COMPARISON Comparison of incidence rate of endophthalmitis after 25 guage sutureless versus 20 guage sutured vitrectomy on a large cohort of patients operated with a standardized perioperative anti-infection protocol.

Of 3372 PPV surgeries meeting inclusion and exclusion criteria, 1948 and 1424 surgeries were 20- and 25-gauge PPVs, respectively. Average age (± standard deviation) of patients was 54.6 (± 22.6) and 64.4 (± 16.5) years in the 20- and 25-gauge PPV groups, respectively (P<0.0001). Median post-PPV follow-up time was not significantly different between the 2 groups (12.5 vs 13.0 months; P = 0.69). Endophthalmitis was observed in 1 patient (0.07%; 95% confidence interval, 0%–0.21%) from the 25-gauge group and none in the 20-gauge group (P = 0.42; Fisher exact test, 2-tailed). The use of air/gas endotamponade (P<0.0001) and intravitreal triamcinolone (P<0.001) was more common in 25- versus 20gauge PPV . CONCLUSION The incidence of endophthalmitis was low in both groups,but the study was unable to show any significant difference between the incidence after 25 guage and 20 guage and thus concluded that preioperative antiinfection control may reduce the risk associated with 25 g PPV to that of 20 g PPV.

PULSED ELECTRON AVALANCHE KNIFE IN VITREORETINAL SURGERY:

:

precise,cold and tractionless dissection of tissue in liquid media.



greatly facilitate both posterior surgeries like membrane dissection and sheathotomy as well as anterior segment procedures trabeculectomy and iridectomy.

ADVANTAGES OF PEAK Sharpely defined transection &incision of epiretinal membranes.  Fine coagulation of vascularized epiretinal tissue during surgery for traction RD.  Traction free dissection of attached and elevated retina. 



Mid infra red laser based cutting in vitreoretinal surgery-to minimize the collateral damage with high cutting,minimize the liquification rates.

CONTRAINDICATIONS OF VITRECTOMY Failure to obtain appropriate informed consent  Bleeding diathesis/anticoagulation  Corneal/other opacity precluding adequate visualization  Scleromalacia or otherconditions that may prevent adequate wound healing  Suspected neoplasm as retinoblastoma[seedingorbit]  Other medical contraindication to anaesthesia/surgical procedure. 

British journal of ophthalmology 2009,93 787-90

25 GUAGE FOR PAEDIATRIC VITREORETINAL CONDITIONS. C R GONZALES,S SINGH, S D SCHWARTZ To evaluate the feasibility and safety of 25-gauge vitrectomy for various vitreoretinal indications in the paediatric population. intervention, choroidal detachment, endophthalmitis or sclerotomy related retinal breaks.

Results: 56 eyes in 49 children (16 girls and 33 boys) were included. Intraoperative unplanned events or complications included: conversion to 20-gauge vitrectomy (four), conversion of one port to a 20-gauge sclerotomy (two), suspected lens damage (one) and intraoperative bleeding from a vascular ridge (one). Postoperative complications included cataract (five), rhegmatogenous retinal detachment (four) and vitreous haemorrhage (three). The four retinal detachments were either recurrent or occurred in eyes with complex ocular pathology and were not felt to be related to the surgical technique. There were no cases of postoperative hypotony requiring intervention, choroidal detachment, endophthalmitis or sclerotomy-related retinal breaks.

25 guage vitreoretinal techniques can be used in various paediatric Vitreoretinal diseases.It actually facilitates access to small spaces of Paediatric eye.

RETINAL DETACHMENT REPAIR SCLERAL BUCKLING - a surgical procedure in which a piece of silicone plastic or sponge is sewn onto the sclera at the site of a retinal tear to push the sclera toward the retinal tear. The buckle holds the retina against the sclera until scarring seals the tear.  PNEUMATIC RETINOPEXY  VITRECTOMY- Recommended in situations like large &posterior retinal tears vitreous haemorrhage giant retinal tears advanced retinal scarring(PVR) 

SCLERAL BUCKLING Anaesthesia-local(peribulbar) preferred  Circumcorneal conjunctival incision(peritomy)-at the limbus /4mm posterior to it.  Each of the 4 recti muscles-isolate with a muscle hook,2-0 silk under the insertion  Localization of the retinal breaks  Chorioretinal adhesion-retinopexycryotherapy,diathermy,photocoagulation(laser)  Securing the scleral buckle  Drainage of subretinal fluid  closure 

CRYOPEXY/CRYOTHERAPY

POSTOPERATIVE COMPLICATIONS OF SCLERAL BUCKLING SURGERY Choroidal detachment  Elevated IOP  Cystoid macular edema  Endophthalmitis  Infection/extrusion of buckling element  Diplopia  Proliferative vitreoretinopathy  Persistent/recurrent retinal detachment 

AMERICAN JOURNAL OF OPHTHALMOLOGY,JUNE 2008 Primary Vitrectomy without Scleral Buckling for Pseudophakic Rhegmatogenous Retinal Detachment To report the anatomic and functional results of primary vitrectomy without scleral buckling for the treatment of pseudophakic rhegmatogenous retinal detachment (PsRD) Results Mean follow-up ± standard deviation (SD) was 12 ± 6.3 months (range, seven to 36 months). Mean final visual acuity ± SD was 0.42 ± 0.45 logarithm of the minimum angle of resolution (logMAR) compared with 0.95 ± 0.73 logMAR before surgery (P < .01). Mean number ± SD of retinal breaks found before surgery was 1.36 ± 1.12 (range, zero to five), and an additional 1.58 ± 2.26 (range, zero to 15) retinal breaks were found during surgery. The retina was reattached successfully after a single surgery in 92 eyes (92%). Recurrence of retinal detachment occurred in eight eyes (8%), caused by proliferative vitreoretinopathy in six eyes (75%) and by new breaks in two eyes (25%). Final anatomic reattachment was obtained in these cases after a mean of 1.75 subsequent operations.

Three eyes required permanent silicone oil tamponade so that final anatomic success was achieved in 97 eyes (97%). The most common postoperative complication was ocular hypertonia of more than 21 mm Hg, observed in 36 (36%) eyes, which was managed successfully.

CONCLUSION Primary vitrectomy was successful in terms of anatomic success without scleral buckling in patients with Ps RD associated with few complications.

JOURNAL OF RETINA ,AUG 2008 VOL 28 ISSUE 7 PG 931-936 Primary Repair of Retinal Detachment With 25-Gauge Pars Plana Vitrectomy Miller, Daniel ; Riemann, Christopher ; Foster, Robert E. ; Petersen, Michael R. To evaluate 25-gauge pars plana vitrectomy (PPV) for primary repair of rhegmatogenous retinal detachment Results: Most patients had pseudophakic RRD (36 [85.7%] of 42 eyes). The crystalline lens was present in the remaining 6 eyes (14.3%). Of 42 eyes, 28 (66.7%) had macula-on RRD, while 14 (33.3%) had macula-off RRD. Four surgeons contributed to this study, and 25-gauge PPV instrumentation, a wide-angle viewing system, endolaser photocoagulation, and gas tamponade were used in each case. The single surgery anatomical success rate was 92.9% (39 of 42 eyes). For eyes with macula-on RRD, best-corrected visual acuity was 20/50 (0.43 logMAR [logarithm of the minimum angle of resolution]) preoperatively and 20/30 (0.23 logMAR) postoperatively (P = 0.24

. For eyes with macula-off RRD, best-corrected visual acuity was 5/200 (1.56 logMAR) preoperatively and 20/30 (0.23 logMAR) postoperatively (P = 0.001). Three eyes required additional surgery for final reattachment. Final reattachment was achieved in 100% of patients (mean follow-up, 8 months).

CONCLUSION 25 guage PPV with laser retinopexy,plus gas tamponade is effective for primary repair of RRD.This single operation has got anatomical success rate comparable to vitrectomy with primary vitrectomy done with 20 guage instrumentation,scleral buckling and combined vitrectomy /scleral buckling.

PNEUMATIC RETINOPEXY 

A gas bubble is injected into the vitreous cavity which closes the tear in the retina. Subsequently laser or cryotherapy is performed to treat the edges of the tear.

BRITISH JOURNAL OF OPHTHALMOLOGY,JULY-AUG2006,VOL.9 NO.4 PNEUMATIC RETINOPEXY:SUCCESS RATE AND COMPLICATIONS A A ZAIDI,R ALVARADO,A IRVINE To evaluate the success rate and complications of pneumatic retinopexy performed at a university hospital and to identify which patients are best suited for pneumatic Retinopexy Results:33 of 61 (54%)caseswere successful with a single procedure.40 of 61(66%)Caseswere success ful with a repeat injection ofgas or laser retinopexy alone.AllCases had anatomic success at final followup.age,myopia,lens status,an dno.of breaks Were not proved to be risk factors for failure.The average duration of follow up was 15 months.

CONCLUSION PR was less effective for repair of RRD than most published reports.however, Repair by scleral buckling or pars plana vitrectomy didn’t influence the visual Acuity at final follow up.

COMPARISON SCLERAL BUCKLE 1.

More conjunctival scarring and external globe manipulation

2.

This surgery may be more difficult in very high myopes with thin sclera

3.

Cataract is less common.

4.

Extraocular muscle imbalance and induced myopia due to globe distortion.

VITRECTOMY 1.

2. 3. 4.

5.

Peribulbar anaesthesia.

6.

Small gas bubble.

5.

7.

Less demand on technology.

6. 7.

Minimal conjunctival scarring.suitable in glaucoma patients who may require subsequent trabeculectomy ,filtering surgery Longer instruments in large eyes. Risk of cataract(depending on pts age) No disturbance within the muscles and globe is not distorted. Peribulbar anaesthesia Large gas bubble High demand on technology and instrumentation

BRITISH JOURNAL OFOPHTHALMOLOGY,2008,92,148387 23 GUAGE VERSUS 20 GUAGE SYSTEM FOR PARS PLANA VITRECTOMY:A SYSTEM FOR PROSPECTIVE RANDOMISED CLINICAL TRIAL. Aim: To compare the sutureless 23-gauge system with a standard 20gauge system in pars plana vitrectomy. . Results: Conjunctival injection (p = 0.0003) and postoperative pain (p = 0.01) were significantly reduced following 23-gauge vitrectomy compared with the 20-gauge procedure. Opening (p = 0.006) and closure times (p<0.00001) were significantly shorter, and vitrectomy time (p = 0.001) significantly longer in the 23-gauge system compared with 20-gauge vitrectomy. However, retinal manipulation and overall surgery times did not differ significantly between both groups. The same applies for eye pressure, distance and reading acuity. Regarding complications, two choroidal haemorrhages and one flat serous choroidal detachment occurred in the 23-gauge group. CONCLUSION 23

guage system for Pars plana vitrectomy offers more

GRAEFE’S ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLGY,APR 2009,VOL.247,NO.4,PG495-502 WILLIAM GUALTIERI ONE PORT PLANA VITRECTOMY(25 G MICROINCISION) A pilot study to test a novel, minimal invasive vitrectomy, through oneport pars plana sclerotomy, by 25-G instruments, for selected vitreous, macular and vitreomacular interface disorders Results All OPPPVs by 25 G were completed as planned. Anatomical surgical objectives were fulfilled on all eyes; functional ones on 13 out of 14 eyes. The whole OPPPV group and four of the phaco OPPPV subset of patients tolerated comfortably less than 30′ surgical time, and three phaco OPPPV ones less than 45′. Full regimen anti-inflammatory therapy for 2 weeks kept ten eyes out of 14 stable. Post-operatively, two eyes developed a transient alteration of the intraocular pressure. At the end of the follow-up, neither retinal detachment nor endophthalmitis occurred.

CONCLUSION OPPPV by 25 G techniques promise to be an effective,comfortable, possible office-based alternative “micro-incisional, minimal invasive vitreous surgery” for selected vitreous, macula and vitreomacular interface disorders. Future research on the safety of the OPPPV by 25 G techniques compared to conventional ones is encouraged.

VITREOUS SUBSTITUTES To restore intraocular volume after drainageof subretinal fluid or vitrectomy  To hydrokinetically manipulate retina  To complement the surgical techniques employed in membrane dissection(delamination &retinotomy)  as postoperative adjunct to vitreoretinal surgery for internal tamponade. 

SUBSTANCES USED INTRAOPERATIVELY 

Balanced salt solution



Air and other gases

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Viscoelastic fluids(sodium hyaluronate,chondroitin sulfate,HPMC)

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SILICON LIQUID

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LOW VISCOSITY PFCL(PERFLUORO N OCTANE)

INTRAOCULAR GASES     

xenon Air Sulfur hexafluoride Perfluoroethane perfluoropropane

JOURNAL OF RETINA,MAY 2009,VOL29 ISSUE 5 PG 677-681 Effects of Perfluorocarbon Liquids and Silicone Oil on Human Retinal Pigment Epithelial Cells and Retinal Ganglion Cells INOUE, MAIKO MD; IRIYAMA, AYA MD; KADONOSONO, KAZUAKI MD, PhD; TAMAKI, YASUHIRO MD, PhD; YANAGI, YASUO MD, PhD To examine the effects of perfluorocarbon liquid (PFCL) and silicone oil (SO) on human retinal pigment epithelium (RPE) cells and retinal ganglion cells (RGCs) in vitro. Results: Perfluorocarbon liquid affected the survival of ARPE-19 cells and RGCs when compared with the nontreated control group. ARPE-19 cells decreased significantly after being in contact with PFCL at the baso-lateral side for 7 days. However, PFCL contact at the apical side reduced the number of RGCs in a time-dependent manner. In case of SO, the viability of the ARPE-19 cells decreased significantly after being in contact with SO at the baso-lateral side for 7 days. However, SO did not reduce the number of RGCs after a 3-day exposure.

CONCLUSION Perfluorocarbon liquid is directly toxic to ARPE-19 cells when exposed to the cells for 7 days. On the contrary, it seems that RGCs are damaged in a time-dependent manner by the more mechanical rather than toxic effects of PFCL. Silicone oil seems to exert mechanical rather than toxic effects on ARPE-19 cells. When PFCL is used as a postoperative tamponade clinically, understanding the difference in the effects will lead to more effective and safer results.

CURRENT OPINION IN OPHTHLAMOLOGY 20(3):195-199, MAY 2009 Spirn, Marc J COMPARISON OF 25,23 AND 20 GUAGE VITRECTOMY

The history and development of 25-gauge and 23-gauge vitrectomy are reviewed in this paper and compared with 20-gauge vitrectomy, the historical gold standard. Current advantages and disadvantages of each are delineated

. Recent findings: Transconjunctival sutureless vitrectomy continues to offer advantages of increased patient comfort decreased operative times and improved postoperative astigmatism. These advantages, however, must be weighed against the possibility of increased rates of postoperative hypotony and endopthalmitis.

CONCLUSION Both 25-gauge and 23-gauge instruments continue to evolve, and have improved significantly since their introductions. Most cases can now be performed using either 25-gauge or 23-gauge techniques with success rates comparable to 20-gauge. Despite these advantages, there are still cases where 20-gauge is appropriate and preferable. Clinical experience, innovations and further studies will help dictate the future course of pars plana vitrectomy instrumention

1.15 mm incision 0.55 mm

0.72mm

Requiring suture sutureless

sutureless

Inner dia =0.91mm

Inner=0.65mm Outer=0.75mm

Inner=0.57mm Outer=0.62mm

Wt(g/4mm)130g 14gm

35gm

2500 cuts/min

1500cuts/min

2500 cuts/min

Distance(tip to port)=0.43mm

0.33mm

0.23mm

Illumination(xeno 30lumens n)65 lumens

37 lumens

Increased incisional inflammation

decreased

decreased

Longer visual faster recovery period

faster

Low risk of Known risk endophthalmitis

Unknown risk

ADVANTAGES OF MIVS(23G,25G) OVER TRADITIONAL 20 G VITRECTOMY Sutureless  Self sealing incisions  Less conjunctival scarring  Less corneal astigmatism  Less operating time  Less postoperative inflammation  Rapid visual recovery  Patient comfort  Reduced incidence of vitreous prolapse(cannula system) 

LIMITATIONS OF MIVS FLEXIBILITY  LEARNING CURVE  COST 

RECENT DEVELOPMENTS Macular translocation  RPE Transplantation  Retinal cell transplantation  Retinal prosthesis  Stem cell research  Iris pigment epithelial cell transplantation  Sustained release ganciclovir implant(vitrasert)  Intravitreal drugs(dexamethasone,triamcinolone) 

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