Tunnel Architecture Assessment In Manual Small Incision Cataract Surgery And Its Relation With Astigmatism

Phacoemusification is nowadays the gold standard of cataract surgery. Nevertheless, it‘s important to master the manual small incision cataract surgery (mSICS) in order to deal with difficult cataract cases. Added to the fact that it does not require the use of any machine, surgically induced astigmatism in MSICS is known to be less severe than with classic corneal cataract extraction, as the main tunnel is scleral.  

The purpose of our study is to assess the architecture of the scleral tunnel using the anterior segment optical coherence tomography and determinate whether it has a relation with post operative refractive astigmatism.

Military hospital of tunis, Tunisia

Methods: we have conducted a prospective study including 23 patients that were operated on for senile cataract with mSICS. Patients with corneal dystrophy or primary or recurrent pterygium were excluded. Preoperative assessment noted the refractive astigmatism. The surgery was done by a single surgeon and we performed anterior segment OCT at 1 month follow-up for all the patients to assess the depth of the scleral tunnel from the limbus.  Post operative refractive astigmatism was also mentioned.

The mean age of patients was 70.17 ± 5.3 years. Eleven patients had temporal incision and 12 patients had superior one based on the preoperative astigmatism value. On post operative AS OCT, 9 patients had a tunnel depth of more than ≥370 mm and 14 patients has a tunnel depth ≤399 mm. Mean post-operative refractive astigmatism was -1,67± 1.2 D. Correlation analysis showed that patients with scleral tunnel depth ≤369 mm developed the lowest degree of post-operative refractive astigmatism (p< 0,05)

Increased depth of the scleral tunnel induces less post-operative astigmatism with a greater wound stability and a greater surface for healing.