In the current study, 41 patients (including 30 eyes with FEVR, 6 with PHPV, and 5 with ROP) with a total absence of AC were enrolled. We found that this novel iris incision approach was simple, safe, and effective in supporting the formation of absent AC in a paediatric population with advanced vitreoretinopathies. AC formation was achieved in 95.1% of the eyes after 1 or 2 episodes of iris incision.
Advanced paediatric vitreoretinopathies tend to be more aggressive and to lead to severe complications. Surgeries for vitreoretinopathies are more challenging in paediatric than in adult patients. In advanced paediatric vitreoretinopathies complicated with total retinal detachment, the disappearance of the AC can be caused when the lens and iris are pushed into a more frontal position. Traditionally, external drainage of SRF could be indicated to achieve AC formation in cases with flat AC.[3, 4, 6] However, this procedure could be complicated by haemorrhage, incarceration of the retina, and/or vitreous or retinal perforation.[6, 7] In addition to these conventional complications, the author’s personal experience indicates that the sudden rapid outflow of SRF can also lead to iridodialysis. The constant outflow of SRF can decrease the definition of the surgical field and lead to subconjunctival effusion. Thus, to address these external SRF drainage-related problems, the authors were inspired by the notion of iridotomy to make creative usage of iris incision to assist in the formation of AC in patients with absent AC due to advanced vitreoretinopathies. In these cases, as the pressure in the posterior chamber was high, the aqueous humour in the posterior chamber could have outflowed through the iris incision site(s), thus reforming the AC for further manoeuvres.
The use of iris incision has several advantages over the use of external drainage of SRF. First, the use of iris puncture is effective in the formation of AC. In the current study, AC formation was achieved in 95.1% of the eyes that underwent up to 2 episodes of iris incision. Second, the use of iris puncture simplified the surgical procedures and resulted in a shorter total operative time. Third, the site(s) of puncture was (were) chosen according to the requirements of further surgical manoeuvres. Thus, no extra incisions were required. Fourth, there were few related complications. In the current study, only iris incarceration was observed during the surgery, and no related complications were observed in any cases at the last follow-up. Fifth, iris incision, unlike external drainage of SRF, does not affect the surgical visual field. Sixth, this technique is simple to perform and has a short learning curve.
In the current study, AC formation was achieved in 28 (68.3%) eyes with only 1 initial episode of iris incision and in 11 (26.8%) eyes with 2 episodes of iris incision. Only 2 (4.9%) patients needed a combination that included 1 episode of external SRF drainage. The major intraoperative complication of this iris incision approach was iris incarceration, and the iris was easily returned to the AC. The AC remained deep and stable in all cases.
Our study has limitations. Due to a lack of cooperation, ultrasound biomicroscope was not performed in all patients. However, all patients underwent indirect ophthalmoscopy to detect the condition of the AC. In addition, all surgical procedure were performed by a single surgeon, thus minimizing the effect of surgical procedures.
In conclusion, the creative use of iris incision proposed here was effective, simple and safe in the management of absent AC caused by various advanced paediatric vitreoretinopathies. Compared to the external drainage of SRF, this technique involved a simpler surgical manoeuvre and decreased the incidence of surgical complications.