STRABISMUS STUDY

Refractive surgery is safe and effective in patients with strabismus over the longer term, suggests new data presented at the 2013 Irish College of Ophthalmologists Annual Conference in Killarney, Ireland. Stephen Farrell MD, Mater Private Hospital, Dublin, presented the study data, which examined the long-term outcomes and safety of refractive surgery on ocular alignment, motor fusion and stereoacuity in adult patients with accommodative and non-accommodative strabismus.

Refractive surgery in this cohort usually carries greater risk, particularly in relation to decompensation of ocular alignment over time, thus careful patient selection is vital. Under the Irish study, all patients with manifest strabismus undergoing refractive surgery, including LASIK, LASEK or phakic intraocular lens (IOL) insertion, over a 27-month period at a single centre were included. Patients with best-corrected visual acuity (BCVA) of worse than 6/18 in either eye, a greater than two dioptre change in refraction following cycloplegia, and those unavailable for long-term follow up were excluded, Dr Farrell said.

This left 14 patients in the study, who had a mean follow-up duration of 4.5 years (range of 3.5 to 6.5 years). Six of these patients had accommodative esotropia, three had non-accommodative esotropia and five had exotropia. Following analysis, postoperative uncorrected Snellen visual acuity was found to be within one line of preoperative BCVA in all cases, and no patients suffered from diplopia at follow-up, Dr Farrell told the meeting.

There was also no significant difference between the angle of deviation preoperatively with spectacle correction and postoperatively unaided at follow-up in all groups. Stereoacuity decreased in one patient, increased in four patients and remained unchanged in nine patients.

Dr Farrell said the study confirmed the efficacy and safety of refractive surgery in this cohort over the longer term – no patients developed decompensation of strabismus or diplopia, and ocular alignment unaided remained similar to pre-operative ocular alignment with spectacles.

Safe and effective

“This study provides strong evidence that refractive surgery is safe and effective over the longer term. With a mean follow-up of 4.5 years this study provides longer follow-up than any other study published to date, “ he commented.

As well as refractive surgery providing all the benefits of being spectacle-free for these patients, it has now been found to be as effective as glasses at controlling strabismus over the longer term. “We would always stress the importance of careful patient selection and detailed orthoptic assessment preoperatively, however,” he remarked.

When asked about the potential for paediatric patients, he noted refractive surgery on children is usually for anisometropia rather than strabismus. “With longer follow-up of phakic intraocular lenses in children, they may in the future be an option for patients with strabismus, but given the changing nature of children's refraction spectacles are likely to remain the mainstay of treatment,” he told EuroTimes.