Economic Evaluation of Cataract: A Systematic Mapping Review.

INTRODUCTION: The purpose of this article was to ascertain the existing literature and find the gaps in economic evaluations of cataracts. METHODS: Systematic methods were used to search and collect the published literature on economic evaluations of cataracts. A mapping review of studies published in the following bibliographical databases was performed: the National Library of Medicine (PubMed), EMBASE, Web of Science (WOS), and the Central of Reviews and Dissemination (CRD) database. A descriptive analysis was conducted and relevant studies were classified into different groups. RESULTS: Among 984 studies screened, 56 studies were included in the mapping review. Four research questions were answered. There has been a progressive increase of publications during the last decade. The majority of the included studies were published by authors from institutions in the USA and UK. The most commonly investigated area was cataract surgery followed by intraocular lenses (IOLs). The studies were classified into different categories according to the main outcome evaluated, such as comparisons between different surgical techniques, costs of the cataract surgery, second eye cataract surgery costs, quality of life gain after cataract surgery, waiting time of cataract surgery and costs, and cataract evaluation, follow-up, and costs. In the IOL classification, the most frequently studied area was the comparison between monofocal and multifocal IOLs, followed by the comparison between toric and monofocal IOLs. CONCLUSIONS: Cataract surgery is a cost-effective procedure compared with other non-ophthalmic and ophthalmic interventions and surgery waiting time is an important factor to consider because vision loss has a huge and broad-ranging impact on society. Numerous gaps and inconsistencies are found among the studies included. For this reason, there is a need for further studies according to the classification described in the mapping review.

Comparison of the Cost-Effectiveness of SMILE, FS-LASIK, and PRK for Myopia in a Private Eye Center in Spain.

PURPOSE: To describe and compare the cost-effectiveness of small incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and photorefractive keratectomy (PRK) for treating myopia and myopic astigmatism in a private eye center. METHODS: The perspectives for this cost-effectiveness analysis were for the payer and the health care sector. For the payer's perspective, a decision tree model was made, with a time period of 30 years, and the average weighted utility values and quality-adjusted life years (QALY) were computed for each procedure. The average weighted costs were derived for each procedure and divided by the QALY to obtain the incremental cost-effectiveness ratios (ICER). For the health care sector's perspective, the direct and indirect costs of acquiring the equipment and maintaining the facilities-including consumables and personnel salaries-were obtained to compute the minimum number of patients treated per year. RESULTS: The weighted utility values were 0.8 for SMILE and PRK and 0.77 for FS-LASIK. The weighted QALYs were 24 for SMILE and PRK, and 23.1 for FS-LASIK. The average weighted costs were 335.45, 443, and 346.96€, respectively. The resulting incremental cost-effectiveness ratios were 13.98 €/QALY for SMILE, 18.46 €/QALY for PRK, and 15.02 €/QALY for FS-LASIK. There was a negative correlation between the ICER and the time (in years) after the surgery. To achieve a profit, the minimum number of patients treated per year is 155 for SMILE, 136 for PRK, and 155 for FS-LASIK. CONCLUSIONS: Laser corneal refractive surgery is cost-effective for a person desirous of refractive correction for myopia. SMILE had the lowest ICER, followed by FS-LASIK and PRK. This trend was noted at all time periods. The cost of investing in laser refractive surgery facilities is outweighed by the potential income in high-volume eye centers. [J Refract Surg. 2022;38(1):21-26.].

Pupil dependence assessment with multifocal intraocular lenses through visual acuity and contrast sensitivity defocus curves.

PURPOSE: To identify the most sensitive visual performance metric for evaluating the pupil-dependency of a multifocal intraocular lens (MIOL) and to determine the pupil measurement method most correlated with such metric. METHODS: Twenty-seven right eyes implanted with a MIOL were included in the analysis. Three pupil size measurements were obtained preoperatively and at 1 month after surgery with the Keratograph 5M system: photopic (PP), mesopic (MP), and the average from both (AP). Pupil was also measured with a rule (RP) under the same light conditions of postoperative visual performance measurements that included, corrected visual acuities (VA) at three distances (far, 67 cm and 40 cm), visual acuity (VADC) and contrast sensitivity defocus curves for optotype sizes of 0.3 logMAR (CSDC3) and 0.7 logMAR (CSDC7). Differences in visual performance were also analyzed for eyes with RP > 3 mm (Group A) and RP ⩽ 3 mm (Group B). RESULTS: PP diameter decreased after surgery by 16% (p = 0.001), whereas MP (p = 0.013) and AP (p = 0.008) decreased by 10%. The best agreement with RP was obtained for AP. Group B showed a trend to better performance than Group A for all the included metrics (p > 0.05). From the three types of defocus curves, CSDC3 obtained generally highest statistical power for testing differences between groups. The strongest statistically significant correlations between pupil size and CSDC3 were obtained for RP and AP. CONCLUSION: The CSDC3 was the most sensitive metric to detect MIOL pupil-dependency. PR and AP were more correlated with CSDC3 than PP and MP.

Agreement and repeatability of objective systems for assessment of the tear film.

PURPOSE: To assess the agreement and repeatability of two objective systems for measuring the tear film stability. METHODS: Retrospective analysis of the tear film stability of 99 healthy right eyes measured with a videokeratoscope (VK) and the Optical Quality Analysis System (OQAS, Visiometrics). Two consecutive measures were taken with both systems, with an interval of 10 min between them. Variables included in the study were first and mean non-invasive break-up times (NIBUT and MNIBUT) measured with VK, and mean and standard deviation of the optical scattering index (OSIm and OSIsd) measured with OQAS. The agreement and repeatability of grading scales provided by both devices were also evaluated using the Cohen's k with quadratic weights. The Ocular Surface Disease index (OSDI) questionnaire was also passed out to all subjects. Correlations and associations between subjective and objective metrics were analyzed. RESULTS: Significant differences were found between consecutive measurements of NIBUT (p = 0.04) and MNIBUT (p = 0.01), but not for OSIm (p = 0.11) and OSIsd (p = 0.50). Grading scales resulted in fair (k = 0.20) or poor agreement (k = 0.04) between systems depending if the first or second trial was considered. The repeatability of the grading scale was good for OQAS (k = 0.59) and fair for VK (k = 0.37). No significant correlations or associations were found between OSDI and any of the metrics obtained with both devices (p ≥ 0.36). CONCLUSIONS: The two devices evaluated cannot be used interchangeably for the assessment of tear film stability. Good intrasession repeatability was obtained for tear film grading of the OQAS whereas it was fair for VK.

In Vitro Aberrometric Assessment of a Multifocal Intraocular Lens and Two Extended Depth of Focus IOLs.

PURPOSE: To analyze the "in vitro" aberrometric pattern of a refractive IOL and two extended depth of focus IOLs. METHODS: A special optical bench with a Shack-Hartmann wavefront sensor (SH) was designed for the measurement. Three presbyopia correction IOLs were analyzed: Mini WELL (MW), TECNIS Symfony ZXR00 (SYM), and Lentis Mplus X LS-313 MF30 (MP). Three different pupil sizes were used for the comparison: 3, 4, and 4.7 mm. RESULTS: MW generated negative primary and positive secondary spherical aberrations (SA) for the apertures of 3 mm (-0.13 and +0.12 µm), 4 mm (-0.12 and +0.08 µm), and 4.7 mm (-0.11 and +0.08 µm), while the SYM only generated negative primary SA for 4 and 4.7 mm apertures (-0.12 µm and -0.20 µm, resp.). The MP induced coma and trefoil for all pupils and showed significant HOAs for apertures of 4 and 4.7 mm. CONCLUSIONS: In an optical bench, the MW induces negative primary and positive secondary SA for all pupils. The SYM aberrations seem to be pupil dependent; it does not produce negative primary SA for 3 mm but increases for higher pupils. Meanwhile, the HOAs for the MW and SYM were not significant. The MP showed in all cases the highest HOAs.

Estimation of the central corneal power in keratoconus: theoretical and clinical assessment of the error of the keratometric approach.

PURPOSE: The aim of this study was to analyze theoretically the errors in the central corneal power calculation in eyes with keratoconus when a keratometric index (nk) is used and to clinically confirm the errors induced by this approach. METHODS: Differences (ΔPc) between central corneal power estimation with the classical nk (Pk) and with the Gaussian equation ((Equation is included in full-text article.)) in eyes with keratoconus were simulated and evaluated theoretically, considering the potential range of variation of the central radius of curvature of the anterior (r1c) and posterior (r2c) corneal surfaces. Further, these differences were also studied in a clinical sample including 44 keratoconic eyes (27 patients, age range: 14-73 years). The clinical agreement between Pk and (Equation is included in full-text article.)(true net power) obtained with a Scheimpflug photography-based topographer was evaluated in such eyes. RESULTS: For nk = 1.3375, an overestimation was observed in most cases in the theoretical simulations, with ΔPc ranging from an underestimation of -0.1 diopters (D) (r1c = 7.9 mm and r2c = 8.2 mm) to an overestimation of 4.3 D (r1c = 4.7 mm and r2c = 3.1 mm). Clinically, Pk always overestimated the (Equation is included in full-text article.)given by the topography system in a range between 0.5 and 2.5 D (P < 0.01). The mean clinical ΔPc was 1.48 D, with limits of agreement of 0.71 and 2.25 D. A very strong statistically significant correlation was found between ΔPc and r2c (r = -0.93, P < 0.01). CONCLUSIONS: The use of a single value for nk for the calculation of corneal power is imprecise in keratoconus and can lead to significant clinical errors.