BACKGROUND: To review the refractive outcome of cataract surgery in eyes with keratoconus. METHODS: We retrospectively reviewed the medical records of 64 consecutive patients (92 eyes) who underwent cataract surgery with implantation of a spherical intraocular lens (IOL). We recorded the method of refractive correction and the effect of the keratometry (K) on the biometry prediction error (BPE). RESULTS: 35 eyes had mild keratoconus (mean K<48 dioptres (D)), 40 had moderate keratoconus (mean K 48 D to 55 D) and 17 had severe keratoconus (mean K>55 D). Actual K values were used in all eyes with mild or moderate keratoconus with a target refraction of approximately -1.0 D in mild keratoconus and -1.5 D in moderate keratoconus that resulted in a mean BPE of 0.0 D and +0.3 D, respectively. The actual K values were used in eight of the 17 eyes with severe keratoconus with a mean target refraction of -5.4 D, which resulted in a mean BPE of +6.8 D. In the remaining nine eyes, a standard K value of 43.25 D was used with a mean target refraction of -1.8 D, which resulted in a mean BPE of +0.6 D. CONCLUSIONS: Using the actual K values with a target of low myopia is a suitable option for spherical IOL selection for eyes with a mean K of ≤55 D. When there is severe keratoconus, the use of actual K values can result in a large hyperopic error and the use of standard K value in these eyes should be considered.
BACKGROUND: To review the refractive outcome of cataract surgery in eyes with keratoconus. METHODS: We retrospectively reviewed the medical records of 64 consecutive patients (92 eyes) who underwent cataract surgery with implantation of a spherical intraocular lens (IOL). We recorded the method of refractive correction and the effect of the keratometry (K) on the biometry prediction error (BPE). RESULTS: 35 eyes had mild keratoconus (mean K<48 dioptres (D)), 40 had moderate keratoconus (mean K 48 D to 55 D) and 17 had severe keratoconus (mean K>55 D). Actual K values were used in all eyes with mild or moderate keratoconus with a target refraction of approximately -1.0 D in mild keratoconus and -1.5 D in moderate keratoconus that resulted in a mean BPE of 0.0 D and +0.3 D, respectively. The actual K values were used in eight of the 17 eyes with severe keratoconus with a mean target refraction of -5.4 D, which resulted in a mean BPE of +6.8 D. In the remaining nine eyes, a standard K value of 43.25 D was used with a mean target refraction of -1.8 D, which resulted in a mean BPE of +0.6 D. CONCLUSIONS: Using the actual K values with a target of low myopia is a suitable option for spherical IOL selection for eyes with a mean K of ≤55 D. When there is severe keratoconus, the use of actual K values can result in a large hyperopic error and the use of standard K value in these eyes should be considered.
Authors: L Fernández-Vega-Cueto; V Romano; R Zaldivar; C H Gordillo; F Aiello; D Madrid-Costa; J F Alfonso Journal: J Ophthalmol Date: 2017-12-18 Impact factor: 1.909