Characteristics of the participants: A total of 166 NHV, were enrolled, two subjects discontinued their participation because of either AE (ocular hypotonia and rhinitis), other for protocol deviations , and another due to poor adherence of indicated treatment (<80%). Therefore, 162 NHV completed their entire protocol without deviations up to the safety call, instilling ID or AD during a study from different therapeutic areas, including lubricants, hypotensive agents and antibiotics see Figure 1. There were no demographic or clinically relevant differences at baseline between treatment groups. Mean age ± standard deviation (SD) was 27.41 ± 6.6 years (range 18 – 45), 53.6% of the NHVs were female (Fisher exact test, p=0.641), see Table 2.
Visual Comfort: Baseline OCI score (mean ± SD) was similar between lubricant and hypotensive treatment groups (see Table 2); meanwhile, the antibiotic group had a lower basal OCI score (F(2,165)=11.760; p=0.0001). On the final visit, 72.3%, 39.6% and 66.7% of the NHV in each group improved their initial score (Pearson Chi-square test, p=0.001). The mean of change ± SD from baseline to final visit was -6.24 ± 12.5 for lubricant, 2.12 ± 10.9 for hypotensive and, -3.31 ± 9.8 for antibiotic group. The hypotensive group showed a significant increase in their score compared to lubricant (Tukey test, p=0.0001). Additionally, no significant differences between type of drug (ID or AD) were observed (F(1,158)=0.011, p=0.924), also between-factor interaction (treatment x type of drug) was not significant (p=0.356), see Table 3.
Laboratory Evaluations: As expected for NHV, laboratory results for hematological and biochemical parameters were within normal ranges at baseline. We did, however, find statistically significant differences on HTC, HGB and MCV levels (all of them, under ULN). The hypotensive group levels were higher than that of lubricant and antibiotic groups (Tukey test, p<0.05). On the final visit, the MCV level was significantly different between treatments (p=0.0001), also we found differences between type of drug, on AST and total bilirubin (p<0.05), however between-factor interaction (visit x treatment x type of drug) was not significant (p>0.05), see Table 4. ALT and AST elevations were observed in three subjects under lubricants and other on hypotensive study group (2.4%), from baseline to final visit (reported as an AE). Two subjects (AD) had values greater than 1.2 times ULN-AST. For ALT levels, two NHV had values 1.5 times higher, and other 2.6 times higher, meanwhile only one NHV in ID had one value greater than 1.02 times ULN during the treatment. LAE were resolved by the end of follow-up study period and no safety additional issues were raised.
Vital Signs: As expected for NHV vital signs parameters were within normal ranges at baseline. Relatively few vital signs values were statistically lower between treatments at baseline. The RR in hypotensive group (F(2,164)=4.209; p=0.017), the SBP in antibiotic (F(2,164)=3.446; p=0.034) and, the DBP in lubricant group (F(2,164)=4.180; p=0.017) were consistently and significantly lower at the final visit (p-values: 0.001, 0.049 and, 0.006 respectively). However, the interactions between-factors (visit x treatment and visit x type of drug) were not significant (p>0.05), see Table 5. On final visit, only 1 (0.6%) NHV had high HR, 12 (7.3%) NHV had high SBP, and 3 (1.8%) NHV had high DBP. However, these findings were not reported as AEs.
Visual acuity (VA) and intraocular pressure (IOP): Baseline VA was similar between groups however, the mean value for the antibiotic group was lower compared with the other treatments (F(2,302)=19.956, p=0.048). The type of drugs was different too (p=0.048), but the interaction (treatment x type of drug) was not significant (p=0.681). On the final visit, no significant differences between treatments, or types of drugs, were observed (p>0.05). The visit x treatment interaction was significant (p=0.016) but visit x type of drug and between-factors interactions were not significant (0.166 and 0.562, respectively), see Table 3.
Baseline IOP was similar between treatments and type of drug, without differences (p-values: 0.062 and 0.691, respectively). On the final visit, as expected, the IOP decreased significantly by 2.3 mmHg in the hypotensive agents group (p=0.0001), without differences between the type of drug (p=0.913). The visit x treatment interaction was significant (p=0.0001) but visit x type of drug and between-factors interactions were not significant (0.830 and 0.298, respectively), see Table 3.
Fluorescein and lissamine green staining: On the final visit, fluorescein staining was graded as absent (grade 0, Oxford scale) for 81.3% and as minimal-to-mild (grade I or II) for 18.7% of NHV exposed to lubricants. Meanwhile 89.6% and 94.8% were absent and 10.4% and 5.2% were grade minimal for hypotensive and antibiotic treatments, respectively (Pearson Chi-square test, p=0.088). No differences were observed between the factor type of drug on baseline and at the final visit (Pearson Chi-square test, p-values; 0.915 and 0.416). Similar percentages for LGS were observed on final visit, 85.3% was absent and 14.7% minimal-to-mild for lubricant, 88.5% absent and, 11.5% was minimal-to-mild for hypotensive, meanwhile 96.6% was absent and 3.4% minimal for antibiotic group (Pearson Chi-square test, p=0.051). No differences were observed between the factor type of drug on baseline and at the final visit (p-values; 0.257 and 0.053), see Table 3.
Conjunctival hyperemia and chemosis: Similar findings were observed in the analysis of conjunctival hyperemia; after the intervention time and compared with baseline, there was no significant improvement in all groups, It was graded as trace to mild hyperemia for lubricant (20.7%), hypotensive (26%) and antibiotic groups (5.2%) (Pearson Chi-square test, p=0.006). The type of drug was significant on baseline (p=0.022), but this finding was not retained in the final visit (Pearson Chi-square test, p=0.638). Finally, no participants presented chemosis before or after their respective treatment, see Table 3.
Adverse events: A total of 205 AE occurred in 59.6% of NHV (99/166). The hypotensive group had a higher incidence of AE than that the other treatments (Pearson Chi-square test, p=0.0001). A total of 65 AEs/39 NHV were reported for lubricants (46.2% for ID vs 53.8% in AD, p=0.781), 117 AE/43 NHV for hypotensive agents (47% for ID vs 53% in AD, p=0.705), and 23 AE/17 NHV (56.5% for ID vs 43.5% in AD, p=0.559) for antibiotic drugs. The most common class of reported AE were burning (30.7% [26.2%, 27.4%, and 60.9% in lubricant, hypotensive and antibiotic treatments respectively]), followed by conjunctival hyperemia (11.7% [19.7% and 4.3% in hypotensive and antibiotic treatments]), and itching (10.7% [15.4%, 6.8%, and 17.4% in lubricant, hypotensive and antibiotic treatments respectively]), see Figure 2. There was a total of 201 mild AE (98% of the total AE), 3 moderate (1.4%), and one serious AE (0.5%, ocular hypotonia), without differences between treatments (Pearson Chi-square test, p=0.667). Only 14.6% of the AE were deemed unrelated to the study medication. No deaths were reported. The logistic regression (used to calculate ORs), found that in lubricant trials, the ID had a lower risk of incidence of AE than AD, OR 0.856, 95% CI, [0.365, 1.999]. Similar results occurred in hypotensive drugs, OR 0.636, 95% CI, [0.096, 4.197], nevertheless for antibiotic drugs, the risk of incidence for ID was higher than AD, OR 1.313, 95% CI, [0.309, 5.583]. For all groups, no differences between the risk for occurrence of AE in ID versus AD were observed, OR 1.008, 95% CI, [0.541, 1.887].
Burning, itching and FBS, were considered the parameters to evaluate discomfort. In all studies, lubricants and antibiotics were well tolerated. At the final visit, burning sensation was reported in 19.5% NHV for lubricants and 27.6% for the antibiotic group (Pearson Chi-square test, p=0.191). No significant differences were observed between types of drugs in each treatment (p>0.05). Findings were similar for itching between treatments: 23.2% for lubricant, and 17.2% for antibiotic group reported itching at the final visit (Pearson Chi-square test, p=0.650). For each treatment, there were no differences between ID and AD (Pearson Chi-square test, p-values; 0.343 and 0.741). Additionally, only 13.4% of NHV exposed to lubricants reported FBS at the final visit (Fisher exact test, p=0.003), however, these findings were not statistically different in the analysis between types of drugs (Fisher exact test, p=1.000). Finally, compared to baseline, there was a significant increase in conjunctival goblet cell density (280.2 ± 140.3 cell/mm2 vs 332.3 ± 126.7 cell/mm2, p=0.001) by the final visit in the lubricants group. At baseline, 37.8% NHV were classified as having normal CIC grade-0 (classification of Nelson), by the final visit, 41.5% had grade 0, without significant differences (p=0.700). No significant differences were observed between type of drugs on baseline and final visit (Pearson Chi-square test, p-values; 0.957 and 0.533).