Change on refraction after Nd:YAG laser posterior capsulotomy

A retrospective study with analysis of medical records of patients treated at a hospital, with diagnosis of opacification of posterior lens capsule treated with Nd:YAG laser posterior capsulotomy, from October 2019 to March 2021. The comparison of refraction before and after the procedure was performed by calculating the spherical equivalent. Changes in visual acuity (VA), measured by LogMAR, were also evaluated.

Results:

A total of 90 medical records (140 eyes) of patients submitted to Nd:YAG laser posterior capsulotomy were analysed. The mean pre-procedure spherical equivalent was -0.07±0.89D, minimum of -3.0D and maximum of +2.5D, median (interquartile range) of 0.0D (-0.50D to +0.375D). The post-procedure mean was -0.18±0.86D, minimum of -3.5D and maximum of +2.25D, median (interquartile range) of -0.125D (-0.50D to 0.0D), with p <0.0082. Of the 140 eyes, 66 underwent myopia and 37 hyperopia, the mean change in the general spherical equivalent was -0.12±0.51D, minimum -2.50D and maximum +1.25D, median (interquartile range) of 0.0D (-0.375D to +0.125D). When comparing the difference between the spherical equivalent before and after the procedure of the group of eyes that underwent myopia (n=66) or hyperopia (n=37), separately, both obtained p<0.0001. When comparing all eyes that suffered any change on refraction (n=103), the p value was 0.008. The mean pre-procedure visual acuity was 0.23±0.32, minimum of 0.0 and maximum of 2.3. After the procedure, the mean was 0.06±0.13, minimum of -0.12 and maximum of 0.7, p<0.0001.

Conclusion:

Nd:YAG laser posterior capsulotomy significantly improved visual acuity of patients in this study; however, it also led to a significant change on refraction after the procedure, both for myopization, which was more frequent, and for hyperopization.

Keywords:
Posterior capsulotomy; Refraction; Cataract; Phacoemulsification

Dados
Pacientes		90
Olhos		140
Sexo
	Masculino	38 (42,2)
	Feminino	52 (57,8)
Olho operado
Direito		71 (50,7)
Esquerdo		69 (49,3)
Idade, meses
	Geral	67,8±11,6
	Homens	77,2±5,2
	Mulheres	60,8±9,9
Meses entre facoemulsificação e capsulotomia		15,8 (6,1-28,2)

	Antes	Depois	Valor de p
Equivalente Esférico pré e pós-YAG (em dioptrias)			0,0082 ^* * Teste t pareado.
Média ± DP	-0,07±0,89	-0,18 ± 0,86
Mediana (IIQ)	0,0 (-0,50–+0,375)	-0,125 (-0,50-0,0)
Mínimo-máximo	-3,0-+2,5	-3,50-+2,25
Diferença entre o EE geral pré e pós YAG
Média±DP	-0,12±0,51D
Mediana (IIQ)	0,00 (-0,375-+0,125)

Alteração refracional pós-YAG (em dioptrias)
Miopização em 66 olhos
	Máxima (n)	-2,50 (1)
	Média ± DP antes	0,14±1,0	p<0,0001 ^* * Teste t pareado.
	Média ± DP depois	-0,35±0,9
	Média ± DP da diferença antes/depois	-0,50±0,42
Hipermetropização em 37 olhos
	Máxima (n)	+1,25 (1)
	Média ± DP antes	-0,33±0,72	p<0,0001 ^* * Teste t pareado.
	Média ± DP depois	0,13±0,79
	Média ± DP da diferença antes/depois	0,46±0,27
Qualquer alteração refracional em 103 olhos
	Média ± DP antes	-0,03±0,94	p=0,008 ^* * Teste t pareado.
	Média ± DP depois	-0,18±0,91	p=0,008 ^* * Teste t pareado.
Sem alteração refracional		37 olhos

Acuidade visual pré e pós-YAG (LogMAR)	Antes	Depois	Diferença	Valor de p
Média±DP	0,23±0,32	0,06±0,13	-0,16±0,31	<0,0001 ^* * Teste t pareado.
Mediana (IIQ)	0,1 (0,0-0,3)	0,0 (0,0-0,1)	-0,08 (-0,18-0,0)
Mínimo e máximo	0,0±2,3	-0,12±0,7	-0,4±0,12

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E-mail: rbo@sboportal.org.br

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[1] Autor correspondente: Bruno Hirt, Rua Professor Pedro Viriato Parigot de Souza, 3.155 – Mossunguê CEP: 81200-100 – Curitiba, PR, Brasil. E-mail: brunohirt.med@gmail.com