Longitudinal Changes in Layered Retinal Thickness during Axial Elongation in Healthy Myopic Eyes
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3341/jkos.2021.62.2.230
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Min Seob PARK
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Kyoung Min LEE
			        		
			        		;
		        		
		        		
		        		
			        		Martha KIM
			        		
			        		;
		        		
		        		
		        		
			        		Ho-Kyung CHOUNG
			        		
			        		;
		        		
		        		
		        		
			        		Sohee OH
			        		
			        		;
		        		
		        		
		        		
			        		Seok Hwan KIM
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
            
            
            	- From:Journal of the Korean Ophthalmological Society
	            		
	            		 2021;62(2):230-236
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:Korean
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	 Purpose:To investigate longitudinal changes in foveal retinal sublayer thicknesses during axial elongation. 
				        	
				        
				        	Methods:From February 2013 to September 2014, a prospective cohort was established comprising pediatric patients aged < 13 years exhibiting myopia with a spherical equivalent of less than -0.75 diopters (D). At each visit, the foveal retinal thickness was measured using spectral-domain optical coherence tomography and sublayers were distinguished as follows: 1) total retinal layer, 2) inner retinal layer, 3) retinal nerve fiber layer, and 4) ganglion cell-inner plexiform layer. The average thickness was calculated based on the nine subfields of the Early Treatment Diabetic Retinopathy Study (ETDRS) map and compared between the initial and final visits. Intra-individual correlations were analyzed using a linear mixed-effects model. 
				        	
				        
				        	Results:Twenty-three subjects (46 eyes) were observed for 2.7 ± 1.0 years. During that period, the myopia progressed (spherical equivalent of cycloplegic refraction: from -4.26 ± 2.34 to -6.09 ± 2.64 D; p < 0.001, paired t-test), and the axial length increased from 24.80 ± 1.28 to 25.58 ± 1.38 mm (p < 0.001, paired t-test). Nevertheless, the thicknesses of foveal retinal layers (total retinal layer, inner retinal layer, retinal nerve fiber layer, ganglion cell-inner plexiform layer) showed no significant change in any of the nine ETDRS subfields (all p > 0.05, linear mixed-effects model). 
				        	
				        
				        	Conclusions:The foveal retinal sublayers maintained their thicknesses despite axial elongation, indicating that the foveal retinal structure, which is critical to visual acuity, is preserved even in elongated, myopic eyes.