Objective To observe the relationship between shallow optic cup,small disc and occurrence in patients with nonarteritic anterior ischemic optic neuropathy (NAION).Methods Ninetysix patients(96 diseased eyes)who accorded with the diagnosis criteria for NAION,with duration ge; three months and optic disc edema in paracmasis were selected. The fellow eyes of 96 NAION patients and 80 normal eyes were selected in our study. The horizontal and vertical disc and cup diameters,optic cup depth, and peripapillary retinal nerve fiber layer (RNFL) thickness were measured by quot;crossquot; and quot;ringquot; scan of optical coherence tomography (OCT,Humphrey 2000,German Carl Zeiss Company) inspection system. The cup depth were classified four grades by cup shape according to OCT images:GradeⅠ,bottom of optic cup above the anterior plane of peripapillary neuroepithelial layer(PNL);GradeⅡ,bottom of optic cup above the plane of PNL;Grade Ⅲ,bottom of optic cup between the plane of PNL and choroidal pigment epithelium;Grade Ⅳ,bottom of optic cup under the plane of choroidal pigment epithelium connection. The grades of optic cup and value in three groups were statistically analyzed. The follow up ranged from six months to three years.Results The disc diameter in horizontal scanning of diseased eyes,fellow eyes and normal eyes were (1.29plusmn;0.19), (1.32plusmn;0.17), (1.40plusmn;0.15) mm,and diameters in vertical scanning were (1.52plusmn;0.14), (1.49plusmn;0.17), (1.60plusmn;0.22) mm, respectively. Compared the diseased eyes and fellow eyes with normal eyes,the difference were statistically significant in horizontal scanning (t=4.291,3.315; P<0.05) and in vertical scanning (t=2.812, 3.654; P<0.05). Compared the diseased eyes with fellow eyes,the difference of average diameter were not statistically significant in horizontal and vertical scanning (t=1.153,1.335; P>0.05). Of the diseased eyes,GradeⅠoptic cup in 36 eyes(37.50),Grade Ⅱ-Ⅲoptic cup in 52 eyes(54.17%),Grade Ⅳoptic cup in eight eyes(8.33%),and GradeⅠ-Ⅲ optic cup in 88 eyes(91.67%)were found. Of the fellow eyes,GradeⅠoptic cup in 18 eyes(18.75%),Grade Ⅱ-Ⅲoptic cup in 69 eyes(71.88%),Grade Ⅳoptic cup in nine eyes(9.34%),and GradeⅠ-Ⅲ optic cup in 87 eyes(9066%)were found. Compared the average RNFL thickness of diseased eyes with the fellow eyes and normal eyes,the differences were statistically significant in temporal, upper, nasal, lower quadrant(t=12.862,10.147,15.046,8.180,12.859,9.562,12.174,8.632;P<0.001). Compared the average RNFL thickness of the fellow eyes and normal eyes,the differences were not statistically significant in all quadrants(t=1.040,1.576,1.062,1.192;P>0.05). During the followup,eight eyes with recurrence which optic cup were GradeⅠand Ⅱin diseased eyes;44 eyes(45.8%)occurred NAION. Correlation analysis showed that there was negative correlation between incidence of fellow eye and optic cup depth(t=-0.757, P=0.000). Conclusion Optic cup and disk in NAION patients are smaller than that in the normal,the anatomical characteristics of shallow cup and small disc was one of the NAION pathogenesis.
Objective To evaluate the changes of optic nerve head (ONH) and the thickness of peripapillary retinal nerve fiber layer (RNFL) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography (OCT). Methods Circular and cross-sectional OCT scans of an area with a diameter of 3.38 mm surrounding the optic disc were performed for 108 eyes (96 cases) with NAION, including 96 eyes (96 cases) in acute edema phase and 41 eyes (37 cases) in resolving phase. Follow-up period was 2 weeks to 24 months, with an average of 6 months. Results The RNFL was thickener with shallow cup or small cups in the acute edema phase. Comparing with the RNFL in the ischemic sector, the thickness of peripapillary RNFL in the nonischemic sector was greater in 59 eyes (59 cases, 61%), lesser in 26 eyes (26 cases, 27%) and no difference in 11 eyes (11 cases, 12%). During the treatment NAION eyes were dynamically observed by OCT. While ischemic edema of the optic disc resolved in about two weeks, non-ischemic edema subsided in 3-6 weeks. After 1 month in the resolving phase, the thickness of peripapillary RNFL in the ischemic sector of 35 cases (95%) was thinner than the thickness of non-ischemic sector and fellow normal controls. After 3 month in the resolving phase, 26 cases (70%) showed thinner RNFL of whole optic disc. Conclusion The thickness of RNFL in NAION patients in acute edema phase is thicker than that in the fellow normal eyes, and is also thicker in ischemic sector than that in non-ischemic sector. In resolving phase, the thickness of RNFL is thinner in NAION eyes than that in the fellow normal eyes.
Objective To observe the characteristics of morphosis parameter of the optic disc of physiologic large cup. Methods 100 eyes with physiologic large cup and 74 eyes with normal cup were examined by Heidelberg Retina Tomograph (HRT ). The differences of morphosis parameters between two groups were analyzed comparatively on disc area (DA), cup volume (CV), cup/disc area ratio (C/DR), rim area (RA), cup volume (CV), rim volume (RV), mean cup depth (MeCD), maximum cup depth (MxCD), cup shape measure (CSM), height variation contour (HVC), mean retinal nerve fiber layer thickness (mRNFLt), and retinal nerve fiber layer cross-section area (RNFLcsa). The characteristics of the inferior, superior, nasal, and temporal quadrants of the physiologic large cups were analyzed. Results DA, CA, C/DR, CV, MeCD, CSM (P=0.00, respectively)and MxCD (P=0.04)were significantly larger in eyes with physiologic large cup than in eyes with normal cup. RA, RV, HVC, mRNFLt, RNFLcsa (P=0.00, respectively) were significantly smaller in eyes with physiologic large cup than in eyes with normal cup. The temporal quadrant of RV of the physiologic large cup is the narrowest. RNFLcsa decreased as the fol lowing order: superior, inferior, nasal, and temporal(P<0.05). Conclusions Mo rphosis parameter of the optic discs of physiologic large cup has its own repres entation on characteristics. Compared to normal cups, physiologic large cups had larger discs but smaller mRNFLt. The nasal quadrant of DA was larger than the i nferior quadrant. (Chin J Ocul Fundus Dis,2008,24:213-216)