Infant aphakia treatment
IOL implantation in infants with congenital cataracts is safe, but decision must still be made on a case-by-case basis. Roibeard Ó hÉineacháin reports
Ramesh Kekunnaya MD, FRCS
The landmark infant aphakia treatment study (IATS) showed that aphakia is safe in very young infants. However, the decision to perform the surgery must be based on a range of considerations and equivalent or better results can be achieved by implanting an IOL in infants, notes Ramesh Kekunnaya MD, FRCS, LV Prasad Eye Institute, Hyderabad, India.
“IOL implantation can be considered even in selected babies who are less than six months of age. But the decision must be decided on case-by-case basis, not purely based on age. One must acquire adequate skills. If IOL implantation is not feasible, aphakia can be an effective alternative,” Dr Kekunnaya told the ESCRS/WSPOS symposium at the 38th Congress of the ESCRS.
He noted that based on current evidence, most paediatric ophthalmic surgeons are comfortable performing IOL implantation in infants between seven months and one year and age. Beyond 12 months there is little controversy regarding the safety and efficacy of IOL implantation. However, between zero and six months some doubt remains owing to the considerable changes that occur in axial length and keratometry that occur in that stage of an infant’s eye development.
The IATS study is a randomised, multi-centre clinical trial involving 114 infants ranging in age from four weeks to seven months with unilateral congenital cataract who underwent cataract surgery either with IOL implantation or with contact lenses.
The IATS study has generated several peer-reviewed reports regarding its short-term and long-term outcomes complications in the two study groups. Most recently, a publication in JAMA Ophthalmology showed that after a follow-up of 10 years implanting an IOL was neither beneficial nor detrimental in terms of visual outcomes (Lambert et al, JAMA Ophthalmol 2020; 138: 365-372).
The most common complications at five years were glaucoma suspect (19%) and contact lens related (18%) complications in the aphakia group and lens cell proliferation in the visual axis (40%), pupillary membrane (28%) and corectopia (28%) in the IOL group. There was also a 19% incidence of glaucoma in the IOL group, Dr Kekunnaya said.
In addition, 72% of patients in the IOL group required additional surgeries during five years of follow-up. That compared to only 16% of patients in the aphakia group. The most common follow-up surgery in the IOL group was clearance of visual axis opacities (68%). 14% of patients in the contact lens group required the same procedure.
However, most of the secondary surgeries in the IOL group were carried out in the first year after their cataract procedure and the number of surgeries required during second-to-third postoperative year were identical in the two groups.
Moreover, during postoperative years six through 10, half of those in the contact lens group underwent secondary IOL implantation, and four underwent glaucoma surgery. In the IOL group there were only four patients who required IOL exchange, one required glaucoma surgery and one underwent repair of a retinal detachment.
Overall there were more complications and more parental stress in the IOL group and greater expense during the first year than in the contact lens group. However, costs were greater after the first year in the contact lens group.
Important factors requiring consideration
The IATS study had a number of limitations that make translation of the findings to clinical decision making difficult, Dr Kekunnaya observed. Those limitations include the random allocation of patients to each patient group and the range of corneal diameters the groups. Furthermore, intraoperative findings were not included in the analysis. There were also variable dosages of steroids administered postoperatively.
“Basically, we need to take preoperative, intraoperative and postoperative factors into consideration. Also, we need to take socioeconomic factors into consideration. IATS was a study where insurance was available, it was not really representing the real world. IATS had a perfect situation, its results cannot be extrapolated to every patient,” he said.
Another factor to take into consideration is the compliance with follow-up visits. A study he and his associates conducted in India showed that attendance at follow-up visits fell of dramatically after the first six months among both paying and non-paying patients.
In addition, most congenital cataracts occur in Asia and Africa where most cases are bilateral. In the IATS study all were unilateral. Furthermore, in many parts of the developing world contact lenses are not as easily available. Moreover, the surgeon treating the patient must have adequate experience to perform the complex surgery involved in implanting the IOLs in infant eyes.
“We cannot say with the toss of a coin whether this patient will get an intraocular lens and that patient will get a contact lens, we need to look into the eye factors, the age factor and other factors before making the decision which surgery to perform,” Dr Kekunnaya added.
Ramesh Kekunnaya: firstname.lastname@example.org