Accuracy Of Predictive Refraction In Transscleral Fixation Of Intraocular Lens In Trabeculectomized Eyes With Glaucoma

To investigate the accuracy of predictive refraction and the changes of intraocular pressure in transscleral fixation of intraocular lens (IOL) in trabeculectomized eyes with glaucoma.

Tertiary university hosptital

We retrospectively reviewed the medical records of patients who underwent transscleral fixation of IOL due to IOL dislocation from January 2010 to July 2022. Of them, eyes that had previously undergone trabeculectomy and controlled intraocular pressure (IOP) were included. All transscleral fixation of IOL surgeries were done using Ab externo technique. The predictive refraction was calculated by using the SRK/T formula. The refractive errors were converted into spherical equivalents. Main outcome measures were the accuracy of predictive refraction [the difference between the predictive and postoperative values was within ±0.5 diopter (D) and within ±1.0 D] and change in IOP.

Eleven eyes were included. Mean age was 67.27 years old. The axial length was 23.64 mm. The predictive refraction was -0.02 ± 0.46 D. The postoperative refraction was -0.80 ± 0.98 D. There was a significant difference between predictive refraction and postoperative refraction outcome. (p=0.029) The postoperative refraction outcome showed a tendency toward myopia of -0.78 ± 1.11 D, compared to the predictive refraction. The accuracy of predictive refraction was 36.4% for ±0.5 D and 72.7% for ±1.0 D. The IOP did not change during the follow-up period (13.18 ± 4.56 mmHg at the baseline, 12.82 ± 5.88 mmHg at 1 week, and 12.73 ± 4.58 mmHg at 3 months).

In trabeculectomized eyes, transscleral fixation of IOL did not affect IOP. The postoperative refraction outcome became myopic shift, compared to the predictive refraction. Therefore, the target power of IOL should be determined regarding this condition when performing transscleral fixation of IOL in the trabeculectomized eyes.