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

Abstract

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% G 0.76% (SD) (range 7.5% to 10.8%), and the mean maximum density was 27.96% G 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 (r Z 0.661, P < .001 and r Z 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.

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

“…These results are in agreement with Sachdev et al [ 21 ] and Rocha et al [ 22 ] who evaluated the level of high order aberrations (HOAs) in eyes with cortical and nuclear cataracts. On the contrast, Lee et al [ 23 , 24 ], Wu et al [ 25 ], and Faria-Correia et al [ 26 ], conversely to previous authors, reported that negative internal SA was increased in nuclear cataract as well as Kuroda et al [ 27 ] and Zhu et al [ 28 ] who also suggested that the opposite happens in cortical cataracts, with an increase of the positive total SA measured with Hartman–Sack aberrometers. This was attributed to the fact that wavefront in the central pupillary area relatively delays in nuclear cataracts and relatively advances in normal subjects and cortical cataract [ 27 ].…”

Applications of Scheimpflug Imaging in Glaucoma Management: Current and Potential Applications

“…Based on these measurements, the Pentacam can be equipped with software that then assigns a grade of nuclear sclerosis on a scale of 1–5 (Pentacam Nuclear Staging or PNS). The PNS score has been shown to correlate well with Snellen acuity and LOCS III grade, validating the Pentacam's automated assessment of nuclear sclerosis [67]. Furthermore, the Pentacam's densitometric parameters have been positively correlated with higher-order aberrations (HOAs) obtained from wavefront analyses [67].…”

“…The PNS score has been shown to correlate well with Snellen acuity and LOCS III grade, validating the Pentacam's automated assessment of nuclear sclerosis [67]. Furthermore, the Pentacam's densitometric parameters have been positively correlated with higher-order aberrations (HOAs) obtained from wavefront analyses [67]. A consideration of HOAs may enable clinicians to better appreciate why patients with relatively good Snellen acuity may complain of poor vision quality.…”

“…Measurements of lens densitometry enable a quantitative evaluation of a nuclear sclerosis; this may help guide the selection of phacoemulsification technique or use of a femtosecond laser for lens fragmentation. It should be mentioned, however, that lens densitometry measurements are currently less precise for higher-grade nuclear cataracts [67]. Scheimpflug imaging has been shown to be helpful for evaluating intraocular lens tilt and decentration following cataract extraction [68, 69].…”

Clinical Evaluation of Toric Intraocular Lens Implantation Based on iTrace Wavefront Keratometric Astigmatism

“…internal aberrations were calculated by subtracting the corneal wavefront aberrations from those of the entire eye measured by the ray-tracing aberrometer using the built-in program [7].…”