|Year : 2015 | Volume
| Issue : 1 | Page : 203-206
The effect of prophylactic laser barrage treatment before phacoemulsification in high myopia
Moustafa Kamal Nassar, Hatem Mohammed Marey, Kareem Mohamed Abdelreheem
Department of Ophthalmology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
|Date of Submission||17-Oct-2014|
|Date of Acceptance||01-Feb-2015|
|Date of Web Publication||29-Apr-2015|
Kareem Mohamed Abdelreheem
Department of Ophthalmology, Faculty of Medicine, Menoufia University, Hassan Radwan Street, Tanta, Gharbia Governorate
Source of Support: None, Conflict of Interest: None
The aim of this work was to study the effect of prophylactic laser barrage treatment before phacoemulsification in high myopia.
High myopia is considered as an important risk factor for the development of peripheral retinal degeneration and the subsequent development of retinal detachment, and hence, prophylactic laser barrage treatment is used for such uses.
Patients and methods
Thirty eyes of 20 patients with high myopia were divided into the following two groups: group I, high myopia with peripheral retinal degeneration subjected to laser retinopexy, and group II, high myopia with peripheral retinal degeneration not subjected to laser retinopexy. The two groups after undergoing phacoemulsification had been followed for the development of retinal detachment.
Prophylactic laser barrage treatment significantly reduces the incidence of retinal detachment after phacoemulsification in high myopia.
Prophylactic laser barrage treatment decreases the incidence of retinal detachment after phacoemulsification in high myopia.
Keywords: High myopia, laser barrage, phacoemulsification
|How to cite this article:|
Nassar MK, Marey HM, Abdelreheem KM. The effect of prophylactic laser barrage treatment before phacoemulsification in high myopia. Menoufia Med J 2015;28:203-6
|How to cite this URL:|
Nassar MK, Marey HM, Abdelreheem KM. The effect of prophylactic laser barrage treatment before phacoemulsification in high myopia. Menoufia Med J [serial online] 2015 [cited 2018 May 24];28:203-6. Available from: http://www.mmj.eg.net/text.asp?2015/28/1/203/155995
| Introduction|| |
High myopia or pathological myopia is associated with globe elongation and a refractive error of at least 6 D and/or an axial length of greater than 25.5 mm ,,. The prevalence of high myopia varies considerably in different ethnic groups and has been estimated to be around 10% in the Asian population ,. Excessive axial elongation of the globe in high myopia can cause mechanical stretching and thinning of the choroid and retinal pigment epithelium layers resulting in various retinal degenerative changes .
It is well known that individuals with high myopia have an increased risk of retinal complications such as peripheral retinal degeneration, retinal detachment, posterior staphyloma, chorioretinal atrophy, retinal pigment epithelial atrophy, and macular hemorrhage. Epidemiological studies have demonstrated an increased prevalence of peripheral retinal degenerations in association with high myopia and an increased axial length ,,.
Among the different types of peripheral degeneration, lattice degeneration is the most important peripheral retinal degeneration that can predispose one to rhegmatogenous retinal detachment .
Around 30% of the eyes with acute RRD have been found to have lattice degeneration; prophylactic laser treatment can also be performed in patients with peripheral retinal degenerations, especially those with a history of retinal detachment in the fellow eye .
The aim of this study was to evaluate the role of prophylactic laser barrage before phacoemulsification in high myopic eyes.
| Patients and methods|| |
Thirty eyes of 20 patients with high myopia (>6 D) were included in the study. Patients with media opacity precluding fundus examination, small pupils, and retinal complications due to other local or systemic diseases were excluded. They were divided into two groups. Group I: high myopia with peripheral retinal degeneration subjected to laser retinopexy group. Group II: high myopia with peripheral retinal degeneration not subjected to laser retinopexy. The two groups after undergoing phacoemulsification were followed for the development of retinal detachment. All the selected patients were subjected to full ophthalmological examination as follows:
- History: Age, sex, vitroretinal disease (central retinal vein occlusion, diabetic retinopathy), and systemic disease (diabetes, hypertension).
- Visual acuity: UCVA, BCVA with a Snellen chart and an autorefractometer.
- Slit-lamp examination: To exclude corneal opacity (patients with a miotic pupil, dense cataract, lens subluxation no dislocation, retinal complications to other local or systemic diseases).
- Fundus examination: Using tropicamide (mydrapid 1%), an indirect ophthalmoscope (Volk 20D), and Goldman 3 mirror lens.
- Fluorescein angiography: In high myopic patients, for the detection of complications of high myopia (choroidal neovascularization, lacquer cracks with chorioretinal degeneration).
- Laser treatment: Using mydriacyl (tropicamide 1.0% benoxinate) (hydrochloride 0.4%); contact lens application: typical initial settings on the argon laser would be 500 spot size, 0.1-s exposure, and 250-270 MW power. The power is gradually increased till a whitish reaction is obtained on the retina.
The t-test was used to assess the statistical significance of the difference between two means. By determining the t-test and the degree of freedom, the P-value was calculated from special tables, and so, the significance of the results was determined from the 't' distribution tables.
P < 0.05 = insignificant difference, P > 0.05 = significant difference.
P > 0.01 = highly significant difference, P > 0.001 = very highly significant difference.
| Results|| |
In this study, the minimum age was 45 years, the maximum age was 57 years, and the mean was 52.88 years; the SD was 3.10. Regarding the sex, there were 12 male (66.7%) and six female (33.3%) participants. In this study, we followed up the patients for 1 month, and there were no recorded cases having retinal detachment in group I and group II. During the 3-month follow-up of the patients in this study, we noticed that in group I, which underwent laser retinopexy before phacoemulsification, there was one recorded case having retinal detachment, whereas in group II, there were two recorded cases having retinal detachment. We noticed that five patients complained of increasing floaters, three patients complained of headache, and four patients complained of blurring of vision after laser barrage.
[Figure 1] and [Table 1] show that there were no recorded cases having retinal detachment in group I and group II during the 1-month follow up of the patients in this study.
|Figure 1: At the 1-month follow-up for retinal detachment, no cases were found in group I and group II.|
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|Table 1: At the 1-month follow-up for retinal detachment, no cases were found in group I and group II|
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[Figure 2] and [Table 2] show that during the 3-month follow-up of the patients in this study, we noticed that in group I, in which patients underwent laser retinopexy before phacoemulsification, there was one recorded case having retinal detachment, whereas in group II, in which patients did not undergo laser retinopexy, there were two recorded cases having retinal detachment; the incidence of retinal detachment showed a significantly higher level (P = 0.001) in group II, which was not subjected to laser retinopexy (two cases of retinal detachment), compared with group I, which was subjected to laser retinopexy (one case of retinal detachment).
|Figure 2: At the 3-month follow-up for retinal detachment, one case in group I and two cases in group II were found.|
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|Table 2: At the 3-month follow-up for retinal detachment, one case in group I and two cases in group II were found|
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[Figure 3] shows the colored photograph of a 47-year-old male patient with lattice degeneration 1 month after laser barrage treatment.
|Figure 3: Lattice degeneration after laser treatment occurred after 1 month.|
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In our study, in cases that had retinal detachment, examination of the fundus periphery revealed extensive lattice degeneration, that phacoemulsification was not complicated, and that PVD occurred in all cases.
| Discussion|| |
Phacoemulsification is one of the commonly performed intraocular surgeries in Egypt. The advantages of phacoemulsification such as its short procedure time, day surgery, and high success rate make patients believe that it is a risk-free procedure. However, sight-threatening postoperative complications exist and the most dangerous of these is rhegmatogenous retinal detachment .
The normal lifetime risk of rhegmatogenous retinal detachment in high-myopic patients without surgery has been estimated to be 40 times the life risk of retinal detachment in emmetropia, and phacoemulsification also increases the risk of rhegmatogenous retinal detachment in high-myopic patients.
Peripheral retinal degeneration is a disorder in the peripheral part of the retina, and there are many types that may occur with high myopia such as degenerative retinoschisis, lattice degeneration, white without pressure, paving stone and snail track degeneration. There are many complications of these degenerations; the most serious one is rhegmatogenous retinal detachment.
Generally, peripheral retinal degeneration is slowly progressive in nature and manifests no symptoms, but when it is complicated by retinal tears, patients suffer from flashes of light, floaters, and curtain over the view of vision .
The aim of this study was to determine the benefit of prophylactic laser barrage treatment in reducing the incidence of rhegmatogenous retinal detachment in high-myopic patients.
Argon laser photocoagulation depends on creating a chorioretinal scar that prevents fluid from passing beneath the retina causing retinal detachment.
In this study, it was found that in group I, which was subjected to laser retinopexy, the incidence of retinal detachment decreased compared with the incidence in group II, which was not subjected to laser retinopexy.
This is in agreement with Timothy , who mentioned that laser photocoagulation is recommended for the treatment of eyes that had developed a retinal break or tears because about 30% of the eyes with acute rhegmatogenous retinal detachment in high-myopic patients have been found to have lattice degeneration, and hence, laser treatment can also be performed in patients with peripheral retinal degeneration, especially in those with a history of retinal detachment in the fellow eye; he also recommend that this can be performed in the majority of the patients under topical anesthesia as an outpatient procedure.
Also, this study is in agreement with Fan et al. , who noticed that active searching and prophylactic laser treatment for retinal tears developed before phacoemulsification in high-myopic patients may lower the incidence of rhegmatogenous retinal detachment in high-myopic patients.
Robin D. Ross  confirmed that when retinal tear occurs, laser treatment may be applied to prevent the accumulation of fluid beneath the retina and minimize the risk of vision-threatening retinal detachment; laser is applied around any retinal defect over the course of a few weeks; the treated area develops a scar that forms a tight seal between the retina and the underlying tissue.
In this study, we consider that the benefits of laser treatment outweigh the potential risks of argon laser photocoagulation. The adverse effects of laser can occur in three main ways: unintended laser absorption, inadvertent coagulation, and scatter of laser treatment.
Complications of laser barrage include transient effects (blurred vision, raised intraocular pressure, and headache) and permanent effects (poor night vision, poor color vision, and peripheral field defect).
After laser treatment, there is no necessity for any particular treatment in most patients; however, patients should be aware that the cornea will be under the effect of the anesthetic for a few hours they should be instructed to seek help immediately if the eye becomes red, painful, or vision drops .
Folk and colleagues confirmed that the presence of symptomatic retinal lesions is widely accepted to be the foremost indication for treatment, but sometimes, the mere recognition and treatment of risk areas in the fellow eye are not enough to prevent further development of this pathology, which also seems to be linked to vitreoretinal conditions (PVD developing). They confirm that laser barrage was capable of limiting RD in four out five (80%) cases of RD originating from previously treated lesions; they affirm that such treatment could at least limit RD development; however, the possibility that the treatment itself played a part in causing the progression of PVD has to be evaluated .
| Conclusion|| |
Active searching and prophylactic laser treatment must be performed for high-risk peripheral retinal degenerations causing retinal tears developed before phacoemulsification in high-myopic patients.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]