To The Question Of Calculating The Power Of The Implanted Intraocular Lens For Cataract Surgery In Avitreal Eyes

Published 2022 - 40th Congress of the ESCRS

Reference: PP13.10 | Type: ESCRS 2022 - Posters | DOI: 10.82333/727q-jb39

Authors: Aziz Azadillayevich Tashmukhamedov* ¹ , Azizbek Aktamov ¹ , Sardor Ubaydullayev ²

¹Ophthalmology,JV Ophthalmologic clinic Sihat Koz,Tashkent,Uzbekistan, ²Ophthalmology,Republic specialized scientific and practical medical center of eye microsurgery,Tashkent,Uzbekistan

Purpose

Analysis of our research when calculating the optical power of an intraocular lens (IOL) with correction in cases of cataract phacoemulsification in avitreal eyes

Setting

The study was conducted in the ophthalmological clinic JV LLC Sihat Ko'z (Tashkent, Uzbekistan). The analysis was carried out in 65 patients (65 eyes) in 2019-2022. All patients underwent cataract phacoemulsification with IOL implantation after subtotal vitrectomy for macular hole (45 cases (69%)) and removal of the epiretinal membrane (20 cases (31%)). The age of the patients ranged from 25 to 72 years, on average 52 ± 12 years, including 17 men and 48 women.

Methods

Operations were performed in 2 stages: Stage 1. Vitrectomy with or without gas tamponade. Stage 2. Calculation of IOL power on the avitreal eye. Phacoemulsification of cataract with IOL implantation. All operations were performed by one surgeon - Dr. A.U. In all cases, monofocal IOLs were implanted with different values of constant A from 118.0 to 119.3. Clinical refraction after surgery was assessed after an average of 3 months. Keratometry and evaluation of clinical refraction were performed by autoceratorefractometry on a Shin Nippon Acuref K-900 device (Japan). A retrospective analysis of refractive results was performed using the reverse calculation method. The Barrett Universal II Formula was used to calculate the IOL power.

Results

The results showed that, when implanting an IOL with a constant of 118 and 118.4, the average value of the difference in the predicted and received refractions was high - 0.43 (±0.15) and 0.27 (±0.1), for an IOL with a constant of 119 and 119.3 was minimal - 0.03 ± 0.06 and 0.02 ± 0.05, respectively.

Based on these, it can be assumed that the error (difference) in refractions can be minimized by implanting IOLs with a constant of 119 and 119.3.

Conclusions

As we know, the constant A is an abstract characteristic of the stability of the position of the IOL (the position of the IOL optics) in the eye after implantation. The greater the value of the A-constant , the further the IOL optics from the top of the cornea. Therefore, an IOL with a high A- contant value will blend less forward towards the corneal apex. Based on this, we can conclude that in cataract surgery after vitreoretinal surgical interventions, it is preferable to implant an IOL with a high constant (119 or more).