Assessing visual function behind cataract: preoperative predictive value of the Heine Lambda 100 retinometer

Retinometer predicts visual outcome in Descemet membrane endothelial keratoplasty

PURPOSE

To analyze the preoperative predictive value of retinometer visual acuity (VA) in eyes following Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Patients undergoing DMEK between August 2011 and July 2020 were included. Preoperative interference visual acuity was assessed using Heine Lambda 100 Retinometer. Depending on the presence or absence of concomitant ocular disease, the Retinometer was evaluated for its ability to preoperatively predict best-corrected visual acuity (BCVA) six months after surgery using correlation, simple and multiple linear regression, contingency analyses, and receiver operating characteristic (ROC) analysis. Preoperative corneal backscatter was correlated with Retinometer prediction accuracy.

RESULTS

A total of 198 eyes were included in the analysis. There was a significant correlation between Retinometer VA and postoperative BCVA (r = 0.647, P < 0.001). Regardless of the presence or absence of concomitant ocular disease and the surgery procedure (DMEK & triple DMEK), Retinometer VA was the most significant predictor of postoperative BCVA (P < 0.001). ROC analysis revealed reliable diagnostic performance of the Retinometer (AUC = 0.829, P < 0.001). A Retinometer VA ≥ 0.5 accurately predicted a postoperative BCVA ≥ 0.5 in 91% of cases. No association was found between corneal backscatter and prediction accuracy (P = 0.566).

CONCLUSIONS

Retinometer VA can be used for preoperative prediction of postoperative BCVA in DMEK and triple DMEK patients, independent of increased backscatter values and the presence or absence of concomitant ocular disease. By using this simple but effective tool, indication for DMEK can be facilitated and postoperative outcomes can be realistically predicted preoperatively.

Predicting Post-Cataract Surgery Visual Acuity in Vitrectomized Eyes: The Efficacy and Accuracy of "Lambda" Retinometry

BACKGROUND AND OBJECTIVE

Determine the ability of Lambda retinometry to predict post-cataract surgery visual acuity in vitrectomized eyes.

PATIENTS AND METHODS

Prospective study including 47 cataract surgery candidates with a history of pars plana vitrectomy (PPV). Lambda retinometry using a hand-held Lambda retinometer and best-corrected visual acuity (BCVA) were measured preoperatively, and BCVA was reassessed postoperatively.

RESULTS

Lambda predictions strongly correlated with postoperative BCVA (logarithm of the minimum angle of resolution [logMAR]) (P < .001, r² = 0.57), especially combined with preoperative BCVA (logMAR) (P < .001, r² = 0.65). In 89% of cases, postoperative BCVA was equal to or higher than the prediction. Neither cataract grades nor indications for PPV were associated with the accuracy of Lambda predictions (P = .882 and P = .790, respectively). Underestimation of visual outcome was more common than overestimation. A Lambda prediction of ≥ 20/40 (Snellen) had a positive predictive value of 85.7% and a negative predictive value of 73.6% for the postoperative outcome.

CONCLUSIONS

Lambda retinometry can reliably predict the postoperative BCVA in cataract patients who previously underwent PPV, with a tendency towards underestimation. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:535-542.].

Accuracy of the refractive prediction determined by intraocular lens power calculation formulas in high myopia

Purpose:

Our study was conducted to evaluate and compare the accuracy of the refractive prediction determined by the calculation formulas for different intraocular lens (IOL) powers for high myopia.

Methods:

This study reviewed 217 eyes from 135 patients who had received cataract aspiration treatment and IOL implantation. The refractive mean numerical error (MNE) and mean absolute error (MAE) of the IOL power calculation formulas (SRK/T, Haigis, Holladay, Hoffer Q, and Barrett Universal II) were examined and compared. The MNE and MAE at different axial lengths (AL) were compared, and the percentage of every refractive error absolute value for each formula was calculated at ±0.25D, ±0.50D, ±1.00D, and ±2.00D.

Results:

In all, 98 patients were recruited into this study and 98 eyes of them were analyzed. We found that Barrett Universal II formula had the lowest MNE and MAE, SRK/T and Haigis formulas arrived at similar MNE and MAE, and the MNE and MAE calculated by Holladay and Hoffer Q formula were the highest. Barrett Universal II formulas have the lowest MAE among different AL patients, whereas it reached the highest percentage of refractive error absolute value within 0.5D in this study. The MAE of each formula is positively correlated with AL.

Conclusion:

Barrett Universal II formula rendered the lowest predictive error compared with SRK/T, Haigis, Holladay, and Hoffer Q formulas. Thus, Barrett Universal II formula may be regarded as a more reliable formula for high myopia.

Preoperative evaluation for cataract surgery

PURPOSE OF REVIEW

To provide a consolidated update regarding preoperative evaluation for cataract surgery.

RECENT FINDINGS

Visual acuity alone is a poor gauge of cataract disability. Modalities such as wave front aberrometry, lens densitometry, and light-scatter assessments can quantify optical aspects of cataract and may prove clinically useful in surgical evaluation. Advances in biometry are driving improvements in refractive outcomes, which in turn have increased patient expectations. Future advances in biometry technology may include three-dimensional imaging of the cornea and lens. Screening for ocular comorbidities has become increasingly important, particularly to guide lens selection. Risk stratification systems can help guide surgical decisions and may decrease intraoperative complication rate. A comprehensive medical history and physical is currently mandated for all Medicare patients undergoing cataract surgery but may be of limited utility for low-risk patients.

SUMMARY

Rising patient expectations and a growing number of surgical choices have expanded the cataract preoperative evaluation. A systematic and comprehensive examination which includes identifying any ocular comorbidity is essential for surgical planning and counseling on visual prognosis. New technologies will continue to inform, but not replace, sound clinical judgment.