Selective loss of inner retinal layer thickness in type 1 diabetic patients with minimal diabetic retinopathy.
OBJECTIVE
To determine whether type 1 diabetes preferentially affects the inner retinal layers by comparing the thickness of six retinal layers in type 1 diabetic patients who have no or minimal diabetic retinopathy (DR) with those of age- and sex-matched healthy controls.


METHODS
Fifty-seven patients with type 1 diabetes with no (n = 32) or minimal (n = 25) DR underwent full ophthalmic examination, stereoscopic fundus photography, and optical coherence tomography (OCT). After automated segmentation of intraretinal layers of the OCT images, mean thickness was calculated for six layers of the retina in the fovea, the pericentral area, and the peripheral area of the central macula and were compared with those of an age- and sex-matched control group.


RESULTS
In patients with minimal DR, the mean ganglion cell/inner plexiform layer was 2.7 microm thinner (95% confidence interval [CI], 2.1-4.3 microm) and the mean inner nuclear layer was 1.1 microm thinner (95% CI, 0.1-2.1 microm) in the pericentral area of the central macula compared to those of age-matched controls. In the peripheral area, the mean ganglion cell/inner plexiform layer remained significantly thinner. No other layers showed a significant difference.


CONCLUSIONS
Thinning of the total retina in type 1 diabetic patients with minimal retinopathy compared with healthy controls is attributed to a selective thinning of inner retinal layers and supports the concept that early DR includes a neurodegenerative component.
van Dijk
Hille W
HW
Department of Ophthalmology, Academic Medical Center, Amsterdam, the Netherlands. h.w.vandijk@amc.nl
Kok
Pauline H B
PH
Garvin
Mona
M
Sonka
Milan
M
Devries
J Hans
JH
Michels
Robert P J
RP
van Velthoven
Mirjam E J
ME
Schlingemann
Reinier O
RO
Verbraak
Frank D
FD
Abràmoff
Michael D
MD
D000328:Adult; D000465:Algorithms; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000209:etiology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D010781:Photography; D012162:Retinal Degeneration / Q000175:diagnosis* / Q000209:etiology; D055351:Retinal Neurons / Q000473:pathology*; D041623:Tomography, Optical Coherence
D006442:Glycated Hemoglobin