Ординатура / Офтальмология / Английские материалы / Small Incision Cataract Surgery (Manual Phaco)_Singh_2002

Fig. 30.4a: Radial sutures reapproximate the edges of external incision, pulling the cornea and sclera to a new, unphysiological position, disturbing the internal entry site which is the true astigmatism control site

The comparison of horizontal vs vertical sutures are shown in Figures 36.4a and b. In the end we can advice, if you are in doubt that the tunnel incision is not selfsealing do not feel nicer in applying suture, never depend on nature because nature may be against you, as it is rightly said that “a stitch in time save a nine.”

Fig. 30.4b: Horizontal sutures flatten the tunnel creating a more physiological closure of internal incision, thus decreasing the degree of astigmatism

SUGGESTED READING

1.Fiche H: Infinity suture: Modified horizontal suture for 6.5 mm incisions in Gills JP, Sanders DR (Eds): SICS Me Stitch Surgery: Thordfare, NJ Slack, 191-96, 1990.

2.Manual small incision cataract surgery: an alternative technique to instrumental phaco-emulsification publisher Arvind Publications, Madurai, India 33-34, 2000.

3.Masket S : Horizontal anchor suture closure method for SICS.

J Cat Refr Surg (Suppl.) 689-95, 1991.

The ultimate goal of the surgeon and the patient both is achieving good vision. Keeping this in mind the surgeon should never mind converting to

conventional Extra Capsular Cataract Extraction (ECCE). While operating, if there is insistence of completing the surgery through small incision, bad results are sure to occur. Postoperatively the results can even make you think against the choice of this surgery. It is always better to learn from other’s experience and faults. Followings are the pearls for the beginners:

Preoperative assessment should be immaculate because some cases are difficult to manage by this technique especially for the beginners. Elder the patients more are chances of large nucleus and also poor endothelial cells count. These patients should be avoided initially. Patients with Fuch’s Endothelial Dystrophy, small pupils, old uveitis, hypotony, and black cataracts are good for conventional ECCE. Selection of softer cataracts in younger patients (less than 55 years) is excellent to begin with and patients between 55 to 60 years are good candidates. Beyond this age surgeon’s skill and hardness of cataract will come into play.

WHEN TO CONVERT?

It is important to keep in mind that our aim is to give vision to the patient. Beginners may stick to the original plan despite facing complications. I have seen most successful and experienced cricketers change their stance on the quality of balling attack. Sachin is a great player because he can adjust to the all kinds of balling techniques. These may be spin, medium pace or fast balling. Similarly the experienced surgeons change their technique depending upon the difficulties encountered. Following points need to be taken care of:

a.Small pupil Manual phaco is difficult to manage in small pupils. Small pupil can be present preoperatively. In this case it is better not to plan manual phaco, because large capsulorhexis is not possible,

consequently nucleus prolapse in anterior chamber will not be possible, and cortical cleanup will also be difficult. During delivery of nucleus the iris starts coming out first. So it is better not to plan manual phaco. But in case the pupil becomes small during the surgery one should convert to conventional incision of ECCE.

b.Incision size I can make an incision as large as 7.5 mm if the need arises, e.g. in black hard cataract there is no point keeping length of incision at 5.5 mm as described in the standard textbooks. If I find slightest difficulty in delivering the nucleus out, I am ready to increase the length of incision (Fig. 31.1), or to convert

Fig. 31.1: The incision should be extended as long as in conventional ECCE

to conventional ECCE. As a beginner I used to deliver the nucleus out through smaller incisions and faced the music as I got white cornea the next day. So moral of the story is never hesitate in increasing the length of incision or converting to conventional ECCE in hard cataracts.

c.Tunnel If the tunnel is not nicely made, you are sure to land into trouble. Premature entry into anterior chamber will lead to iris prolapse during procedures like delivery of nucleus and washing of cortical matter. Hyphaema and even iridodialysis may occur. In this situation it is better to convert.

d.Difficulty in nucleus prolapse If the nucleus prolapse is not possible by a few manoeuvres. One should convert. The factors responsible for difficulty in nucleus prolapse are small capsulorhexis and hypotony. If capsulorhexis is small one can give relaxing incisions at ten and two O’clock position. One more trial should be given for prolapsing the nucleus. Still if it is not possible to prolapse the nucleus conversion is the best answer. Hypotony causes maximum hindrance in prolapse of the nucleus. If hypotony is too much the surgeon will feel as if there is a vacuum pump inside the eye, which is pulling the lens back. In this case also the author suggests conversion to conventional ECCE.

e.Posterior capsule rupture After the delivery of nucleus during cortical cleanup at first sight of posterior capsule rupture, the mind should be set for conversion because

the complications can be dealt with easily when you are in the midst of your well-recognised surgery. So converting to conventional ECCE is advised. Although this complication can be managed nicely in closed chamber. Vitrectomy if vitreous has come in anterior chamber, removal of the cortical matter, and implantation, all are possible within the chamber.

So, to conclude to my mind small pupil, unexpected large nucleus, iris prolapsing through the tunnel, difficulty in prolapsing the nucleus and posterior capsule rupture are the main culprits and one should not hesitate in converting.

HOW TO CONVERT?

Conversion is very simple. The scleral incision is extended towards the limbus with the help of corneal section enlarging scissors. Then the incision is extended on the limbus on both temporal and nasal sides. The incision is extended to the usually performed ECCE length so that there is no undue pressure required for extraction of the nucleus (Figs 31.2a and b).

SUGGESTED READING

1.Bhattacharjee H, Singh S, Deka S: Small incision cataract surgery (SICS) In Printers and Publishers. 133-91, 1998.

2.G Natchiar: Manual Small Incision Cataract Surgery. Arvind Publishers: Madurai, India 6768, 2000.

3.Jaffe NS, JaffeMS, Jaffe GF: Surgical techniques in cataract surgery and its complications. Mosby 65-131, 1997.

Cataract Surgery

Kamaljeet Singh

Shweta Pandey

Monika Joshi

Preoperative use of medication varies from place to place and surgeon to surgeon. In some centres too many drugs are used and at others too few.

Moreover, there is always addition to the existing list of availability of medicines. Antibiotics, steroids, povidone iodine and non-steroidal anti-inflammatory drugs are the mainstays of the pre, intra and postoperative treatment available today. In this article we will discuss the present scenario of their usage under following heads:

l. Antibiotics

2.Corticosteroids

3.Non-steroidal anti-inflammatory drugs.

Antibiotics

It is very clear now that most important source of postoperative infection is patient’s own flora. Therefore preoperative antibiotics eye drops are used commonly. These days commonly used preoperative antibiotic drops are ciprofloxacin, tobramycin and ofloxacin. The question is which antibiotic is the best amongst the presently available medicines. In a study: by Durmazetal1 to compare the aqueous humour concentrations of topically applied ciprofloxacin, ofloxacin and tobramycin in 30 patients undergoing cataract or trabecullectomy surgery. These eye drops were used for six times at an interval of 15 minutes beginning 90 minutes before the surgery. The mean aqueous humour level of ciprofloxacin was 0.02+/ -0.077 microgram/ml, ofloxacin 0.964+/–0.693 microgram/ml. Tobramycin did not reach the concentration that could be detected by the applied method. The study concluded that aqueous humour levels of ofloxacin and ciprofloxacin were more than the minimum inhibitory concentration (M1C) levels for most of the pathogens that may cause postoperative endophthalmitis. In another study by Akkan et al 2 comparison of 0.3 per cent

ciprofloxacin, 0.3 per cent ofloxacin and 0.3 per cent norfloxacin was done. Topical ofloxacin achieved a significantly higher mean level in aqueous humour than ciprofloxacin, and both were higher than norfloxacin. These MICs were good enough to combat most of ocular pathogens that may cause postoperative endophthalmitis. For the above three antibiotics another study was carried out by Von Keyserlingk et al.3 They concluded that these antibiotics achieved higher concentration for majority of the gram-negative bacteria but these are not prophylactically effective against Streptococcus pneumonie or Pseudomonas aeruginosa. It seems that of the currently available antibiotics for preoperative topical use ofloxacin is the best antibiotic but may not be prophylactically very effective against Streptococcus pneumonie or Pseudomonas aeruginosa.

Povidone iodine five per cent, an iodine-releasing polymer has shown to destroy bacteria in 30 seconds and its efficacy being equal to 3-day antibiotic eye drops containing polymixin, gentamicin and neomycin. It has antibiotic, antifungal and antiviral properties. When antibiotic drops and povidone iodine both are instilled together the effect achieved is additive and further decrease in antimicrobial load results. Povidoneiodine five per cent should be practiced as a routine before cataract surgery. It has also been found that when IOLs are implanted they carry some microbials with them due to contact with the bulbar conjunctiva. Povidoneiodine applied before the surgery can be very useful in this aspect as well.

Subconjunctival injections of antibiotic: Bacteria have been isolated from the anterior chamber after the surgery despite above measures. Luckily the body resistance is such that these are taken care of. But still this provides enough evidence of the use of antibiotics by sub-conjunctival route.4 There are two schools of

thought for their usage through this route. One school does not subscribe to the idea of use of subconjunctival injection and the other does. The first says that endophthalmitis developed despite injection being given and organism being sensitive to the antibiotic used. This school argues that there are chances of globe perforation. The other school recommends subconjunctival injection of antibiotic and most commonly used antibiotic for this purpose is gentamicin.

Intracameral Use of Antibiotic

This method of use of antibiotic is also an important method. Frequently used antibiotics by this method are gentamicin and vancomycin. Antibiotics are injected into the infusion bottle in the hope that the incidence of postoperative endophthalmitis will reduce. But this aspect is also controversial. Greatest problem with wide spread usage of the antibiotics is development of resistance. In addition, there are chances of toxicity to the retina if they are not properly used. The Endophthalmitis Vitrectomy Study found that systemic antibiotics were not required in addition to intravitreal antibiotics for the treatment of postoperative endophthalmitis. This paper5 also suggests the reason for this; eighteen patients with postoperative endophthalmitis were studied, following intravenous injection of 1g of vancomycin in 14 patients and intravitreal injection of 1mg in four patients. The concentration of vancomycin in the vitreous ranged from 0.4-4.5 mg per ml in the patients who had received intravenous injections, which was lower than the minimal inhibitory concentrations (MICs) required for the causative bacteria isolated from the same samples. In contrast, the concentration of vancomycin in the four patients who received intravitreal injection varied from 25-182 mg per ml. Also of note is that the vancomycin was still present upto 72 hours from the time of the intravitreal injection. There is little need to add intravenous administration to an intravitreal injection of vancomycin. Vancomycin is very effective against the gram-positive cocci that are likely to be responsible for more than 90 per cent of confirmed cases of bacterial endophthalmitis. It is worrying; therefore, that many cataract surgeons are using low-dose vancomycin in their infusion fluids as a prophylactic, which is probably not reaching the MICs required and may in fact be encouraging resistance to this extremely useful, low toxicity drug. Several studies have been done to prove or disprove the above point. Adenis et al6 recommend the use of vancomycin on the basis that the concentration achieved after the surgery were quite effective. Shimuzu and Shimuzu observed that their incidence of

endophthalmitis reduced from .08% to .05% by intracameral use of carbapenem and imipenen in 2160 cases. O’Brien7 reported that intracameral use of antibiotic polymixin and bactracin in both in vitro and in vivo rabbit models results in statistically significant reduction in bacterial colonisation. Other authors like Feys et al8 found that addition vancomycin had no effect on the occurrence of intraocular contamination. Lehman9 reports that intracameral gentamicin is cleared so fast from the antibiotic the bactericidal effects are difficult to reach in that short time. Ferro et al10 are also of the opinion that the intracameral use of antibiotic may not be of much help. The Center for Disease Control11 has issued a warning to limit the use of vencomycin because of the reported development of resistance. Thus exact recommendation of intracameral use is still lacking.

Non-steroidal Anti-inflammatory Agents

Several non-steroidal anti-inflammatory agents like flurbiprofen, indomethacin, diclofenac, ketorolac are used preoperatively for maintenance of pupillary dilatation postoperatively to reduce the reaction after cataract surgery. Many studies have been done on the above drugs comparing their effects with each other and with steroids as well. Recently voltaren has been introduced and several studies reported its beneficial effect over other anti-inflammatory eye drops. In a study conducted by Ostrov et al12 no significant difference was found between ketorolac, prednisolone acetate, and dexamethasone in the postoperative period in the cells and flare in aqueous. In fact incidence of postoperative cystoid macular oedema was less common in patients who used ketorolac eye drops. Another study conducted by Schmidt et al13 showed that the reduction in anterior chamber flare as measured by laser flare meter was significantly greater with flurbiprofen or with indomethacin. In a double masked conducted by Butt et al14 comparison of the effect of voltaren-gentamycin combination with dexame- thasone-neomycin-polymixin combination no statistically significant difference was found in anterior chamber after the extracapsular cataract surgery. Similarly other authors Rowen et al and Roberts et al15 found voltaren to be very effective in preventing postoperative reaction and almost as effective as steroid and better than other nonsteroidal anti-inflammatory agents.

Corticosteroids

Corticosteroids are commonly used anti-inflammatory agents after cataract surgery. Their anti-inflammatory

effect is considered more superior than the non-steroidal anti-inflammatory agents, but the greatest problem with their use is rise in the intraocular pressure. Commonly used corticosteroids are dexamethasone, prednisolone, fluromethalone. Intraoperatively used method is by subconjunctival route. Many surgeons prefer to use this route others do not. In order to lay this controversy to rest Nakamura et al15 conducted a study comparing this route with those who did not receive intraoperative injection. Weijtens et al16 differ and showed that a subconjunctival injection of steroid resulted in significant aqueous and vitreous concentrations. In 50 patients undergoing vitrectomy for various indications, 2.5 mg of dexamethasone was injected subconjunctivally after topical anaesthesia, and aqueous, vitreous and serum samples were taken at the beginning of surgery. There was no control peribulbar steroid group; instead the aqueous and vitreous concentrations were compared with those from previous studies of peribulbar dexamethasone injections. High aqueous concentrations of dexamethasone were found, and the mean peak vitreous concentration was found to be 12 and 3 times higher than after oral and peribulbar administration, respectively. The authors of the paper feel that these results warrant a randomised trial to establish whether subconjunctival corticosteroids administration, particularly for delivering dexamethasone to the posterior segment.

The other route is by intraocular use. Chang et al17 report in their study that the use of an intraocular biodegradable polymer dexamethasone drug delivery system (DEX DDS), placed between the iris and anterior surface of the intraocular lens at the time of cataract surgery, in reducing postoperative inflammation. This was a randomised, double-masked, parallel group study comparing two dose levels of the preparation with placebo and no-treatment groups. Animal studies have shown that dexamethasone is released for 7-10 days, after which levels become undetectable. The anterior chamber (AC) cells and AC flare were assessed for 60 days postoperatively using slit-lamp examination. The number of patients in each group requiring additional anti-inflammatory medication was also noted. At week two, 80% of the controls required additional topical steroid medication compared with seven per cent of those with the DEX DDS. By month 2, 12% of the DEX DDS patients required topical steroid, compared with 83% of those in the control placebo group. There were no significant complications from the intraocular steroid; in particular, there was no elevation of intraocular pressure. The rebound inflammation at 7-10 days, when the

intraocular steroid preparation would no longer be active, was seen only infrequently. DEX DDS may prove useful in postoperative treatment regimens where antibiotic drops are not given either, for it means that the patient does not need to use postoperative drops at all.

Rimexolone and loteprednol are two recently introduced steroids in USA. In studies done by Leibowitz et al18 and Novack et al19 it has been reported that loteprednol is less likely to cause postoperative rise of intraocular pressure than prednisolone and has equal effect in anterior chamber flare after the surgery

CONCLUSIONS

Ofloxacin and ciprofloxacin are good antibiotics because of better bioavailabiltiy in aqueous humour. They may be used both preoperatively and postoperatively. Voltaren, a non-steroidal anti-inflammatory agent can be used safely for preventing intraoperative miosis and can also be used in place of steroids in postoperative period for reducing the anterior chamber reaction and for prevention of cystoid macular oedema.

Subconjunctival injection of antibiotic and steroids remains a controversial subject. Intracameral use of antibiotic also remains a controversial topic. Intraocular use of steroid is a new method of delivery.

REFERENCES

1.Durmaz B, Marol S, Durmaz R et al: Aqueous humour concentration of topically applied ciprofloxacin, ofloxacin and tobramycin. Arzneimitt for Schung 47: 413-15, 1997.

2.Akkan AG, Mutlu I, Ozyazgan S et al: Penetration of topically applied ciprofloxacin, norfloxacin and ofloxacin into the aqueous humor of the uninflamed human eye. J Chemother 9: 257-62, 1997.

3.von Keyserlingk J, Beck R, Fischer U et al: Penetration of ciprofloxacin, norfloxacin and ofloxacin into the aqueous humours of patients by different topical application modes.

EurJ CLh Pharmacol 53: 251-55, 1997.

4.Ferencz JR, Assia EL, Diamantstein L et al: Meir vancomycin concentration in the vitreous after intravenous arid intravitreal administration for postoperative endophthalmitis I-losp, Kfar Saba Israil Arch Ophthalmil 117: 1023-27, l999.

5.Adenis JP, Robert PY, Mounier M et al: Anterior chamber concentrations of vancomycin in the irrigating solution at the end of cataract surgery. J Cataract Refract Surg 23: 11114, 1997.

6.O’Brian TP, Kirn KB, Barequet I: Effect of intracameral antibiotic supplementation at the end of cataract surgery: An experimental model (abstract). Invest Ophthalmol Vis Sci 38: S1-4, 1997.

7.Feys J, Salvanet-Bouccara A, Emond JP et al: Vancomycin prophylaxis and intraocular contamination during cataract surgery. J Cataract Refract Surg 23: 891-97, 1997.

8.Lehmann OJ, Roberts CJ, Ikram K et al: Association between non-administration of subconjunctival cefuroxime and postoperative endophthalmitis. J Cataract Refract Surg 23: 889-93, 1997.

9.Ferro JF, de-Pablos M, Logrono MJ et al: Postoperative contamination after using vancomycin and gentamicin during phacoemulsification. Arch Ophthalmol 115:165-70, 1997.

10.Hospital Infection Control Practices Advisory Committee (NICPAC): Recommendations for preventing the spread of vancomycin resistance. Infect Control hosp Epidemiol 16: 105-13, 1995.

11.Ostrov CS, Sirkin SR, Deutsch WE et al: Ketorolac, prednisolone, and dexamethasone for postoperative inflammation. Clin Ther 19: 259-72, 1997.

12.Schmidi B, Mester U, Diestelhorst M et al: Laser flare measurement with 3 different non-steroidal anti-inflammatory drugs after phacoemulsification with posterior chamber lens implantation. Ophthalmology 94: 33-37, 1997.

13.Butt Z, Fsadni MG, Sunder RP: Diclofenac-gentamicin combination eye drops compared with corticosteroid

antibiotic combination eye drops after cataract surgery. Clin Drug lnvest, 15: 229-34, 1998.

14.Roberts CW: Pretreatment with topical diclofenac sodium to decrease postoperative inflammation. Ophthalmology 103(15): 636-39, 1996.

15.Weijtens O, Feron EJ, Schoemaker RC et al: High concentration of dexamethasone in aqueous and vitreous after subconjunctival injection. Rotterdam Eye Hosp, Rotterdam, The Netherlands. Am J Ophthalmol 128: 192-97, 1999.

16.Chang DF, Garcia IH, Hunkeler JD et al: Phase II results of an intraocular steroid delivery system for cataract surgery. Altos Eye Physicians, Los Allos, CA, USA. Ophthalmologica

106(1): 1 172-77, 1999.

I7. Leibowitz IM, Bartlett JD, Rich R et al: Intraocular pressureraising potential of 1 .0% rimexolone in patients responding to corticosteroids. Arch Ophthalmol 14(1): 933-37, 1996.

18.Novack GD, Towes J, Crockett RS et al: Change in intraocular pressure during chronic use of loteprednol etabonate. J Glaucoma 7: 266-69, 1998.

Majority of the complications associated with phacoemulsification and extracapsular surgery are common to manual phaco. We shall discuss

here the specific complications of manual phaco. The complications of manual phaco can be divided into following subheads.

INTRAOPERATIVE COMPLICATIONS

1.Complications associated with wound construction.

2.Complications associated with AC maintenance.

3.Complications associated with capsulotomy.

4.Complications associated with nucleus prolpase in AC.

5.Complications associated with delivery of nucleus.

6.Complications associated with debris clean-up.

7.Complications associated with implantation.

Complications Associated with

Wound Construction

It is the most significant step in any sutureless surgery, whether in phaco or in manual phaco, or even in conventional ECCE. Proper wound construction and tunnel formation is most important in manual phaco because wound is bigger and tunnel should have more length to keep it self-sealing. Most common complication associated with this step is premature entry into the anterior chamber. This causes iris prolapse during various manoeuvres (Fig. 33.1) and increases the chances of Descemet’s tears. Other common complication is button holing of the sclera if the depth in the scleral tunnel is too shallow. Deeper dissection can also be a problem as superficial sclera may disinsert from the deeper sclera. This is called scleral disinsertion. Excessive bleeding may occur while constructing the wound as the incision here is given about 2 mm behind the limbus, which has more capillaries. Bleeding can be taken care of by doing careful bipolar cautery.

Fig. 33.1: Iris prolapse through the wound due to premature entry

Management Keeping the crescent blade in one plane can prevent premature entry. If it occurs immediately the dissection should be abandoned. Begin dissecting from the other end of the tunnel, or one can choose other site, or dissection from other plane should be started. This wound is likely to leak. Therefore, it will need suturing.

Button holing can be prevented by avoiding dissection at shallow plane while doing scleral dissection. If small hole is there, then second plane at deeper site may be selected, If the hole is large the site of incision needs to be changed.

Avoiding deep dissection can prevent scleral disinsertion. If it occurs, radial sutures are applied to secure the wound. If Descemet’s detachment occurs we have to inject air (Fig. 33.2).

Complications Associated with AC Maintainer

Problem most frequently seen with AC maintainer is—it comes out from the wound, if the tunnel for AC maintenance is wide. In contrast, if it is too tight the AC

Fig. 33.2: Detachment of Descemet’s membrane-injecting air bubble is enough for reattachment

maintainer enters in AC with a bang and may injure iris. Author once entered in AC with such force that it caused subluxation and the surgery was abandoned. Therefore, one should make a tunnel about 2 mm long and entry should not have great resistance. The AC maintainer should be of 20G as advocated by Blumenthal.

Complications during Capsulotomy

If surgeon chooses to do this surgery with capsulorhexis, it should be not less than 6.5 mm. Making a large capsulorhexis is difficult because it may extend in the

periphery. If smaller capsulorhexis is done the ECCE may turn to ICCE while prolapsing the nucleus. Capsulorhexis is not a must here as in phacoemulsification. The simplest and best is to make an envelope type capsulotomy. In those technique where two instruments are used, like in sandwich, phacosection or phacofragmentation anterior capsule also gets sandwiched between two instruments and can lead to zonular disinsertion in inferior position. Here the surgeon should keep other instruments under direct supervision. This complication does not occur when capsulorhexis or Beer can-opener technique is used.

Management Small capsulorhexis can be turned to beer can-opener in the upper aspect from 11 to 1 O’clock by applying several cuts on the margin of capsulorhexis. Several cuts should be made. Only one cut may extend in the periphery while prolapsing the nucleus (Fig. 33.3). Zomular disinsertion necessitates implantation in ciliary sulcus (Fig. 33.4).

Complications Associated with

Hydrodissection and Hydrodelineation

Two problems can occur during these procedures. The hydrodissection may be insufficient to cause rotation. More hydrodissection is required in this case. Keep doing hydrodissection till rotation is achieved. Secondly, there can be posterior capsular rupture. This occurs due to too much fluid going in a bolus, or fluid getting stuck in between posterior capsule and nucleus. For avoiding this complication, one can inject fluid and then should

Fig. 33.4: Zonular distinsertion-Implantation in ciliary sulcus

depress the nucleus so that the fluid may not remain there at one point and fluid may move. If this is not carried, there are chances of even posterior dislocation of nucleus.

Complications During Nuclear Prolapse in AC

The beginner faces biggest problem in prolapsing the nucleus in AC. This difficulty occurs when there is hypotony, pupil is small, capsulorhexis is small, or nucleus is soft. Therefore, this step should be practiced in canopener technique, as the prolapse is easiest in this method. Diamox or pinky ball should not be applied as it causes hypotony. If hypotony is too much and nucleus does not prolapse, one may have to convert to ECCE. A few cases of capsular dialysis have been reported during accidental dialing of capsulorhexis edge in place of nucleus. If the pupil is small one can do a sector iridectomy and proceed or convert to ECCE. In case the nucleus is soft and does not rotate, one can wash the cortical matter. Now the nucleus view will be better and prolapse will be possible. Actually in this case for rotation the surgeon does not go deep enough and remains in the cortex and the perinuclear plane.

Complications during Delivery of Nucleus

Several techniques of delivering of nucleus have been described in this book. One problem of transient corneal oedema is common in all the techniques, due to nucleus touch to the endothelium. This touch should be avoided and the delivery should be made easy. As during the delivery of a child episiotomy is given, similarly if delivery of nucleus becomes difficult one should increase the length of the incision. If corneal valve remains formed,

Fig. 33.5: Dialysis of iris

incision up to 8 mm long can safely remain sutureless. In techniques where two instruments are used to handle the nucleus, there are chances of iridodialysis at the site of entry. This may occur when the viscoelastics are scanty in the AC and it is not deep. Care should be taken to displace the anterior capsule inferiorly if envelope type capsulotomy has been made when sandwich technique is used. Otherwise it may lead to disinsertion of zonules in the inferior position while delivering the nucleus out.

Complications Associated with Debris Cleanup

Posterior capsule rupture can occur which should be managed by doing vitrectomy, if vitreous has came into the anterior chamber. If there is small repture, which is detected early IOL can be easily implanted in the bag (Fig. 33.6). Any cortical matter left should be aspirated by dry suction method. The issue is described in detail elsewhere. Subincisional cortical matter is difficult to clean. For this ‘J’ shaped cannula can be used or separate entry at 7 O’clock should be made. The cortex can also be disengaged while dialing the IOL.

Complications Associated with Implantation

The biggest problem is implanting the lens in the bag, because we are implanting lens through a tunnel. The tilted lens cannot go in the inferior side, as the tunnel is horizontally long. The inferior haptic in this case, may be left on anterior surface of iris. The superior haptic is then implanted in the bag and inferior haptic is dialed into the bag. The other complication occurs when the chamber is not filled with viscoelastics. The IOL implantation can cause endothelial touch.