ABSTRACT
Aims: In this study, we aimed to investigate the intercorrelations between tear film break up time, measured non-invasively using non-invasive keratographic break-up time (NIKBUT), higher order aberrations (HOA) and quality of vision (QoV) in pseudophakic patients.Study Design: Cross-sectional.Methods: Thirty-five pseudophakic aged patients aged 50 years or older, and 35 control phakic patients aged 17 to 23 years with corrected visual acuity of 20/20 were included in this study. All subjects underwent similar examination including QoV questionnaire, aberrometry to measure HOA, and NIKBUT. HOA was measured with the OPD-Scan/ ARK 10000 corneal analyzer (Nidek CO. Ltd), expressed as Root Mean Square (RMS) HOA and NIKBUT was assessed using non-invasive TF-Scan module Keratograph 5M (K5M), equipped with modified tear film scanning function (Oculus, Wetzlar, Germany). Statistical analysis was performed to find the correlation between NIKBUT, HOA and QoV.Results: Patients in the pseudophakic group were significantly older (median age 66 vs. 20 years; P<0.01), had shorter NIKBUT (10.5 vs. 17.2; P<0.01), lower QoV score (1.63 vs. 0.68; P=0.04), and higher RMS HOA (0.5 vs. 0.26; P<0.01) compared to control group. NIKBUT was inversely correlated with RMS HOA (r = -0.19; p = 0.03) and RMS HOA was significantly correlated with QoV, even after adjustment for age and gender (r = -0.21; P0.04). NIKBUT <9.93s was correlated with lower QoV. The area under the curve was 0.81 (95% CI = 0.67 � 0.95, p = 0.012), and had 100% sensitivity and 61% specificity.Conclusion: Shorter NIKBUT was correlated with greater HOA and greater HOA was correlated with lower QoV. NIKBUT value of shorter than 9.93s could potentially predict pseudophakic patients who will likely experience visual symptoms leading to decreased QoV; thus, the use of artificial tears might be beneficial.
ABSTRACT
Aims: Image-guided systems are the gold standard for determining toric intraocular lens (IOL) axis alignment. However, their high cost prevents widespread use of these systems. As an alternative, a simpler and affordable method could be performed manually using a slit-lamp biomicroscope. This study aims to compare the accuracy of manual toric IOL axis marking using a slit-lamp compared to the CALLISTO eye image-guided system.Study Design: Prospective comparativeMethods: In this prospective study, toric IOL axis alignment of 42 eyes with cataract and coexisting corneal astigmatism were evaluated using manual slitlamp method and CALLISTO eye image-guided method. Preoperative and postoperative uncorrected visual acuity, best corrected visual acuity, amount of spherical and astigmatic refractive errors, and postoperative IOL axis alignment were evaluated. Intraclass correlation of the manual method was calculated and the difference of IOL axis alignment to the image-guided method was compared.Results: Toric IOL implantation reduced the amount of astigmatic refractive error from -1.63 � 0.65 D to -0.50 � 0.19 D in the image-guided group and from -1.93 � -0.90 D to -0.87 � 0.26 D in the manual slitlamp group. As many as 90.5% of eyes in the image-guided group and 81.0% of eyes in the manual slitlamp group reached the target induced astigmatism (p=0.38). Manual axis marking showed intraclass correlation of 99.3%. However, when the manual method was compared to the image-guided method a mean difference in axis alignment of 10.98o (95% confidence interval: 9.32o - 12.63o) was observed.Conclusions: Alignment of toric IOL axis using the manual method demonstrated a consistent result; yet producing a considerable difference to the result of the image-guided method.