Objective To explore the correlation between retinal extracellular edema and vitreous contraction in rabbits. Methods Seventeen pigmented rabbit models with retinal vein occlusion (RVO) was set up by laser photocoagulation. Retinal vascularity area was pathologically examined 1 month later. The vitreous gel length under the gravity condition and the percentage of its weight in the rabbits with extracellular edema was observed. The mechanisms were investigated by Western immunoblotting of type Ⅱ collagen. Results Extracellular edema was found in 13 experimental eyes 1 month after the formation of RVO (76.5%) with contracted vitreous gel and released watery liquid, and the ? component of type Ⅱcollagen was cross-linked together to form high-molecular-weight components of ? and ?, which weakened the stability of collagen net structure. Conclusions Vitreous contraction and retinal extracellular edema were correlated. The main reason may be the cross-links of vitreous collagen that damages the stability of collagen structure.

0.05).②Laser retinal visual acuity was from 0.12 to 0.4 preoperatively,and from 0.2 to 0.63 postoperatively,the difference was significant (P

Objective To explore the changes of multifocal electroretinogram (mERG) before and after retinal detachment surgery and its clinical significance. Methods Eighteen patients suffered from rhegmatogenous retinal detachment underwent mERG before and after surgery using VERIS Science TM 4.0. The mERG at different area was compared between preoperative and postoperative surgery. Results Preoperatively, the latencies of a wave and b wave in detached area were statistically longer than in attached area ( t =4.541 and 6.784, P

Objective To explore the clinical application value of multifocal oscillatory potentials (MOPs) in retinal vein occlusion (RVO). Methods MOPs were tested using VERIS 4.0 visual evoked response imaging system for 19 cases (19 eyes) of RVO,among them 8 cases of central retinal vein occlusion (CRVO) and 11 cases of branch retinal vein occlusion (BRVO). Twenty normal subjects were as normal control group. The stimulative visual angles subtended ?26.6? horizontally and ?22.1? vertica lly. The filter setting was bandpass 100～1 000 Hz. The retinal responses from 103 hexagons were recor ded in 4 min (8 segments). Results In normal control group, OP 1, OP 2 and OP 3 were recorded during 37 ms for first order and 47 ms for second order first slice in whole test field and 5 ring retinal regions, the oscillatory wave shapes of second order were clearer than those of first order. In RVO groups, 91.6% latencies of OP 1, OP 2 and OP 3 were delayed, and 70.8% amplitudes of OP 1, OP 2 and OP 3 were reduced. The delay of the latencies and the decrease of the amplitude in CRVO were more markedly than those in BRVO. Conclusion MOPs can be effectively and quantitatively used to evaluate the retinal function of the different location in RVO.

OBJECTIVESTo explore the changes of multifocal electroretinograms (mfERG) before and after retinal detachment surgery and to evaluate its clinical significance.

METHODSTwenty-three patients (23 eyes) with rhegmatogenous retinal detachment underwent mfERG before and after surgery. The latencies and average response densities of N(1)-wave and P(1)-wave of mfERGs in detached areas, attached areas, fovea and the entire tested area were compared before and after surgery.

RESULTSPreoperatively, the average response densities of N(1)-wave and P(1)-wave in the detached area were significantly smaller than those in attached areas (t = 3.68, t = 4.26, P < 0.01), and the latencies of N(1)-wave and P(1)-wave in detached areas were significantly longer than those in attached areas (t = 3.07, t = 3.89, P < 0.01). Postoperatively, the average response densities of N(1)-wave and P(1)-wave in detached areas, fovea and the entire tested area increased, and there were significant differences pre- and postoperatively (P < 0.05). However, the latencies of N(1)-wave and P(1)-wave before and after surgery showed no significant differences (P > 0.05).

CONCLUSIONSThe mfERG is a useful tool to evaluate the recovery of posterior retinal function after retinal detachment surgery. The response density is a more sensitive index than latency to evaluate retinal function of retinal detachment.

Adult ; Aged ; Electroretinography ; Female ; Humans ; Male ; Middle Aged ; Retinal Detachment ; physiopathology ; surgery ; Visual Acuity

OBJECTIVETo identify the characteristics of and evaluate surgical impact on idiopathic macular hole (IMH) by using an optical coherence tomography (OCT) scanner.

METHODSSixty-five cases (70 eyes) experiencing IMH were examined using OCT, then graded by their clinical characteristics. Nineteen cases (19 eyes) were scanned and measured using OCT before and after surgery.

RESULTSOf the 70 eyes,the number of stage I-IV macular holes were 11, 12, 36 and 11, respectively. For stage I holes, the OCT images revealed flattened or nonexistent fovea and minimally reflective space within or beneath the neurosensory retina; stage II holes appeared to be full-sized with attached operculum and surrounding edema; stage III holes were also full-sized with surrounding edema; finally, stage IV holes were full-sized and completely separated the posterior hyaloid membrane from the retina. Through quantitative measurements, OCT determined that the values for mean hole diameter, mean halo diameter and mean thickness of the hole's edge were reduced from 570.95 +/- 265.59 to 337.05 +/- 335.95 microm, 1043.53 +/- 278.8 to 695.00 +/- 483.00 microm and 389.78 +/- 60.58 to 298.78 +/- 109.80 microm, respectively in 19 IMH cases after surgery. In 17 eyes, the holes or halos eventually closed or were reduced in size, or the edges of the holes thinned out. The anatomic successful rate of the surgery was 89%.

CONCLUSIONOCT can exhibit the characteristics of IMH and measure the diameter of holes quantitatively. This method can also judge the surgical impacts of IMH objectively, accurately and effectively.

Adult ; Aged ; Female ; Humans ; Macula Lutea ; pathology ; Male ; Middle Aged ; Retinal Perforations ; pathology ; surgery ; Tomography ; methods