A prospective contralateral eye comparison of the tolerability of two artificial tears with different physical properties in patients with dry eye disease

Background: Artificial tears (ATs) are widely used in ophthalmic practice with various formulations, mainly as a treatment for dry eye, owing to their rapid ability to alleviate the signs and symptoms of this condition. We aimed to investigate drop comfort and subjective ocular symptoms after instillation of the following ATs with different physical properties: Optive® non-preservative (OUD) and Systane® Hydration non-preservative (SHUD). Methods: This was a prospective, double-blind, randomized, contralateral eye comparison study. A rheometer and a digital pH meter were used to evaluate the viscosity and pH of both ATs prior to instillation. We recruited 36 patients with dry eye disease. Single standardized AT volumes were set using a micropipette for all patients. Ocular discomfort was assessed using the Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ; 0 – 5 scale) before and 60 min after instillation. Drop comfort was assessed using the Ora Calibra™ Drop Comfort Scale (0 – 10 scale) immediately after AT instillation. The difference in the drop comfort score (DCS) between the two ATs and ocular discomfort scores using OOD4SQ before and 60 min after instillation of each AT were recorded and compared. Results: The viscosities and pH of SHUD and OUD were 32.73 centipoise (cP) and 7.74 and 14.42 cP and 7.19, respectively. The mean (standard deviation) DCS was higher in the SHUD group than in the OUD group (1.83 [1.21] versus 1.67 [1.12]); however, the difference was not statistically significant (P > 0.05). There was a significant reduction in all parameters of OOD4SQ including overall discomfort, burning, dryness, grittiness, and stinging 60 min after OUD instillation (all P < 0.05), while a significant difference was only noted in dryness (P < 0.05) in the SHUD group. Conclusions: OUD, which has a lower viscosity and pH compared to SHUD, provides less subjective sensation and better ocular comfort 60 min after instillation. Further randomized clinical trials including patients with dry eye disease of different severities, larger sample sizes, and longer follow-up periods are required to verify our findings

Immediate effects of artificial tears with and without preservatives containing hyaluronic acid and carboxymethyl cellulose

Background: Currently, hyaluronic acid (HA) and carboxymethyl cellulose sodium (CMC) are common polymers incorporated in artificial tears (ATs). The aim of the present study was to evaluate the immediate effect of preservative- and preservative-free HA- and CMC-containing ATs on tear-film parameters and determine patient preference after AT instillation. Methods: In this prospective, double-blind, randomized, comparative study, we assessed fluorescein tear break-up time (TBUT), bulbar redness, and tear ferning pattern (TFP) up to 60 min after the instillation of ATs with and without preservatives containing HA and CMC in the recruited participants. To test patient preference, each patient was administered with the Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ; scale of 0–5) before and 60 min after the instillation of ATs. The selection of 14 descriptive words based the 11-point Ora Calibra™ Drop Comfort Scale (ODCS; scale of 0–10) was administered immediately after instillation of each AT to test the drop comfort score. Results: We enrolled 200 eyes of 200 patients, including 163 (81.5%) women and 37 (18.5%) men, with a mean (standard deviation) age of 28.38 (5.42) years. Immediately or 5, 15, or 60 min after the instillation, the mean TBUT did not differ by presence of preservatives, HA, or CMC (all P > 0.05). However, it was significantly higher 5-min post-instillation compared to baseline and significantly lower 15- and 60-min post-instillation (all P < 0.05). The mean grade of bulbar redness immediately or 3, 5, 15, or 60 min after instillation did not differ by presence of preservatives for HA or CMC containing ATs (all P < 0.05). It did not differ significantly 3-, 5-, 15-, or 60-min post-instillation compared to baseline (all P > 0.05). The mean drop comfort scale after the instillation of ATs did not differ significantly by presence of preservatives, HA, or CMC (all P < 0.05). Positive descriptive words were selected by a higher proportion of participants in both groups. According to OOD4SQ, the overall discomfort and mean dryness scores improved significantly after instillation of HA-containing ATs (both P < 0.05), while the mean burning sensation, grittiness, and stinging scores remained unchanged (all P > 0.05). The overall discomfort and mean scores for each ocular symptom (P < 0.05), except for stinting (P > 0.05), improved significantly after instillation of CMC-containing ATs. The TFP did not change significantly from baseline to 60 min after the instillation of any AT (P > 0.05). Conclusions: Both ATs with and without preservatives containing HA and CMC produced positive short-term objective and subjective effects. However, TBUT, TFP, bulbar redness, and patient feedback were comparable for both HA- and CMC-containing ATs. Further trials with longer observation periods or the recruitment of patients with different severities of dry eye could provide more robust and clinically applicable conclusions

Immediate effects of artificial tears viscosity and pH on ocular signs and symptoms

Purpose: To evaluate the short-term effects of artificial tears (ATs) with different viscosity and pH; Systane® Hydration preservative (SH) and non-preservative (SHUD), Optive® preservative (O) and non-preservative (OUD) on patients’ signs and symptoms in normal and dry eye (DE) groups. Methods: 120 participants (55: DE group, 65: normal group) involved in this prospective, double-masked randomized study. Rheometer and digital pH-meter were used to evaluate the viscosity and pH of all ATs. Ocular discomfort between pre and post- instillation (after 60 minutes interval) was evaluated using Ora CalibraTM Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ). Drop comfort immediately assessed after ATs instillation using Ora CalibraTM Drop Comfort Scale (ODCS). Tear break-up time (TBUT) and tear meniscus height (TMH) were measured at baseline, 5, 15 and 60 minutes after instillations. Tear ferning pattern (TFP) were observed and compared at baseline and 60 minutes after instillation. Results: Viscosity of all ATs were; SHUD: 32.73cP, SH: 26.7cP, OUD: 14.42cP and O: 13.88cP with pH of 7.74 (SHUD), 7.85 (SH), 7.19 (OUD) and 7.24 (O). Highest DCS was found in SH for both DE (2.00±1.042) and normal group (1.84±0.963). Significant reduction (p<0.05) in all parameters of ocular symptoms (OOD4SQ) were found after instillation of OUD in both groups. TBUT and TMH for both groups increased significantly (p<0.05) from baseline at all time-interval (except TBUT for O in normal group at 5 minutes post-instillation). TFP improved significantly after 60 minutes instillation of all ATs in both groups. Conclusion: All ATs improved TBUT, TMH and TFP in both groups, regardless their viscosity and pH. OUD showed better ocular symptoms improvement and less subjective sensation compared to other tested ATs

The evaluation of pinhole glasses as visual therapy in improving refractive error

Introduction: Visual therapy or eye exercise, which is widely used in behavioral optometry, has been successfully helping some visual disorders, especially binocular vision problem. In Bates System of Eye Exercise, it is claimed that eye exercise can restore vision with refractive error by completely relaxing the eyes. One of the ways to relax the eyes is by wearing the pinhole glasses as the pinhole placed before the eyes will help to relax accommodation and temporarily improving vision by reducing the size of blur circle. Pinhole glasses have been marketed as a visual therapy device, with the claim that continuous use of these glasses will improve refractive error. Although only anecdotal evidences have been provided on the efficacy of this product, the society are still interested to use the pinhole glasses and believe that their vision could be improved by simply wearing this device. Aim: The purpose of this study was to compare the refractive error of myopic participants before and after wearing the pinhole glasses for 3 weeks. Methodology: Fifteen participants were recruited in this study and all of the participants wore the pinhole glasses while performing near works for 20 minutes/day, anytime from 9 p.m. to 11 p.m. everyday for 3 weeks. Results: The refractive error before and after the intervention was then being compared and the results showed that there was no significant difference in refractive error of both right (p= 0.08) and left eyes (p= 0.09) of myopic participants before and after wearing the pinhole glasses. Conclusion: Our results suggest that pinhole glasses did not improve the refractive error of myopic participants

Intraocular pressure: the effect of short-term fasting and its association with fluid and fat status

Introduction: Short-term fasting may influence intraocular pressure (IOP) due to alteration of fluid (total body water; TBW, and water intake) and fat (total body fat; TBF). This study aimed: i) to compare IOP values within and between, fasting and non-fasting periods; and ii) to assess the association between IOP and, TBW and TBF. Methods: Thirty healthy participants aged 21.8±1.1 years were assessed on two different periods (fasting vs. non-fasting). During each period, the IOP, TBW and TBF values were assessed for four times (morning, afternoon, evening, late-evening). The IOP was measured using AccuPen® tonopen, while TBW and TBF were assessed by using a Tanita body composition analyser. Results: During fasting, the IOP value in the afternoon (14.53±2.33 mmHg) was significantly higher than in the evening (12.43±2.73 mmHg, p=0.009) and late-evening (12.60±2.44 mmHg, p=0.003). No significant difference in IOP was observed during non-fasting period. The mean of IOP in the evening was significantly lower during fasting compared to non-fasting (12.43±2.73 mmHg vs 13.75±2.53 mmHg, p=0.044). The IOP and TBW were negatively correlated (r=-0.268; p=0.011) during non-fasting and showed no association during fasting period. There was no significant correlation between IOP and TBF during both fasting and non-fasting periods. Conclusion: IOP reduction during short-term fasting, together with the no association with TBF and TBW suggested that IOP is an independent factor that reduces during fasting in healthy population

Intraocular pressure : the effect of short-term fasting and its association with fluid and fat status

Introduction: Short-term fasting may influence intraocular pressure (IOP) due to alteration of fluid (total body water; TBW, and water intake) and fat (total body fat; TBF). This study aimed: i) to compare IOP values within and between, fasting and non-fasting periods; and ii) to assess the association between IOP and, TBW and TBF. Methods: Thirty healthy participants aged 21.8±1.1 years were assessed on two different periods (fasting vs. non-fasting). During each period, the IOP, TBW and TBF values were assessed for four times (morning, afternoon, evening, late-evening). The IOP was measured using AccuPen® tonopen, while TBW and TBF were assessed by using a Tanita body composition analyser. Results: During fasting, the IOP value in the afternoon (14.53±2.33 mmHg) was significantly higher than in the evening (12.43±2.73 mmHg, p=0.009) and late-evening (12.60±2.44 mmHg, p=0.003). No significant difference in IOP was observed during non-fasting period. The mean of IOP in the evening was significantly lower during fasting compared to non-fasting (12.43±2.73 mmHg vs 13.75±2.53 mmHg, p=0.044). The IOP and TBW were negatively correlated (r=-0.268; p=0.011) during non-fasting and showed no association during fasting period. There was no significant correlation between IOP and TBF during both fasting and non-fasting periods. Conclusion: IOP reduction during short-term fasting, together with the no association with TBF and TBW suggested that IOP is an independent factor that reduces during fasting in healthy population