Post-operative Refractive Prediction Error After Phacovitrectomy: A Retrospective Study

Abstract

IntroductionMany authors have reported on a myopic post-operative refractive prediction error when combining phacoemulsification with pars plana vitrectomy (phacovitrectomy). In this study we evaluate the amount of this error in our facility and try to elucidate the various factors involved.MethodsThis was a retrospective study which included 140 patients who underwent phacovitrectomy (39 with macular holes, 88 with puckers, and 13 with floaters). Post-operative refractive error was defined as the difference between the actual spherical equivalent (SEQ) and expected SEQ based on the SRK/T and Holladay-II formulas. Both univariate (paired t test, independent t test, one-way analysis of variance, or Mann–Whitney test) and multivariate (regression analysis) statistical analyses were performed.ResultsOverall, a refractive error of − 0.13 dpt (p = 0.033) and − 0.26 dpt (p < 0.01) were found in the SRK/T and Holladay-II formulas, respectively. For the independent diagnoses, only macular holes showed a myopic error with the SRK/T (− 0.31 dpt; p < 0.01) and Holladay-II (− 0.44 dpt; p < 0.01) formulas. In univariate analysis, significant factors involved in myopic refractive error were macular hole as diagnosis (p < 0.01 for SRK/T and Holladay-II), gas tamponade (SRK/T p = 0.024; Holladay-II p = 0.025), pre-operative myopia (p < 0.01 for SRK/T), and optical technique for axial length measurement (SRK/T and Holladay-II p < 0.01). In the multivariate analysis, pre-operative axial length (p = 0.026), optical technique for axial length measurement (p < 0.01), and pre-operative SEQ (p < 0.01) were independent predictors for myopic refractive error in the SRK/T formula. For the Holladay-II formula, optical technique for axial length measurement (p < 0.01) and pre-operative SEQ (p = 0.04) were predictive.ConclusionVarious factors are involved in determining the myopic refractive error after phacovitrectomy. Not every factor seems to be as important in each individual patient, suggesting a more tailored approach is warranted to overcome this problem.

Combining cataract surgery with 25-gauge high-speed pars plana vitrectomy: A prospective study

“…As previously reported by some authors, 15–17 during the postoperative follow-up visits of our patients, a myopic shift from −0.25 to −0.50 was found, but this refractive error was not statistically different ( p > 0.05) between the two Groups (A and B).…”

Postoperative Refractive Prediction Error Measured by Optical and Acoustic Biometry after Phacovitrectomy for Rhegmatogenous Retinal Detachment without Macular Involvement

“…In contrast, Manvikar et al [8] reported that there was no tendency for a myopic shift in IOL power estimation using optic biometry, while Falkner-Radler et al [7] reported that optic biometry detected a myopic change after combined phacovitrectomy despite the IOL power calculation. Higher myopic shifts after vitrectomy with gas tamponade have been reported in eyes with MH than in eyes with ERM [9]. However, in eyes with poor visual acuity, the axial length cannot be measured accurately because of poor fixation, which leads to deviation of the visual axis [12].…”

“…Myopic shift has been observed when the macula is not attached in eyes with RRD because of errors in the measurement of axial length [10]. However, myopic shift of refractive error has also been reported after phacovitrectomy in eyes with ERM and in those with MH, in which the measurement of axial length is not considered to be difficult [6, 7, 9, 11]. Gas tamponade during anterior intraocular lens (IOL) replacement has been identified as a cause of myopic shift in eyes with MH [9].…”

“…However, myopic shift of refractive error has also been reported after phacovitrectomy in eyes with ERM and in those with MH, in which the measurement of axial length is not considered to be difficult [6, 7, 9, 11]. Gas tamponade during anterior intraocular lens (IOL) replacement has been identified as a cause of myopic shift in eyes with MH [9]. Axial length measured by optic biometry is not accurate in patients with poor fixation because of deviation in the visual axis [12].…”

Two-stage or single-stage vitreoretinal surgery with phacoemulsification in patients with advanced proliferative diabetic retinopathy?

“…Также в литературе в последнее время значительное внимание уделяют наличию рефракционных ошибок после факовитрэктомии [29,30]. Они обусловлены рядом факторов: заменой стекловидного тела, изменением данных кератометрии, ошибками при измерении переднезадней оси глаза при расчете ИОЛ, разницей между актуальной и планируемой позициями ИОЛ, наличием витреоретинальной патологии в макулярной области, таких как диабетический макулярный отёк и отслойка сетчатки [31].…”