We would like to address an important comment in relation to the case report on intraocular lens (IOL) implantation in a child with monocular cataract and anterior persistent hyperplastic primary vitreous by Morita et al.1
The term phacoemulsification is used by the authors several times to describe the surgical technique to aspirate the lens of the child. The authors imply that they routinely use this technique when dealing with pediatric cataracts “to maintain the posterior capsule in case of future IOL implantation.” Phacoemulsification involves the use of an ultrasonic vibrating tip that fragments a hard nucleus and creates an emulsification with irrigating fluid, which is then aspirated through a small incision (as per adult cataract surgery). Phacoaspiration (a term used in the pediatric cataract unit at Great Ormond Street Hospital for Children) is the simple aspiration of lens matter, which may or may not be automated, also through a small incision.
Various authors have referred to phacoemulsification as simple aspiration of the lens; others actually use it as the procedure of choice.2–7 We believe that this may be misleading and suggest that the term phacoaspiration is more appropriate.
The nucleus in children is soft and can be easily aspirated in a short period without causing major endothelial damage. We have never required the use of ultrasound high frequency vibration to “soften” the lens matter before aspiration. There are isolated circumstances in which simple aspiration is not feasible, such as membranous cataracts in which the lens material leaks and absorbs, leaving behind the fused capsular bag with a variable amount of residual lens matter, or in babies with persistent hyperplastic primary vitreous who have thick retrolenticular membranes in which intraocular scissors and intraocular diathermy are required.8–10 The vitrector alone or phacoemulsification devices do not work in these cases. Occasionally, there are calcified cataracts with particles of varying degrees that can be manually removed with an intraocular forceps or can be washed out through the surgical wound with gentle irrigation gradients.
It has been demonstrated that not only the probe tip and the lens fragments can cause endothelial damage, but also the air bubbles produced by the phacoemulsification port.11,12
Although the endothelial cell count in children is much higher than in adults, loss of endothelial cells must be avoided since these children need a healthy endothelium for many years ahead. All these important aspects have to be taken into account when considering cataract surgery in children; the safest, fastest, and simplest approach should be considered. After all, the goal of adult cataract surgery is to remove the cataract with minimal phacoemulsification power and maximum safe aspiration. In pediatric cases the maximum phacoemulsification power should be zero. Phacoaspiration and not phacoemulsification is the surgical technique of choice for removal of pediatric cataracts.
Luis Amaya MD
David Taylor MD
Isabelle Russell MD
Ken Nischall MD
aLondon, UK England
1. Morita S, Kora Y, Takahasi K, et al. Intraocular lens implantation in a child with monocular cataract and anterior persistent hyperplastic primary vitreous. J Cataract Refract Surg 2001; 27:477-480
2. O'Keefe M, Mulvihill A, Yeoh PL. Visual outcome and complications of bilateral intraocular lens implantation in children. J Cataract Refract Surg 2000; 26:1758-1764
3. Hamill MD, Koch D. Pediatric cataracts. Curr Opin Ophthalmol 1999; 10(1):49
4. Ritzinger I. Phacoemulsification in infants. Klin Monatsbl Augenheilkd 1982; 181:130-131
5. Hiles DA, Carter BT, Chotiner B. Phacoemulsification of infantile cataracts. Trans Pa Acad Ophthalmol Otolaryngol 1978; 31(1):30-37
6. Bobrova VF, Varga T. An improvement in the technique and results of phacoemulsification of congenital cataracts in children. Oftalmol Zh 1989; 3:137-142
7. Bobrova VF. Variants of the phacoemulsification technique in various clinical forms of pediatric cataracts and their effectiveness. Oftalmol Zh 1988; 5:290-294
8. Pollard ZF. Treatment of persistent hyperplastic primary vitreous. J Pediat Ophthalmol Strabismus 1985; 22:180-183
9. Scott WE. Treatment of congenital cataracts and persistent hyperplastic primary vitreous. Trans New Orleans Acad Ophthalmol 1986; 34:461-477
10. Stark WJ. Surgical management of persistent hyperplastic primary vitreous. Aust J Ophthalmol 1983; 11:195-200
11. Beesley RD, Olson RJ, Brady SE. The effects of prolonged phacoemulsification time on the corneal endothelium. Ann Ophthalmol 1986; 18:216-219
12. Kim EK, Cristal SM, Geroski DH, et al. Corneal endothelial damage by air bubbles during phacoemulsification. Arch Ophthalmol 1997; 115:81-88