Comparison of the Effects of Patterned and Conventional Laser Photocoagulation in Branch Retinal Vein Occlusion

Young-Gun Park; Dong Hyun Jee; Ji-Wook Yang

doi:10.3341/jkos.2010.51.10.1368

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Park, Jee, and Yang: Comparison of the Effects of Patterned and Conventional Laser Photocoagulation in Branch Retinal Vein Occlusion

Original Article

J Korean Ophthalmol Soc 2010;51(10):1368-1373.

Published online: 7 September 2010

DOI: https://doi.org/10.3341/jkos.2010.51.10.1368

Comparison of the Effects of Patterned and Conventional Laser Photocoagulation in Branch Retinal Vein Occlusion

Young-Gun Park, MD, Dong Hyun Jee, MD, Ji-Wook Yang, MD

Department of Ophthalmology and Visual Science, The Catholic University of Korea School of Medicine, Seoul, Korea

Address reprint requests to Ji-Wook Yang, MD Department of Ophthalmology, Uijeongbu St. Mary's Hospital #65-1 Geumo-dong, Uijeongbu 480-717, Korea Tel: 82-31-820-3110, Fax: 82-31-847-3418, E-mail: quintet@catholic.ac.kr

Received 25 February 2010 Accepted 6 July 2010

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To compare the clinical effect and complications between patterned laser photocoagulation with short exposure time and conventional laser photocoagulation for neovascularization in branch retinal vein occlusion (BRVO).

Methods

A prospective study was conducted on 36 patients (39 eyes) who required laser photocoagulation for neovascularization due to BRVO. The patients were divided into 2 groups, the patterned laser photocoagulation group (laser exposure time 0.02 sec, 3 × 3 array patterned photocoagulation) and conventional laser photocoagulation group (laser exposure time 0.2 sec). Other laser parameters (burn intensity and spot size) were the same. Pain score at the time of treatment was monitored after the laser photocoagulation. In addition, best-corrected visual acuity as well as central macular thickness measurements were performed before the treatment and after 2, 4, 8, and 12 weeks. The regression of neovascularization in fluorescein angiography was monitored during follow-up periods.

Results

The patterned laser photocoagulation group had a greater reduction in pain during laser photocoagulation, and a decreased change in central macular thickness after laser photocoagulation than the conventional laser photocoagulation group. In particular, the patterned laser photocoagulation group had a statistically significant difference between the 2 groups at postoperative 8 and 12 weeks. The regression rate of neovascularization between the 2 groups had no statistically significant difference.

Conclusions

Patterned laser photocoagulation with a short exposure time decreases pain and postoperative macular edema with no difference in regression of neovascularization. Patterned laser photocoagulation with a short exposure time can be considered as a useful and efficient method for neovascularization in BRVO.

Keywords: Branch retinal vein occlusion, Exposure time, Patterned laser photocoagulation

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Figure 1.

Changes in best-corrected visual acuity (BCVA) after laser photocoagulation in patterned group and conventional group. Preoperaive and postoperative BCVA are not statistically significantly different between the two groups (p = 0.657, 0.721, 0.215, 0.286, 0.504, repeated measure ANOVA).

Figure 2.

Changes in central macular thickness (CMT) after laser photocoagulation in patterned group and conventional group. There is no statistically significant difference in CMT preoperatively and at postoperative 2 and 4 weeks (p = 0.790, 0.730, 0.534, repeated measures ANOVA). But there is a statistically significant difference between the two groups at post-operative 8 and 12 weeks (p = 0.013, 0.027, repeated measures ANOVA).

Table 1.

Baseline clinical characteristics of the patients in patterned group and conventional group

Characteristics	Patterned group^‡	Conventional group^§	p value
Number (number of eyes)	19 (20)	17 (19)	
Age (yr)	57.94 ± 9.57	61.64 ± 12.29	0.072^*
Sex (male/female)	8/12	8/11	0.157^†
Hypertension	12 (60.0%)	7 (37.4%)	0.119^†
Follow-up periods (mon)	11.8 ± 2.5	12.3 ± 1.84	0.507^*
Lens status (eyes)			
Clear/pseudophakia	4	6	0.678^†
Mild cataract	16	13	0.285^†

^* Student t test

^† Fisher's exact test

^‡ Patterned group = patterned (3×3 spot) retinal photocoagulations were done with laser exposure time 0.02 sec

^§ Conventional group = single spot retinal photocoagulations were done with laser exposure time 0.2 sec.

Table 2.

Comparisons of laser parameters, procedure time and pain in patterned group and conventional group

	Patterned group	Conventional group	p value^*
Laser power (mW)	424.37 ± 91.51	316.44 ± 79.32	0.038
Number of laser burns (pulse)	508.14 ± 101.08	434.74 ± 92.27	0.135
Laser exposure time (sec)	0.02	0.2	
Fluence (J/cm²)	85.08 ± 22.30	632.88 ± 78.66	<0.001
Procedure time (min)	4.18 ± 0.75	7.27 ± 2.11	0.027
Visual analogue pain scale	4.34 ± 1.27	7.31 ± 2.24	<0.001

^* Student t-test.

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