Tear Liquid for Predictive Diagnosis of Alzheimer’s Disease

Round 1

Reviewer 1 Report

The authors examined the Amyloid Beta-42 in tears from patients with or without familiarity for Alzheimer disease. They proposed this method as an earlier diagnosis, more accessible as compared to other invasive methods.

I consider that the manuscript is valuable if the results are reproducible on many patients.

Did you perform a tear liquid analysis on a patient with confirmed Alzheimer disease?

Unfortunately, I consider that this manuscript is not well written and it can be accepted only after a major revision.

In the Introduction, the role of Amyloid Beta-42 in the pathology of Alzheimer disease should be better highlighted.

Minor comments:

Correct the first phrase in Abstract, please write what OCT means, “used” instead of “use”, etc.

Figure A should be Figure 1. “Retinal” instead “retinal”. The pictures should have a similar size.

Please insert also a picture with a normal retinal area.

Figure B should be Figure 2. Please explain what is in the picture and write what indicates the arrow. each figure must be independent (the reader should understand what is in the picture based on the legend of the figure, before reading the text of the manuscript)

Figure C should be Figure 3.

Figure D should be Figure 4. Write that CP means a positive control. Insert the arrow in the right position, not outside the picture.

Delete the extra spaces in the text of the manuscript, for example: “( 45 years old”, but there are many more extra spaces.

“Fig 1A” instead of “fig. a1”

Separate the Section “Materials and methods” in two Sections. In the Section “Materials” write the materials that you used and from where you purchased them, for instance, the amyloid Beta 42 and the antibody from where you bought them, etc.

Write the references at the end of the phrases, for example [7]

Author Response

Dear reviewer, my group thanks you for your suggestions and below I list the responses and changes we have made.

Reviewer 1

First question:

We used the purified beta amyloid protein 1-42 as a positive control, to have a reliable and reliable reference of the visualization in optical microscopy of the staining that the primary antibody linked to DAB can give. Furthermore, if the presence of beta amyloid 1-42 in plaque Alzheimer's is questioned, we reported, as requested by the reviewer 1, for an in-depth clarification in the introduction with the addition of 2 further references documenting its presence (attached downside). Since it is a preliminary study, it seemed more reliable to use a certified protein to demonstrate the diagnostic efficacy of the method used.

Additional references:

• Lue, L. F., Kuo, Y. M., Roher, A. E., Brachova, L., Shen, Y., Sue, L., Beach, T., Kurth, J. H., Rydel, R. E., and Rogers, J. Soluble amyloid beta peptide concentration as a predictor of synaptic change in Alzheimer's disease (1999) Am. J. Pathol. 155, 853–862
• McLean, C. A., Cherny, R. A., Fraser, F. W., Fuller, S. J., Smith, M. J., Beyreuther, K., Bush, A. I., and Masters, C. L. Soluble pool of Abeta amyloid as a determinant of severity of neurodegeneration in Alzheimer's disease (1999) Ann. Neurol. 46, 860–866

Second question:

Following the instructions of the reviewer we have made changes to the text in the form by recorrecting the text and trying to make it more usable.

Third question: In the Introduction, the role of Amyloid Beta-42 in the pathology of Alzheimer disease should be better highlighted

We have included in red the corrections and additions as requested by the reviewer 1

Minor comments:

Correct the first phrase in Abstract, please write what OCT means, “used” instead of “use”, etc.

We correct it

Figure A should be Figure 1. “Retinal” instead “retinal”. The pictures should have a similar size.

We have expanded the description of all images with more precise and descriptive references

Please insert also a picture with a normal retinal area.

Insert it

Figure B should be Figure 2. Please explain what is in the picture and write what indicates the arrow. each figure must be independent (the reader should understand what is in the picture based on the legend of the figure, before reading the text of the manuscript)

Figure C should be Figure 3.

Figure D should be Figure 4. Write that CP means a positive control. Insert the arrow in the right position, not outside the picture.

Delete the extra spaces in the text of the manuscript, for example: “( 45 years old”, but there are many more extra spaces.

“Fig 1A” instead of “fig. a1”

Separate the Section “Materials and methods” in two Sections. In the Section “Materials” write the materials that you used and from where you purchased them, for instance, the amyloid Beta 42 and the antibody from where you bought them, etc.

Write the references at the end of the phrases, for example [7]

We have reformulated the arrangement of the figures, inserted the required corrections and expanded the captions, trying to be clearer, the figures are clear to the reader even if independent from the text. The normal retinal figure was added.

Reviewer 2 Report

The topic of the MS is quite interesting; and the hypothesis relevant. The MS is interesting for this journal. It describes quite well three cases and the results found. However, the authors should be more realistic in their conclusions and state that the findings are preliminary and hypothetical. The findings in two healthy men can not be linked with the illness; if they have been diagnosed after it should be cited. Only correlates well with a familiar predisposition (sounds good but it needs to be proved to assure the predictive value in the diagnosis of this new technique).  

Author Response

Reviewer 2

The topic of the MS is quite interesting; and the hypothesis relevant. The MS is interesting for this journal. It describes quite well three cases and the results found. However, the authors should be more realistic in their conclusions and state that the findings are preliminary and hypothetical. The findings in two healthy men can not be linked with the illness; if they have been diagnosed after it should be cited. Only correlates well with a familiar predisposition (sounds good but it needs to be proved to assure the predictive value in the diagnosis of this new technique).  

We thank you for your useful comments and we have made the suggested measures to the text

Round 2

Reviewer 1 Report

The manuscript was improved after this revision and therefore I consider that it can be accepted for publication.