A Study Investigating the Safety, Tolerability, and Efficacy of Elamipretide Topical Ophthalmic Solution for the Treatment of Fuchs' Corneal Endothelial Dystrophy (FCED)

Number of participants who had a change from baseline from normal or abnormal not clinically significant, to abnormal clinically significant (CS) findings for slit lamp examinations (SLE) for Part A. Part B is reported as separate outcome since unit of measure is number of eyes.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, and Week 16

Population: All participants for whom slit lamp outcomes were measured.

Number of eyes with a change from baseline from normal or abnormal not clinically significant, to abnormal clinically significant (CS) findings for slit lamp examinations (SLE) for Part B. Part A is reported as separate outcome.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, and Week 16

Population: All participants for whom slit lamp outcomes were measured with both baseline and post-baseline measurements.

Change from Baseline in intraocular pressure (IOP) using Goldmann applanation tonometry for Part A

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12

Population: All participants for whom intraocular pressure was measured. Part B is reported as a separate Outcome Measure.

Change from Baseline in intraocular pressure (IOP) using Goldmann applanation tonometry for Part B. Part A is reported separately.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12 , and Week 16 or early discontinuation visit

Population: All participants for whom intraocular pressures were measured.

The incidence and severity of ocular treatment emergent adverse events (TEAEs)

Time frame: Screening Visit, Baseline (Day 1), Week 1, Week 4, Week 8, Week 12, and Week 16

Population: All participants for whom ocular TEAEs were measured.

The incidence and severity of systemic treatment emergent adverse events (TEAEs)

Time frame: Screening Visit, Baseline (Day 1), Week 1, Week 4, Week 8, Week 12, and Week 16

Population: All participants for whom systemic TEAEs were measured. For Part A systemic events were not necessarily attributed to either intervention or placebo.

Best corrected visual acuity (BCVA) using the using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale by visit. ETDRS charts present a series of five letters of equal difficulty on each row, with standardized spacing between letters and rows; there is a total of 14 lines (70 letters), with letter size increasing further geometrically and equivalently in every line by a factor of 1.2589 (or 0.1 log unit), moving up the chart. Minimum score of zero, maximum score of 100. Change from baseline: a more negative score is worse outcome, a more positive score is better outcome. A lower score means less letters were read correctly (worse outcome) and a higher score means more letters were read correctly (better outcome).

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16

Population: All participants for whom BCVA score was measured.

Central Corneal Thickness: by-subject data as measured by Pachymetry and Pentacam. Part A is reported as a separate outcome measure.

Time frame: Baseline (Day 1), Week 1, Week 4, Week 8, Week 12, and Week 16, or Early discontinuation visit

Population: All participants for whom Central Corneal Thickness was measured. Part A is reported as a separate Outcome Measure.

Change From Baseline in Endothelial Cell Hexagonality in Percentage Over All 12 Weeks for Part A. Specular microscopy is a noninvasive photographic technique that allows visualization and analyzation the corneal endothelium. Using computer-assisted morphometry, specular microscopes analyzes the size, shape and population of the endothelial cells. Histologically, healthy corneal cells initially have a hexagonal shape. As endothelial cells die, neighboring cells enlarge to cover the empty space once occupied by the cell. This, in turn, causes the remaining cells to lose their hexagonal shape. Assessments were performed using the flex center and full auto methods for Part A and data from the flex center method was summarized. The flex center method was used for Part B. The percent of Part B is entered as a separate outcome measure. A decrease from baseline in % cell hexagonality means worse outcome, a increase from baseline means better outcome.

Time frame: Baseline, Week 1, 4, 8, and 12

Population: All participants had images taken; data was analyzed for those whose images were of sufficient quality.

Best corrected visual acuity (BCVA) using the using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale by visit. ETDRS charts present a series of five letters of equal difficulty on each row, with standardized spacing between letters and rows; there is a total of 14 lines (70 letters), with letter size increasing further geometrically and equivalently in every line by a factor of 1.2589 (or 0.1 log unit), moving up the chart. Minimum score of zero, maximum score of 100. Change from baseline: a more negative score is worse outcome, a more positive score is better outcome. A lower score means less letters were read correctly (worse outcome) and a higher score means more letters were read correctly (better outcome). Part B was listed separately.

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16

Population: All participants for whom BCVA score was measured.

Change from Baseline in Central Corneal Thickness by Visit as measured by Pachymetry for Part A. Part B is reported as a separate outcome measure.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, and Week 16

Population: All participants for whom central corneal thickness was measured. Part B is reported as a separate Outcome Measure.

Change from Baseline in contrast sensitivity over all 12 weeks log score at 3, 6, 12, 18 cycles per degree (cpd) using Vector Vision's CSV-1000E. Standard tables for the VectorVision's CSV-1000E model were used to convert linear results to the log values. Lower log scores equals lower contrast sensitivity and worse outcome. Higher log scores mean higher contrast sensitivity and better outcome. For 3cpd, range is 0.7-2.08; 6 cpd: 0.91-2.29; 12 cpd: 0.61-1.99; 18cpd: 0.17-1.55, unless no gratings were visible. If no gratings were visible, .3 log was subtracted from the lowest score for 3, 6, and 12cpd. For 18cpd .01 log was used, or essentially 100% contrast.

Time frame: Baseline, Week 1, 4, 8, 12 weeks

Population: All participants for whom contrast sensitivity was measured

Change from Baseline in corneal area affected by microcysts by visit for Part A.

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16

Population: All participants for whom corneal area affected by microcysts was measured.

Count of participants in number, size and location of bullae by treatment. Part B is listed separately.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, Week 16

Population: All participants for whom corneal bullae were measured.

Change From Baseline in Endothelial Cell Coefficient of Variation Over All 12 Weeks. Coefficient of variation (CV) is Standard deviation (SD) of cell area divided by the mean cell area of endothelial cell analyzed. CV represents the coefficient, or degree, of variation in the sizes of the endothelial cells (polymegethism). By measuring the variation in size between endothelial cells, the system can measure how much cell loss is occurring. The more variation, the worse the outcome. Part B is is entered as a separate outcome measure.

Time frame: Baseline, Week 12

Population: All participants had images taken; data was analyzed for those whose images were of sufficient quality.

Change From Baseline in Endothelial Cell Counts, or density (Counts/mm\^2) over all 12 weeks for Part A. Part B is entered as a separate outcome measure.

Time frame: Baseline, Weeks 1, 4, 8, and 12

Population: All participants for whom endothelial cell counts were measured. All participants had images taken; data was analyzed for those whose images were of sufficient quality.

Change from baseline in severity of corneal stromal folds by visit. Descriptive assessment made by Investigator; severity is not assessed using a scale.

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16

Population: All participants for whom corneal stromal folds was measured.

Part B, By-subject data for all time points where images were readable. For all time points where there were Poor Quality Images or too few cells to register there were no data available. CoV represents the coefficient, or degree, of variation in the sizes of the endothelial cells. By measuring the variation in size between endothelial cells, the system can measure how much cell loss is occurring. A CoV less than 40 is normal.

Time frame: Baseline, Weeks 1, 4, 8,12, and 16

Population: All participants for whom Corneal Endothelial Cell Counts/Density was measured. Part A is reported as a separate Outcome Measure. All images from Participant 205 were poor quality images and hence, no data was available.

Contrast Sensitivity log score at 3, 6, 12, 18 cycles per degree (cpd) using Vector Vision's CSV-1000E by-subject data, Part B. Part A is listed separately. Standard tables for the VectorVision's CSV-1000E model were used to convert linear results to the log values. Lower log scores equals lower contrast sensitivity and worse outcome. Higher log scores mean higher contrast sensitivity and better outcome. For 3cpd, range is 0.7-2.08; 6 cpd: 0.91-2.29; 12 cpd: 0.61-1.99; 18cpd: 0.17-1.55, unless no gratings were visible. If no gratings were visible, .3 log was subtracted from the lowest score for 3, 6, and 12cpd. For 18cpd .01 log was used, or essentially 100% contrast.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, Week 16, or early discontinuation visit

Population: All participants for whom contrast sensitivity was measured.

Corneal area affected by microcysts: by-subject data for Part B. No microcysts were present for any timepoints.

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16, or early discontinuation visit

Population: All participants for whom corneal area affected by microcysts was measured.

Number, size and location of Corneal bullae: By-subject data: Part B.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, Week 16, or early discontinuation visit

Population: All participants for whom corneal bullae were measured.

Corneal Endothelial Cell Density: Part B, By-subject data for all time points where images were readable. For all time points where there were Poor Quality Images or too few cells to register, there were no data available, and these were not listed below.

Time frame: Baseline, Weeks 1, 4, 8, 12, and 16.

Population: All participants for whom Corneal Endothelial Cell Counts/Density was measured. Part A is reported as a separate Outcome Measure. All images from Participant 205 were poor quality images and hence, no data was available.

Corneal Endothelial Cell Hexagonality in Percentage by-subject data: Part B. Data was only listed in weeks where images were good enough quality to quantify. Specular microscopy is a noninvasive photographic technique that allows visualization and analyzation the corneal endothelium. Using computer-assisted morphometry, specular microscopes analyzes the size, shape and population of the endothelial cells. Histologically, healthy corneal cells initially have a hexagonal shape. As endothelial cells die, neighboring cells enlarge to cover the empty space once occupied by the cell. This, in turn, causes the remaining cells to lose their hexagonal shape. The flex center method was used for Part B. A decrease in percent of cell hexagonality from baseline means worse outcome, an increase from baseline means better outcome.

Time frame: Baseline, Week 1, Week 4, Week 8, Week 12, and Week 16 or early discontinuation visit

Population: All participants for whom Corneal Endothelial Cell Hexagonality was measured. Part A is reported as a separate Outcome Measure. For images with poor quality or too few cells to register, there was no data available.

Severity of corneal stromal folds by-subject data by visit. Descriptive assessment made by Investigator in the following categories: Not present, trace, mild.

Time frame: Baseline, Week 1, 4, 8, 12, and 16, or early discontinuation visit

Population: All participants for whom corneal stromal folds was measured.