Comparison of the potential acuity meter and pinhole tests in predicting postoperative visual acuity after cataract surgery

Visual Acuity Outcomes after Phacoemulsification in Eyes with Good Visual Acuity before Cataract Surgery

OBJECTIVE

to analyse cataract surgery outcomes and related factors in eyes presenting with good visual acuity.

SUBJECT AND METHODS

A retrospective longitudinal study of patients undergoing phacoemulsification between 2014 and 2018 in Moorfields Eye Hospital was conducted. Pre- and post-operative visual acuities were analysed. Inclusion criteria were age ≥40 years and pinhole visual acuity ≥6/9 pre-operatively. Exclusion criteria were no post-operative visual acuity data. The visual acuity change variable was also defined according to post-operative visual acuity being above or below the Snellen 6/9 threshold.

RESULTS

2,720 eyes were included. The unaided logMAR visual acuity improved from 0.54 to 0.20 (p < 0.001), the logMAR visual acuity with glasses improved from 0.35 to 0.05 (p < 0.001), and the logMAR pinhole visual acuity improved from 0.17 to 0.13 (p < 0.001); 8.1% of patients had Snellen visual acuity <6/9 post-operatively. Mean follow-up period was 23.6 ± 9.9 days. In multivariate analysis, factors associated with visual acuity <6/9 post-operatively were age (OR = 0.96, 95% confidence interval [CI] [0.95, 0.98], p < 0.001), vitreous loss (OR = 0.21, 95% CI [0.08, 0.56], p = 0.002), and iris trauma (OR = 0.28, 95% CI [0.10, 0.82] p = 0.02).

CONCLUSIONS

Visual acuity improved significantly, although at least 8.1% of them did not reach their pinhole preoperative visual acuity. Worse visual acuity outcomes were associated with increasing age, vitreous loss, and iris trauma. The 6/9 vision threshold may not be able to accurately differentiate those who may benefit from cataract surgery and those who may not.

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.

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.

Predicting postoperative visual outcomes in cataract patients with maculopathy

Purpose:

To assess the accuracy of the potential acuity meter (PAM) in predicting postcataract surgery visual acuity outcome in patients with healed inactive maculopathies.

Study Design:

Prospective interventional clinical trial.

Patients and Methods:

Patients scheduled for phacoemulsification had preoperative and 1 month postoperative best-corrected visual acuity (BCVA), PAM test, fluorescein angiography, and macular optical coherence tomography. Patients were grouped to following preoperative BCVA: PRE1: 0.29 and better, PRE2: 0.25–0.13, and PRE3: 0.1 or worse; age: G1 <60, G2 = 60–70, and G3 >70 years. PAM accuracy was divided into: Grade 1: Postoperative BCVA ≤1 or less line error of the PAM score, Grade 2: Between 1 and 2 lines error, and Grade 3: ≥3 lines or more error.

Results:

This study enrolled 57 patients with a mean age of 71.05 ± 6.78 years where 34 were females. There were 21 (36.84%) patients with diabetic maculopathy and 36 (63.16%) with age-related macular degeneration. The mean preoperative BCVA was 0.198 ± 0.12 (0.1–0.5). The mean PAM score was 0.442 ± 0.24 (0.1–1.3). The mean postoperative BCVA was 0.4352 ± 0.19 (0.17–1.00). The PAM score was in Grade 1, 2, and 3 in 46 (80.7%), 54 (94.7%), and 56 (98.2), respectively. There was a highly significant correlation between the PAM score and the postoperative BCVA (P < 0.001, Chi-square test). There was no correlation between the PAM test accuracy and age, gender, diagnosis, and preoperative BCVA (P = 0.661, 0.667, 0. 0.991, 0.833, Chi-square test; respectively).

Conclusion:

The PAM is an accurate method of predicting postoperative visual acuity for eyes with nuclear cataracts Grade I and II and inactive maculopathies.

Cataract surgery after pars plana vitrectomy

PURPOSE OF REVIEW

To review recent studies and advances and their possible implications in the care of patients undergoing cataract surgery after pars plana vitrectomy.

RECENT FINDINGS

Optical biometry has shown to be superior to ultrasound biometry in vitrectomized eyes but still not achieving as good results as it does in nonvitrectomized eyes. Blue light-filter intraocular lenses, with their possible advantage of macular protection, have shown no operative or functional disadvantages in vitrectomized eyes, and thus their routine use can be justified. However, presbyopia-correcting intraocular lenses, at least at their current stage of development, generally, are still not accepted for vitrectomized eyes. Combining cataract surgery with intravitreal injections of bevacizumab or triamcinolone acetonide in patients with macular edema and cataract is advisable to avoid exacerbation of the condition and improve visual outcome. Despite the recent advances, incidences of posterior capsular opacification and retinal detachment are still considerable.

SUMMARY

Understanding ocular anatomical alterations imposed by the previous pars plana vitrectomy surgery and the underlying vitreoretinal disease will allow the surgeon to address the special challenges. Despite that, recent advances in techniques and instrumentation have improved the surgical safety and outcomes, reported complications rates are still relatively high.

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.

Comparison of adapted Vryghem macular function test and Lotmar-light interferometer in predicting visual acuity after cataract surgery

PURPOSE

To assess the accuracy of a newly described macular function test (Vryghem macular function test) adapted to our examination equipment and to compare it to the Lotmar-light interferometer for the preoperative evaluation of cataract patients at the University Eye Clinic, Geneva, Switzerland.

METHODS

This prospective study included 71 consecutive patients (72 eyes) who were undergoing uneventful cataract surgery. Testing with the Lotmar-light interferometer and an adapted form of Vryghem macular function test (AVMFT) using a Birkhauser reading chart, a hyperaddition of +8 D and halogen illumination were performed to assess macular function and to predict postoperative visual acuity (VA). The duration of each test and the density and location of lens opacities were also noted. Best-corrected postoperative VA was compared to the predicted values of each test.

RESULTS

The positive predictive value was 94.2% for AVMFT compared to 92.2% for the Lotmar-light interferometer. The negative predictive value was 50% for AVMFT compared to 42.9% for the Lotmar-light interferometer. The sensitivity was 83.1% for AVMFT and 79.7% for the Lotmar-light interferometer. The specificity was 76.9% for AVMFT and 69.2% for the Lotmar-light interferometer. The correlation coefficient for AVMFT and preoperative Lotmar results (both in LogMAR) with postoperative best-corrected VA (poBCVA; LogMAR) were similar (0.74 and 0.77 respectively).

CONCLUSION

The results of this study suggest that AVMFT is as reliable as the Lotmar-light interferometer in predicting postoperative VA after uneventful cataract surgery. The correlation coefficients with postoperative VA were 0.74 and 0.77, respectively. Both tests showed a high positive (94.2% and 92.2%, respectively) but a low negative (50.0% and 42.9%, respectively) predictive value.