Abstract
Purpose: :
To determine the range and frequency of normal and abnormal findings invisible to ophthalmoscopy but revealed by SD OCT in normal patients.
Methods: :
500 randomly selected eyes from 500 asymptomatic and clinically normal patients (20/20 BCVA and a normal ophthalmoscopic exam of the posterior pole) were evaluated with 1 of 3 different SD OCT’s (Topcon 3D OCT, Zeiss Cirrus HD or Heidelberg Spectralis) using standard testing protocols recommended by the manufacturer. The ages ranged from 20 to 96 and refractive error ranged from +5 to -10 D with a mean RE of -3D. Generally, a 6 mm x 6 mm square was imaged around the disc and also around the macula and 128 scans (both color and grey scale) per square were analyzed. Specific attention was paid to the vitreal- retinal interface, the Inner Segment/Outer Segment -IS/OS Junction, gaps or splits in the retina and shape deviations.
Results: :
The IS/OS Junction was clearly present under the foveal pit in all 500 eyes imaged. The junction was thinner in the higher myopes and occasionally found to be discontinuous outside the fovea in the 7-10 D myopes. Bergmeister’s Papillae (BP) was found in 251 eyes but was age dependent. Patients under 30 had BP in 73% of eyes but over the age of 50 only 35% of eyes had BP. Vitreal retinal traction was more common in patients between 50-65 while total vitreal separation was more common in the over 70 age group. Vitreal-macula syndrome was found in 3 of 500 eyes (all 3 had 20/20 VA and a normal fundus exam). The most common shape deviation was posterior staphyloma in the higher myopes. 3 myopic eyes between 7-10 D had mini-bulges believed to be early staphylomas and 2 had vascular microfolds, one with vitreal traction. Also, 2 myopic eyes had retinoschisis around the optic nerve head. Some form of epi-retinal membrane was present in about 1/3 of eyes over the age of 50.
Conclusions: :
: SD OCT reveals an array of normal and abnormal findings invisible to ophthalmoscopy in clinically normal patients. A normal IS/OS junction in all 500 eyes evaluated suggests that an abnormal junction is not found in normal patients and hence when abnormal it may indicate loss of photoreceptor integrity. BP is very common in normals (without clinical significance) but may complicate OCT disc assessment in diabetics with possible disc neo. Myopes between 5-10 D have myriad abnormalities invisible to ophthalmosocpy including mini-bulges, staphylomas, vascular microfolds and retinoschisis.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • retina