effects of chalazion on refractive error and corneal topography

purpose: to evaluate the effect of location and size of chalazia on refractive error, corneal topography and visual acuity. methods: this randomized non-controlled clinical trial was conducted on patients with chalazion aged more than 3 years with minimum duration of one month. all patients underwent chalazion excision by the internal or external approach. results: two-hundred and fifty-three eyelids of 228 eyes of 195 patients (85 male, 110 female) with mean age of 31±14 (range 7-71) years underwent chalazion excision. mean duration of presenting symptoms was 4±2.8 (range 1-24) months. chalazia were single in 172 (88.2%) and multiple in 23 (11.8%) patients. single chalazia were distributed almost identically in medial, central and lateral sites of lids. mean difference of pre- and postoperative best-corrected visual acuity was 0.0004 logmar (p=0.3). mean differences in pre- and postoperative values of sphere, difference in keratometry (dk) or cylinder and spheric equivalent (se) were 0.005 d (p= 0.9), 0.17 d (p<0.001) and 0.006 d (p= 0.08), respectively. mean differences between pre- and postoperative topographic indices including surface regularity index, surface asymmetry index, keratometry (d) and potential visual acuity (logmar) were 0.13 (p<0.0001), 0.09 (p<0.0001), 0.34 (p<0.0001) and 0.05 (p<0.0001), respectively. in comparison of single-central-firm chalazion with multiple-peripheral-soft type chalazia, the difference in mean dk was 0.53±0.15 d (p<0.0001) and the difference of mean changes of se was 0.45±0.11 d (p=0.2). mean difference of dk was 0.1±0.06 d in upper lid (p= 0.03) and 0.02±0.03 in lower lid (p=0.1).    conclusion: excision of chalazion can decrease corneal astigmatism and irregularity, which is more prominent in single-central-firm and upper lid chalazia. in children who are at risk of amblyopia, any attempt to improve the refractive state is worthwhile.