Predictions of postoperative visual outcome in subjects with cataract: a preoperative and postoperative study

Trichromatic critical flicker frequency as potential visual test in cataract and macula disease patients

PURPOSE

To investigate the capacity of critical flicker frequency (CFF) in discriminating cataract eyes with or without macula disease using trichromatic flickers, and to develop a model to predict postoperative best corrected visual acuity (BCVA).

METHODS

Patients were divided into two groups based on the presence or absence of macular disease. CFF threshold measurements of red (R-CFF), green (G-CFF), and yellow (Y-CFF) flickers were conducted both preoperatively and postoperatively. A generalized estimating equations model (GEE) was employed to examine the relationship between CFF threshold and 3-month postoperative BCVA.

RESULTS

A total of 115 eyes were enrolled, with 59 eyes in the cataract alone group and 56 eyes in the cataract with macular disease group completing the follow-up. R-CFF was found to be consistent before and after cataract removal (P = 0.06), even in cases where OCT was not performed successfully (P > 0.05). Y-CFF showed the highest AUC (0.798) for differentiating ocular comorbidities. According to the GEE model, in patients with a CFF threshold below 26 Hz, the odds ratios for achieving a postoperative VA of 20/40 or better were 34.8% for R-CFF, 26.0% for G-CFF, and 24.5% for Y-CFF.

CONCLUSION

CFF emerges as a promising tool for predicting postoperative BCVA, providing valuable supplementary insights when fundus examination is obstructed. R-CFF demonstrates the best resistance to cataracts, while Y-CFF exhibits the highest sensitivity both in identifying macular diseases and predicting postoperative BCVA of 20/40 or better.

Prediction of postoperative visual acuity in patients with age-related cataracts using macular optical coherence tomography-based deep learning method

Background

To predict postoperative visual acuity (VA) in patients with age-related cataracts using macular optical coherence tomography-based deep learning method.

Methods

A total of 2,051 eyes from 2,051 patients with age-related cataracts were included. Preoperative optical coherence tomography (OCT) images and best-corrected visual acuity (BCVA) were collected. Five novel models (I, II, III, IV, and V) were proposed to predict postoperative BCVA. The dataset was randomly divided into a training (n = 1,231), validation (n = 410), and test set (n = 410). The performance of the models in predicting exact postoperative BCVA was evaluated using mean absolute error (MAE) and root mean square error (RMSE). The performance of the models in predicting whether postoperative BCVA was improved by at least two lines in the visual chart (0.2LogMAR) was evaluated using precision, sensitivity, accuracy, F1 and area under curve (AUC).

Results

Model V containing preoperative OCT images with horizontal and vertical B-scans, macular morphological feature indices, and preoperative BCVA had a better performance in predicting postoperative VA, with the lowest MAE (0.1250 and 0.1194LogMAR) and RMSE (0.2284 and 0.2362LogMAR), and the highest precision (90.7% and 91.7%), sensitivity (93.4% and 93.8%), accuracy (88% and 89%), F1 (92% and 92.7%) and AUCs (0.856 and 0.854) in the validation and test datasets, respectively.

Conclusion

The model had a good performance in predicting postoperative VA, when the input information contained preoperative OCT scans, macular morphological feature indices, and preoperative BCVA. The preoperative BCVA and macular OCT indices were of great significance in predicting postoperative VA in patients with age-related cataracts.

The theory of critical flicker fusion frequency and its application in cataracts

Background

Due to media opacity, it is usually difficult to accurately evaluate the postoperative visual acuity in cataracts patients. As a small and portable tool, the critical flicker fusion frequency (CFF) device reflects the temporal resolution of visual function and has been widely used in clinical research. However, poor understanding of the technique and equipment limitations have restricted its clinical application in China.

Main text

There was a decrease in the CFF value in various ophthalmic diseases, indicating that the CFF is sensitive to detect visual functional changes. A number of studies have shown that the CFF test can accurately distinguish patients with simple cataracts from those with cataracts combined with fundus disease, and, as a visual test, it can more accurately predict postoperative visual acuity without being affected by media opacity. This study comprehensive reviews the basic principles of CFF and its application in ophthalmology, especially in cataracts.

Conclusions

As one of the tools for dynamic visual function detection, the CFF test could help doctors to assess the possible presence of fundus disease in cataracts patients, especially in eyes with dense cataracts, and more precisely provide a reasonable visual prognosis than other available visual tests.

The clinical application of critical flicker fusion frequency in demyelinating optic neuritis

Purpose

To investigate the application of critical flicker fusion frequency (CFF) in demyelinating optic neuritis (DON).

Methods

A cross-sectional study. A total of 127 eyes in 69 DON patients and 63 eyes in 33 healthy control (HC) groups were included between January 2021 to September 2021 from Department of Ophthalmology, PLA General Hospital. Patients underwent best-corrected visual acuity (BCVA), visual field, optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and CFF examinations. The affected eyes were divided into aquaporins 4 (AQP4-), myelin oligodendrocyte glycoprotein (MOG-), and double negative DON according to serum antibody; mild, moderate, severe degree visual impairment according to BCVA ≥ 0.5, 0.1-0.5, < 0.1; and 4 groups: < 1, 1 ∼< 3, 3 ∼ < 6 and > 6 months according to time interval from onset to CFF examination. One-way ANOVA was used to perform above subgroup analysis. The correlations between CFF and F-VEP peak time, peak value, BCVA and mean visual filed defect (MD) were analyzed in order via Pearson correlation analysis.

Results

he trichromatic values of red, green, and yellow in DON affected eyes were 21.83 ± 9.03, 23.66 ± 10.21, 24.09 ± 10.77 Hz, respectively, which was significantly reduced compared with the HC group (t = -14.82, -14.22, -14.00; P < 0.001). The subgroup analysis showed no significant difference between different antibody subtypes (P = 0.914 <0.848 <0.604), whereas, a significant decrease of CFF trichromatic value was found in severe visual acuity impairment group (P < 0.001). There was a significant difference in CFF- trichromatic values at different time points (P < 0.001), to be specific, CFF fluctuated under 20Hz within 3 months after onset and tended to be stable around 24-28Hz. Correlation analysis showed that the peak time of F-VEP (r = -0.486, -0.515, -0.526; P < 0.001), BVCA (r = -0.640, -0.659, -0.642; P < 0.001), were negatively correlated with CFF trichromatic values, MD and CFF were positively correlated (r = 0.486, 0.453, 0.476; P = 0.003, 0.006, 0.004).

Conclusions

A significant decrease of CFF value was found in DON-affected eyes, and it has a good correlation with BCVA, MD and latency of F-VEP, and can better reflect the impairment of visual function.

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.].

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

PURPOSE

To analyze the accuracy of the Lambda 100 (Heine) potential visual acuity (VA) measurements in subjects undergoing cataract surgery.

METHODS

The medical records of all consecutive patients who underwent clear corneal incision phacoemulsification cataract surgery by a single surgeon between 2010 and 2012 at the Department of Ophthalmology, Hadassah Medical Center, a tertiary care hospital in Jerusalem, Israel, were reviewed. Subjects age 18 or older with a follow-up time of at least 30 days were included. Subjects with previous ocular comorbidities other than glaucoma were excluded. In addition, patients with intraoperative or perioperative complications that could affect final VA were excluded. Analyses were performed to analyze the accuracy of preoperative retinometer potential VA as a predictor of postoperative best-corrected VA.

RESULTS

A total of 374 operated eyes were included. There was a moderate positive correlation between Lambda estimated VA potential and postoperative achieved best-corrected VA (BCVA) (β coefficient 0.35, p<0.0001). Overall Lambda accurately (within 2 Snellen lines) estimated postoperative BCVA results in 60% of cases. The accuracy of prediction was significantly better in moderate cataracts when compared with advanced cataracts (p<0.01) with a twofold tendency towards underestimation in advanced cataracts. A Lambda ≥0.5 decimal has a calculated positive predictive value of 82% and a negative predictive value of 40% for predicting postoperative BCVA outcome ≥0.5 decimal.

CONCLUSIONS

Lambda may be used to relatively accurately predict postoperative BCVA in cataract patients, specifically in those with moderate cataracts.

Indication for cataract surgery. Do we have evidence of who will benefit from surgery? A systematic review and meta-analysis

The need for cataract surgery is expected to rise dramatically in the future due to the increasing proportion of elderly citizens and increasing demands for optimum visual function. The aim of this study was to provide an evidence-based recommendation for the indication of cataract surgery based on which group of patients are most likely to benefit from surgery. A systematic literature search was performed in the MEDLINE, CINAHL, EMBASE and COCHRANE LIBRARY databases. Studies evaluating the outcome after cataract surgery according to preoperative visual acuity and visual complaints were included in a meta-analysis. We identified eight observational studies comparing outcome after cataract surgery in patients with poor (<20/40) and fair (>20/40) preoperative visual acuity. We could not find any studies that compared outcome after cataract surgery in patients with few or many preoperative visual complaints. A meta-analysis showed that the outcome of cataract surgery, evaluated as objective and subjective visual improvement, was independent on preoperative visual acuity. There is a lack of scientific evidence to guide the clinician in deciding which patients are most likely to benefit from surgery. To overcome this shortage of evidence, many systems have been developed internationally to prioritize patients on waiting lists for cataract surgery, but the Swedish NIKE (Nationell Indikationsmodell för Katarakt Ekstraktion) is the only system where an association to the preoperative scoring of a patient has been related to outcome of cataract surgery. We advise that clinicians are inspired by the NIKE system when they decide which patients to operate to ensure that surgery is only offered to patients who are expected to benefit from cataract surgery.

Posterior segment causes of reduced visual acuity after phacoemulsification in eyes with cataract and obscured fundus view

Purpose

To determine posterior segment causes of reduced visual acuity after phacoemulsification in eyes with cataract and obscured fundus view.

Patients and methods

Retrospective review of medical records of patients with cataract, obscured fundus view, and normal B-scan ultrasonography, undergoing phacoemulsification from May 2005 to March 2012 was conducted. Eyes with fundus pathology, previous trauma, surgery, glaucoma, amblyopia, or uveitic cataract were excluded. Ocular comorbid conditions, preoperative visual acuity (VA), intraoperative and early postoperative complications, and final best corrected visual acuity (BCVA) at 1 month were abstracted from the records.

Results

All 201 eyes of 179 patients studied had a preoperative VA of ≤6/60. Preoperative ocular comorbidity was present in 31 eyes (15.5%). Intraoperative complications occurred in 20 eyes (10%). Postoperative complications developed in 34 eyes (17.0%). One month postoperatively, 175 eyes (87.1%) achieved a BCVA of ≥6/12; whereas 26 eyes (12.9%) achieved a BCVA of ≤6/18. The most common posterior segment causes of reduced VA in the 26 eyes were age-related macular disease in ten eyes (38.5%) and diabetic maculopathy in six eyes (23.1%). Similar fundus pathology was seen preoperatively in the fellow fundus in 10 of the 26 eyes (38.5%).

Conclusion

One month after phacoemulsification in eyes with cataract and obscured fundus view, age-related macular disease and diabetic maculopathy were the most common posterior segment causes of reduced final BCVA. To avoid postsurgical dissatisfaction, patients with obscured fundus view in their preoperative eye should be counseled, especially if posterior segment pathology exists in their fellow eye.

Clinician versus potential acuity test predictions of visual outcome after cataract surgery

BACKGROUND

The aim of this study was to compare the ability of potential vision tests and clinical judgement to predict postoperative visual acuity after uneventful cataract surgery.

METHODS

Sixty-two subjects (median, 74.5 years) were included in the study. Preoperative measurements included a clinical judgement prediction (based on case history and ocular examination alone), 2 super-illuminated pinhole techniques (distance and near), Potential Acuity Meter and interferometer. Postoperative visual acuity was used as the outcome measure to evaluate the accuracy of the preoperative predictions.

RESULTS

Subjects were categorized as follows: (a) moderate cataract (N = 25); (b) moderate cataract and comorbidity (N = 18), and (c) advanced cataract (N = 19). Preoperative predictions within 2 lines of the postoperative visual acuity were as follows (a, b, and c respectively): clinical judgement (92%, 72%, 58%), super-illuminated pinhole distance (96%, 100%, 21%), super-illuminated pinhole near (92%, 78%, 26%), Potential Acuity Meter (72%, 67%, 21%), and interferometer (56%, 61%, 37%).

CONCLUSIONS

Based on the preoperative predictions above, none of the potential vision tests was useful compared with the clinical judgement in the advanced cataract group. The super-illuminated pinhole (distance) provided additional information beyond clinical judgement in the moderate cataract subgroup. The Potential Acuity Meter and interferometer were inaccurate even in the presence of moderate cataract, and this and other recent findings suggest they should no longer be considered adequate for potential vision assessment.