Abstract
Purpose: :
To evaluate the accuracy of IOL calculations of acute primary angle closure eyes by using A-scan biometry and to compare the results to those of chronic primary angle closure (glaucoma).
Methods: :
Consecutive 34 (6male and 28 female, age 72 +/- 7.34) patients with acute primary angle closure (PAC) who underwent small corneal incision phacoemulsification and aspiration and intraocular lens implantation (PEA-IOL) were studied. 66 patients (19 male and 74 female, age 71.4 +/- 8.45) with chronic PAC patients who underwent PEA-IOL in the same time period were used as control. SRK-T IOL calculation formula was for all patients. Refractive error was measured by auto-refractometer (NIDEK, Aichi, Japan), and central anterior chamber depth before and after PEA-IOL was measured by A-mode ultrasound sonography (TOMEY, Aichi, Japan).
Results: :
The mean of the absolute value lens prediction error from the desired postoperative refractive result for acute PAC (-0.021+/-0.89D) was smaller than that for chronic PAC (-0.77+/-0.99D) (P<0.05, Unpaired T-test). There was no difference of axial length of acute (22.4+/-0.66 mm) and chronic PAC (22.4 +/- 0.38 mm). Preoperative central anterior chamber depth of acute PAC (2.25+/-0.20) was shallower than that of chronic PAC (2.49+/- 0.28) (P<0.01, unpaired t-test); however postoperative central anterior chamber depth of acute PAC (4.08+/-0.30) was deeper than that of chronic PAC (3.82+/-0.30) (P<0.01unpaired t-test).
Conclusions: :
This retrospective, comparative study showed significant difference in IOL prediction error between acute and chronic PAC eyes. Difference of change in central anterior chamber depth between acute and chronic PAC may account for the difference of the lens prediction error from the desired postoperative refractive result.
Keywords: anterior chamber • cataract • depth