Accuracy of corneal power measurements for intraocular lens power calculation after myopic laser In situ Keratomileusis

Helaly, Hany Ahmed; El-Hifnawy, Mohammad A.M.; Shaheen, Mohamed Shafik; El-Kheir, Amr F Abou

doi:10.4103/0974-9233.171755

Cited by 18 publications

(14 citation statements)

References 24 publications

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“…Among these, three studies did not have percentage data, 16 studies included only one of the selected formulae, five studies were hyperopic laser refractive surgery or radial keratotomy surgery. After the exclusion of these studies, 16 articles were used for analysis [5,[12][13][14][15][16][17][22][23][24][25][26][27][28][29][30].…”

Section: Resultsmentioning

confidence: 99%

Accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes: a meta-analysis

Nan

et al. 2020

Eye and Vis

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Background: To compare the accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes. Methods: We searched the databases on PubMed, EMBASE, Web of Science and the Cochrane library to select relevant studies published between Jan 1st, 2009 and Aug 11th, 2019. Primary outcomes were the percentages of refractive prediction error within ±0.5 D and ±1.0 D. Results: The final meta-analysis included 16 studies using seven common methods (ASCRS average, Barrett True-K no history, Double-K SRK/T, Haigis-L, OCT formula, Shammas-PL, and Wang-Koch-Maloney). ASCRS average yielded significantly higher percentage of refractive prediction error within ±0.5 D than Haigis-L, Shammas-PL and Wang-Koch-Maloney (P = 0.009, 0.01, 0.008, respectively). Barrett True-K no history also yielded significantly higher percentage of refractive prediction error within ±0.5 D than Shammas-PL and Wang-Koch-Maloney (P = 0.01, P < 0.0001, respectively), and a similar result was found when comparing OCT formula with Haigis-L and Shammas-PL (P = 0.03, P = 0.01, respectively). Conclusion: The ASCRS average or Barrett True-K no history should be used to calculate the intraocular lens power in eyes after myopic laser refractive surgery. The OCT formula if available, can also be a good alternative choice.

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Section: Resultsmentioning

confidence: 99%

Accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes: a meta-analysis

Nan

et al. 2020

Eye and Vis

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“…Their best combination gave RPE within ±0.50 D and ±1.00 D for 67% and 93%, respectively. 44 Two recent studies compared no-history formulas with conventional formulas using TCP from an IOLMaster 700: Yeo et al found the best prediction errors using TCP with the EVO (a new unpublished formula), Barret TK NH, and Haigis formulas with 69%, 64% and 64%, respectively, within ±0.5 D and 83% within ±0.75 D for all three formulas, which was better than both the Barret TK NH and the Haigis-L. 45 Lawless et al found the best results with the Barret TK (TCP), followed by Barret TK NH and Haigis TCP with; 35%, 38% and 40%, respectively, within ±0.25 D; 75%, 63% and 60%, respectively, within ±0.50 D; 90%, 83% and 80%, respectively, within ±0.75 D. 46 Both these studies show that the use of TCP is likely to improve IOL-calculations in post-LVC patients. This could be expected as and both the Haigis-L and Barret TK NH uses a regression equation, with its inherent variance, to account for the altered corneal power in post LVC corneas.…”

Section: Discussionmentioning

confidence: 99%

Refractive Precision of Ray Tracing IOL Calculations Based on OCT Data versus Traditional IOL Calculation Formulas Based on Reflectometry in Patients with a History of Laser Vision Correction for Myopia

Gjerdrum¹,

Gundersen²,

Lundmark³

et al. 2021

OPTH

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Purpose To compare the refractive predictability of ray tracing IOL calculations based on OCT data versus traditional IOL calculation formulas based on reflectometry in patients with a history of previous myopic laser vision correction (LVC). Patients and Methods This was a prospective interventional single-arm study of IOL calculations for cataract and refractive lens exchange (RLE) patients with a history of myopic LVC. Preoperative biometric data were collected using an optical low coherence reflectometry (OLCR) device (Haag-Streit Lenstar 900) and two optical coherence tomography (OCT) devices (Tomey Casia SS-1000 and Heidelberg Engineering Anterion). Traditional post LVC formulas (Barret True-K no-history and Haigis-L) with reflectometry data, and ray tracing IOL calculation software (OKULIX, Panopsis GmbH, Mainz, Germany) with OCT data were used to calculate IOL power. Follow-up examination was 2 to 3 months after surgery. The main outcome measure, refractive prediction error (RPE), was calculated as the achieved postoperative refraction minus the predicted refraction. Results We found that the best ray tracing combination (Anterion-OKULIX) resulted in an arithmetic prediction error statistically significantly lower than that achieved with the best formula calculation (Barret True-K no-history) (−0.13 D and −0.32 D, respectively, adjusted p = 0.01), while the Barret TK NH had the lowest SD. The absolute prediction error was 0.26 D and 0.35 D for Anterion-OKULIX and Barret TK NH, respectively, but this was not statistically significantly different. The Anterion-OKULIX calculation also had the highest percentage of eyes within ± 0.25, compared to both formulas and within ±0.50 and ±0.75 compared to the Haigis-L ( p = 0.03). Conclusion Ray tracing calculation based on OCT data from the Anterion device can yield similar or better results than traditional post LVC formulas. Ray tracing calculations are based on individual measurements and do not rely on the ocular history of the patient and are therefore applicable for any patient, also without previous refractive surgery.

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“…Based on axial length, IOL power was calculated using the SRK/T, Hoffer, or Holladay formula. [ 8 ] Technicians from the ultrasonography department performed all measurements using a consistent standard to minimize inter-observer variation.…”

Section: Methodsmentioning

confidence: 99%

Visual outcomes and refractive status after combined silicone oil removal/cataract surgery with intraocular lens implantation

Al-Habboubi¹,

Al-Zamil²,

Al-Habboubi³

et al. 2018

J Ophthalmic Vis Res

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Purpose:To evaluate refractive status and identify predictors of surgical success following a combined silicone oil removal/cataract surgery with intraocular lens (IOL) implantation procedure.Methods:In this single-armed, retrospective study, we reviewed patients who underwent vitreoretinal surgery followed by a combined silicone oil removal/cataract surgery procedure between 2009 and 2013. Preoperative data included patient demographics, refractive status, IOL power, and axial length (measured with the IOL Master). Postoperative data were obtained from the 8-week follow-up visit and from the last follow-up visit attended that included refractive error (RE) evaluation (e.g., myopic, hyperopic, and astigmatic). Associations between variables and refractive status were examined. Blindness was defined as a best-corrected visual acuity (BCVA) worse than 3/60.Results:Nighty-eight eyes were ultimately included in analyses. Following surgery, 37.0% of eyes achieved BCVA better than 6/18. The incidence of blindness (BCVA worse than 3/60) was reduced from 47.0% before surgery to 17.3% after surgery. Additionally, 33.7% of eyes did not require refractive correction. Forty-two percent of eyes were under-corrected (>0.5 D hyperopia) following surgery. Age, gender, silicone oil viscosity, axial length, IOL type, initial vitreoretinal pathology, surgeon, and IOL calculation formula were not significantly associated with surgical outcomes (all P > 0.05).Conclusion:A combined silicone oil removal/cataract surgery with IOL implantation procedure restored functional vision in approximately one-third of cases. However, nearly half of patients were under-corrected. Unfortunately, we did not identify any factors that predicted surgical success.

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Accuracy of corneal power measurements for intraocular lens power calculation after myopic laser In situ Keratomileusis

Cited by 18 publications

References 24 publications

Accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes: a meta-analysis

Accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes: a meta-analysis

Refractive Precision of Ray Tracing IOL Calculations Based on OCT Data versus Traditional IOL Calculation Formulas Based on Reflectometry in Patients with a History of Laser Vision Correction for Myopia

Visual outcomes and refractive status after combined silicone oil removal/cataract surgery with intraocular lens implantation

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