Intraoperative quantitative crystalline lens nuclear opacities analysis based on crystalline lenSx platform.

PURPOSE: The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract. METHODS: This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract. RESULTS: The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability. CONCLUSION: The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.

In vivo ultraosound elastographic evaluation of the age-related change of human lens nuclear stiffness.

BACKGROUND: To evaluate the age-related changes in the stiffness of the human lens nucleus in vivo. METHODS: A total of 78 volunteers with best-corrected visual acuity of 20/20with a mean ± standard deviation intraocular pressure (IOP) of 16 ± 2.5 mmHg were divided into 3 groups of 26. The mean ages of Groups A, B and C were 81 ± 5.5, 44 ± 3.2 and 21 ± 2.5 years, with mean axial lengths of 23.8 ± 0.5 mm, 23.8 ± 0.4 mm and 23.9 ± 0.3 mm, respectively. Using an elastographer, the ultrasound echolucency and elastic strain rate of the lens nucleus of one eye, selected randomly, of each subject were measured three times. The strain rate of the lens cortex could not be assessed. The qualitative differences in the strain rates across the groups were assessed, and differences in the strain rate ratios of the lens nuclei across groups were analysed by one-way ANOVA. RESULTS: The strain rates of the lens nuclei of Group A were much lower than those in Groups B and C, as assessed qualitatively; the elastograph images of the lens nuclei of the older group showed a blue colour.The strain rate ratios of the lens nuclei of Groups A, B and C were 0.02 ± 0.08, 0.69 ± 0.12 and 1.95 ± 0.85, respectively. The differences in the lens nucleus strain rate ratios across the groups were statistically significant, with p-values < 0.05. CONCLUSIONS: Ultrasound elastography demonstrated in vivo that an older age is associated with a statistically significantly lower lens nucleus strain rate ratio and therefore a markedly higher lens nuclear stiffness.

Phacolytic glaucoma: A nearly forgotten entity.

PURPOSE: To report a case of phacolytic glaucoma with rupture of anterior lens capsule in a case of hypermature cataract. METHODS: Case report and literature review. RESULTS: An 80-year-old woman presented with cloudiness and pain in the left eye for 1 day. The patient had visual acuity limited to perception of light with raised intraocular pressure of 70 mm Hg. Careful slit-lamp evaluation revealed corneal epithelial edema in superior quadrant and a deep and turbid anterior chamber. Ultrasound biomicroscopy confirmed the presence of a deep anterior chamber, a hypermature cataractous nucleus with lax capsular bag, and ruptured anterior lens capsule. The patient underwent extracapsular cataract extraction. Cytological examination of the lenticular fluid revealed the presence of lens protein-laden macrophages. Post-operatively, the patient had best-corrected visual acuity of 6/60 with advanced glaucomatous optic neuropathy. CONCLUSION: Phacolytic glaucoma can present with a cloudy cornea and a turbid anterior chamber mimicking endophthalmitis. Careful examination and ancillary investigations including ultrasound biomicroscopy was helpful in making an accurate diagnosis.

Lens nuclear opacity quantitation with long-range swept-source optical coherence tomography: correlation to LOCS III and a Scheimpflug imaging-based grading system.

PURPOSE: To quantitate lens nuclear opacity using long-range swept-source optical coherence tomography (SS-OCT) images and to evaluate the correlation of this method to Lens Opacities Classification System III (LOCS III) and a Scheimpflug imaging-based grading system (Pentacam Nuclear Stage function; PNS). METHODS: This study enrolled 120 participants (120 eyes) with age-related nuclear cataracts. The best-corrected visual acuity (BCVA), LOCS III nuclear opalescence (NO) and nuclear colour (NC) were obtained. The nuclear density measured using PNS function (NDPNS) was recorded. Three successive series of long-range SS-OCT images were captured, and the nuclear region was analysed using ImageJ (NIH, Bethesda, Maryland, USA) to generate SS-OCT image-based nuclear density (NDSS-OCT). The repeatability of NDSS-OCT measurement was evaluated using within-subject coefficient of variation (CVw) and intraclass correlation coefficient (ICC). Correlations of NDSS-OCT with NO and NC, BCVA and NDPNS were analysed. According to the integrity of nucleus imaged by Pentacam, patients were divided into two groups, and the parameters were compared between groups. RESULTS: The CVw and ICC for NDSS-OCT measurement were 1.5 % and 0.994, respectively. The NDSS-OCT significantly correlated with NO (r=0.831), NC (r=0.873), BCVA (r=0.655) and NDPNS (r=0.891). The NDSS-OCT, NO and NC, and BCVA were significantly different between the two groups. CONCLUSION: Lens nuclear opacity quantitation using long-range SS-OCT images was repeatable and correlated well with LOCS III and PNS function. The Scheimpflug principle had a limitation in imaging dense nucleus. Long-range SS-OCT seems more promising for objectively and quantitatively assessing lens nuclear opacity.

Validation of the Nuclear Cataract Grading System BCN 10.

PURPOSE: To evaluate a new nuclear cataract grading system which is intended as a surgical guidance system to predict lens hardness before cataract surgery. METHODS: The new BCN 10 grading system consists of frontal and cross-sectional slit-lamp images of human eye lenses, ranging from a completely transparent lens nucleus to a totally black nuclear cataract. Validation was done with 9 observers for 110 cases. Two modalities were applied, and observers were asked to use only whole digits and then half digits for grading. RESULTS: Repeatability with regard to test-retest differences showed a mean limit of agreement of 1.70 for whole digits and 1.32 for half digits. The absolute test-retest difference was close to zero for low as well high degrees of cataracts. Reliability for the entire group of 9 observers yielded an intraclass correlation coefficient which was within the same confidence interval, i.e., 0.991-0.995, for whole digits and half digits. CONCLUSIONS: BCN 10 grading repeatability was not affected by the severity of the cataract. It showed very good repeatability. Repeatability was significantly higher when the observers used half digits compared to whole digits. Reliability was found to be very good as well, independently of the use of whole or half digits.

Scheimpflug lens densitometry and ocular wavefront aberrations in patients with mild nuclear cataract.

PURPOSE: To test correlations between Scheimpflug optical densitometry and ocular higher-order aberrations (HOAs) in patients with mild nuclear cataract. SETTING: Cornea and Refractive Surgery Department, Hospital de Braga, Braga, Portugal. DESIGN: Retrospective single-center study. METHODS: In eyes with mild nuclear cataract, lens densitometry was evaluated by Scheimpflug imaging (Pentacam HR), which provided an objective quantification (mean density and maximum density) and grading (nuclear staging score) of the crystalline lens. A visual function analyzer that combines ray-tracing aberrometry and Placido disk-based topography (iTrace) was used to evaluate the total ocular and internal HOAs. RESULTS: The study comprised 40 eyes of 30 patients. The mean density of the lens nucleus was 8.99% ± 0.76% (SD) (range 7.5% to 10.8%), and the mean maximum density was 27.96% ± 6.97% (range 16.9% to 56.1%). Regarding the score of nuclear staging of the Scheimpflug device, 28 eyes had level 0 and 12 eyes had level 1. Significant positive correlations were found between the mean density and maximum density parameters and the internal HOAs (ρ = 0.661, P < .001 and ρ = 0.570, P < .001, respectively). CONCLUSIONS: There were significant correlations between the quantification parameters derived from Scheimpflug lens densitometry and ocular HOAs. The integration of these technologies can help in clinical decision making and in understanding the subjective symptoms of patients with mild nuclear cataracts. FINANCIAL DISCLOSURE: Dr. Ambrósio is a consultant to Oculus Optikgeräte GmbH, Alcon Surgical, Inc., and Carl Zeiss Meditec AG. None of the other authors has a financial or proprietary interest in any material or method mentioned.

[Clinical study of phacoemulsification with NeoSoniX handpiece].

OBJECTIVE: To evaluate the outcomes of phacoemulsification with NeoSoniX handpiece. METHODS: It was a prospective random controlled clinical trial. Six hundred and fifty-nine cases (659 eyes) having phacoemulsification were prospectively comprised in this study. All cases were divided into two groups randomly. Group 1(NeoSoniX handpiece) include 317 cases. Group 2 (standard handpiece) include 342 cases. Preoperative measurements included best correct visual acuity (BCVA) and cataract grade according to the Emery classification. Intraoperative measurements included active power (AP) and effective phaco time (EPT). Postoperative measurements included BCVA and corneal edema. RESULTS: Grade I to III nuclear sclerosis, the AP was 3.53% +/- 1.76% with NeoSoniX and 3.84% +/- 1.93 % with standard handpiece, the EPT was (0.23 +/- 0.15) minutes and (0.25 +/- 0.19) minutes, respectively. There was no significant difference in the postoperative BCVA and cornea edema between the two groups. Grade IV or V nuclear sclerosis, the AP was 6.31% +/- 2.78 % with NeoSoniX and 9.45% +/- 4.17 % with standard handpiece, the EPT was (0.55 +/- 0.28) minutes and (0.83 +/- 0.44) minutes, respectively. There was significant difference in the postoperative 1 day BCVA and cornea edema between the two groups. There was significant difference in the postoperative 7 days BCVA and cornea edema between the two groups. CONCLUSIONS: Ultrasound energy consumption with NeoSoniX was significantly less than with US alone in emulsifying cataracts of optimum density and dense hard cataracts.

Determining the acoustic properties of the lens using a high-frequency ultrasonic needle transducer.

Ultrasonic parameters including sound velocity and attenuation coefficient have recently been found to be useful in characterizing the cataract lens noninvasively. However, the regional changes of these acoustic parameters in the lens cannot be detected directly by those ultrasonic measurements. This prompted us to fabricate a 46-MHz needle transducer (lead magnesium niobate-lead titanate [PMN-PT] single crystal) with an aperture size of 0.4 mm and a diameter of 0.9 mm for directly measuring the sound velocity and frequency-dependent attenuation coefficient in lenses. These parameters have been shown to be related to the hardness of a cataract, and hence this technique may allow surgeons to detect the acoustic properties of the cataract via a small incision on the cornea before/during phacoemulsification surgery. To verify the performance of the needle transducer, experiments were performed on porcine lenses in which two types of cataracts (nucleus and cortical) were induced artificially. The needle transducer was mounted on a positioning system and its tip was inserted into the lens, allowing the anterior-to-posterior profiles of acoustic parameters along the lens axis to be obtained immediately. The experimental results show that the acoustic parameters are not constant within a single normal lens. The sound velocity and ultrasound attenuation coefficient (at 46 MHz) were 1701.2 +/- 8.4 m/s (mean +/- SD) and 9.42 +/- 0.57 dB/mm, respectively, at the nucleus, and 1597.2 +/- 9.6, 1589.3 +/- 6.1 m/s and 0.42 +/- 0.26 and 0.40 +/- 0.33 dB/mm close to the anterior and posterior capsules, respectively. Finally, the data obtained demonstrate that regional variations in the acoustic properties of lenses corresponding to the hardness of different types of cataract can be detected sensitively by a needle transducer.

[Characteristics of non invasive ultrasound determination of mechanical lens hardness].

Sixty-two patients with varying maturity cataract were examined to assess a new noninvasive method for determining the mechanical hardness of the nucleus of the lens. There was an inverse relation of the hardness of the nucleus to its relative acoustic density (delta). Comparison of the ultrasound density of the lens and the mechanical characteristics of its nucleus has provided the following classification: the lens hardness is high at delta of 0 to 0.2; average at 0.3 to 0.5, and low at 0.6 or higher. Determination of relative acoustic density by measuring the parameter delta substantially enhances the accuracy ofpreoperative prediction of the hardness of the nucleus of the lens when a surgical option for cataract removal is chosen.

[Optimization of energy parameters of ultrasound and laser cataract surgery with a preliminary transcorneal endocapsular YAG-laser impact exerted on the cataract lens nuclei]. / Optimizatsiia énergeticheskikh parametrov ul'trazvukovoi i lazernoi khirurgii katarakty s pomoshch'iu predvaritel'nogo transkorneal'nogo éndokapsuliarnogo IAG-lazernogo vozdeistviia na iadra kataraktal'nykh khrustalikov.

The values of the main energy and time parameters of ultrasound and laser fragmentation of different-hardness cataract-lens nuclei were analyzed in patients of various age groups after a preliminary transcorneal endocapsular YAG-laser treatment of the lens. The results show, in all cases, lower key energy and time characteristics, which primarily concerns a total energy index of the ultrasound and laser effect of no less than 20% versus the ordinarily used parameters.