Citation: De Bernardo M, Abbinante G, Cembalo G, Rosa N. Comment on
“Two-stage procedure in the management of selected cases of keratoconus: clear
lens extraction with aspherical IOL implantation followed by WFG-PRK”. Int J
Ophthalmol 2019;12(8):1369-1370. DOI:10.18240/ijo.2019.08.24
·Comment·
Comment
on “Two-stage procedure in the management of selected cases of keratoconus:
clear lens extraction with aspherical IOL implantation followed by WFG-PRK”
Maddalena De Bernardo, Giulia Abbinante, Giovanni
Cembalo, Nicola Rosa
Department
of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of
Salerno, Baronissi 84081, SA, Italy
Correspondence
to: Maddalena De
Bernardo. Department of Medicine, Surgery and Dentistry “Scuola Medica
Salernitana”, University of Salerno, Via S. Allende, Baronissi 84081, Salerno,
Italy.
mdebernardo@unisa.it
Received:
DOI:10.18240/ijo.2019.08.24
Citation: De
Bernardo M, Abbinante G, Cembalo G, Rosa N. Comment on “Two-stage procedure in
the management of selected cases of keratoconus: clear lens extraction with
aspherical IOL implantation followed by WFG-PRK”. Int J Ophthalmol
2019;12(8):1369-1370
Dear Editor,
We read with
great interest the article by Abou Samra et al[1]
about the management of selected keratoconus cases.
We would
like to congratulate the authors for the originality of this study, but in our
opinion there are some points that need to be clarified.
The authors
included in this study 13 eyes of 11 patients. This number seems to be too
small, to make a definite conclusion. Moreover from this number it is clear
that in some patients both eyes have been evaluated while, in the others, only
one eye has been evaluated, introducing in this way a bias in the study.
Another
problem is related to the way the astigmatic correction has been estimated.
According to the published data, it seems that astigmatic correction has been
assessed without taking into account the vector analysis, which in these cases
is mandatory, because it is necessary to analyze both the astigmatic power and
the axis changes. In fact, a shift of the astigmatic axis correction could
influence both astigmatic and spherical changes, and the only way to detect
such influence is the vector analysis[2-3].
Another
issue that we would like to comment is the choice to perform a wave
front-guided photorefractive keratotomy (WFG-PRK) without cross linking. In our
opinion this could be dangerous, because keratoconus is an evolutionary disease
over a period of months, so the 6mo follow-up would not be sufficient to rule
out a possible slatentization after surface refractive surgery.
To support
their choice, the authors cited some papers previously published, but the
reported papers seem to be quite different. In fact Sachdev et al[4] analyzed healthy patients who underwent photorefractive
keratotomy (PRK) versus patients with fruste keratoconus, who underwent corneal
collagen cross-linking (CXL) and PRK, Xie et al[5]
analyzed patients with keratoconus who underwent PRK after a previous
epikeratophakia, and lastly Khakshoor et al[6]
assessed patients with naturally stable keratoconus or after crosslinking,
making in all these cases the comparison with the patients described in the
paper by Abou Samra et al[1] meaningless.
Lastly, as
the authors utilized Pentacam to detect the keratoconus progression, we would
like to suggest to utilize the corneal volume instead of the minimum corneal
thickness to detect such a progression[7-10].
ACKNOWLEDGEMENTS
Conflicts of
Interest: De
Bernardo M, None; Abbinante G, None; Cembalo G,
None; Rosa N, None.
REFERENCES