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

INTRODUCTION

Medical Science has seen tremendous advancements in last three decades worldwide. Ophthalmology specially cataract surgery has undergone significant changes from ICCE-ECCE with IOL-Phacoemulsification– Microphaco and coaxial Phaco. Phaco and Microphaco surgery is being performed by Eye surgeons all over the world specially in developed countries. This is most elegant surgery but with a high cost which cannot be 100% practicable in developing countries where cataract surgery volume is very high. Manual small incision cataract surgery (MSICS) has emerged as first choice alternative to phacoemulsification which retains most of the advantages of phaco can be delivered at a lower cost even in high volume cataract surgery programmes. MSICS achieves a best unaided visual acuity with rapid Post-surgical recovery and minimal surgery related complications. MSICS is a precise surgery for primary to the most advance level of patient care in modern cataract era. MSICS techniques have been neglected in the world literature except for few quality international books and journals. Clinical significance of MSICS has increased manifold related so safety provided by small incision and neutrality in astigmatism, a vital factor in realization of best postoperative visual acuity and ability to implant modern intraocular lenses and faster rehabilitation.

MSICS is the effective and best way of removing large back log of cataract surgery in developing countries at a affordable cost with similar visual results as in phacoemulsification. Moreover, in high grade density cataracts MSICS is certainly better than phaco in terms of visual results and corneal endothelium

Ashok Garg (India)

protection. A number of leading international cataract surgeons have shown in their parallel clinical trials (MSICS Vs Phaco) that MSICS is certainly better in all types and grades of cataracts with lost cost and maintenance demand of the equipments. In my opinion as a frequent worldwide guest faculty speaker as Brand Ambassador of World Health Organization that any eye surgeon doing MSICS can be assured that they are performing state-of-the-art cataract surgery for their patients with visual results as good as phacoemulsification.

As compare to phacoemulsification MSICS has less steep and less expensive learning curve. MSICS is much easier to learn and master even for the novice. However, one step is important to begin with conversion from ECCE to MSICS should focus on the making of a tunnel which differentiates MSICS from ECCE. One should have enough experience of tunnel making on goat’s eye before converting to MSICS.

OBJECTIVES

The main objective in modern cataract surgery is to achieve a betterunaided visual acuity with rapid postsurgical recovery and minimal surgery related complications. Early visual rehabilitation and betterunaided vision can be achieved only by reducing the incision size. The size of the incision in turn depends on mode of nucleus delivery and type of intraocular lens (rigid or foldable). In standard extracapsular cataract extraction, the incision needs to be 10 to 12 mm for safe delivery of nucleus. In manual small incision cataract surgery (MSICS) it is between 5.5 and 7 mm and in instrumental phaco it varies from 3 mm to 6 mm

depending on the technique and implant. The use of smaller incision with advantages of faster rehabilitation, less astigmatism and better postoperative vision without spectacles led to phacoemulsification becoming the preferred technique where resources are available.

Despite excellent facilities and skilled surgeons, the poor in the developing world and even deprived of the visual benefits on the IOL because of their inability to afford them. With this background phacoemulsification with all its benefits may not be an affordable technique due to the cost involved in the developing countries. Alternatively manual SICS with its relatively smaller incision has similar advantages to phacoemulsification and is affordable.

Manual SICS has evolved as an effective alternative to phacoemulsification in the present times. Recent studies have proved that Manual SICS is cost-effective and has more benefits than conventional ECCE. To list a few of them are as follows:

•Better and early wound stability

•Less postoperative inflammation

•Can avoid suture and suture related complications (e.g. iris prolapse, suture infiltrate, bleeding)

•Less postoperative visits

•Early reduction and stability of surgically induced astigmatism.

Moreover, manual SICS can be performed in almost all type of cataracts in contrast to phacoemulsification where case selection is extremely important for an average surgeon. The duration of surgery and phaco power varies with the nucleus density, as also the incidence of intraocular complications, whereas in manual SICS, the time spent on nucleus delivery does not vary from case to case. In cataracts with dense nuclei, with the incision enlarged to 7 mm, the nucleus cannot delivered with an irrigating vectis. An alternative technique for extraction through a smaller wound is phacosandwich technique. This is a bimanual technique where under the cover of viscoelastics the nucleus is delivered bimanually with a vectis and Sinskey hook. Phacofracture is another technique used in manual SICS to bring out nuclei of varying grades through a smaller tunnel up to 4 or 5 mm.

Hypermature cataracts with liquefied cortex hard nuclei can get excellent results with manual SICS. To handle hypermature cataracts is phaco becomes difficult because of the fibrosed capsule, weak zonules, hard mobile, etc. Again traumatic cataract following penetrating trauma, colobomas, cataract following RD surgery, etc. are better tackled by this procedure.

Capsulorhexis is mandatory for phaco but manual SICS can also be done with the can opener technique. In a study where the learning curve in residents learning phaco was analyzed four patients had to convert to extracapsular cataract extraction and in three patients the reason for ‘bailing out’ was the absence of an intact rhexis. In MSICS the conversion to ECCE due to an absence of capsulorhexis is not necessary as the nucleus is delivered comfortably even with a can opener capsulotomy.

Incidence of intraoperative complications like posterior capsule rupture is less common in MSICS has compared to phaco. Yet another recent study compared the safety of ECCE, MSICS and phaco and reported a lower intraoperative and immediate postoperative complications in the MSICS group when compared with rest. Certain phaco related complications such as corneal burns due to the phaco probe and iris chaffing are not encountered in manual SICS. The endothelial cell counts in this subgroup of patients are no different from those who have had phacoemulsification. Endothelial cell loss in phaco depends on the density of the nucleus in contrast to manual SICS where the skill of the surgeon plays an important role.

Published evidence points out that surgically induced astigmatism following ECCE is 3.91 times higher than MSICS. Their results show that the difference in surgically induced astigmatism between MSICS and phaco with rigid IOL was not statistically significant. Implantation of foldable IOL though a standard procedure in the developed countries, is used only among the affluent society in developing countries. This is because of foldable IOL costs as much as 10 times as that of a rigid IOL. The final visual acuity between these two groups is also comparable. Our own data shows that the final postoperative visual acuity in both MSICS and phaco are similar.

Surgical time in phacoemulsification is dependent on the type of cataract. In a study performed in a rural eye camp in India manual SICS was performed within 3.8 to 4.2 minutes. Being a faster procedure, manual SICS can be performed in a high volume set up. In an Indian study where cost comparison between the two procedures was done, the average cost for the provider was US$ 16.82 for ECCE and US$ 16.68 for SICS. Both these surgeries are thus economical. Yet another study points out the cost to be US $ 17 for ECCE, US$ 18 for MSICS and US$ 32 for phacoemulsification. Though the provider cost are similarly for MSICS and ECCE, Patient’s costs might be lower for SICS patients

considering the fewer postoperative medications, follow-up visit spectacles and the total cost may thus work out to be more economically. Another major advantage of manual SICS is that, it is not a machine dominated procedure. The surgical skills and experience of the surgeon play a significant role in the results. Also considerable expense in acquiring and maintaining a machine is not required.

Transition to phacoemulsification is easier if one has mastered Manual SICS, as he is familiar with steps such as sclera pocket incisions, capsulorhexis, hydroprocedures, etc. Familiarity with these steps helps reduce the incidence of complications while learning phaco. There are instances where we have to convert from phacoemulsification to extracapsular cataract surgery. One study reports the conversion rate from phaco to extracapsular by an experienced surgeon to be 3.7%. Converting to an extracapsular result in a larger, unstable wound than manual SICS. If one is familiar with the manual nucleus delivery techniques with the self-sealing wound one can reduce suture induced astigmatism and other complications.

Phacoemulsification being an expensive technique cannot be employed as the standard procedure in developing countries with a cataract backlog and is a strain on the economy. High quality, high volume cataract surgery has been popularized in eye care centers in India to effectively manage the large backlog of cataract blindness.

In an era advances are linked to expensive innovative technology, it is exciting to witness the evolution of simplified, low cost alternatives. Manual small incision cataract surgery offers the smaller incision size of phacoemulsification and the added advantage of not requiring expensive equipment. Manual SICS offer all the merits of phacoemulsification with the added advantages of having wider applicability, better safety, with shorter learning curve and lower cost.

ADVANTAGES OF MSICS

•Small incision 2.5-5 mm—sutureless

•Low cost of lens implantation

•Short duration surgery

•Faster turn around for high volume

•Low cost in term of equipments

•Successful visual recovery in almost 100% cases

•Can be done in all types of cataracts specially dense cataracts.

DISADVANTAGES OF MSICS

•Requires larger incision than Phaco and Microphaco resulting in more post operative induced astigmatism

•High tech foldable lenses cannot be implanted

•Not suitable for Keratorefractive surgery.

International Society of Manual Small Incision Cataract Surgery (ISMSICS) under the leadership of Dr. Amulya Sahu is pioneer in the propagation of science of MSICS at an international level. ISMSICS has organized four international conferences on MSICS in various Asian countries where live surgery and skill transfer course were conducted on the various techniques of MSICS in an effective way. ISMSICS has also recognized various MSICS training centres in India and abroad for the practical training of MSICS techniques for beginners.

CONCLUSION

Manual small incision cataract surgery is safe, reliable, most affordable and less time consuming, high volume surgery with excellent visual results and minimal complications. I recommend to even those eye surgeons who are dong 100% phaco may encounter cases of rockhard cataracts and intraoperative phaco complications which can be certainly better managed by manual SICS. MSICS is better alternative to high cost instrumental phaco with similar results.

INTRODUCTION

Aside from the minimal and manageable surgeryrelated complications, the prime objectives in modern cataract surgery include excellent unaided visual acuity and shorter recovery time. This can be achieved by a good preoperative evaluation and preparation, a surgical technique with minimized intraoperative manipulation, and a simple postoperative requirement. While good presurgical selection of patients is important in achieving targeted results, the quality of unaided postoperative vision on the other hand, is inversely related to the size of corneal incision—the smaller the better. This becomes the main topic of discussion.

The transition from intracapsular to extracapsular cataract surgery has opened the surgical arena flooded with outstanding modifications from experts and innovators around the world bringing in modern approaches and tools aimed at a common purpose— to extract the cataractous lens safely, quickly, and effectively. These include the implantation of intraocular lenses (IOLs), and cataract management utilizing either the highly technical mechanical phacoemulsification or the simpler manual small incision cataract extraction. Both phacoemulsification and manual small incision surgery enjoy the benefit of a sutureless procedure compared to the traditional extracapsular cataract extraction (ECCE) resulting to a better visual results, shorter recovery time, an expected much improved quality of life, and the dramatic acceptance of the treatment in a wide spectrum of cataract management in most surgical conditions, either ideal or not. For many years, ECCE with IOL has been the primary choice in the management of cataract. Its inherent delayed visual improvement, wound and

Kadil Jojo Jr Sinolinding (Philippines)

suture related complications, including its unreliable wound integrity during healing period has led surgeons to improve existing technique paving the way to more efficient and reliable phacoemulsification and MSICS.

In manual small incision cataract surgery (MSICS), nucleus extraction is done through a 4 to 8 mm diameter incision depending on the method and intraocular lens used. Common among all techniques is the construction of a self-sealing sclero-corneal tunnel that functions like a one way valve that generally requires no suturing but provides a watertight stable wound. In the end, achieving a cost-effective, and highly predictable surgical outcome is one of the prominent advantages the MSICS offers.

Nucleus extraction in MSICS can be achieved through:

1.Hydroexpression technique. This technique uses hydrostatic pressures in the anterior chamber to aid nucleus delivery either using an irrigating vectis popularized by Dr. Natchiar of Aravind Hospital Systems or an anterior chamber maintainer connected to an IV line with a specific bottle height as popularized in the Dr. Blumenthal’s Mini-Nuc technique. Dr. Ruit’s Tilganga Eye Center technique utilizes modified I and A cannulae in the extraction of cataract. This technique is highly recommended for softer cataracts but dense ones can easily be managed by enlarging the wound and the tunnel.

2.Fish hook technique popularized by Dr. Hennig, using bent gauge 30 needle introduced and engaged in the posterior face of the nucleus. Because of the non-visualization of the hook while behind a dense cataract, many surgeons are having second thoughts despite its relative ease, effectiveness, and simplicity.

3.Hook-Sandwich technique uses a specially designed hook engaged on top and a lens loop sandwiching the nucleus as a double protection approach to preserve the integrity of the posterior capsule while keeping the endothelium from damage during nucleus delivery. This was introduced by Dr. Sinolinding few years back. Because of the visibility of instruments used and the predictability of lens extraction, this has received wide acceptance among Filipino Ophthalmologists.

4.Phaco-Sandwich technique is the original version of two instrument nucleus extraction introduced by Dr. Fry in 1985 using a lens loop and a Sinskey hook. Because of its limitation to hold hard cataracts in tight sclerocorneal tunnel, modifications were introduced then. Still, many surgeons are using this technique.

5.Manual phacofragmentation

a.“Phaco non-phaco technique” was introduced by Drs. Wirilayappa, Kongsap, and Samporn. This technique requires much dexterity and skills. The nucleus is pre-chopped intracamerally into small fragments before being delivered piece by piece through a 4 mm corneoscleral incision or through a modified tube (phaco-drainage technique). Foldable IOLs are used in this method.

b.Phacofracture technique using bi-sector, trisector, wire loop, and other devices designed to split the nucleus into pieces before extraction. Phacofracture of lens in the tunnel is also used by other surgeons.

6.And many more techniques and modifications are used that I missed to mention.

Basic Questions

Some basic questions in our choice of cataract surgery technique include:

•Adaptability to all types of cataracts?

•Scientifically proven to be effective: evidence based results?

•Learning curve among new learners?

•Acceptable and manageable complications?

•Capital outlay and available instrumentation?

•Cost effectiveness especially to patients?

What explains the low acceptance of the MSICS technique among many surgeons are due to limited exposure and confidence among “mentors” in training hospitals, wrongly perceived higher complication rate and difficult learning curve, limited support and scarcity teaching materials in many institutions, and minimal support from funding (Ophthalmic) companies

Despite little support, the MSICS advocates managed to come up with modifications and studies supported by facts and figures making it time-tested technique with good if not excellent results through the years. Recently in many developing countries, more and more cataracts are managed this way that offers comparable results with the highly technical and expensive mechanical phacoemulsification in terms of safety, visual rehabilitation, applicability in all surgical center conditions and most importantly, its affordable cost.

In as much as manufacturers and surgeons would want to be perfect, no one can achieve either 100% phacoemulsification or 100% MSICS as we avoid the unreliability of visual result of the conventional ECCE or the ICCE, mostly depending on the judgment and comfort of the surgeon. In most developing countries around the globe, a white cataract is not unusual. In the Philippines alone, of the almost 4 million visually impaired affecting one or both eyes prevalence in 2002, about 41% is due to cataract.2 And many are mature upon diagnosis. Poverty undeniably, is claimed to be one of the reasons why people shun from early treatment. So, despite satisfactory results have been reported and published by phaco advocates regarding white cataract, mechanical phacoemulsification is still far from being an ideal method in the management of cataract considering its cost and maintenance.

The purpose of this surgical approach is to simplify the process of final technique selection on the management of cataract in all surgical conditions offering the surgeon a wide variety of choices, making him comfortable with the problem. The assumption is that the surgeon must be comfortable at any time using any of the acceptable standard techniques of cataract surgery: ECCE, MSICS, and Phacoemulsification.

Why Learn Simplified 3-in-1 Technique?

•Adaptation to actual capability of surgical centers. As all eye surgeons are expected to know the three techniques, not all hospitals have state-of-the-art equipments that include phacoemulsification machine. While most paying patients are managed in adequately equipped medical centers promoted and supported by its manufacturers, a great number are still managed in modified set-up but still coming up with comparable results in terms of ease of surgery and visual outcomes.

•Promote versatility and flexibility of the technique in unusual cases. When dealing with soft cataracts, the choice will be easier. When patient had

preference on a specific technique as requested, you are faced with a double challenge—to remove the cataract the way our patient wanted it. And if faced with dense brunescent super hard cataract, dislocated, posterior polar, pseudoexfoliation, postuveitic, or any unusual types of cataracts, you will start making the wisest choice of approach with minimal preparation.

•Easy conversion during unwanted situations. No surgeon can achieve a “100% phaco” even manufacturers designed the newer machines with more outstanding features. On the other hand, MSICS cannot guarantee the same as well. Many factors have to be considered: machine failure, power failure, and even surgeon failure. Learning the 3-in- 1 bails out the surgeon during surgical difficulties. It doesn’t guarantee a 100% success rate, but assures us of a better outcome. Problems arise even in a seemingly easy and innocent looking case. And complications should not be a bigger problem than not knowing how to deal with it.

•Inherent limitations of each technique. Despite their “almost 100% phaco” claim, in many instances there are “shifts” done before the onset of surgery, or worse during surgery when reality of surgical limitations and surgeons comfort zones become apparent. While phaco technique offers the benefit of using a foldable lens through a 2-3 mm bloodless incision, cataract in many parts of the world are becoming “phaco-challenge” that makes the relatively safe procedure a bit risky and uncertain. This is true with hard cataracts. MSICS on the other hand becomes the preferred choice. However, patients on anti-coagulant/ thrombolytic medications are best managed with the bloodless phacoemulsification approach.

•Achieve the confidence of a Total Cataract surgeon.

Easy conversion and flexibility of the surgeon towards difficult cases and unusual situations offers an advantage of a “Total Cataract Surgeon”. It simply explains the capability of the surgeon to finish the task with optimal result regardless of the situation and problem.

Advantages of the 3-in-1 Approach

•All grades, all types of Cataracts

•All types of IOLs

•All set-up of surgical centers (eye camp to medical centers)

•All-time all-situation, ideal for outreach or in-reach ophthalmic expeditions

•All-flexible cost of surgery

•Acceptable, minimal, and predictable complications

Patient Preparation

Patient preparation includes:

•Nitroglycerin patch ½ hour prior to surgery for >40

•Use 5% povidone iodine eye drops preoperative

•Keep BP < 130/80

•Keep pupil maximally dilated

•O2 inhalation during surgery

•Put up ear shield for fluid drips

•Make eye sheet and eye towel light but adequate, and good smelling

•Keep in touch with the patient through a relaxed conversation

•Give anxiolytic drugs (to selected patients).

The 3-in-1 Technique Precautions

•Fat, short neck patients

•Small eyes with shallow chamber

•Tight inter-palpebral fissure

•Small, non-, or poorly-dilating pupil

•High IOP

•Pseudoexfoliates at AC, weak zonules

•Cataracts: Posterior sub-capsular/ polar, Inflammatory type

•Hypertensives

•Under aspirin or anticoagulant maintenance

•Patients prostate medication

•Anxious patients

Presurgical Reminders

•Prepare all instruments (basic and others) in one tray

•Prepare Phaco Machine (if available)

•Use only sharp knives to decrease tissue damage

•Adequate anesthesia

MSICS (HOOK SANDWICH), PHACOEMULSIFICATION, AND THE ECCE TECHNIQUES: THE 3-IN-1 SIMPLIFIED APPROACH (The Sinolinding Approach)

Planning and Evaluation

I need to emphasize that often neglected little things may save our day if we mind them ahead.

Patient Selection

Although some techniques of MSICS work better in specific type and grade of cataract, the Hook Sandwich

Technique encompasses all the barriers even on cases that requires extreme care and holds more risks.

Type of cataract All types, all grades. The harder the nucleus, the hook works better but soft cataract can be managed easily as well.

Patient preparation A good medical history, including allergies must be considered.

Preoperative antibiotic eye drops is recommended. My choice is Tobramycin 4 x a day for at least 3 days prior to surgery.

Aspirin and other anti-coagulant medications must be discontinued 2 weeks prior to surgery. Choice of surgery must be planned out well if such medications cannot be stopped.

Consider sedation to anxious patients. Constant communication and assurance to patient allays apprehension better.

Maintain blood pressure below 140/80 prior to surgery. Hypertension may lead to hyphema and unpleasant subconjunctival hemorrhage.

Use light but adequate drapes. Cloth made of cotton that smells good is recommended. Make sure the patient is comfortable with the drape on by asking prior to surgery.

Use improvised ear shield to seal off fluid from entering into the external auditory meatus. Some patients make unnecessary quick head turns as water drips during irrigation and aspiration.

Oxygen inhalation set at minimal level, preferable 2-3 Li/min.

Nitroglycerin patch should be in place 1 hour prior to surgery among >40 years old patients or among those with heart problems. It must immediately be removed after the surgery to minimize adverse reactions such as headache and flushing to some susceptible patients.

Anesthesia

1.Topical-Subtenon-Intracameral (TSI) anesthesia is my preferred choice (Table 2.1). The TSI avoids the

unwanted complications related to infiltration and inhalation anesthesia. Although it may have certain precautions among severely anxious and “terrified” patients towards surgery, generally, more than 95% of my patients are comfortable under TSI.

2.Retrobulbar/peribulbar

3.GA: Inhalation or IV

Surgical Procedure

Instruments Used for MSICS Hook Sandwich Technique

Lid retractor, SRB forcep and needle holder with silk 4-0 (for retro/peribulbar/general anesthesia), Westcott scissor, Cautery spear or wet field bipolar, Caliper, Knives (angled Crescent knife and 3.0 slit keratome), Blade holder with blade #15, Wilder type lens loop, Lens dialer/manipulator, “Sinolinding” Nucleus Hook, I and A Simcoe cannula, Angled 11 mm lens forcep, .12 tissue forceps.

Standby instruments: Vannas scissor, Corneal scissor, Needle holder.

Additional Instrument for Phacoemulsification

Chopper, preferably by Dr. Nagahara.

The Technique

Initial Phase (The Crossroad)

This phase is the most important part in the 3-in-1 approach. You can freely convert from one contemplated technique to another during this stage.

After an adequate anesthesia, a clear cornea side port (paracentesis) at 8:00 (another at 2:00 for Phaco) is created (Figure 2.1).

Through the side port, a commercially available tryphan blue may be used to stain anterior capsule surface especially when dealing with white cataracts. During the process, an air is introduced first creating a

•Topical drops initially with Propacaine 1% then may use Lidocaine 2% into the conjunctiva as maintenance

•Subtenon injection at incision site with .3 ml premixed lidocaine 2% + 1:10000 epinephrine solution (dental anesthetic solution)

•Intracameral injection with .1 ml, .8% Lidocaine preservative-free solution (mix 2 ml preservative-free lidocaine 2% and 3 ml BSS)

•Infiltration block with 2.5 cc (2% Lidocaine + .5% isobaric Bupivacaine solution) + hyaluronidase

Figure 2.1: Corneal side port at 8:00

Figure 2.2: Intracameral tryphan blue

bubble inside the eye that protects the endothelium from staining. The dye is thoroughly washed off using BSS after about 15 seconds (Figures 2.2 and 2.3).

Adequate amount of hydroxymethylcellulose (viscoelastic gel) is introduced to deepen the anterior chamber. It also displaces the air bubble (Figure 2.4).

A capsulotome made from a bent gauge 26 needle attached to a water-filled tuberculin syringe is inserted through the primary side port to complete a continuous curvilinear capsulorhexis (Figure 2.5).

Care must be observed not to overfill the AC. This avoids the build-up of too much intraocular pressure that may unnecessarily injure the endothelium and the Descemet’s membrane. After CCC, hydrodissection/ hydrodelineation is done to separate the nucleus from

Figure 2.3: Washing off of tryphan blue

Figure 2.4: Viscoelastic gel into the anterior chamber (AC)

the cortex or the capsule using the same BSS filled capsulotome syringe (Figure 2.6).

Hints

1.In dealing with entumescent cataract, nick the anterior capsule to displace liquefied cortex into the AC. Introduced air will further displace liquefied cortex into the periphery and seep outside through the capsulotome side port making the CCC easier to manage.

2.A superior rectus bridle suture is necessary if you chose to do the surgery under retrobulbar/ peribulbar/or general anesthesia.

After this stage, you may choose your final technique of cataract surgery.

Incision Phase (Figures 2.7 to 2.13)

MSICS After a fornix based conjunctival flap with single temporal relaxing incision is completed, a selective and conservative hemostasis of superficial blood vessels using either a heat cautery or wet field bipolar to avoid shrinking the sclera. Using a caliper, a 5-8 mm length initial frowning scleral incision (depending on the estimated size of the lens nucleus and IOL to be used) with the apex of the frown at least 1 mm below the limbus, either at superior, superotemporal, or temporal is preferred, depending on the preference of the surgeon. Using a crescent knife and starting in the middle, keep the blade parallel with the sclerocorneal plane, insinuated in between scleral tissues until 2 mm past the limbus. Tunnel is extended

towards the peripheral limbus in a straight line forming a “V” shaped tunnel. A keratome is then insinuated in the tunnel following the initial wound, careful enough not to make another surgical plane. By tilting the tip of keratome downward, a corneal “dimple” becomes visible and a gentle forward movement of the knife penetrates the cornea. A sudden gush of viscoelastic gel is apparent once cornea is penetrated. The internal wound is extended from one end to the other following the internal corneal line. The tunnel is now shaped like a funnel with a much wider internal opening than the outer.

Phaco After a clear cornea main side port (paracentesis) at 8:00, a second side port at 2:00 is done. The former is for the capsulotome and the irrigating-aspirating