Effect of changing from preserved prostaglandins to preservative-free tafluprost in patients with glaucoma on tear film thickness.

PURPOSE: Long-term glaucoma therapy with preservative-containing eye drops may impact ocular surface health. This study was performed to investigate whether a switch from preserved topical prostaglandin therapy to preservative-free tafluprost therapy improves precorneal tear film thickness in patients with glaucoma or ocular hypertension. METHODS: A total of 30 patients who were under topical preservative-containing prostaglandin monotherapy for at least 6 months were included. Patients were then switched from preserved prostaglandin therapy to unpreserved tafluprost drops once daily. Tear film thickness was measured at baseline and 4 and 12 weeks after therapy change with an ultrahigh-resolution optical coherence tomography system. Furthermore, clinical measures of ocular surface disease were determined and symptoms were assessed using the Dry Eye-Related Quality-of-Life Score. RESULTS: After switching to unpreserved tafluprost, tear film thickness significantly increased from 4.7 ± 0.5 to 5.0 ± 0.6 µm 4 weeks after therapy change and still tended to be increased after 12 weeks (4.8 ± 0.7 µm). Breakup time significantly increased from 5.1 ± 2.3 to 7.2 ± 3.4 s and to 10.1 ± 3.6 s after therapy change. In addition, a significant decrease in corneal staining score from 1.8 ± 0.7 to 1.4 ± 0.8 after 4 weeks and to 0.7 ± 0.7 after 12 weeks treatment was observed. Switching to preservative-free drops reduced Dry Eye-Related Quality-of-Life Score from 11.4 ± 11.0 to 5.7 ± 6.4 and to 4.7 ± 7.5. CONCLUSION: Our data show that switching to preservative-free tafluprost leads to an increase in tear film thickness, breakup time, and an improvement of Dry Eye-Related Quality-of-Life Score. Our results therefore indicate that a switch to unpreserved tafluprost is beneficial for ocular surface health in patients under long-term preserved prostaglandin eye drops.

Effect of different lubricant eye gels on tear film thickness as measured with ultrahigh-resolution optical coherence tomography.

PURPOSE: To compare the effect of a single drop of different lubricant eye gels on tear film thickness (TFT) as measured with ultrahigh-resolution optical coherence tomography (UHR-OCT) in patients with mild-to-moderate dry eye disease (DED). METHODS: The study followed a randomized, single-masked, observer-blinded parallel group design. Patients received a single dose of either unpreserved trehalose 3% + hyaluronic acid 0.15% (TH), hyaluronic acid 0.2% (HA) or polyethylene glycol 0.4% + propylene glycol 0.3% (PP) eye drops. In total, 60 patients were included and TFT was measured using a custom-built UHR-OCT system. RESULTS: The mean TFT at baseline was 3.5 ± 0.7 µm. There was a significant difference in the time-course of TFT between the three groups (p = 0.001 between groups). Ten minutes after instillation, TFT increased by 155.8 ± 86.6%, 65.7 ± 71.5% and 33.4 ± 19.6% in the PP, TH and HA group, respectively (p < 0.001 between groups). Thirty minutes after instillation, the effect of all three different agents on TFT was comparable. Sixty and 120 min after administration, a significant increase in TFT was only seen for the TH group, but not for the other products (60 min: p < 0.021 between groups; 120 min: p < 0.037 between groups). CONCLUSION: In conclusion, we observed differences in TFT after administration of the lubricant gels. Ten minutes after instillation, a pronounced increase in TFT was observed in all groups. As compared to the other products, the combination of trehalose 3% + hyaluronic acid 0.15% offers a significantly longer increase in TFT indicating for a longer residence time.

Tear film thickness after treatment with artificial tears in patients with moderate dry eye disease.

PURPOSE: This study was designed to investigate the effect of a single-drop instillation of different lacrimal substitutes on tear film thickness (TFT) assessed with optical coherence tomography in patients with mild to moderate dry eye disease. METHODS: The study was performed in a randomized, double-masked, controlled parallel group design. Patients received a single dose of either unpreserved trehalose 30 mg/mL and sodium hyaluronate 1.5 mg/mL (TH-SH, Thealoz Duo), unpreserved sodium hyaluronate, 0.15% (HA, Hyabak) or sodium chloride, 0.9% (NaCl, Hydrabak) eye drops. Sixty patients finished the study according to the protocol. TFT was measured with a custom-built ultrahigh-resolution Fourier domain optical coherence tomography system providing a resolution of 1.2 µm. RESULTS: The mean TFT before treatment was 2.5 ± 0.4 µm. Ten minutes after instillation, TFT significantly increased in the TH-SH group from 2.4 ± 0.4 to 3.1 ± 0.9 µm (P < 0.01) and in the HA group from 2.4 ± 0.3 to 2.9 ± 0.5 µm (P < 0.01), whereas no significant change was observed in the NaCl group (from 2.6 ± 0.4 to 2.7 ± 0.4 µm, P = 0.76). The increase in TFT remained statistically significant up to 240 minutes after administration of TH-SH. In contrast, the increase in TFT after administration of HA was only statistically significant at 10, 20, and 40 minutes after drop instillation. CONCLUSIONS: The findings of this study indicate that single instillation of TH-SH and HA eye drops increases TFT in patients with dry eye disease. The data also indicate longer corneal residence of the TH-containing eye drops. The effect of multiple instillation and long-term use of artificial tears on TFT warrants further investigation.

The association between subjective and objective parameters for the assessment of dry-eye syndrome.

PURPOSE: The aim of the present study was to evaluate the association between symptoms and different clinical signs in patients with dry-eye syndrome (DES). METHODS: Fifty-two patients with DES were included in the present cross-sectional study. For assessment of symptoms, the Ocular Surface Disease Index (OSDI) was used. Clinical parameters included measurement of tear break up time (BUT), corneal fluorescein staining, tear osmolarity, and ocular scattering index (OSI). Tear film thickness (TFT) was assessed using a custom-built optical coherence tomography (OCT) system with an axial resolution of 1.2 µm. In addition, impression cytology was performed. Correlation coefficients were calculated using linear regression analysis. RESULTS: The mean OSDI in the present study population was 28.9 ± 17.6, the mean TFT was 4.1 ± 1.3 µm. A significant negative correlation was found between OSDI and TFT (r = -0.34, P = 0.01). Tear film thickness correlated positively with BUT (r = 0.35, P = 0.01), but with no other signs of DES. No association was found between OSDI and the other evaluated signs. CONCLUSIONS: The study population mainly comprised of patients with mild to moderate DES. Tear film thickness as measured with a custom-built OCT device correlated with subjective symptoms in these patients. In agreement with previous data, the association between other signs and symptoms was weak in the present study. Measurement of TFT with OCT may become a valuable tool in the management of DES patients. (ClinicalTrials.gov number, NCT01753687.)

Effect of hyaluronic acid on tear film thickness as assessed with ultra-high resolution optical coherence tomography.

PURPOSE: The aim of this study was to assess the effect of a single drop of hyaluronic acid on tear film thickness (TFT) in healthy subjects. METHODS: Sixteen healthy subjects (eight male/eight female) aged between 20 and 36 years were included in this randomized, double-masked placebo-controlled study. One eye received a single dose of hyaluronic acid (Olixia pure(®) ; Croma Pharma, Korneuburg, Austria) eye drops, and the fellow eye received physiologic saline solution as placebo control. The study eye was chosen randomly. TFT as measured with a custom-built Fourier-domain optical coherence tomography (FD-OCT) system was the main outcome variable and measured before and every 10 min until 1 hr after topical administration. RESULTS: Baseline TFT was 4.8 ± 0.5 µm in the study eye and 5.0 ± 0.4 µm in the control eyes. Hyaluronic acid significantly increased TFT (p = 0.008 versus placebo) with a maximum effect 10 min after instillation (13.9 ± 11.9%). Post hoc analysis revealed that an increase in TFT was seen until 30 min after administration compared to placebo. Data in the placebo group show high reproducibility with an intraclass correlation coefficient of 0.93 and a coefficient of variation of 5.4 ± 3.3%. CONCLUSION: The data of this study indicate that hyaluronic acid increases TFT for as long as 30 min in healthy subjects. In addition, our data provide evidence that our custom-built OCT system is capable of measuring residence time of lubricants on the ocular surface.