7.1 MICS in Special Cases: Incomplete Capsulorhexis

7.1MICS in Special Cases: Incomplete Capsulorhexis

Arturo Pérez-Arteaga

Core Messages

ßWhile performing Cataract Surgery with MICS, the surgeon has a better potential to solve prob-

lems related to an incomplete capsulorhexis.

ßCapsulectomy with micro-scissors in the dominant hand, while holding the eye with the non-

dominant hand is an important maneuver to direct the course of a failed capsulorhexis and is also very helpfulin cases of zonular weakening.

ßIf the surgeon is unsure of the completion of capsulorhexis, special care should be taken

and the case should be proceeded with assuming that it is incomplete, to avoid further complications.

ßThe key to the management of an incomplete capsulorhexis case is to work at the iris plane,

avoiding applying forces to the capsular bag and the zonular ligament.

ßThe prechop maneuvers can be easily done with MICS at the iris plane. The “lens salute tech-

nique” is a good maneuver for MICS surgeons to use in these particular cases.

7.1.1 Introduction

To deal with an incomplete capsulorhexis is a situation, which directly affects the knowledge and the skills of the ophthalmic surgeon. Every surgeon who has faced this stressful situation knows about the significant complications that can occur, if an appropriate management is not done. In fact, it is a particular situation that predisposes to other complications. It is better termed as a particular event or feature occurring during the start of lens extraction. With proper management, the surgeon may avoid most of the potential complications such as vitreous loss, nuclear, and epinuclear fragments dislocated to the vitreous, complete luxation of the nucleus to the vitreous cavity, and problems in intraocular lens (IOL) placement that can range from decentration to a

complete dislocation. This is the interesting feature of this situation. It is almost a complication, but not a complete one. The proper management of this situation will help the surgeon avoid dealing with true complications.

It is also a situation that cannot be defined in one single term. “Incomplete Capsulorhexis” can include a wide variety of situations, ranging from a single accidental tear occurring in the anterior capsule that can be corrected by performing a wider capsulorhexis, to a bigger tear involving the posterior capsule that will change the entire management of the case. This is what is interesting about this situation.

In the past years, the biaxial approach has proved to be more advantageous in managing an anterior capsule tear than the coaxial approach, not only in routine microcapsulorrhexis, but also in the management of surgical complications that can occur during this step (Fig. 7.30). This chapter will first discuss the correct way to perform biaxial microcapsulorrhexis in order to decrease the rate of complications. Then, the different types of “incomplete capsulorrhexis” that can occur and their management using the biaxial approach will be described. Finally, some variations in the technique of phacoemulsification that should be done in these particular cases will be discussed, emphasizing the advantages of biaxial phaco over coaxial phaco, and therefore, encouraging more surgeons worldwide to adopt this technique for their patients’ benefit.

Many techniques described here regarding coaxial and biaxial cataract surgery and their differences, have been part of several publications. Some are part of instructional courses of MICS presented at international meetings (AAO, ASCRS, ESCRS). Finally some of the techniques

Fig. 7.30 Performing Microcapsulorhexis in Biaxial Approach

belong to the authors’ personal experience in the operating room. Science is always changing. With the passing of time, improvements in the technique will come. At this moment, this is the best, we ophthalmologists have.

7.1.2Avoiding Complications While Constructing Your Microcapsulorhexis

The biaxial surgeon has many advantages in comparison with the coaxial surgeon in constructing a capsulorrhexis:

1.The incisions are smaller and so, both the anterior chamber depth and positive intraocular pressure are maintained, because of minimal leakage at the incision sites (Fig. 7.30).

2.The microcapsulorrhexis forceps does not have the “opening mechanism” at the incision site unlike conventional capsulorrhexis forceps, decreasing in this manner, the trauma to the corneal tissue and possible leakage (Fig. 7.31).

3.The nondominant hand is holding the eye through the side incision. It helps in decreasing the movement of the eye while performing the capsulorrhexis. It also helps to reposition the eye for better visualization of the capsule, capsular reflex and the red reflex during this step (Fig. 7.30).

4.It may be helpful if the instrument held in the nondominant hand is a viscoelastic cannula, so that the

Fig. 7.31 Microcapsulorhexis forceps. Notice the stability of the chamber and the incision

surgeon can inject the viscoelastic, if needed, maintaining a positive IOP during the entire step, and thereby eliminating the need for changing instruments (Fig. 7.30).

5.The surgeon can have two (and sometimes three) angles to approach the capsulorrhexis,so that he can switch to either incision site to insert the forceps depending on the particular case or situation.

These advantages of the biaxial technique during capsulorrhexis will be of particular benefit in avoiding complications, and this is more important in the management of an incomplete capsulorhexis. So the biaxial surgeon must try to perform each and every capsulorrhexis under these conditions.

A step-by-step guide on how to avoid an incomplete capsulorrhexis during cataract surgery will be described in the succeeding paragraphs. Other possible surgical maneuvers and/or devices such as capsular rings and capsular staining will not be discussed, because the focus of the authors is the biaxial approach of managing a complicated capsulorrhexis:

(a)Initial Capsule Puncture: Before performing the first puncture in the anterior capsule (with coaxial forceps or with cystotome), the anterior chamber should be completely filled with the viscoelastic. Otherwise, if low IOP is present during this first step, the rhexis can run easily to the periphery. Complete visualization of what is being done is essential. The nondominant hand can aid the surgeon to fixate the eye in the position where he can have the best view of his surgical field. During the puncture, the elasticity of the capsule can be felt. If it is too fibrotic, the surgical plan can be changed. The same is true if there is movement of the entire crystalline lens. Weak zonules (e.g., pseudoexfoliation syndrome, high myopia) should be noted at this time. The initial puncture is the perfect time to obtain invaluable information regarding the capsule, the zonules and the density of the cataract (Fig. 7.32).

(b)Cutting instead of pulling the capsule for cases with weak zonules: If a fibrotic capsule is present or if there is excessivemovement in the lens, avoid, pulling the anterior capsule, as much as possible. “To cut the capsule” (micro-capsulectomy) is the recommended technique, which avoids the transmission of forces to the capsular bag and to the zonules. The biaxial approach can be performed by taking advantage of the bimanual stabilization of

Fig. 7.33 Biaxial Micro-capsulectomy. Notice he micro-scis- sors in biaxial approach

the eye (Fig. 7.33.). The viscoelastic cannula is held with the nondominant hand and maintained inside the wound to fixate the eye. Then a micro-scissors on the dominant hand is inserted through the main incision. The capsule is cut with the micro-scissors as far as it can be reached to advance the CCC. Once this has been done, it is possible to change to the micro-capsulorrhexis forceps to complete the CCC as planned. With this maneuver, the initial capsular pull is avoided and less transmission of forces against the capsule occurs. Although capsular tension rings are always useful for these situations, rin this chapter, the advantage of the biaxial capsular maneuver in order to decrease complications is emphasized.

(c)Pulling towards the meridian of the forceps insertion (Fig. 7.34): By pulling, instead of pushing towards the meridian of the forceps insertion during the initial creation of the capsulorrhexis, the surgeon can control the eye with the nondominant hand, counteracting the movement of the eye to the opposite meridian. Also, one can decrease with this maneuver, the transmission of forces to the capsular bag and zonules. Initiating the capsulorrhexis too peripheral should be avoided. In fact, after the completion of capsulorrhexis 360° and after passing through the starting point, if the size of the rhexis is not adequate enough, the rhexis can be enlarged by extending more peripherally. If it is started para-cen- trally, there will be more space to enlarge the rhexis, and enough time to stop, in case a peripheral tear starts. In these cases, stop for a whilefill the anterior chamber again with the viscoelastic, and then proceed to continue with the CCC once or twice. If the peripheral tear can be controlled by pulling the anterior capsule toward the same meridian,

(d)Pulling to the opposite side (Fig. 7.35): What is to be avoided, when a capsular tear has started, is further complications of letting it run to the periphery. So, if by trying to pull the same capsule flap, an even larger tear is created, the surgeon should leave this first capsular flap and start a second one. The surgeon should grasp the anterior capsule at the site of first puncture and perform the capsulorrhexis going to the opposite direction. Since every precaution was made not to start the initial flap at the periphery, this second capsulorrhexis can be moved far away from the initial flap. The eye should be stabilized

Fig. 7.35 Performing CCC in the opposite direction that it starts; the initial point will be covered by the CCC

Fig. 7.37 Micro-scissors entering at a new angle to create a new capsular flap

Fig. 7.36 Two differents points of start CCC were done in the anterior capsule

with the viscoelastic cannula through the incision site on the nondominant hand. If needed, the surgeon should fill the anterior chamber with viscoelastic at all times. This biaxial approach makes it possible to perform this maneuver with ease.

(e) Performing a new puncture (Fig. 7.36): Sometimes it is difficult to create a new tear in the same site. Pulling the flap several times as one tries to salvage the capsulorrhexis may not be possible and so it is better not to attempt any furtheras there is a high risk of a peripheral tear while trying to pull to the opposite meridian. In such cases, stay calm, fill the anterior chamber with the viscoelastic, and forget about the first capsular puncture, and create a new puncture in another meridian of the anterior cap-

sule. This new site should be easily accessible and be visualized very well. The nondominant hand should always be used to stabilize the eye and provide better visualization.

(f)Microcapsulectomy to redirect capsulorhexis (Fig. 7.37): Since the surgeon is working with both hands in the biaxial approach, he may use micro-scissors whenever required. . Sometimes, if there is a failure in creating a good capsular flap, it is best to direct the new flap in another area of the anterior capsule with capsular scissors. This maneuver is possible only in a biaxial approach, because the micro-scissors can go inside the eye through a 0.7-mm incision. The “opening mechanism” is not in the incision site and the maintenance of a well formed AC is guaranteed, because the surgeon can perform the maneuvers without any leakage. Hence, the surgeon should perform an initial flap with scissors, and then move to the micro-forceps to continue the creation of CCC.

(g)Multiple capsulectomies (Fig. 7.38): If there is still some difficulty in controlling the anterior capsule and the possibility of a peripheral tear exists, the surgeon can use the micro-scissors to cut the capsule in a continuous curvilinear manner. The surgeon can perform one or two clear corneal incisions in other meridians for this purpose, to help redirect the capsule while he is advancing the CCC. For this maneuver, it is very useful to always keep the eye stable with the use of the cannula in his nondominant hand. It is sometimes difficult to perform, particularly for the beginning biaxial surgeon, but it is the safest way to control the size and direction of the CCC.