Grid-like argon ion laser photocoagulation treatment of macular edema in retinal vein occlusion
Author: Liao Hua-ping, ZHANG Shi-sheng, Zhu Cai-Hong,
Zhou Ying-ming, Sun Yue, Shi Haiyun, Wang Ling
【Abstract】 Objective: To evaluate the grid-like argon ion
laser photocoagulation treatment of retinal vein occlusion, macular edema due to clinical efficacy. Methods: Retinal vein occlusion induced macular edema 56 cases of 56, using argon ion laser eye treatment instrument for macular grid
photocoagulation samples, spot diameter of 50 ~ 100μm,
exposure time 0.1s, laser energy 100 ~ 200mW, take the whole retina photocoagulation in the macular grid laser photocoagulation samples carried out after the completion of follow-up 3 ~ 18mo, observed before and after treatment the changes in visual acuity and macular edema. Results: In 56 eyes, visual acuity improvement of 37 (66.1%), visual acuity change 14 (25.0%), decreased visual acuity in 5 eyes (8.9%); macular edema disappeared completely 31 (55.4%), macular edema improved 21 (37.5%), macular edema remain unchanged or even increased 4 (7.1%). Conclusion: Early photocoagulation for macular grid-like help with retinal vein occlusion caused by macular edema subsided, can effectively preserve and even
enhance the risk of visual acuity.
Key words macular edema and retinal vein occlusion grid-like
argon ion laser photocoagulation
Retinal vein occlusion (retinal vein occlusion, RVO) is second only to diabetic retinopathy and the second-largest
blinding retinal vascular disease, and macular edema is the
main reason for decreased vision caused by RVO [1-5]. Macular
edema can be expressed as subcutaneous fluid on the retinal neurons can also be expressed as cystoid edema. Macular edema
can cause long-term plasma proteins, lipids, fibrinogen, and other ingredients deposited in the macular center area; or lead to localized thinning of the retina, there lamellar hole; In addition, cystoid macular edema, cystoid late can form
scar, These may also lead to irreversible eye damage, severe cases lead to blindness [2,3]. We use argon ion laser on RVO caused by sample grid photocoagulation for macular edema, and achieved a certain degree of clinical efficacy is as follows.
An object and method
1.1 Object 2003-01/2005-10 eye hospital between RVO
patients diagnosed 56 cases of 56, all by fundus fluorescein angiography confirmed accompanied by macular edema. Male 35, female 21; age 48 to 75 (mean 59.2 ? 6.2) years of age; best
corrected visual acuity of 0.01 ~ 0.4, an average of 0.20 ?
0.16; superior temporal branch vein occlusion 23, the temporal branch of vein occlusion, 15, the central vein occlusion 18; course 3wk ~ 2a, the median 6mo; the same time with hypertension and diabetes in 15 patients with hypertension or diabetes alone in 28 cases.
1.2 treatments over Korea before the United States and fully scattered large pupil, Aier Ka due to topical anesthesia, using Coherent argon ion laser eye treatment instrument, through the Goldmann three-mirror, an outsider
from the foveal 500μm spot photocoagulation photocoagulation staggered three-rows, spot diameter of 50 ~ 100μm, power 100
~ 200mW, exposure time 0.1s, retinal photocoagulation intensity grade ? suitable, photocoagulation spot an interval
of approximately one spot diameter; for a greater range of peripheral retinal capillary non-perfusion area or have been
retinal neovascularization occurs, could add as quadrant or full-retinal photocoagulation in order to prevent
neovascularization and vitreous hemorrhage. Extent of the
lesion the smaller the completion of a second kind of laser photocoagulation and grid photocoagulation quadrant of the lesion while those staging a broader treatment, usually first conduct a kind of macular grid photocoagulation, interval 1 ~
2mo again panretinal photocoagulation . After laser therapy on a regular basis review, observation of visual acuity and
macular edema and to record its changes, the general review 3mo after FFA, if you find that there is leakage re-grille-
like laser treatment. Disappearance of macular edema completely dissipated leakage, leakage to narrow the scope of edema improved; visual acuity chart by international standards, inspections, increased visual acuity improvement of ? 1 behavior decreased ? 1 behavior decreased visual acuity, the borderline between the two for the visually stable. Vision "of 0.1 persons, in order to increase or decrease in 0.02 as the standard.
2.1 In general after treatment follow-up 3 to 18 (mean
9.2 ? 2.8) mo; in 56 eyes, the treatment of a sub-37,
treatment 2 times 14, treatment 3 times 5; of these are from the treatment of a second course of BRVO, or " 3mo, mostly those who need repeated treatment duration of CRVO or> 3mo person.
2.2 The last meeting follow-up, visual acuity visual
acuity improved in 37 eyes (66.1%), unchanged in 14 eyes (25.0%), decreased in 5 eyes (8.9%); of these course <3mo of 37 eyes of 30 (81.1%) have different visual acuity higher levels, while the duration of> 3mo only seven of 19 eyes
(36.8%), visual acuity improved; 38 BRVO eyes 28 (73.7%), visual acuity improved, 18 CRVO eyes 9 (50.0%), visual acuity improved. The average visual acuity after treatment from 0.20 ? 0.16 increased to 0.40 ? 0.29 (Table 1).
2.3 macular edema after treatment on a regular basis, and FFA examination by ophthalmoscope macular edema about the situation, compared with the previous photocoagulation, 31 eyes (55.4%), macular edema completely subsided, 21 (37.5%), edema improved, four (7.1%), macular edema at the same or increase; BRVO 38 eyes of 37 (97.4%), macular leakage mitigation or dissipated, CRVO 18 eyes of 15 (83.3%), macular edema, or dissipated; macular edema was first found in the grid-like after photocoagulation 1mo, 3mo, when about 30% of
patients with edema subsided, 6mo majority of patients when the absorption of macular edema (Table 1).
Within the retinal veins (mainly including the sieve plane crossing the central venous and arterial branches of
veins, etc.) thrombosis, blood returning blocked vein pressure is increased, there retinal edema or hemorrhage involving the macula macular edema may occur, resulting in decreased visual acuity, with the disease can develop retinal capillary occlusion, arterial blood flow reduction, resulting in retinal ischemia and hypoxia, increased edema, or even serious complications such as retinal neovascularization further affect the visual acuity [1-3]. Disease occurrence and
arteriosclerosis, hypertension, high blood viscosity, as well
as diabetes and other systemic factors [2,3,7]. Use of anticoagulant drugs or even through surgery to eliminate dilution of the blood vessels within the thrombus and restore retinal perfusion and other methods are conducive to control
the occurrence and development of RVO, but has formed such as macular edema and neovascularization Quewu significant effect on [8-10]. Can focus the laser photocoagulation were complications can be obtained good results [6,11,12]. Photocoagulation for macular edema-like grid to reduce the
possible mechanisms [6,11,12], including: ? through the
destruction of photoreceptors, reducing the outer retinal oxygen consumption, thereby increasing the inner retinal oxygen supply, so that the blood vessels, retinal blood flow
reduction and can reduce vascular leakage; ? generated
photocoagulation scar, so that edema of the retina closer to the choroid, is conducive to choroidal oxygen supply to the retina, thereby improving the local metabolism, so that edema;
? to macular part of a small artery stenosis, lower macular As the vein occlusion caused by pressure between the capillaries in order to reduce leakage; ? selective
photocoagulation of retinal pigment epithelium damage, promoting retinal capillary and venous endothelial
proliferation are conducive to the blood - retinal barrier
repair, to reduce leakage; also likely to enhance the the outer blood-retinal barrier, is conducive to the flow of liquid from the retina choroid, thereby reducing macular edema; ? photocoagulation can be directly reduced or closed expansion to reduce retinal edema, capillary leak; ?
photocoagulation in the macular area to form a barrier to to prevent the other branches of vascular leakage into the center concave. Reposted elsewhere in the paper for free download
Ohashi et al  had 37 patients with severe macular edema in BRVO patients with type grid photocoagulation, 1,3,6 mo follow-up found that the whole foveal thickness and visual acuity were significantly improved, and the foveal thickness
of thin and the visual acuity was improved significantly correlated. Our results also indicate that grid-like
photocoagulation therapy, 66.1% of patients visual acuity improved. One course <3mo of 37 eyes of 30 (81.1%), visual
acuity increased to varying degrees, course> 3mo only seven of 19 eyes (36.8%), visual acuity improved; 38 BRVO eyes 28 (73.7%), visual acuity improved, 18 CRVO eyes of nine (50.0%), visual acuity improved. This shows that the visual improvement after treatment with the scope and duration of vein occlusion related to the scope of a small block, the shorter duration, visual acuity increased significantly; vein occlusion, range, course quite a long time, visual acuity was improved not obvious. The reason generally is: vein occlusion range, affect the macular area high probability of venous drainage, there a high risk of macular edema, affecting visual acuity; course length, macular possible irreversible organic changes, easy to miss treatment opportunities, therefore, of RVO caused by
macular edema should conduct a comprehensive inspection as soon as possible to strive for early diagnosis and early treatment [2,3,12]. We also found that: 38 BRVO eyes, 37 (97.4%), macular leakage to reduce or disappear, 28 (73.7%),
visual acuity improved; 18 CRVO eyes, 15 eyes (83.3%), macular edema, 9 ( 50.0%) visual acuity improved. Note that not all patients with macular edema and improvement in visual acuity will be increased. 3mo course within the visual improvement was significantly higher in patients with more than 3mo, indicating retinal photocoagulation should be OK as soon as possible, although the latter part of macular edema subsided, but the improvement of visual acuity Quewu. In fact, RVO's visual prognosis affected by many factors, in addition to the above factors, but also with newly diagnosed or pre-treatment
visual acuity levels, RVO whether the lack of blood type and other relevant. Sun Xin et al  had 105 cases of 108 patients with CRVO had laser treatment and found that the
initial visual acuity ? 0.5 persons, the majority of vision
can be maintained; "0.1 persons, visual prognosis is poor; range of between 0.1 to 0.4, visual different prognosis, it may increase (24%), unchanged (44%), also may be
deteriorating. Huirong, etc.  found that RVO patients, ischemic patients with low vision and blindness were higher
than those of non-ischemic (29.9%, 25.1% vs 5.1%, 1.0%). The Ohashi, etc.  that the pre-treatment associated with
serous retinal detachment of patients, even after treatment
can absorb, but also does not help to improve vision. In addition, if patients with central macular hemorrhage, blood cells in iron-containing heme can damage the macula center of the cone cells and retinal pigment epithelial cells, leading
to advanced macular retinal epithelial hyperplasia and scar formation, the final visual acuity can not be restored.
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