Dear editor
We read with great interest the article by Beato et al about the evaluation of corneal structure and endothelial morphological characteristics in type 2 diabetic and non-diabetic patients.1
We would like to congratulate the authors for their impressive paper, because a precise corneal thickness measurement is very important, for example, in evaluating the intraocular pressure2 in diabetic patients and we appreciate the authors evaluated the central corneal thickness (CCT) related with the corneal volume, that could better be correlated with eventual endothelial changes.3–6
However, we would like to make some comments on this article, because in our opinion there are some points that need to be clarified.
In a previous paper, we found that CCT obtained with Topcon SP-3000P was thinner than the measurements obtained with Pentacam, and we proposed a regression formula to make the measurements comparable.7 As the authors utilized the same devices, we wonder if they had a similar experience.8,9
Moreover, we read in Table 1 that an important number of the diabetes mellitus (DM) group and not-diabetes mellitus (not-DM) one were affected by systemic hypertension, dyslipidemia and BMI >25 kg/m2; we wonder if the similarity between the two groups could be related to the presence of metabolic syndrome,10 that probably affected an important number of patients in both groups, and, according to Su et al, is correlated with a greater CCT.
In our opinion, it would be interesting in a future study to compare the CCT and CV in DM and not-DM patients in absence of other factors and diseases that could increase CCT.
Disclosure
The authors report no conflicts of interest in this communication.
References
- 1.Beato JN, Esteves-Leandro J, Reis D, et al. Evaluation of corneal structure and endothelial morphological characteristics in type 2 diabetic and non-diabetic patients. Clin Ophthalmol. 2020;14:1993–1999. PMID: 32764865; PMCID: PMC7369306. doi: 10.2147/OPTH.S256244 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Lanza M, Borrelli M, De Bernardo M, Filosa ML, Rosa N. Corneal parameters and difference between Goldmann applanation tonometry and dynamic contour tonometry in normal eyes. J Glaucoma. 2008;17:460–464. doi: 10.1097/IJG.0b013e31816224bd [DOI] [PubMed] [Google Scholar]
- 3.De Bernardo M, Capasso L, Lanza M, et al. Long-term results of corneal collagen crosslinking for progressive keratoconus. J Optom. 2015;8(3):180–186. PMID: 26105541; PMCID: PMC4502088. doi: 10.1016/j.optom.2014.05.006 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Rosa N, De Bernardo M, Borrelli M, Filosa ML, Lanza M. Effect of oxybuprocaine eye drops on corneal volume and thickness measurements. Optom Vis Sci. 2011;88(5):640–644. PMID: 21358446. doi: 10.1097/OPX.0b013e3182114303. [DOI] [PubMed] [Google Scholar]
- 5.Rosa N, De Bernardo M. Central corneal thickness determination in corneal edema. Graefes Arch Clin Exp Ophthalmol. 2017;255(6):1251–1252. PMID: 28299437. doi: 10.1007/s00417-017-3634-9 [DOI] [PubMed] [Google Scholar]
- 6.De Bernardo M, Rosa N. Central corneal thickness after cross-linking using high-definition optical coherence tomography, ultrasound, and dual scheimpflug tomography: a comparative study over one year. Am J Ophthalmol. 2017;176:254. PMID: 28159112. doi: 10.1016/j.ajo.2017.01.007 [DOI] [PubMed] [Google Scholar]
- 7.De Bernardo M, Borrelli M, Mariniello M, Lanza M, Rosa N. Pentacam vs SP3000P specular microscopy in measuring corneal thickness. Cont Lens Anterior Eye. 2015;38(1):21–27. PMID: 25240777. doi: 10.1016/j.clae.2014.08.006 [DOI] [PubMed] [Google Scholar]
- 8.De Bernardo M, Vitiello L, Abbinante G, et al. Comparison between two devices in the detection of corneal thickness changes after cataract surgery. Sci Rep. 2021;11(1):6709. PMID: 33758298; PMCID: PMC7988103. doi: 10.1038/s41598-021-86158-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.De Bernardo M, Rosa N. Comparison of specular microscopy and ultrasound pachymetry before and after cataract surgery. Graefes Arch Clin Exp Ophthalmol. 2017;255(4):837–838. PMID: 28154931. doi: 10.1007/s00417-017-3604-2 [DOI] [PubMed] [Google Scholar]
- 10.Su DH, Wong TY, Foster PJ, Tay WT, Saw SM, Aung T. Central corneal thickness and its associations with ocular and systemic factors: the Singapore Malay eye study. Am J Ophthalmol. 2009;147(4):709–716.e1. PMID: 19152872. doi: 10.1016/j.ajo.2008.10.013 [DOI] [PubMed] [Google Scholar]