Effect of Narrow-Band Ultraviolet B Therapy of Psoriasis Vulgaris on Skin Directional Reflectance, Skin Density and Epidermal Thickness

Round 1

Reviewer 1 Report

This paper describes the effect of NB-UVB phototherapy on optical properties of normal human skin and skin affected by psoriasis before and after 10 and 20 therapeutic exposures.

(1) Purpose of the study: From the introduction it is not clear to me, what the value of such findings could be besides being purely descriptive, which also would be okay. Was there any potential benefit of these findings considered in the planning of the investigation?

One objective ("allows to determine what range of radiation is reflected and what is absorbed/transmitted, which is important in phototherapy") sounds reasonable, but the relevant wavelength 311 nm is not included. The cited statement is also from the Materials and Methods section, as is the subsequent paragraph, that describes in detail optical properties of skin components that play a role in the visible range but may not affect UVB at all. All this clearly belongs in the introduction.

(2) Methods: The description of the actual therapeutic process is missing. For example, what was the regimen for moisturizing? Regular moisturizing can definitely change the surface properties of skin.

All the data show large variation, which is not surprising, because epidermal and dermal properties including thickness vary depending on the anatomic location. Therefore a comparison of means is likely not the best way to look at these data but rather paired comparisons of the same lesions. That may increase the relevance and power of the data.

There are minor problems with the English throughout the manuscript that should be easily fixed by the editorial process. The medical terminology in the description of psoriasis should be reviewed by a dermatologist, as they describe e.g. psoriatic scales as "plaques", which is incorrect

Author Response

Thank you for reviewing the manuscript. Your comments are very valuable to us.

(1) In our opinion, this study may have practical applications. It was aimed at answering the question whether the reflectometer is suitable for assessing the condition of skin without psoriasis and psoriatic lesions, and whether changes in the measurement results occur during therapy. It also answers the question of whether a reflectometer can be used to quantify the improvement of the skin condition after the applied therapy. The essence was also to check how UVB affects healthy skin. Our study was also aimed at checking whether the differences in reflectance are visible and if attempts at analysis in a further, more accurate range (e.g. using a hyperspectral camera) make sense. Measurement data could be used in the future, e.g. for automatic assessment using neural networks (e.g. treatment progress / therapeutic dose selection). Thank you for your remark. We didn't make it clear in this sentence ("allows to determine what range of radiation is reflected and what is absorbed/transmitted, which is important in phototherapy"). The reflectance measurement allows to determine what range of radiation is reflected and what is absorbed/transmitted, which allows to check how the skin reacts to phototherapy. The wavelength range of 311 is outside the range we investigated due to the limitations of the reflectometer. For our study, the measurement from 300 nm would not matter much because we would only get information about the reflectance for melanin, and this is what the measurements for the 335-380 nm range inform us.

We have moved the paragraphs you mentioned to the introduction.

(2) Thank you very much for your observation. I added a paragraph about limitations, because unfortunately we had no influence on the type of emollients used by the volunteers.

Statistical analysis was based on the median and not the mean, due to non-parametric data, therefore Friedman's ANOVA and Dunn's post-hoc test was used. We made changes to tables 3 and 4 and in the text under table 3.

Reviewer 2 Report

It is true that phototherapy is still not thoroughly studied and there are certainly many new findings that could be innovative (e.g. what is the effect/safety of combining UVB 311 nm phototherapy with the very latest types of biologics, combining systemic psoralens with UVB 308 nm phototherapy on psoriatic nail changes, etc.).

But I'm sorry, in your article it is impossible to find a meaning/impact to practice, which should be the main purpose of any study.

Author Response

Thank you for reviewing the manuscript. In my opinion, this study may have practical applications. It was aimed at answering the question whether the reflectometer is suitable for assessing the condition of skin without psoriasis and psoriatic lesions, and whether changes in the measurement results occur during therapy. It also answers the question of whether a reflectometer can be used to quantify the improvement of the skin condition after the applied therapy. The essence was also to check how UVB affects healthy skin. Our study was also aimed at checking whether the differences in reflectance are visible and if attempts at analysis in a further, more accurate range (e.g. using a hyperspectral camera) make sense. Measurement data could be used in the future, e.g. for automatic assessment using neural networks (e.g. treatment progress / therapeutic dose selection)

Reviewer 3 Report

Comments to Authors

 

- The cited references are relevant to the research and OK.

 

Introduction section:

 

Review writing issues.

 

Line 44. “It leads to a reduction the number of Langerhans cells and dendritic cells. Causes the keratinocytes apoptosis and increases reactive oxygen species.”

 

Suggestion to change to: It leads to a reduction in the number of Lahgerhans cells and dendritic cells, causes keratinocytes apoptosis and increases…

 

- I found the following sentence difficult to understand.

 

Line 47. “Narrowband UVB phototherapy associated with the irradiation of the patient's entire body and contributes to the large amount of cumulative UVB exposure.”

 

Suggestion to change to: “Narrowband UVB phototherapy associated with the irradiation of the patient's entire body contributes to the large amount of cumulative UVB exposure.”

 

I found the following sentence difficult to understand and suggest to rewrite.

 

Line 51. “In the course of psoriasis, comes to transformation of the local microvascular system.”

 

 

- In my opinion the design is appropriate to the proposed study.

 

- The methods are well described, but I suggest some changes:

 

Line 87 – Figure 1. I am not sure if it is necessary to fully describe the concept of directional reflectance. Maybe the Journal Editor could suggest if it will be adequate for publication, or could be suppressed.

 

Line 99. Although the concepts are important to understand the HDR measurements, I think the description is very extensive and it is not necessary in the Materials and Methods section.

 

Line 114. Same as line 99.

 

- Some results are not very clear to understand, I suggest some review.

 

Line 162. I suggest to begin the Results section with some text, instead of directly the Table (Table 2). I would be easier to understand.

 

Line 183 to 187.

 I found it difficult to understand what is written on the text related to the Table data and statistics. I suggest the authors to rewrite the table, text and to check if statistics is correct.

 

 

- The conclusions are OK.

 

I suggest to review writing issues, especially in the introduction section.

Author Response

Thank you for reviewing the manuscript.  I appreciate all the comments and suggestion.

Line 44, 47, 51 - Have now been amended

Line 51 - We changed this line

Line 87, 99  & 114 - Thank you very much for your opinion. We wanted to introduce the principle of operation of the reflectometer due to the fact that this device has not been used in skin research.
We will also be grateful for the Editor's opinion and if it coincides with your opinion, We will make appropriate changes.  At the moment, we have moved some information from the materials and methods section to the introduction.

Line 162- Changes have been made as suggested

Line 183 to 187- Thank you very much for this comment. We have made a correction

Round 2

Reviewer 1 Report

There are inherent limitations of the study because of excluding measurements in the therapeutic wavelength range, however, this cannot be fixed without repeating the whole study.Therefore this will remain a purely observational study without a clear path to biomedical application.

 

Please proofread for English language and spelling , e.g. Langerhans cell, not Lahgerhans cell (Line 44)

Author Response

Thank you for this opinion. We have added this information in "limitations".

Line 44- thank you for noticing the spelling mistake. We made corrections.

Author Response File: Author Response.docx