Review Article Surgery for Congenital David Yorston ber of tests and investigations on all children FRCS FRCOphth with cataract. It is better to take a careful his- Specialist Registrar tory, including a family history, from the Moorfields Hospital parents. Ask about any illnesses or drugs City Road used during the pregnancy, and find out if London EC1V 2PD the child is developing normally. UK Remember that all blind children will expe- rience some developmental delay, and this in children, although is usually reversed if vision is restored. complex and time-consuming, can have Introduction However, speech and hearing development excellent results Photo: David Yorston The management of is should be normal. will require a general anaesthetic. There very different to the treatment of a routine If possible, the child should be examined may be associated cardiac or other congen- age-related cataract. In adults, surgery may by a paediatrician, who can look for other ital anomalies. The infant eye behaves very be delayed for years without affecting the congenital anomalies, and can determine if differently to an adult eye. Congenital visual outcome. In infants, if the cataract is the child is fit for general anaesthesia. If the cataract surgery should only be performed not removed during the first year of life, the history and examination do not give any in centres that are suitably equipped to carry vision will never be fully regained after clues to the cause of the cataract, there is lit- out these demanding procedures (Box 2). surgery. In adults, if the is not cor- tle point in doing any further investigations. Children do not have a hard nucleus, rected immediately, it can be corrected so it is possible to remove the entire cataract later. In young children, if the aphakia is not When to operate by aspiration alone. There are two opera- corrected, the vision will never develop nor- The rules for operating on cataract are quite tions that are widely used for congenital mally. simple. should only be removed cataract. when: Pre-operative Evaluation Lensectomy 1. They are interfering with a person’s Because the whole process of managing a quality of life In a lensectomy, most of the lens (including congenital cataract is much more complex, 2. There is a reasonable prospect that the posterior capsule) and anterior vitreous it is very important to make the right deci- surgery will lead to a significant imp- is removed. This leaves a permanently sions during the pre-operative evaluation. rovement in vision. clear visual axis. However, it requires a In adults, we know that most of the poor out- vitrectomy machine, and any interference comes following cataract surgery are due to This is true for congenital cataract as well. with the vitreous may increase the risk of poor case selection. Poor decision making at Unfortunately, it can be very difficult to late . this stage can result in children being blind answer these two questions in children. As My preferred technique is to use an ante- for the rest of their lives. a general rule, if a child is behaving and rior chamber maintainer inserted through Congenital cataract affects not only the developing normally, do not operate, but the . I then remove the anterior lens child but also their immediate family. keep under review. As the child grows, the capsule with the vitrector, leaving an intact Money spent on treatment means less is visual demands will also increase. For rim of capsule. The lens matter is aspirated, available to send other children to school. It example, a mild cataract may not interfere and then the posterior capsule and anterior is very important to ensure that the family with playing outside the house when a child vitreous are removed using the cutting understands the prognosis and duration of is four years old, but does cause problems at action of the vitrector. treatment because they are going to be school when he or she is learning to read at Provided an intact rim of capsule is r e s p o n s i b l ef o ri m p l e m e n t i n gm o s to fi t .T h e the age of six or seven. Do not be misled by retained, it is possible to insert an IOL at the families have to become our partners and the , as children may see remark- time of surgery or later as a secondary colleagues in treating their own children. ably well despite a zonular cataract through procedure. which no red reflex is visible. Remember Investigations that removing a cataract in a child removes Extra-capsular Cataract Extraction their ability to accommodate. They may be (ECCE) Age-related cataract usually occurs in isola- better off with 6/18 and a full range of The anterior capsule of a child is much more tion, and we rarely investigate patients to than they would be with elastic than an adult lens. This makes con- look for some underlying cause for their 6/9 and no depth of field. tinuous curvilinear capsulorhexis (CCC) lens opacity. However, in children, cataract Although cataract surgery in children more difficult. The rhexis should be kept is much less common, and is more likely to should be done as early as possible, if there small (4–5mm) as the lens matter can easily be associated with some systemic condi- is real doubt about whether children will be aspirated with a Simcoe cannulae, and tion. There are numerous different condi- benefit, they are unlikely to come to serious there is no large nucleus to remove. tions that may be associated with cataract in harm by waiting a little longer. As they grow Alternatively, a standard can-opener capsu- childhood (Box 1). Most of these are rare, older, it becomes easier to test their vision, lotomy can be performed. and in many children we do not know what and to determine if they need an operation. causes the cataract. Even in rich countries, If the capsule is left intact, it will opacify. In adults, most patients do not develop visu- with almost unlimited resources, no cause is Surgery found for the majority of cataracts occurring ally significant posterior capsule opacity. in children. Cataract surgery in children is very different However, in children, every eye will even- There is no benefit in doing a large num- to cataract surgery in adults. The operation tually need a capsulotomy. Some surgeons Community Eye Health Vol 17 No. 50 2004 23 Review Article perform a primary capsulotomy at the end of months until two years old, reducing to an the ECCE. However, this frequently closes annual check after the age of five. and requires revision, particularly in younger children. My own preference is to do a lensectomy Most children with congenital cataract will on most children under five years old, and be amblyopic. Because the retinal image has an ECCE on most older children. The ratio- been blurred by the cataract, vision does not nale for this is that older children are at develop properly, and the brain cannot much less risk of amblyopia, so vision lost make sense of the information it receives from capsule opacity can be regained. In from the eye. Removing the cataract, and younger children, capsule opacity can lead correcting the aphakia, will restore image to irreversible amblyopia and must be pre- clarity but the brain still needs to learn to vented. see, and this takes time. If the have never had clear vision, they will not fixate Intra Ocular Lenses (IOLs) accurately and this can lead to . If In infants it is essential to correct aphakia as the vision is restored, the nystagmus will The spectacles should be fitted as soon as the child is able to wear them soon as possible after surgery. One option is often resolve, so nystagmus in a child is not Photo: Clare Gilbert to implant an IOL when the cataract is a contra-indication to surgery. removed. Unfortunately, it is not that sim- Frequently one eye will do better than the which makes the other eye amblyopic. The ple. At birth the human lens is more spheri- other and this will become the preferred eye, only way to detect this is to measure the best cal than in adults. It has a power of about 30D, which compensates for the shorter Box 1: Causes of Congenital Cataract axial length of a baby’s eye. This decreases 1. Prenatal (intra-uterine) infection e.g. rubella, , . to about 20–22D by the age of five. This 2. Prenatal (intra-uterine) drug exposure e.g. , vitamin A. means that an IOL which gives normal 3. Prenatal (intra-uterine) ionizing radiation e.g. x-rays. vision to an infant will lead to significant 4. Prenatal / peri-natal metabolic disorder e.g. maternal diabetes. when he or she is older. It is further 5. Hereditary (isolated - without associated eye or systemic disorder) e.g. autosomal complicated by changes in the power of the dominant inheritance. cornea and axial lengthening of the . 6. Hereditary with associated systemic disorder or multi-system syndrome. These changes are most rapid during the a) Chromosomal e.g. Down’s syndrome (trisomy 21), Turner’s syndrome. first few years of life and this makes it b) With skeletal disease or muscle disorder e.g. Stickler syndrome, Myotonic almost impossible to predict the correct dystrophy. power of lens for any infant. c) With central nervous system disorder e.g. Norrie’s disease. IOL implantation has become quite rou- d) With renal disease e.g. Lowe’s syndrome, Alport’s syndrome. tine for older children, but it is still very con- e) With mandibulo-facial disorder e.g. Nance-Horan cataract-dental syndrome. troversial in younger children, particularly f) With dermatological disorder e.g. Congenital icthyosis, . those under two years old (see Community Box 2: Minimum Facilities for Congenital Cataract Surgery Eye Health Vol.14 No.40, 2001). 1. An anaesthetist with suitable equipment and skills to treat infants and small children. Post-operative Care 2. A vitrectomy instrument (and/or anterior vitrectomy) to deal with the posterior capsule. 3. An ophthalmologist with experience in treating children. In adults, little post-operative care is 4. Access to paediatric care for children with associated problems. required, apart from the provision of eye 5. Access to low vision services to ensure that the child’s vision develops as well as drops and spectacles – if required. In possible. children, the surgery is only the beginning of a prolonged course of treatment and this needs to be emphasised from the beginning.

Refraction The first priority is to correct the aphakia and this should be done as early as possible. In rich countries contact lenses are widely used. They can be changed easily and the power can be modified. However, they require meticulous hygiene and this makes them inappropriate in situations with inade- quate water and sanitation. Alternatives are to use spectacles or an IOL. Even if an IOL is used there will be some residual and spectacles will be necessary to get the best possible vision. The spectacles should be fitted as soon as the child is able to wear them. The refraction must be checked regularly, at least every four Fig. 1: Results of Cataract Surgery in Young Children in East Africa 24 Community Eye Health Vol 17 No. 50 2004 Evidence-based Eye Care corrected vision regularly in each eye. If one an opening in the capsule with a Nd:YAG cataract. It often occurs very late, on aver- eye is two or more lines worse than the laser or a needle. Alternatively, the posteri- age 35 years after the operation. If any other, with no other apparent explanation, it or capsule and anterior vitreous can be patient complains of sudden loss of vision, is probably amblyopic and the child needs removed with a vitrector. If the capsule is even if it is years after their operation for occlusion treatment of the preferred eye. opened without removing the vitreous, the congenital cataract, it should be assumed to The risk of amblyopia is greatest during the opacification may recur on the anterior be due to retinal detachment until proven first year of life and declines rapidly after hyaloid face. Loss of vision in one eye from otherwise. the age of five. increasing capsule opacity will be asympto- Providing optimum care is provided, the matic and the only way to detect this is by Conclusion visual prognosis is good. In Kenya, 47% of regular examinations. eyes achieved 6/18 or better and only 5% may occur after lensectomy, The management of congenital cataract is were less than 6/60.1 Almost all these particularly if it is carried out in the first complex, and should only be carried out in children will be able to attend a normal week of life. This glaucoma is very difficult specialist centres. However, every eye school (Fig.1). to treat and frequently leads to blindness. worker can play a role by assisting with case Delaying surgery until after the child is 3–4 finding and follow-up. Complications months old makes it unlikely that the eyes will recover 6/6 vision but it reduces the risk Reference Every child who does not have a posterior of glaucoma. capsulotomy will develop posterior capsule Yorston D, Wood M, Foster A. Results of cataract Retinal detachment is more common in surgery in young children in East Africa. Br J opacification. This can be treated by making eyes that have had surgery for congenital Ophthalmol. 2001; 85 (3):267–271. Evidence-based Eye Care Evidence for the Effectiveness of Interventions for Congenital, Infantile and Richard Wormald Treatment of Bilateral Cases hard to determine which are the key com- MSc FRCS FRCOphth ponents to improved outcome. There are numerous surgical procedures Since 2001, seven new trials have so far Co-ordinating Editor described for the treatment of cataract been identified including a large one from C o c h r a n eE y e sa n dV i s i o nG r o u p( C E V G ) including peripheral iridectomy (for cen- China comparing acrylic and polymethyl International Centre for Eye Health tral opacities), needling and aspiration, methacrylate lenses (though it is not clear if London School of Hygiene and Tropical lensectomy, optic captured posterior cham- this was truly randomised) and four on var- Medicine ber after phaco-emulsifica- ious aspects of technique relating to optic Keppel Street, London WC1E 7HT tion (termed ‘bag in the lens’ procedure by capture. The other two are on the use of try- one group). So what is the best procedure pan blue for capsulorhexis and a compari- Introduction in terms of visual outcome, short and long son of two methods of hydrodissection. Certain groups are often excluded from term complications and cost-effectiveness? A Cochrane Systematic review was pub- Treatment of Unilateral Cases trials of new interventions, typically preg- lished in 2001 asking the question “What is nant women and children, but also people the effectiveness of surgical interventions The treatment of unilateral congenital unable to give informed consent. Children for bilateral congenital cataract”. As in most cataract is another question and is the sub- are not included perhaps because of a dis- Cochrane reviews, only the best evidence ject of much discussion though so far there taste for ‘experimenting’ on little ones and was included, i.e. randomised controlled are no trials. A study examining the feasi- a reluctance to admit to clinical uncertainty trials. Only one trial was found comparing bility of randomising children in USA to when faced with anxious parents. lensectomy to lens aspiration intraocular lens or correction of Unfortunately such attitudes lead to con- and primary capsulotomy. Though both aphakia has been published in the Journal of tinuing uncertainty about the effectiveness groups did well in terms of visual outcome, Amerian Association of Pediatric Ophthal- of key interventions in these population there were more complications in the aspi- mology and (AAPOS). This subgroups who are often, ironically, the ration group but follow-up was not long article also describes the considerable subject of our special concern. enough to address the important concern amount of stress that such interventions Cataract in children is an important cause about late glaucoma after lensectomy. The place on both the child and parents when the of and treatment can review is now in the process of being results of preserving useful sight in the make a difference if it can be delivered updated. Since it was published, clinical cataractous eye are not great. effectively and in time. But there are many practice has been changing and lens The treatment of stimulus deprivation questions about how this is best achieved – implantation in the bag with or without pri- amblyopia in both unilateral and bilateral clinical questions which need good mary posterior capsulotomy or with cap- cases is also in need of good evidence of evidence for an answer. And before ture of the optic within anterior and poste- effectiveness and a title for a Cochrane addressing these, there are others – about rior capsulorhexis is becoming more com- review on this subject has been registered. how best to detect cataracts in babies (there mon. The age at which surgeons are happy are no randomised trials as yet) and whether to intervene is also falling. Conclusion or not there is any potential for prevention. The situation is made more complex by Immunisation for rubella is relevant, and, of the fact that several different parameters are This remains an issue of intense importance course, understanding genetics. being modified simultaneously so that it is in the control of childhood blindness and, as Community Eye Health Vol 17 No. 50 2004 25