Laser photocoagulation for retinopathy of prematurity: structural and functional outcome

Abstract

ABSTRACT.Background: To report the structural and refractive outcome after laser photocoagulation for retinopathy of prematurity (ROP). Methods: Nineteen consecutive patients who had undergone photocoagulation for ROP between 1997 and 2002 at our clinic were examined for this noncomparative, consecutive, interventional, retrospective case series. A total of 37 eyes received either transscleral or transpupillary laser treatment. Data consisted of grade of ROP pre-and postoperatively, birth weight, perioperative and postoperative complications and refraction. Based on indirect ophthalmoscopy, independent observers graded the extent of ROP and determined the postoperative refraction by retinoscopy. Results: A total of 97% of all eyes responded to laser treatment with regression of ROP. Only one eye out of 37 progressed to stage IV B despite photocoagulation and therefore an encircling procedure was performed. After further progression a vitrectomy was carried out. Perioperative complications included haemorrhages in 22% that resorbed spontaneously and cataract formation in one eye (3%). Postoperative refractive errors at mean ages of 23 ± 12 months and 45 ± 14 months were evaluated in 15/19 patients (79%). The spherical equivalents ranged between -8 D and +6 D at the first examination and between -12 D and +7 D at the second examination. In all only 14% of the refracted eyes were myopic. Conclusions: Photocoagulation for ROP in our patients resulted in regression of threshold ROP. In addition, the analyses of the refractive outcomes demonstrated a predominance of hypermetropia in our patients.

Treatment success of laser therapy for retinopathy of prematurity in referred and non-referred patients

“…The ET-ROP study emphasized that patients who require treatment should be treated within 48 h (8) . We found that treatment timing in the non-referred patient group was consistent with many previous studies and that treatment timing in the referred patient group was approximately 2 weeks later than the average of previous studies (23,24) . This situation may be a factor explaining the difference in success rate between the two groups.…”

“…According to the ET-ROP and CRYO-ROP study results, the threshold ROP was set to nearly 37 weeks in patients with BWs <1,251 g (8,22) . In several studies, patients were treated between 34 and 37 weeks, which may be the critical time interval for the progression of the ROP (23,24) . After establishing a diagnosis of ROP and identifying an indication for treatment, treatment should be immediately initiated.…”

Diode Laser Photocoagulation for Retinopathy of Prematurity: Outcomes After 7 Years of Treatment

“…It has to be performed at a point in the natural history where vasoproliferation can be reversed, because once the vitreoretinal traction commences it is difficult to control the disease and prevent the retinal detachment with subsequent visual loss. 7 Knowing the progression of ROP in correlation with time is crucial for a correct screening. ROP usually does not develop within the first 2 weeks after birth.…”

“…Therefore, ROP is understood as a two-phase process: an acute phase, generated by the relative hyperoxia of the extra-uterine environment, characterized by vaso-obliteration and non-vascularization of the anterior retina, and a chronic phase, defined by vasoproliferation. 7,8 The rationale for ROP treatment by laser photocoagulation is to destroy the non-vascularized retina to remove the source of the angiogenic factors, thus interrupting the pathogenic mechanism of the vasoproliferation and subsequent retinal detachment. 4,9 This was achieved for the first time in 1988 by cryotherapy, which proved its efficacy in preventing blindness caused by ROP.…”

A role for photoreceptors in retinal oedema and angiogenesis: an additional explanation for laser treatment?

“…It is accepted on the basis of clinical experience and the results of randomised trials that laser panretinal photocoagulation is an effective treatment for proliferative diabetic retinopathy [15][16][17] and that laser treatment is of benefit in controlling the neovascularisation that characterises the retinopathy of prematurity 18,19 and ischaemic branch retinal vein occlusion. 20,21 In spite of the fact that laser panretinal photocoagulation for diabetic retinopathy has been used since it was first suggested by Meyer-Schwickerath almost 50 years ago, 22 and that grid laser treatment in the management of macular oedema has been used for some 40 years, 23 some aspects of the mode of action of laser in these and similar conditions remain incompletely explained.…”