1.Comparison of Immediate Effects on Usage of Dual Polymer Artificial Tears on Changes in Tear Film Characteristics
Fatin Amalina Che Arif ; Mohd Radzi Hilmi ; Khairidzan Mohd Kamal ; Mohd Hafidz Ithnin
Malaysian Journal of Medicine and Health Sciences 2021;17(No.3):252-258
Introduction: This study aimed to evaluate the short-term efficacy of two comparable formulation of dual-polymer
artificial tears: Systane Hydration preservative (SH) and non-preservative (SHUD) in 60 minutes observation period
compared to normal saline. Methods: Fifty participants involved in this prospective, double-masked randomised
study. Viscosity and pH of artificial tears were evaluated using rheometer and digital pH-meter prior to tear film
assessment. Tear break-up time (TBUT) and tear meniscus height (TMH) were measured at baseline, 5, 15 and 60
minutes after instillation. Tear ferning pattern (TFP) were compared between baseline and 60 minutes after instillation. One-way analysis of variance (ANOVA) and Independent T-test were used to evaluate the effects of SH and
SHUD after instillation and comparison between each specific time-interval respectively. P-value of 0.05 was set
as the level of significance. Results: The viscosity of SH and SHUD was 26.7cP and 32.73cP re-spectively with
pH of 7.85 (SH) and 7.74 (SHUD). Both artificial tears showed significant increment in TBUT between baseline
and 15 minutes (SH:5.82±1.063, p=0.01; SHUD:6.02±0.979, p<0.001), and 60 minutes (SH:6.22±0.616, p<0.001;
SHUD:6.34±0.658, p<0.001). SHUD demonstrated significant increment in TMH at every measurement taken
(0.1996±0.02449, p<0.001 at 5min, 0.2038±0.02276, p<0.001 at 15min and 0.2068±0.02094, p<0.001 at 60min).
Likewise, in SH group, significant increment in TMH at 15 minutes (0.1994±0.02325, p<0.001) and 60 minutes
(0.2012±0.02379, p<0.001) were noted. Both groups revealed improvement in TFP (both, p<0.001) at 60 minutes.
No significant im-provement was noted in control group. Conclusion: Improvement in TMH was prominently faster
in SHUD than SH, although both TBUT and TFP revealed comparable tears quality between both artificial tears.
2.Mesopic Pupillometry in Pre-LASIK Patients by a Placido-Disc Topographer and Hartmann-Shack Aberrometer
Md Mustafa Md-Muziman-Syah ; Muhammad Aiman Suhaimi ; Umar Hakimi Sulaiman ; Noorhazayti Ab. Halim ; Ahmad Tajudin Liza-Sharmini ; Khairidzan Mohd Kamal
Malaysian Journal of Medicine and Health Sciences 2021;17(No.2):197-202
Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size selection in LASIK. Significant difference in the selection induces unwanted postoperative night visual disturbance. Placido-disc topographer
and Hartmann-Shack aberrometer are commonly used in LASIK preoperative assessment. However, little is known
on the precision and agreement of these devices in pupillometry. Hence, this study aimed to evaluate the precision
(repeatability and reproducibility) and inter-device agreement of a Placido-disc topographer and Hartmann-Shack
aberrometer in measuring mesopic pupil size in pre-LASIK patients. Methods: Mesopic pupillometry on 38 pre-LASIK
patients were performed using both devices by two masked operators, on two separate sessions. Intra-session repeatability, inter-operator reproducibility and inter-device agreement were analysed. A disagreement value of ±0.5 mm
and 95% limits of agreement (LoA) were determined. Results: Hartmann-Shack aberrometer demonstrated higher
repeatability and reproducibility than Placido-disc topographer in mesopic pupillometry. Ninety-seven percent and
all of Hartmann-Shack wavefront aberrometer pupillometry were within ±0.5 mm in repeated sessions and between
the operators, respectively. The mesopic pupil size obtained from Placido-disc topographer was significantly larger
than Hartmann-Shack aberrometer results (P = 0.02). The agreement between devices was low (LoA > ±1 mm) and
only 53% of Placido-disc topographer pupillometry were within ±0.5 mm of Hartmann-Shack aberrometer pupillometry. Conclusion: Hartmann-Shack aberrometer has higher precision within sessions and between operators, and
it provides smaller mesopic pupillometry than Placido-disc topographer. Precise mesopic pupillometry could assist
refractive surgeons in choosing a correct ablation OZ size during LASIK surgery to improve postoperative outcome.