Abstract
Purpose :
Fornix-based micro trabeculectomy with adjunctive mitomycin C is a novel minimally invasive procedure that was first introduced at ARVO 2019 (poster #B0083). This study seeks to assess whether this modified technique induces significant astigmatism in pseudophakic patients.
Methods :
This is a retrospective single surgeon case series. Pseudophakic patients who underwent micro trabeculectomy between 1/1/2013 and 1/1/2019 were included. Patients who did not have manifest refraction or demonstrated visual acuity of count fingers or less were excluded. Outcomes included were a change in significant astigmatism, which is defined as 1.0D or more, change in visual acuity (0.2 LogMAR), and shift in axis of astigmatism in the operative eye. Analysis was performed using the Student’s T-Test.
Results :
31 patients had refraction before and after procedure available for comparison, and 21 had a second refraction after at least 1 year. Baseline demographics and primary outcomes for included patients are provided in Tables 1 and 2. The patients included were on average 74.9 years old and 42% male and 58% female. On average micro trabeculectomy was performed 4.3 years after cataract surgery. Average baseline astigmatism prior to surgery was 1.36D while post-procedure average astigmatism was 1.23D. 1 eye experienced an increase in astigmatism postoperatively that resolved after 1 year on repeat refraction. 2 eyes experienced a clinically significant decrease that remained stable after 1 year. 2 eyes that did not have astigmatism prior to the procedure developed astigmatism, however this was not significant (≤1D). 9 eyes experienced no change in astigmatism postoperatively. Analysis showed that there was no statistically significant difference between pre-trab and post-trab astigmatism outcomes (0.620,p>0.05). Similarly, there was no statistically significant difference between baseline astigmatism and astigmatism measured at least one year post-operatively (0.524, p>0.05). Visual acuity remained stable after procedure (0.827, p>0.05). 3 eyes shifted from oblique or no cylindrical astigmatism (sphere only) to against the rule (ATR) astigmatism.
Conclusions :
Incisional surgery can induce astigmatism and affect visual acuity. This study demonstrates that the novel micro trabeculectomy technique does not induce significant astigmatism in pseudophakic patients.
This is a 2021 ARVO Annual Meeting abstract.