Ординатура / Офтальмология / Английские материалы / Master's Guide to Manual Small Incision Cataract Surgery (MSICS)_Garg_2009

Figure 6.8: Cracking the nucleus (Chop-Multisection)

Figure 6.9: Nucleofracture (Chop-Bisection)

I have called this technique “The Chinese Chopsticks Technique“ (Figure 6.12). It allows us to take advantage of the triangular free space that is on both sides of the nuclear fragment, between the limits of the fragment and the extreme edge of the incision. Using this method we achieve a better adjustment between the size of the incision and the size of the nuclear fragments, as we don’t introduce the instruments from above or below the fragments as we do when using the vectis or the sandwich technique.

Once the nuclear fragments are extracted, we luxate the epinucleus into the AC and we hydroexpulsate it. Then we aspirate the cortex fixed to the capsule with a Simcoe cannula, and polish the capsular bag with a Kratz cannula irrigating profusely.

Figure 6.10: Fragments extraction with the vectis (Chop-Bisection)

Figure 6.11: Extraction of the fragments with the chopper and a spatula (Chopsticks technique)

IOL Implant and Incision Closure

We expand the capsular bag by injecting viscoelastic and we implant a foldable lens (Figure 6.13). We close the incision without stitching by hydrating the edges of the incision. We suture (Nylon 10/0) whenever the least minimum doubt of Seidel exists.

POSTOPERATIVE MANAGEMENT

Eye-drops: Antibiotic-corticoid 2 drops every 4 hours for two weeks, NSAIDs 2 drops every 6h for four to six weeks.

Figure 6.12: Chopsticks technique

Shortening the Learning Curve

The learning curve is similar to that of phacoemulsification. In order to shorten the learning curve, you should consider the next items:

1.Practising the phacosection with the chopper on the nucleus we have extracted using EEC (Ab externo).

2.Initially select patients without corneal problems and with soft nucleus.

3.Begin using wide incisions and progressively reduce their size as our expertise increases.

4.Make large capsulorhexis (6 to 7 mm).

5.Hydrodelineate and hydroor viscoexpulsate the hard nuclei to the AC.

6.Use dispersive or high density viscoelastics over and under the nuclei to enlarge the AC and to protect the endothelium, the iris and the incision.

7.Make sure that the incision is completely closed if we prefer not to stitch.

COMPLICATIONS

In a comparative study analyzing about the first 70 cases in each group (Chop-Bisection, chop-trisection, chopmultisection and phacoemulsification (that is including the learnig curve), I have not found significant differences in their frequency (Figure 6.14).

•Capsular rupture (We found a smaller risk of fragments luxation to the vitreous as we do not work with positive pressures in the AC. Only one case in phacoemulsification group)

•Transient corneal edema and endothelial trauma

•Endothelial decompensation

•Iris trauma

Figure 6.13: Foldable IOL implantation

Figure 6.14: Surgical complications in a comparative study between Chop-Bisection, Chop-Trisection, Chop-Multisection and Phacoemulsification

•Iris prolapse and endothelial damage at the fragments extraction time when we make incisions disproportionate to the fragments size and hardness.

•Zonule dialysis

•Bleeding in the AC.

•Descemet’s stripping.

ADVANTAGES AND DISADVANTAGES OF THE

TECHNIQUE (Do’s and Don’ts)

Advantages

•This is a simple technique for medium and small incision carried out by using simple instruments and no device is required.

•We can work through incisions between 2.8 and 5 mm.

•We can fracture any hardness nucleus.

•Nucleus extraction using lateral free space between the fragments and the limits of the incision (chopsticks technique), instead of the superior and inferior used in the sandwich technique or with the vectis.

•This technique may be performed under intracamerular anesthesia, through a temporal incision (if desired, depending on the astigmatism) and with no stitches (similar to phaco).

•We have lower risk of capsule rupture compared to phacoemulsification as we work in the AC and we also have lower risk of nucleus luxation to the vitreous, as we work under low pressure in the AC.

•The practise of this technique facilitates learning the chopper use, the control of the hardness and dimensions of the nucleus and the AC (Helpful in phaco learning).

•This technique allows maintaining incision length in case of conversion from phaco to EEC.

Disadvantages

•Chop-Multisection requires a greater amount of viscoelastic than phacoemulsification, but if we use a chamber maintainer we need less viscoelastic.

•In very hard nuclei it can be difficult to maintain the necessary stability of the nucleus at the time of cutting it (Must maintain 40º between the instruments to avoid this complication).

CONCLUSION

With this manual phacofragmentation technique, we have:

•Simplicity and low cost.

•Fast visual recovery and low astigmatism.

•Excellent results on nucleus of any hardness.

•Convertion from phaco without enlarging incision.

•Similar results to phaco without the sophisticated and expensive technology.

For your information: Dr. Alvarez-Marin does not have any direct financial interest in the manual phacofragmentation system and is not linked financially or otherwise to any of the companies mentioned.

BIBLIOGRAPHY

1.Alvarez-Marín J, Abreu Reyes P. Facofragmentación Bimanual en cámara anterior con choper y espátula. Una alternativa de facofragmentación manual. Arch Soc Esp Oftalmol 2000;75:563-8.

2.Alvarez-Marín J, Hernández Brito A, Pérez Silguero MA, Delgado Miranda JL, Abreu Reyes P. Chop-bisección / Chop-trisección y técnica de los palillos chinos para extracción de los fragmentos nucleares. Arch Soc Canar Oftalmol, 1986-1998;9:123-9.

3.Alvarez-Marín J, Pérez Silguero MA, Abreu Reyes P. Estudio comparativo entre 5 técnicas de cirugía de pequeña y mediana incisión. Resultados Prefínales. Arch Soc Canar Oft 1986-1998;9:93-100.

4.Alvarez Marín J, Abreu Reyes P. Chop-bisección: Una nueva técnica de facofragmentación manual. Libro de resúmenes del LXXII Congreso de la Sociedad Española de Oftalmología. Madrid; 1996:63.

5.Alvarez Marín J, Abreu Reyes P. Chop-bisección: Estudio comparativo con facofragmentación con asa de nailon. Primeros resultados. Libro de resúmenes del LXXII Congreso de la Sociedad Española de Oftalmología. Madrid 1996;35.

6.Ardiaca R, Ferreruela R, Gómez X, et al. Diferencias en el astigmatismo postoperatorio producido con la sutura de nailon 10-0 en puntos sueltos y en sutura continua. Microcirugía Ocular 1995;3:78-81.

7.Ashkenazi I, Avni I, Blumenthal M. Maintaining nearly physiologic intraocular pressure levels prior to tying the sutures during cataract surgery reduces surgically induced astigmatism. Ophtalmic Surg 1991;22:284-6.

8.Beirouty ZA, Barker NH, Shanmugam NS. Sutureless one-handed small incision cataract surgery by manual nucleosuction - a new technique for cataract extraction. Eur J Implant Refract Surg 1995;7:295-8.

9.Boyd B. Atlas de Cirugía Ocular.Panamá: Highlights of Ophthalmology 1995;V:60-4.

10.Bucher P. Manual phaco-fragmentation. A small incision cataract operation technique. Basel: University Eye Hospital 1992.

11.Galand A, Garza O. Reduction du noyau. Technique manuelle d’ECCE avec incision moyenne. An Inst Barraquer (Barc) 1995;25:81-3.

12.Gómez A, Rentería C, Somavilla M y Saiz B. Asa de nailon y división nuclear. Microcirugía Ocular 1995;3(2): 88-9.

13.Gutiérrez Carmona FJ. Nueva técnica e instrumental de facofragmentación manual para incisiones esclerales tunelizadas de 3,5 mm. Libro de resúmenes del LXXII Congreso de la Sociedad Española de Oftalmología. Madrid 1996;36.

14.Heaven CJ, Davison CRN, Boase DL. Learning phacoemulsification: The incidence of complications and the outcome in theses cases. Eur J Implant Refract Surg 1994; 6:324-7.

15.Howard V, Gimbel MD, Jonathan P, Ellant MD, Patrick K, Chin MD. Divide and conquer nucleofractis. Ophthalmol Clin of North Am 1995;8:457-69.

16.Naus NC, Luyten GP, Stijnen T, de Jong PT. Astigmatism and visual recovery after phacoemulsification and conventional extracapsular cataract extraction. Doc Ophthalmol 1995;1:53-9.

17.Olsen T, Bargum R. Outcome monitoring in cataract surgery. Acta Ophthalmol Scand 1995;73:433-7.

18.Quintana M. Pequeña incisión en EEC. Microcirugía Ocular 1993;1:24-32.

19.Rozakis GW. Alternative small incision techniques. Cataract surgery. NJ Slack 1990.

INTRODUCTION

In modern cataract extraction now, Phacoemulsification is done in many countries but it is very expensive and in delveloping country it is not suitable. Small incisional cataract extraction by manual is now coming to interest in delveloping country and there are several techniques to do so. Some techniques require extrainstrument to use in the operation such as prechopper, anterior chamber maintainer, Kansus chopper, etc. Manual Phacocracking is a small incisional cataract extraction that needs only needle no. 21 to do so that the most country in the world can do this technique.

PRINCIPLES

The principles of manual phacocracking is adapted from tunnel cracking in phacoemulsification. The needle no. 21 is bent in the same way as capsulotomy needle and is stabbed into a lens about half thickness of the lens to the center of the lens. The Sinsky hook is embedded above the needle to crack lens into 2 pieces.

SURGICAL TECHNIQUES

The 15 degree blade is used to do paracenthesis at 12 o’clock and 7 o’clock(in the right eye). The parcenthesis at 7 o’clock is larger than 12 o’clock to insert needle no. 21 via this route. Temporal clear corneal incision is done by keratome 3.2 millimeters. Viscoelastics are injected into anterior chamber. Capsulorhesis forcep is used to do capsulorhesis about 7-8 millemeters. Hydrodissection and hydrodelamination are performed to slightly tilt lens into anterior chamber. Viscoelastics are injected in front of the lens and behind

Praputsaorn Kosakarn (Thailand)

Figure 7.1: The 21-gauge needle is bent

the lens to protect the endothelium cell and posterior capsule. A needle no. 21 is bent in the same way as capsulotomy needle and its bevel is down (Figure 7.1). The needle no. 21 is stabbed into lens about half thickness of the lens to the center of the lens (Figure 7.2). A Sinsky hook is embedded above the needle to crack lens into 2 pieces (Figure 7.3). If the lens is not separated completely,the spatula is used with the Sinsky hook to separate lens completely (Figure 7.4). The viscoelastics are injected in anterior chamber again to protect endothelium cell and posterior capsule. The incision is enlarged to 6 millimeters. The Sinsky hook is used to pull each pieces of the lens out of the eye while the spatula is inserting under the lens to guide lens into the incision (Figure 7.5). The lens cortexs are irrigated and

Figure 7.2: The needle penetrates the lens

Figure 7.3: The needle and a second instrument are used to crack the lens

aspirated out by Simcoe cannula. An intraocular lens is implanted into posterior chamber. The viscoelastics are irrigated and aspirated out by Simcoe cannula. The incision is sutured with 10-0 nylon 1 stitch. The anterior chamber is formed by balanced salt solutions.

COMPLICATIONS

The most common complication in the small incision cataract extraction by manual phacocracking is corneal edema (11 eyes in 108 eyes) that it is transient. The corneal edema resolves a few days postoperatively. It

Figure 7.4: The spatula and Sinskey hook are used to separate the lens pieces

Figure 7.5: The lens pieces are removed with the Sinskey hook and spatula

occurs in the case that have a hard nuclear sclerosis. I suggest that this technique is done in the case of mild to moderate nuclear sclerosis. The other complications are posterior capsule ruptured (2 eyes in 108 eyes).

VISUAL OUTCOMES

Postoperative visual acuity is good and stable in a few weeks postoperatively. The visual acuity is better than 20/40 in about 83.39% of the cases that nearly similar to phacoemulsification group.

lens but at one-third of the lens (Figure 7.7). The second cracking is done by stabing needle no. 21 at half of the rest part of the lens (Figure 7.8). Then lens is already divided onto three pieces (Figure 7.9).

BIBLIOGRAPHY

1.Akura J. Quarter extraction technique for small phacofragmentation. J Cataract Refractive Surg 2000;26:1281- 8.

2.Alvary Martin J. Bimanual phacofragmentation in anterior chamber with chopper and spatula. Arch Soc Esp Ophthalmol 2000;75(8):563-8.

3.Blumenthal M. Small incision manual extracapsular cataract extraction using selective hydrodissection. Opthalmic Surg 1992;23:699-701.

4.Hepsen JF. Small incision extracapsular cataract surgery with manual phaco trisection. J Cataract Refractive Surg 2000;26:1048-51.

5.Kansus FG. Small incision cataract extraction and implantation surgery using a manual phacofragmentation technique. J Cataract Refractive Surg 1988;14(1): 328-30.

6.Kosakarn P. Manual phacocracking. Asian Journal of Ophthalmology 2004;5:6-8.

7.Kosakarn P. Manual phacocracking. Ocular Surgery News 2004.

Double nylon loop is made from two lines of nylon 4-0 inserted through the blunted tip needle no. 20 (Figure 8.1). Double nylon loop separates the lens into three pieces by using two nylon loops to cut the lens altogether at one time. So that each pieces of divided lens is less than 4 mm (Figure 8.2) and can get out of the eye through the corneal incision about 4-4.5 mm. Because the wound becomes less smaller than single nylon loop so that surgeon can implant foldable intraocular lens into capsular bag and need not to suture the wound.

INDICATIONS OF DOUBLE NYLON LOOP TECHNIQUE

Double nylon loop can do in all cases and all grade of cataract. Although in the case of lens subluxation can be done with double nylon loop because this technique

Figure 8.2: Diagram for dividing lens

is done in anterior chamber, it does not cause zonule to tear more. Small pupil, pseudoexfoliation syndrome, dark brown cataract, complicated cataract, and

combined with glaucoma surgery also can be done with this technique.

CONTRAINDICATIONS OF DOUBLE NYLON LOOP TECHNIQUE

Double nylon loop should be aware in such case that have low endothelial cell count or prone to delvelop corneal decompensation. Uncontrolled systemic disease or ocular disease should be avoided.

SURGICAL TECHNIQUES

Anesthesia was done with retrobulbar block in all cases. Paracenthesis was performed at 11 o’clock and 7 o’clock (for the right eyes of patient). Temporal clear corneal incision was made for 3.2 mm by keratome. Capsulorhexis was made by forceps about 6-7 mm. Hydrodissection and hydrodelamination were done until the hard core nucleus was loosened. The lens was taken into anterior chamber by sinsky hook. Viscoelastic substances were injected behind and infront of the lens to protect endothelial cells. Double nylon loop (Figure 8.3) was inserted behind the lens in horizontal plane and then double nylon loop was swung up to cover the lens. The sinsky hook was used to arrange double nylon loop to proper position (Figure 8.4). Double nylon loop was pulled together to cut the lens into 3 pieces. The sinsky hook and spatula were used to remove each piece of lens (Figure 8.5). The cortex of lens was irrigated by simcoe cannula. The foldable intraocular lens was implanted into capular bag (Figure 8.6). The incision was hydrated only with balanced salt solution and no suture was required. The anterior chamber was flushed using balanced salt solution.

Figure 8.4: Double nylon loop was swung to cover the lens in the proper position

Figure 8.5: The sinsky hook and spatula was used to remove each piece of lens

RESULTS AND VISUAL OUTCOMES

The nuclear sclerosis of lens was grade 3-4 in 114 eyes (95%) (n = 120). The postoperative best corrected visual acuity better than 20/40 was achieved for 95 eyes (79.2%) (n = 120). While the other reports of MSICS found that visual acuity was better than 20/40 in 74.3- 83.34% of the cases.

The mean endothelial cell loss of cataract surgery was about 0-40 percent of the preoperative endothelial cell count. The mean endothelial cell loss in phacoemulsification with intraocular lens implantation was 0-20 percent of endothelial cell count.

The mean preoperative endothelial cell count was 2368 + 25 cell/mm2. The mean postoperative endothelial cell count at 1 week after surgery was 2227 ± 27cell/mm2. The mean postoperative endothelial cell count at 1 month after surgery was 2149 ± 29 cell/mm2. The mean postoperative endothelial cell loss at 1 week and 1 month after surgery were 140±16cell/mm2 (5.82%), and 218 ± 20 cell/mm2 (9.19%) respectively. However, the comparison between the mean percentage of endothelial cell loss at 1 week and 1 month was found that the difference was statistical significant (p-value 0.000). So that the effects of MSICS for endothelial cell loss should follow up for a long periods. The loss rates was more than physiologic rates according to ages (0.5% per year). Some reports had follow-up patients for 2-5 years and found that loss rates were more than physiologic rates. So that the endothelial cell loss of double nylon loop technique should be reported again in the future.

COMPLICATIONS

No intraoperative complication occurred in any cases. The most postoperative complication in MSICS was corneal edema. The other reports of MSICS had corneal edema in 2.2-10.19% of the cases. Post operative complications of double nylon loop technique were corneal edema 1 eye (0.8%) and hyphema 1 eye (0.8%). No permanent complication such as corneal decompensation occurred in any cases.

The author suggests that surgeons should use viscoelastics substances to protect endothelial cell during surgery and try to avoid to injury endothelial cell and should select patient that the lens is soft to medium nuclear sclerosis in the early phase of learning period.

Double nylon loop technique is a procedure that is safe, sutureless and has good results, few complications (corneal edema 0.8%, hyphema 0.8%). The mean

percentage of endothelial cell loss at 1 week, and 1 month are 5.82, 9.19 respectively.

DO’S AND DON’TS

Double nylon loop can do in all cases and all grade of cataract. Although in the case of lens subluxation. Small pupil, pseudoexfoliation syndrome, dark brown cataract, complicated cataract, and combined with glaucoma surgery can also be done with this technique.

Double nylon loop should be aware in such case that have low endothelial cell count or prone to delvelop corneal decompensation, and shallow anterior chamber.

BIBLIOGRAPHY

1.Akura J. Quarter extraction technique for small phacofragmentation. J Cataract Refract Surg 2000;26:1281-8.

2.Blumenthal M. Small incision manual extracapsular cataract extraction using selective hydrodissection. Ophthalmic Surg 1992;23:699-701.

3.Chulack Lt Jr, Leske MC, Mc Carthy D. Lens opacities classification system 2 (LOCS2). Arch Ophthalmology 1989;107:991-7.

4.Garg A, A Rif Adenwal A. Update on various nucleus delivery technique in manual small incision cataract surgery. In: Garg A (Ed): Advanced in Ophthalmology 2. New Delhi, India, Jaypee, 2005;328-43.

5.George R, Rupauliha P, Sripriya AV, Rajesh PS,Vahan PV, Praveen S. Comparison of endothelial cell loss and surgically induced astigmatism following conventional extracapsular cataract surgery, manual small incision surgery and phacoemulsification. Ophthalmic Epidermiol 2005;12(5):293-7.

6.Gutierrez-Carmona FJ. Manual multiphacofragmentation through 3.2 mm clear corneal incision. J Cataract Refract Surg 2000;26:1523-8.

7.Hepsen IF. Small incision extracapsular cataract surgery with manual phaco trisection. J Cataract Refractive Surgery 2000;26:1048-51.

8.Jaime A, Montemegre R. Hydroecce does not require phaco. Ocular Surgery News. International edition, 1947;8:8-9.

9.Kosakarn P. Endothelial cell loss and visual outcomes of nylon loop technique by resident training at Prapokklao hospital. Thammasat Thai journal of ophthalmology 2008;1:25-31.

10.Kosakarn P. Manual phacocracking. Asian Journal of Ophthalmology 2004;5:6-8.

11.Kosakarn P. Modified hydroecce. J Prapokklao Hosp Clin Med Edu Cent 2000;17:214-20.

12.Lesiewska-Junk H, Kalvzuy J, MalukiewiezWisniewska G. Long term evaluation of endothelial cell loss after phacoemulsification. Eur J Ophthalmol 2002;12(1):30-3.