INTRAOCULAR POWER CALCULATION FOR SCLERAL SUSPENDED IMPLANTS

This study was conducted to verify the A constant (SRK formulas) of 30 scleral-suspended implants to improve intraocular lens (IOL) power ca lculations for this type of implantation. Thirty implants that were IO L sulcus-fixated after extracapsular cataract extraction (ECCE) were t aken as controls. The A constant was calculated after surgery, taking into consideration preoperative IOL power calculations and postoperati ve refraction. The depth of the anterior chamber was calculated by pos toperative ultrasound biometry. IOLs with an A constant of 118.5 were used for the study. The calculated A constant after surgery was 119.22 +/- 1.64 with scleral-fixated IOLs, and it was 118.42 +/- 0.64 with s ulcus-fixated IOLs. Anterior chamber depth was found to be 6.11 +/- 0. 73 and 4.7 +/- 0.48 mm, respectively, depending partially on axial len gth. Some changes in IOL power calculations have to be made when deali ng with scleral-suspended lenses. However, the range of postoperative refractions suggests that less precision has to be expected. The autho rs' data support the suspicion that the loops of the scleral-suspended implants could be located outside the ciliary sulcus.