Objective
To explore the views of specialist ophthalmic surgeons in Wales in the context of planning cataract surgery in patients with amblyopia. To compare dominating views and choices with recommendations in published literature.
Cataract Surgery Planning in Amblyopic Patients
Approach
A cross-sectional study was conducted where all specialist eye doctors working in Wales were welcomed to finish an online study created utilizing the Study Monkey tool (http://www.surveymonkey.com). The study included a scientific scenario including an amblyopic patient with bilateral cataracts with questions designed to elicit responders’ choices with regard to which eye they would run on first in addition to the reasoning behind their medical choice making.
Results
32 out of 42 experts reacted to the survey (a reaction rate of > 75%). With regards to the sequential order of surgery 18 (56.26%) suggested that they would carry out cataract surgery first on the non-amblyopic eye, 11 (34.4%) would surgically address the amblyopic eye first and three (9.4%) suggested that patient choice would dictate the choice concerning the laterality of the eye to be run on first. While 24 responders (75.0%) had actually experienced amblyopic patients who had actually developed problems after cataract surgery just 10 (31.3%) opined that official assistance from the Royal College of Ophthalmologists was necessitated.
Conclusion
These results indicate that awareness of post-cataract surgery diplopia, and in certain fixation switch diplopia, is not widespread amongst expert ophthalmic specialists in Wales.
Cataract Surgery with Amblyopia: Overview
Precise preparation prior to cataract surgery with intraocular lens implantation is essential in order to attain a maximum post-operative outcome. A potentially problematic scenario surrounds the planning of adult cataract surgery in patients with a history of amblyopia, a condition known to impact around 3.6% of the population of the United Kingdom. Fixation switch diplopia is an acquired form of diplopia which can affect patients with a history of youth strabismus and/or amblyopia in which fairly hindered vision in the dominant eye encourages fixation with the non-dominant eye. Post cataract surgery diplopia can influence up to 3% of patients and published literature recommends the exercise of care when deciding to perform cataract surgery on an amblyopic eye prior to that on the more powerful eye in order to avoid such fixation switch diplopia. As soon as this occurs, the treatment of this problem can be tough, with substantial resultant morbidity. In view of this, and the great deals of cataract extractions carried out annually in the United Kingdom4, we set out to investigate existing practices in preparing cataract extractions in such patients amongst consultant ophthalmic specialists in Wales.
Methods of Cataract Surgery with Amblyopia
A cross sectional survey was created in which an e-mail was sent to every expert in Wales welcoming them to participate in an anonymous online study, the link for which was consisted of. The following situation was explained:
” A 56year old gentleman in excellent basic health provides with symptomatic visual disability. Best remedied spatial acuity procedures 6/18 in the right eye and 6/60 in the left. Ocular assessment is unremarkable apart from nuclear cataracts of similar density in both eyes and a hardly noticeable and cosmetically outstanding concomitant left esotropia of 10Δ.
Past ophthalmic history includes left amblyopia (previous documented best-corrected skills are 6/4 right eye and 6/9 left eye). He is eager to continue his occupation as an accounting professional as well as to drive a motor vehicle– and likes surgical intervention.”
Participants were asked which eye they would run on first and why. In addition, participants were asked if they recognized with amblyopic patients who had developed problems following cataract surgery and also whether they thought any formal assistance from the Royal College of Ophthalmologists was called for. An overall of 6 weeks was enabled replies to be gathered. A 2nd wave of email invitations were then sent in order to provide those that had actually not finished the study the first time a chance to do so.
Results of Cataract Surgery in Amblyopia Patients
Thirty two from forty two polled consultants responded to the study, a reaction rate of > 75%. Of the 32 responders to the study 18 (56.26%) decided to perform right (dominant) eye surgery first, 11 (34.4%) opted to perform surgery on the left (amblyopic) eye first and three (9.4%) opted to offer the patient the option. Of those who would operate on the right eye first, 13 (72.2%) specified ‘much better visual capacity’ as a factor while two (11.1%) responders discussed post-operative diplopia as a risk were the non-dominant eye to be run on first. In those deciding to carry out surgery on the amblyopic eye first the commonest factor stated was the worse skill (7 responders– 63.6%) in that eye. An additional two (18.2%) specified that a personnel issue would be less of a problem in an amblyopic eye. In all, while 24 responders (75.0%) had experienced amblyopic patients establish issues after cataract surgery only 10 (31.3%) believed that official guidance from the college was warranted.
Related discussions
The results of this online cross sectional study recommend that awareness of post cataract surgery diplopia, and in certain fixation switch diplopia, is not extensive amongst specialist ophthalmic cosmetic surgeons in Wales.
Implicit to the clinical problem is the fact that, subject to the procedure being uneventful, the post-operative best remedied spatial skill in the left (non-dominant) eye would be 6/9, whilst the acuity of the right (dominant) eye would remain at 6/18– a minimum angle of resolution of double the magnitude– probably conditions that would be perfect for the advancement of FSD.
It is fascinating that 34.4% of responders would run on the amblyopic eye first. Not only would this run the risk of fixation switch diplopia, it would likewise leave unaddressed the primary grievance of the patient– i.e. subjective visual problems, a symptom associated to the dominant eye. Likewise the majority (63.3%) of those who decided to operate initially on the amblyopic eye picked ‘eye with the worse visual skill’ as their reason for doing so. In itself this belies an essential misconception of the nature of amblyopia. It is also of issue that 18.2% showed that they would carry out surgery on the amblyopic eye first on the premises that any complications would be less substantial than were they to occur in the better eye. This leaves unaddressed the fact that the much better eye would still have to go through cataract surgery in order to solve the visual symptoms and arguably, running at first on the amblyopic eye simply delays this risk. Likewise of note is that whilst 75% of responders had personally encountered amblyopic patients with issues following cataract surgery, only 31.3% felt that formal assistance from the college was necessitated. It would appear sensible to presume that these clinicians felt that cataract surgery planning in such patients was currently well understood by the current generation of cataract specialists working in Wales; whereas the outcomes of this research study would recommend otherwise. At the very least in the preparing of such standards top priority might possibly be leant to pre-cataract visual skill function in each eye, an element not routinely taken account during planning of surgery.
