Correlational Analysis of Objective and Subjective Measures of Cataract Quantification

Evaluation value of subjective visual quality examination on surgical indications of the early cataracts based on objective scatter index values

Aim

To evaluate the subjective visual functions of early cataracts patients and assess their surgical indications.

Methods

Eyes were separated into a control group (Group A without cataract) and two early cataracts groups (Group B with 2.0 ≤ OSI < 3.0 and Group C with 3.0 ≤ OSI < 4.0). The objective scatter index (OSI), modulation transfer function cut-off frequency (MTF cut-off), and Strehl ratio (SR) values were applied to measure objective visual functions. The contrast sensitivity (CS) and scores of the questionnaires (QOL and VF-14) characterized subjective visual functions. Above visual functions were compared among three groups. Postoperative visual functions in Group B and C were analyzed to assess the outcome of surgery.

Results

Ninety two subjects (126 eyes) were included in the study. All objective visual function in Group B were significantly better than Group C (all P < 0.01), but worse than Group A (all P < 0.01). Except for 1.5 c/d CS, subjective visual function in Group A were significantly better than Group B and C (all P < 0.05), but there was no significant differences between Group B and C. As for eyes that underwent surgery in Group B and C, all visual functions significantly improved after surgery (P < 0.05), except for 1.5 c/d CS in Group C. There were no significant differences among the three groups after surgery.

Conclusion

The subjective visual function can be impaired in early cataracts patients with OSI < 3.0, whose objective visual functions were statistically better than patients with OSI ≥ 3.0. These patients can benefit equally from surgery as patients with OSI ≥ 3.0. Subjective visual functions can be used as surgical indications for these patients.

Association of optical cataract indices with cataract severity and visual function

PURPOSE

The purpose of this study is to determine the correlation between subjective and optical measurements used during cataract evaluation, including the iTrace Dysfunctional Lens Index (DLI), the HD Analyzer Objective Scatter Index (OSI), Lens Opacities Classification System III (LOCS III), Visual Function-14 Questionnaire (VF-14), and the Pelli-Robson Contrast Sensitivity Chart (PRCSC).

METHODS

Seventy eyes from 70 patients were enrolled, including all stages of age-related nuclear cataracts. The LOCS III-NO with a cutoff of 3.2 was chosen to divide the population into two groups. Eyes with corneal or retinal pathology were excluded. All patients were evaluated with the iTrace's DLI, HD Analyzer's OSI, LOCS III, VF-14, and the PRCSC during each follow-up visit. Correlation analyses were performed using Stata software, version 14.0, StataCorp.

RESULTS

The LOCS III-NO, DLI, OSI, and VF-14 questionnaire each correlated moderately with the BCVA with a Spearman rho value of 0.37, - 0.45, 0.40, and - 0.35, respectively. The DLI correlated moderately with LOCS III-NO with a rho value of - 0.37 and with the VF-14 questionnaire with a rho value of 0.35. The OSI correlated with both the contrast sensitivity and DLI with a rho value of - 0.35 and - 0.55, respectively.

CONCLUSIONS

The DLI correlated with cataract symptoms (measured by the VF-14 questionnaire) in addition to BCVA. The OSI correlated moderately with contrast sensitivity and BCVA. The highest correlation was between DLI and OSI.

Using Optical Quality Analysis System for predicting surgical parameters in age-related cataract patients

The Optical Quality Analysis System (OQAS, Visiometrics) provides objective measurements of image formed onto retina, by combining quantification of ocular media transparency and of optical aberrations. In order to evaluate its contribution in the assessment of age-related cataract, we conducted a monocentric clinical study to determine the relationships between clinical grading of lens opacity, OQAS parameters, and parameters required for cataract surgery by phacoemulsification with ultrasound (called “phacodynamics”). Clinical parameters were: best-corrected visual acuity (BCVA, expressed as Log of minimal angle resolution (logMAR)) and the lens opacity classification system III (LOCS III) as a gold standard determined by two independent observers who graded total cataract and nuclear, cortical and posterior sub capsular components. The OQAS provided an objective scatter index (OSI), a modulation transfer function (MTF, expressed in cycle per degree (cpd)) and a Strehl ratio (SR) used as an aberration marker. Patients were operated on by the same surgeon using a phacoemulsification machine that provided the cumulative dissipated energy (CDE) and total ultrasound time (US time) necessary to extract the lens. Patients with poor compliance, corneal or retinal diseases impairing OSI, or who required surgical settings variation, were excluded. Twenty-one eyes of 21 patients aged 76±8 years were analyzed. They were 11 pure nuclear, 3 pure cortical, and 7 mixed cataracts. Mean LOCS III and OSI were respectively: 4.86 ±2.03 and 6.12 ±3.07 (mean±SD). Medians (10°-90° percentiles) were: for BCVA 0.30 (0.10–0.70) logMAR, for MTF cutoff 9.31 (1.54–30.57) cpd, for SR 0.071 (0.042–0.146), for CDE 8.04 (5.74–23.29) and for US time 58 (39–116) seconds. LOCS III was significantly correlated (spearman r, r_s) with BCVA (r_s = 0.561, p = 0.008), CDE (r_s = 0.457, p = 0.038) and US time (r_s = 0.647, p = 0.002). The three OQAS parameters significantly correlated (all r_s ≥ 0.526, p<0.05) with BCVA, and LOCS III grading, but the strongest correlations were found with OSI for cortical components and with MTF for nuclear components: only OSI may be used objectively to assess the effect of cortical components on optical quality, and MTF cutoff—integrating scattering and aberrations—seems the best objective parameter for clinical assessment of nuclear cataracts. The three OQAS parameters were also significantly correlated (r_s) with CDE, and with US time only for pure nuclear cataracts: OSI had the strongest correlations with phacodynamics (r_s = 0.693, p = 0.022 with CDE and r_s = 0.703, p = 0.019 US time). OSI increased with cortical components not requiring higher CDE. When measured in optimal conditions (good compliance, no retinal or ocular surface or tear film diseases), the three OQAS parameters are complementary for objective grading of cataract. In the future, they may help to optimize surgical parameters, especially energy distribution, in femtosecond laser assisted cataract surgery.

Correlation among Lens Opacities Classification System III grading, the 25-item National Eye Institute Visual Functioning Questionnaire, and Visual Function Index-14 for age-related cataract assessment

Purpose

To evaluate the relationship between cataract types and subjective visual function among patients with age-related cataract.

Methods

This was a prospective, multicenter, 831 Chinese patient-based, cross-sectional study. Patients were administered the Visual Function Index-14 (VF-14) and the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) to evaluate their subjective visual function. Lens Opacities Classification System III (LOCS III) was used to evaluate the type of cataract. Relationships among these parameters were analyzed.

Results

LOCS III cortical (C) and posterior subcapsular scores are negatively associated with VF-14 (r = − 0.188, P < 0.01; r = − 0.146, P < 0.01) and total score of NEI-VFQ-25 (r = − 0.223, P < 0.01; r = − 0.160, P < 0.01), respectively; LOCS III nuclear opalescence (NO) score is positively associated with VF-14 (r = 0.087, P < 0.05) and total score of NEI-VFQ-25 (r = 0.097, P < 0.05). In multiple linear regression, a decrease in the LOCS III C score is a significant predictor for improvement of the total score of NEI-VFQ-25 (β = − 1.286, P < 0.05). In contrast, an increase in LOCS III NO score is a significant predictor for improvement of VF-14 (β = 3.826, P < 0.01) and total score of NEI-VFQ-25 (β = 4.618, P < 0.01). Patients with LOCS III C score ≤ 2 have higher VF-14 (49.38 versus 43.74, P < 0.01), total (80.73 versus 71.58, P < 0.01) and subscale scores of NEI-VFQ-25 than patients with LOCS III C score > 2.

Conclusion

Cortical cataract has adverse effects on subjective visual function, while mild-to-moderate nuclear cataract has positive effects. Furthermore, “LOCS III C score > 2” can be a potential cutoff as a reference for cataract surgery without self-assessing questionnaires.

Electronic supplementary material

The online version of this article (10.1007/s10792-020-01353-0) contains supplementary material, which is available to authorized users.

Quantitative Analysis of Objective Forward Scattering and Its Relevant Factors in Eyes with Cataract

This study was aimed to quantitatively assess objective forward scattering and its relevant factors in eyes having cataract. Our study comprised 192 eyes of 192 patients (mean age, 71.3 ± 9.2 (standard deviation) years) who have cataract formation for surgical consultation. We determined uncorrected and corrected distance visual acuities (UDVA and CDVA), manifest refraction, the grade of nuclear sclerosis, objective scattering index (OSI) with the OQAS II (Visiometrics, Spain), log(s) with the C-Quant (Oculus, Germany), and ocular higher-order aberrations (HOAs) using the wavefront sensor (KR-1W, Topcon, Japan). The mean OSI was 5.11 ± 3.19 (0.90 to 20.90). We found explanatory variables relevant to the OSI to be, logMAR CDVA (p < 0.0001, partial regression coefficient B = 5.917) and log(s) (p = 0.0006, B = 0.911) (adjusted R² = 0.333), in order of influence. No significant correlation was found with other clinical factors such as gender, age, manifest refraction, UDVA, ocular HOAs, or nuclear sclerosis. Eyes with worse CDVA and higher log(s) are more predisposed to show higher OSI in cataractous eyes. It is suggested that objective forward scattering was associated, not only with CDVA, but also with subjective forward scattering, in cataractous subjects.

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.

Near Vision Improvement with the Use of a New Topical Compound for Presbyopia Correction: A Prospective, Consecutive Interventional Non-Comparative Clinical Study

Introduction

To report the outcomes in near vision, optical quality and pupil diameter of a new pharmacological therapy (FOV tears) for presbyopia.

Methods

This was a prospective, consecutive, interventional, non-comparative clinical study in which 117 presbyopic patients were given one drop of the novel therapy (FOV tears) in each eye, followed 2 h after the instillation of the eye drop by an evaluation of the binocular uncorrected near visual acuity (UNVA) and uncorrected distance visual acuity. The objective scatter index and pupil diameter under photopic and scotopic conditions before and after instillation were also assessed. The patients were divided into two groups according to their age, with group 1 patients being 41 and 50 years old and group 2 patients, between 51 and 65 years old.

Results

The mean age of the patients was 50.2 years. The mean UNVA before the use of the eye drop was 0.35 LogMAR, which improved to 0.16 LogMAR at 2 h after the use of the eye drop (p = 0.000). Nine patients did not show an improvement in UNVA, but no patient showed a loss of lines. Fourteen patients (11.9%) reported headaches as a side effect of the therapy.

Conclusion

This pharmacological therapy improved near vision by one or more lines (mean improvement 0.18 lines) in 92.3% of the patients at 2 h following the instillation of the eye drops. The group with the youngest patients gained more lines than the group with the oldest patients.

From Presbyopia to Cataracts: A Critical Review on Dysfunctional Lens Syndrome

Dysfunctional lens syndrome (DLS) is a term coined to describe the natural aging changes in the crystalline lens. Different alterations in the refractive properties and transparency of the lens are produced during the development of presbyopia and cataract, such as changes in internal high order aberrations or an increase in ocular forward scattering, with a potentially significant impact on clinical measures, including visual acuity and contrast sensitivity. Objective technologies have emerged to solve the limits of current methods for the grading of the lens aging, which have been linked to the DLS term. However, there is still not a gold standard or evidence-based clinical guidelines around these new technologies despite multiple research studies have correlated their results with conventional methods such as visual acuity or the lens opacification system (LOCS), with more scientific background around the ocular scattering index (OSI) and Scheimpflug densitometry. In either case, DLS is not a new evidence-based concept that leads to new knowledge about crystalline lens aging but it is a nomenclature change of two existing terms, presbyopia and cataracts. Therefore, this term should be used with caution in the scientific peer-reviewed literature.