Iridocorneal angle characteristics of infants with retinopathy of prematurity (ROP) compared to full-term infants using spectral domain optical coherence tomography

Abstract

Purpose: To compare measurements and morphologic characteristics of the iridocorneal angle in preterm infants with retinopathy of prematurity (ROP) vs full-term infants of the same group of age using spectral domain optical coherence tomography (SD-OCT)

Methods: Children aged under 1 year old were recruited at an ophthalmologic center. SD-OCT was used to obtain one scan per eye, images were analyzed with custom software. Angle recess area (ARA) was located 750 μm anterior to the scleral spur. Angle width was represented by the angle opening distance (AOD) at 500 μm anterior to scleral spur. Angle opening in grades (AOG) was measured at the iridocorneal junction. ROP staging was recorded from previous diagnosis made by a pediatric retinal specialist

Results: Forty-six infant’s eyes (27 with ROP and 21 without ROP) were studied. The mean gestational age and birth weight of the ROP group participants was 30 weeks and 1,500 g. The non-ROP patients were 35 weeks and 2,100 g. Mean age at the moment of the study was 18.1 weeks vs 25.7 wk (ROP vs non-ROP). AOP, AOG, ARA on the ROP group were 477 μm (CI 95% 358 to 597 μm), 37.3 grades (CI 95% 30.4 to 44.3 grades) and 231 mm2 (CI 95% 171 to 291 mm2) respectively. The same parameters on the non-ROP group were 400 μm (CI 95% 333 to 468 μm), 34.7 grades (CI 95% 30.4 to 39 grades) and 203 mm2 (CI 95% 171 to 236 mm2). Mean values for AOD, AOG and ARA by ROP stage were as follows; Stage 1: 780 μm, 49 degrees, 568 mm2; Stage 1+: 701 μm, 51 degrees, 359 mm2; Stage 2: 439 μm, 36 degrees, 224 mm2; Stage 2+: 276 μm, 25 degrees, 132 mm2; Stage 3: 1029 μm, 60 degrees, 510 mm2; Stage 3+: 311 μm, 26 degrees, 138 mm2; Stage 4: 182 μm, 43 degrees, 67 mm2; Stage 5: 440 μm, 31 degrees, 201 mm2. The main descriptive difference was the configuration of the iris, showing a more convex pattern on eyes with ROP than without the disease (56% vs 23%).

Conclusions: Children without ROP showed a smaller AOP, AOG and ARA than children with ROP. It may be due to differences of iris configuration or to different patterns of development in children with ROP. Further studies should be performed to assess our findings.

Keywords: 706 retinopathy of prematurity • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)