|Year : 2009 | Volume
| Issue : 1 | Page : 79-82
Small incision cataract surgery: Review of journal abstracts
Rajesh Sinha, Prakashchand Agarwal, Chandrashekhar Kumar
R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
|Date of Web Publication||12-Dec-2008|
492, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sinha R, Agarwal P, Kumar C. Small incision cataract surgery: Review of journal abstracts. Indian J Ophthalmol 2009;57:79-82
|How to cite this URL:|
Sinha R, Agarwal P, Kumar C. Small incision cataract surgery: Review of journal abstracts. Indian J Ophthalmol [serial online] 2009 [cited 2020 May 27];57:79-82. Available from: http://www.ijo.in/text.asp?2009/57/1/79/44513
Phacoemulsification is the preferred technique for cataract surgery in developed countries, and also to some extent in the developing countries. An alternative surgical technique, manual sutureless small incision extracapsular cataract surgery, has been gaining popularity, as the technique has been shown to yield comparable surgical outcomes as phacoemulsification. Both phacoemulsification and manual small incision cataract surgery (MSICS) achieve excellent visual outcomes with low complication rates, but MSICS is less expensive and requires less technology; hence, preferred by many surgeons in the developing countries.
| Anesthesia|| |
MSICS can be performed under retrobulbar, peribulbar, sub-tenon and topical anesthesia.
Parkar et al . ( Indian J Ophthalmol. 2005;53(4):255-9 ) compared the use of subtenon anaesthesia and peribulbar anaesthesia in MSICS and found no difference in results. About 64.8% patients of the peribulbar group had absolute akinesia during surgery as compared to none (0%) in sub-tenon group. There was no difference in the final visual acuity and the intraoperative and postoperative complications except that the subtenon group had slightly greater incidence of sub-conjunctival hemorrhage.
Bellucci et al . ( Dev Ophthalmol. 2002;34:1-12 ) described the use of topical anesthesia for small incision cataract surgery (SICS).
Kaderli et al . ( Ophthalmic Surg Lasers and Imaging 2004;35(6):460-4 ) successfully performed MSICS using deep topical anesthesia with 4% lidocaine in 326 eyes. They found that the cauterization of the scleral vessels and conjunctiva, and the subconjunctival injection were the stages causing severe pain. The most frequent intraoperative complication was posterior capsular rupture that was seen in 6 eyes (1.8%).
| Indications|| |
SICS can be done in immature, mature, and hypermature cataracts. It has also been done is cases of phacolytic glaucoma and can be combined with trabeculectomy surgeries. Manual SICS is safe in presence of corneal opacity in expert hands.
Venkatesh et al . ( Indian J Ophthalmol. 2005;53(3):173-6 ) performed MSICS in white cataracts with the use of trypan blue as an adjunct for performing continuous curvilinear capsulorrhexis (CCC). They reported that MSICS is a safe and efficacious alternative for white cataracts especially with the adjunctive use of trypan blue dye.
Venkatesh et al . ( Eye 2008 Jun 20 [Epub ahead of print] ) in their study reported good results of MSICS in brunescent and black cataracts.
Venkatesh et al . ( Br J Ophthalmol. 2007;91(3):279-81 ) in another study noted good success rate of MSICS in 33 cases of phacolytic glaucoma.
Titiyal et al . ( Eye 2006;20(3):386-8 ) successfully performed dye-assisted SICS in 12 eyes of 12 patients with cataract and coexisting corneal opacity. The best corrected visual acuity (BCVA) was ≤ 3/60 preoperatively in all the eyes and at 6 weeks postoperatively, this improved to ≥ 6/36 in all the eyes of which 4 eyes had BCVA of ≥ 6/18. In all the eyes, the procedure could be performed successfully and without any complication.
In a retrospective study, Thomas et al . ( J Glaucoma 2003;12(4):333-9 ) compared results of filtration surgery combined with either phacoemulsification or the Blumenthal technique of MSICS and reported equivocal results with both procedures. Thus it was concluded that SICS can be combined with filtration surgery as a 'Triple' procedure.
| Technique of Incision|| |
The scleral tunnel incision in cataract surgery was introduced in the early eighties in an attempt to provide better wound healing with less surgically induced astigmatism. The length of the incision varies from 5 to 8 mm; however it is still called small incision cataract surgery since the architectural design renders sutureless, self sealing property to the incision.
Although, Richard Kratz was the first surgeon to change the cataract incision from limbus to the sclera to produce enhanced wound healing and less astigmatism, Girard and Hoffman ( Am J Ophthalmol 1984;97:450-56 ) were the pioneer to name this posterior incision as Scleral Tunnel Incision.
Singer ( J Cataract Refract Surg. 1991;17 Suppl:677-88 ) described the 'Frown incision' which was a modified pocket incision, curved opposite to limbus. In a series of 62 eyes, he performed postoperative vector analysis calculation of mean induced keratometric astigmatism for the frown incision group versus the scleral pocket incision group. It was 0.80 D versus 1.19 D ( P = 0.02) at day 1; 0.74 D versus 1.03 D ( P = 0.05) at one week; 0.71 D versus 1.07 D ( P = 0.005) at four weeks; 0.84 D versus 1.15 D ( P = 0.007) at six months; and 0.82 D versus 1.30 D ( P = 0.01) at one year. The frown incision group consistently had a lower standard deviation from the mean induced astigmatism than the scleral pocket incision group.
Gokhale et al . ( Indian J Ophthalmol. 2005;53(3):201-3 ) compared the induced astigmatism with various positions of scleral incision (superior, supero-temporal and temporal incision) in MSICS. The study found that induced astigmatism was lower in the temporal and superotemporal groups compared to that in the superior group.
Gayton ( J Cataract Refract Surg. 1996;22(10):1485-91 ) in his study suggested temporal incision for cataract surgery in patients with superior glaucoma filtering blebs.
| Techniques of Nucleus Delivery|| |
Corydon and Thim ( J Cataract Refract Surg. 1991;17(5):628-32 ) explained the concept of hydro- and viscoexpression of the nucleus with the help of specially designed bent cannula for nucleus delivery through a continuous circular capsulorrhexis.
Thim et al . ( J Cataract Refract Surg. 1993;19(2):209-12. ) evaluated the technique of nucleus delivery with visco and hydroexpression in cadaver eyes and concluded that viscoexpression is a safer and easier technique of nucleus delivery. He stressed the need of a large anterior capsular opening for the same.
Bellucci et al . ( Ophthalmic Surg. 1994;25(7):432-7 ) in their study of 142 eyes concluded that viscoexpression of the nucleus through a large (7.0mm) capsulorrhexis is the best method of surgery. Nuclear viscoexpression was successful in 93% cases, with low postoperative inflammation.
Korynta ( Cesk Slov Oftalmol. 1996;52(3):179-84 ) performed viscoexpression in 369 eyes and reported complications in 8.1% cases. Relaxing capsular incision was required in 17.1% cases. The most frequent complication in cases without relaxing incision (82.9%) was asymmetric implantation of IOL (sulcus-bag, 2.6%). In cases with relaxing incision (17.1%) the most frequent complication was posterior capsule rupture with subsequent anterior vitrectomy (7.9% from total of 17.1%).
Burton and Pickering ( J Cataract Refract Surg. 1995;21(3):297-301 ) performed SICS using a limbal incision and delivered nucleus successfully by viscoexpression in 87.7% of eyes (n = 162). There were five cases of zonular dehiscence, one of posterior capsular rupture, and two of vitreous prolapse.
Brierley ( J Cataract Refract Surg. 1993;19(5):666-7 ) in his study reported that hydroexpression of the nucleus can be successfully performed while performing SICS.
Friedburg ( Klin Monatsbl Augenheilkd. 1993;202(4):288-91 ) described the technique of "Viscosurgically Assisted Hydro-Jet Irrigation of Lens Nucleus" in 100 eyes . A bent cannula was used to create a jet stream of fluid separating the nucleus from the cortex and pressing the nucleus out of the bag.
Bayramlar et al . ( J Cataract Refract Surg. 1999;25(3):312-5 ) performed SICS in 37 eyes using the sandwich technique. After capsulorrhexis, hydrodissection, and hydrodelineation, the endonucleus was moved into the anterior chamber and extracted by sandwiching it between the irrigating vectis and iris spatula. Complications were posterior capsule rupture, vitreous loss, and transient corneal edema.
Modified Fish Hook technique
Hennig et al . ( Br J Ophthalmol. 2003;87(3):266-70 ) reported data of 500 eyes in which SICS was performed with nucleus delivery using the fish hook technique. The technique involved sclerocorneal tunnel, capsulotomy, hydrodissection, nucleus extraction with a bent needle tip hook, and posterior chamber intraocular lens (PC-IOL) implantation. The best corrected visual acuity was 6/18 or better in 96.2% of eyes at 6 weeks and in 95.9% at 1 year. The mean duration of surgery was 4 minutes. Intraoperative complications included 47 (9.4%) eyes with hyphaema, and one eye (0.2%) with posterior capsular tear and vitreous prolapse in the anterior chamber. Six weeks postoperatively, 85.5% of eyes had against the rule astigmatism, with a mean induced cylinder of 1.41 D (SD 0.8).
Use of anterior chamber maintainer (ACM)
Blumenthal and Moisseiev ( J Cataract Refract Surg. 1987;13(2):204-6) described the use of an instrument for maintaining a deep anterior chamber during the surgery. They observed that the anterior chamber maintainer (ACM) keeps the pressure in the anterior chamber at uniform levels during various maneuvers, thus making the technique safer and easier to perform.
Blumenthal ( Klin Monatsbl Augenheilkd. 1994;205(5):266-70 ) propagated the use of continuous positive pressure in the anterior chamber using the ACM with good surgical results.
Chawla and Adams ( J Cataract Refract Surg. 1996;22(2):172-7 ) used the ACM in cataract surgery in 258 eyes. They reported that use of ACM increased surgical control of the anterior chamber depth and maintained the position of the posterior capsule during surgery. They concluded that ACM may offer increased safety during anterior segment surgery and requires less use of viscoelastic agents.
Wright et al . ( Br J Ophthalmol. 1999;83(1):71-5 ) reported the results of a prospective clinical trial of 46 eyes in 46 patients undergoing cataract surgery using the ACM without viscoelastic. Postoperatively, 70% of patients had unaided visual acuity of 6/12 or better at 3 months follow up. The mean central and superior endothelial cell losses at 12 months after surgery were 20% and 25% respectively.
Sharma et al . ( Eye. 2000;14 (Pt 4):646-50 ) also reported good results of SICS with intraocular lens implantation using ACM.
Nishi ( Ophthalmic Surg. 1986;17(1):47-9 ) described the use of an irrigating cannula for lens nucleus delivery by extracapsular extraction . It consists of a 20-gauge needle and a flat insertion plate with a flow outlet. The apex, with the flow outlet, is inserted beneath the nucleus during continuous irrigation; the nucleus is thus expelled by the irrigating solution.
Manual phaco - fracture
Bartov et al . ( J Cataract Refract Surg. 1998;24(2):160-5 ) described a technique for planned manual extracapsular cataract extraction (ECCE) incorporating a modification of mini-nuc ECCE in which the scleral tunnel is made wide enough to allow a nucleus of any size to settle in the tunnel. A 5.0 mm, inverted-V chevron incision is made in which the exposed part of the nucleus lodged in the scleral pocket can be manually picked and fragmented until it is small enough to be removed through the incision. Vector analysis of preoperative and 3 month postoperative keratometric astigmatism in 30 patients showed that the surgically induced vector was 0.54 diopter (D) ± 0.58 (SD). Mean reduction in astigmatism was 0.08 ± 0.39 D.
Kansas and Sax ( J Cataract Refract Surg. 1988;14(3):328-30 ) described a new technique in which the lens nucleus is manually split into pieces using Kansas trisector and Kansas vectis, and the fragments are then visco-expressed through a smaller incision.
Hepsen et al . ( J Cataract Refract Surg. 2000;26(7):1048-51 ) performed SICS by manual phacotrisection technique in 59 eyes of 54 patients. After capsulorrhexis and hydrodissection were performed, the endonucleus was prolapsed into the anterior chamber and trisected using an anteriorly positioned triangular trisector and posteriorly placed solid vectis. Postoperatively, best spectacle-corrected visual acuity of 20/40 or better was achieved in 48 eyes (83%) and of 20/25 or better in 28 eyes (47%). The most frequent intraoperative complication was posterior capsular rupture (n = 5). The most significant postoperative complication was transient corneal edema, which developed in 32 eyes (54%). No permanent complications (e.g., corneal endothelial decompensation) occurred in any case.
Two sinskey method
Rao and Lam ( Indian J Ophthalmol. 2005;53(3):214-5 ) described a simple technique using two Sinskey hooks for nucleus extraction from the capsular bag in MSICS. The two Sinskey hooks are introduced through separate paracentesis entry. The left sided hook is slipped under the capsulorrhexis and it engages the nucleus, rotates it, and lifts it at the superior pole towards the wound. The second hook held in the right hand is placed underneath the elevated superior pole of the nucleus to keep it above the margin of the capsulorrhexis, and to prevent it from falling back into the bag when the first hook is retracted.
| Results|| |
Gogate et al . ( Br J Ophthalmol. 2003;87(6):667-72 ) performed a randomized controlled trial to compare the results of ECCE and SICS in 706 eyes. In 135 of 362 (37.3%) eyes that underwent ECCE and in 165 of 344 (47.9%) eyes undergoing MSICS, the uncorrected visual acuity was 6/18 or better at 6 weeks follow up. Both the surgeries were found to be safe and effective for treatment of cataract patients in community eye care settings. They noted that MSICS needs similar equipments as ECCE, but gives better uncorrected vision.
Das et al . ( Kathmandu Univ Med J. 2005;3(4):340-4 ) studied the pattern of intraocular pressure changes following MSICS and noted that sutureless MSICS had lower IOP than those with sutures at the initial post operative period.
Bayramlar et al . ( Can J Ophthalmol. 2007;42(1):46-50 ) reported increased intraoperative posterior capsular complications following MSICS in eyes with pseudoexfoliation syndrome.
Gogate et al . ( Ophthalmology 2007;114(5):965-8 ) reported that MSICS is almost as effective as phacoemulsification, but less expensive.
Kissner et al . ( J Refract Surg. 2006;22(9 Suppl):S1079-82 ) studied corneal aberrations before and after corneal and corneoscleral incisions in SICS and concluded that both the incisions induce higher order aberrations.
Bradfield et al . ( J Cataract Refract Surg. 2004;30(9):1948-52 ) studied astigmatism in children after small-incision clear corneal cataract extraction and intraocular lens implantation. The mean postoperative retinoscopic cylinder in all patients was 0.63 diopter (D) (range: 0.0 to 4.50 D) at 1 month, 0.40 D (range: 0.0 to 1.75 D) at 6 months, and 0.51 D (range: 0.0 to 2.50 D) at 1 year.
Morikubo et al . ( Arch Ophthalmol. 2004;122(7):966-9 ) studied corneal changes after SICS in patients with diabetes mellitus. The study showed more damage to corneal endothelial cells due to cataract surgery and a delay in the postoperative resolution of corneal edema in diabetic patients as compared to non-diabetics.
Manual SICS vs Phacoemulsification
Sitompul et al . ( Cornea. 2008;27 Suppl 1:S13-8 ) described corneal sensitivity changes caused by different incision methods in MSICS and phacoemulsification and their influence on tear film quantity and quality. They did a prospective observational study in 30 subjects undergoing MSICS or phacoemulsification. Corneal sensitivity was assessed by Cochet-Bonnet esthesiometer. Tear meniscus, noninvasive breakup time, lipid pattern, and Schirmer test results were also evaluated. Patient symptoms were reviewed based on the Ocular Surface Disease Index. In the group undergoing phacoemulsification, corneal sensation was found to be decreased at the incision site and at other sites on days 1, 7, and 15 after surgery, whereas in the group undergoing MSICS, no change in corneal sensation was noted. Tear meniscus and tear lipid profile showed no change in either group.
Reddy et al . ( Ann Ophthalmol (Skokie) 2007;39(3):209-16 ) compared the astigmatism induced by superior and temporal incisions in manual SICS, and compared the astigmatism induced by clear corneal incision versus scleral tunnel in phacoemulsification surgery. A total of 64 eyes of 64 patients (34 male/ 30 female) with a mean age of 62.10 years (range 45-82 years) were included in the study. They found a significant against the rule shift in astigmatism in the phacoemulsification group and the manual SICS superior incision group. The manual SICS group with temporal incision had with-the-rule shift in astigmatism. At 90 days, conventional SICS superior incisions showed 1.92 ± 0.53 D of against the rule astigmatism and temporal incisions showed 1.57 ± 0.24 D of with the rule astigmatism. Phacoemulsification with clear corneal incisions and scleral pocket showed 1.08 ± 0.36 D and 1.23 ± 0.71 D of astigmatism respectively.
Ruit et al . ( Am J Ophthalmol. 2007;143(1):32-38 ) compared the efficacy and visual results of phacoemulsification vs MSICS for the treatment of cataracts. They compared cases on parameters like operative time, surgical complications, uncorrected visual acuity (UCVA), BCVA, astigmatism, and central corneal thickness (CCT). They found that both the surgical techniques achieved excellent surgical outcomes with low complication rates. At six months, 89% of the SICS patients had UCVA of 20/60 or better and 98% had a BCVA of 20/60 or better vs 85% of patients with UCVA of 20/60 or better and 98% of patients with BCVA of 20/60 or better at six months in the phaco group ( P = 0.30). Surgical time for SICS was much shorter than that for phacoemulsification ( P < .0001). They concluded that SICS is a more appropriate surgical procedure for the treatment of advanced cataracts in the developing world.
George et al . ( Ophthalmic Epidemiol. 2005;12(5):293-7 ) compared endothelial cell loss and surgically induced astigmatism (SIA) following conventional ECCE, MSICS and phacoemulsification (PE) in 186 eyes with nuclear sclerosis of grade 3 or less. Mean endothelial cell loss was similar in all the three groups ( P = 0.855); ECCE induced a loss of 4.72% (SD: 13.07); SICS 4.21% (SD: 10.29) and PE 5.41% (SD: 10.99). Mean SIA was 1.77D (1.61D) in the ECCE group, 1.17D (0.95D) in the SICS group and 0.77D (0.65D) in the PE group ( P = 0.001). PE induced less astigmatism than SICS and ECCE.
Gogate et al . ( Ophthalmology 2005;112(5):869-74 ) compared the efficacy, safety, and astigmatic change after cataract surgery by phacoemulsification and MSICS. The intraoperative and postoperative complications, UCVA, BCVA, and astigmatism were recorded at 1 and 6 weeks postoperatively. They found that 68.2% patients in the phacoemulsification group and 61.25% patients in the SICS group had UCVA better than or equal to 6/18 at 1 week. At 6 weeks follow up, 81.08% patients in the phacoemulsification group and 71.1% patients in the SICS group had UCVA of better than or equal to 6/18. They concluded that both phacoemulsification and SICS are safe and effective for visual rehabilitation of cataract patients, although phacoemulsification gives better UCVA in a larger proportion of patients at 6 weeks.
Gogate et al . ( Ophthalmology. 2008;115(1):211-2 ) in another study, compared the cost of phacoemulsification with foldable lens with that of MSICS in a hospital setting. The average cost of a phacoemulsification surgery for the hospital was Indian rupees (Rs) 1978.89 ($42.10), and the average cost of a SICS surgery was Rs 720.99 ($15.34), of which Rs 500.99 ($10.65) was the fixed-facility cost common to both. They found that MSICS is far more economical than phacoemulsification.
Thomas et al . ( J Glaucoma 2003;12(4):333-9 ) compared results of filtration surgery combined with either phacoemulsification or the Blumenthal technique of MSICS in 150 patients and intraocular pressure (IOP) reduction and achievement of target IOP were evaluated for 6 months. At 6 months, target IOP was achieved in 75.6% of the PE group and 73% of the Blumenthal group. There was no significant difference in IOP reduction or achievement of target IOP between the two groups.
Parmar et al ( Am J Ophthalmol. 2006;141(6):1160-1 ) compared the per-operative contamination of anterior chamber among eyes undergoing MSICS and phacoemulsification. They studied 150 eyes undergoing cataract surgery. Aqueous samples were taken before and at the end of surgery. Collected material was subjected to standard microbiological analysis. No preoperative antibiotics were used, but povidone-iodine 5% drops were instilled before surgery. They found that the incidence of anterior chamber contamination in the MSICS group (4%) did not differ significantly ( P =0.65) from the PE group (2.7%; P = 0.65).
Tabin et al . ( Curr Opin Ophthalmol. 2008;19(1):55-9 ) reviewed the published literature and concluded that MSICS may be the preferred technique for cataract surgery in the developing world. It is significantly faster, less expensive and requires less technology.