|LETTER TO EDITOR
|Year : 2003 | Volume
| Issue : 3 | Page : 282
Phacoemulsification in subluxated cataract
Praveen Krishna Ratnagiri
Praveen Krishna Ratnagiri
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ratnagiri PK. Phacoemulsification in subluxated cataract. Indian J Ophthalmol 2003;51:282
I read with great interest the article by Praveen et al on "Phacoemulsification in subluxated cataract". The authors must be particularly commended for employing the novel technique of using flexible iris retractors around the edge of the anterior capsulorrhexis for safer phacoemulsification. There are certain points that I would like to make to supplement and clarify the information in the article.
1. Timing of capsular tension ring (CTR) insertion: The authors have mentioned that in their series CTR was inserted only after phacoemulsification and removal of the residual cortex. However in the Discussion they note that presence of CTR enhanced the safety during phacoemulsification and avoided collapse of the bag after the lens was removed from the capsule. This creates confusion as to the exact timing of the CTR insertion in this case series. The timing of CTR insertion is important since it is certainly of greater advantage to insert the CTR prior to emulsifying the nucleus for the following reasons: (a) Reduction of intraoperative herniation of the vitreous into the anterior chamber due to partial reformation of the capsular zonular anatomic barrier. (b) Effective countertraction by the capsular equator (made taut by the CTR) for all traction maneuvers with a decreased risk of extension of the zonular dialysis. There is a circumferential rather than localised distribution of the traction forces to the entire zonular apparatus after the introduction of CTR. (c) Re-establishment of the capsular contour that protects the capsular fornix from being aspirated.
2. It has been mentioned that in two eyes placement of CTR was aborted due to anterior capsular tear. In cases with irregular or large rhexis where danger of capsular tear exists, use of modified versions of CTR incorporating fixation elements is safer. The fixation elements allow the surgeon to suture the ring to the scleral wall, through the ciliary sulcus, without violating the capsular ring.
3. It must be noted that despite all its advantages use of CTR is fraught with certain risks in cases with severe or progressive zonular dehiscence since it might lead to IOL decentration, pseudophacodonesis and rarely the disastrous occurrence of complete dislocation of the bag, CTR and the IOL into the vitreous.
4. The authors have mentioned the Cionni Ring as an alternative for better centration and stability of the IOL. However this ring has certain limitations, such as difficulty in implantation if the capsulorrhexis is small. In such instances the fixation hook in the ring may drag on the edge of the anterior capsule and lead to iris chafing, pigment dispersion and chronic uveitis.
5. An alternative technique that could be employed in cases with severe zonular dehiscence and non-availability of modified CTRs such as the Cionni Ring, is to make a small equatorial capsulorrhexis through which a standard CTR is inserted. A scleral suture is then passed around the exposed CTR that is then used to center the lens before capsulorrhexis.
6. In phacoemulsification for subluxated cataracts, it has been advocated that location of the tunnel incision be placed at the meridian with no zonular dialysis. This is to avoid damage to the zonular fibres with the movement of the phacotip. But controlled phacoemulsification along with surgical expertise makes this paradigm redundant. The authors have to be congratulated for showing this by using a temporal corneal incision for all the patients in this case series.
7. There are certain additional tips when performing a phaco on a subluxated cataract: (a) It is advisable to begin the capsulorrhexis where the zonules are intact and the anterior capsule offers sufficient resistance. (b) Whenever feasible, it is better to insert the hydrodissection cannula in the direction of the zone of disinsertion. (c) In cases of hard cataracts, the surgeon could emulsify them in the anterior chamber rather than within the bag itself in order to avoid putting stress on an already damaged zonular apparatus. (d) During automated cortical aspiration, movements of the tip should not be radial due to the risk of traction on the capsular bag and the CTR. In fact, manual aspiration with a simcoe cannula would be a more controlled alternative to automated aspiration. (e) It is safer to place the IOL haptics in the meridian of the zonular disinsertion whenever possible.
| References|| |
Praveen MR, Vasavada AR, Singh R. Phacoemulsification in subluxated cataract. Indian J Ophthalmol
Menapace R, Findl O, Georgopoulos M, Rainer G, Vass C, Schiuetter K. The capsular tension ring: Designs, applications and techniques. J Cataract Refract Surg
Nishi O, Hishi K, Sakanishi K, Yamada Y. Explantation of endocapsular posterior chamber lens after spontaneous posterior dislocations. J Cataract Refract Surg
Patel N, Las V, Agarwal A, Agarwal A. Phaco in subluxated cataract. Delhi J Ophthalmol