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a r c h s o c e s p o f t a l m o l . 2 0 1 4;8 9(9):387–388
ARCHIVOS DE LA SOCIEDAD
ESPAÑOLA DE OFTALMOLOGÍA
www.elsevier.es/oftalmologia
Letter to the Editor
Effect of posterior capsulotomy with a
neodymium:YAG laser. Assessment of safety
in foveal thickness, intraocular pressure and
endothelial cell counts in pseudophakic patients
with posterior capsular opacity夽
Efecto de la capsulotomía posterior con láser neodymium:YAG.
Valoración de seguridad en el grosor foveal, la presión intraocular
y el recuento de células endoteliales en pacientes pseudofáquicos
con opacidad de cápsula posterior
Dear Editor,
I would like to congratulate Dr. Ruiz-Casas et al. for the recent
paper on the safety of Nd:YAG laser for treating posterior capsular opacification (PCO).1 In said paper, the authors measured
best corrected visual acuity, foveal thickness, intraocular pressure and endothelial cell count before and after capsulotomy
in a group of 31 patients affected by monocular PCO and concluded that after the procedure the only parameter to exhibit
improvement was the best corrected visual acuity, while the
remaining parameters did not exhibit significant changes.
In what concerns one of the variables included in said
paper,1 specifically foveal thickness, signal strength of the
tests is not mentioned. Signal strength is an indicator of image
quality in OCT. Its values range between 1 (poor quality) and
10 (best quality) in Zeiss equipment. An image is considered to
be reliable if the ST value is of ≥5 for Stratus, or ≥6 for Cirrus,
according to the instruction manuals of said devices.
Our group has researched the effects of PCO on the measurement of various macular thickness parameters obtained
by OCT in two studies with sizes similar to that of RuizCasas et al. and also with consecutive patient selection. In
the first,2 carried out with time domain OCT (Stratus) 32 eyes
were assessed, but only 13 (40.62%) were taken as reliable for
pre- and post-laser thickness comparisons. Comparing the
ST of all patients before and after capsulotomy, a significant
increase of said variable was found after applying Nd:YAG
laser. It was concluded that PCO can affect the quality of the
test but, considering only the reliable pre-laser explorations,
no changes were observed after capsulotomy in the 10 macular
thickness variables taking into account.
However, in the second study,3 carried out with spectral
domain OCT (Cirrus), a pre-laser versus post-laser comparison
was made comprising 12 macular evaluation variables including all the eyes in the sample (n = 35) independently of the ST
of each assessment. The result was that all mean thicknesses
were larger after capsulotomy but, when only the initially reliable eyes were selected (these were 12, 34.28% of all eyes), none
of the study parameters exhibited changes after capsulotomy.
As can be appreciated from the above studies,2,3 ST is
important in the interpretation of macular measurements carried out with OCT if PCO is present. It would be interesting if
the authors could share with the readers information about
whether ST was considered in the study as an exclusion criterion as well as about the percentage of eyes with reliable and
unreliable OCT found according to ST, and the change of this
parameter between the pre- and post-capsulotomy assessments.
夽
Please cite this article as: García-Medina JJ. Efecto de la capsulotomía posterior con láser neodymium:YAG. Valoración de seguridad
en el grosor foveal, la presión intraocular y el recuento de células endoteliales en pacientes pseudofáquicos con opacidad de cápsula
posterior. Arch Soc Esp Oftalmol. 2014;89:387–388.
Documento descargado de http://www.elsevier.es el 21/11/2016. Copia para uso personal, se prohíbe la transmisión de este documento por cualquier medio o formato.
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a r c h s o c e s p o f t a l m o l . 2 0 1 4;8 9(9):387–388
references
1. Ruiz-Casas D, Barrancos C, Alio 2nd JL, Ruiz-Guerrero M,
Muñoz-Negrete FJ. Effect of posterior neodymium:YAG
capsulotomy. Safety evaluation of macular foveal thickness,
intraocular pressure and endothelial cell loss in pseudophakic
patients with posterior capsule opacification. Arch Soc Esp
Oftalmol. 2013;88:415–22.
2. Gonzalez-Ocampo-Dorta S, Garcia-Medina JJ,
Feliciano-Sanchez A, Scalerandi G. Effect of posterior capsular
opacification removal on macular optical coherence
tomography. Eur J Ophthalmol. 2008;18:435–41.
3. Garcia-Medina JJ, Gómez-Fernández JJ, Valentino S,
Morcillo-Guardiola M, Villada-Sánchez JC, Pastor Grau A.
Effects of posterior capsule opacification on macular thickness
measurements by spectral domain OCT. SIRCOVA-OFTARED
Congress abstract. Ophthalmic Res. 2013;50:27–53. Available
from: http://www.karger.com/Article/Pdf/351623 [accessed
17.12.13].
J.J. García-Medina a,b,c
a
Servicio de Oftalmología, Hospital General Universitario Reina
Sofía, Murcia, Spain
b Departamento de Oftalmología, Optometría, Otorrinolaringología
y Anatomía Patológica, Facultad de Medicina, Universidad
de Murcia, Murcia, Spain
c Unidad de Investigación Oftalmológica Santiago Grisolía, Hospital
Universitario Doctor Peset, Valencia, Spain
E-mail addresses: [email protected],
[email protected]
2173-5794/$ – see front matter
© 2013 Sociedad Española de Oftalmología. Published by
Elsevier España, S.L.U. All rights reserved.