[Correlation of capillary plexus with visual acuity in idiopathic macular epiretinal membrane eyes using optical coherence tomography angiography]

Objective: To observe changes in foveal avascular zone(FAZ) and capillary plexus in idiopathic macular epiretinal membrane (IMEM) in optical coherence tomography angiography (OCTA) and analyze their correlation with the visual acuity. Methods: Cross-sectional study. 42 patients (15 Males and 27 females, age 64.8) from the Eye Hospital of Wenzhou Medical University were included with 51 eyes diagnosed as IMEM (IMEM group), and 23 normal eyes (9 Males and 14 females, control group). All patients received the examination of fissure lamp combined with fundus pre-set lens, best corrected visual acuity (BCVA), OCT angiography (OCTA) and fundus photo. OCTA was performed on 3 mm× 3 mm sections centred on the fovea. The software automatically measured the superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density(VD) and retinal thickness(RT) and FAZ area. The IMEM eyes were compared with the normal eyes and correlation between the parameters of OCTA and BCVA was analyzed in IMEM. Independent-sample t test and MannWhitney test were used for comparison between groups, and Spearman test was used for correlation analysis. Results: LogMAR BCVA in the IMEM group was 0.40(0.15, 0.70), in the control group was 0.10(0.05, 0.22). FAZ area of IMEM group was (0.09±0.05) mm(2), while that of control group was (0.34±0.13)mm(2).Compared with the control group, in IMEM group, the BCVA was worse (Z=-4.443, P<0.001), FAZ area was smaller (t=-9.198, P<0.001), RT was increased (P<0.001), The foveal DCP and SCP vessel density was increased (t=4.280, 9.079, P<0.01), The parafoveal DCP vessel density was decreased (P<0.05), The parafoveal SCP vessel density was decreased in superior, inferior and nasal side (t=-2.759, Z=-3.998, Z=-2.108; P<0.05). The BCVA was negatively correlated with FAZ area (r=-0.337, P=0.017), positively correlated with center macular thickness (r=0.324, P=0.020). The BCVA was no correlated with foveal VD and parafoveal DCP vessel density (P>0.05), but correlated with SCP vessel density(P<0.05). Conclusions: In the IMEM eyes the BCVA was worse, FAZ area was smaller, foveal vessel density was increased and the parafoveal vessel density was decreased compared with the normal eyes. The smaller the FAZ area, the smaller foveal SCP vessel density, the poorer BCVA. There was no correlation between BCVA and DCP vessel density. Changes in VD in IMEM eyes may lead to changes in vision. (Chin J Ophthalmol, 2019, 55:757-762).

[Risk factors of retinopathy of prematurity in extremely low birth weight infants by strictly controlling oxygen inhalation after birth]

Objective: To observe the incidence and severity of retinopathy of prematurity (ROP) in extremely low birth weight (ELBW) infants by strictly controlling the risk factors of ROP, such as oxygen inhalation after birth, to explore the related factors of ROP in ELBW infants. Methods: This was a cross-sectional study. 166 ELBW infants underwent neonatal screening were enrolled in this study, whose birth weight was less than 1 000 g. There were 79 males and 87 females infants, whose average gestational age was (27.99±1.73)weeks, and average birth weight was (904.45±80.23)g. According to the final screening results, the ELBW infants were grouped as follows: (1)ROP group and non-ROP group; (2)severe ROP group and mild or no ROP group. Risk factors included gestational age, birth weight, test-tube infants, fetuses number, complications during pregnancy, delivery mode and Apgar scores in 1 to 10 minutes, weight and weight gain proportion at 1-6 weeks after birth, postnatal feeding mode, history of oxygen inhalation, anemia and blood transfusion, and other systemic diseases were recorded. And their correlation with severe ROP was analyzed by SPSS 20.0 statistical software. Results: Ninty-four (56.63%) ELBW infants developed ROP, 16 (9.64%) were severe ROP and 14(8.43%) received treatment. Average birth weight between ROP group (911.95±72.80)g and non-ROP group (894.67±88.58)g had no difference(t=1.379, P=0.170). Average gestational age between ROP group (27.49±1.53) weeks and non-ROP group (28.64±1.76) weeks had significant difference(t=-4.491,P<0.001).And pregnancy-induced hypertension during pregnancy (χ(2)=4.479, P=0.034), Apgar score in 5 minutes (t=-2.760, P=0.006) and 10 minutes (t=-2.099, P=0.043), pneumonia (χ(2)=6.233, P=0.013), neonatal pneumonia (χ(2)=18.026, P<0.001) had significant difference between ROP group and non-ROP group. There was no effect on weight (F=0.009,P=0.753) or weight gain proportion (F=2.394,P=0.124) at 1-6 weeks after birth in ELBW infants with or without ROP. Average birth weight between severe ROP group(875.63±74.85)g and mild or no ROP group(907.53±80.41)g had no difference(t=-1.518, P=0.131).Average gestational age between severe ROP group(26.88±1.31)weeks and mild or no ROP group (28.11±1.73)weeks had significant difference(t=-2.766,P=0.006).And only fundus hemorrhage (χ(2)=4.507,P=0.034) had significant difference between severe ROP group and mild or no ROP group. There was no effect on weight (F=2.683,P=0.103) or weight gain proportion (F=0.431,P=0.513) at 1-6 weeks after birth in ELBW infants with or without ROP. Logistic regression analysis revealed that only gestational age was correlated to the incidence (β=-0.437,P<0.001) and severity (β=-0.616,P=0.007) of ROP significantly. Conclusion: By strictly controlling the risk factors of ROP, such as oxygen inhalation after birth, the severe rate of ROP in ELBW infants is low. However, gestational age is still the inevitable independent high risk factor for the incidence of ROP in ELBW infants. (Chin J Ophthalmol, 2019, 55:280-288).

[The efficiency of 23 G vitrectomy combined with preoperative subtenon injection of triamcinolone acetonide for treatment of retinal detachment associated with choroidal detachment]

Objective: To evaluate the efficiency of 23 G vitrectomy combined with preoperative subtenon injecfion of triamcinolone acetonide for treatment of rhegmatogenous retinal detachment associated with choroidal detachment. Methods: A retrospective analysis. Forty-eight (16 males and 32 females, aged 57.3±13.9) consecutive patients (48 eyes) who were diagnosed with rhegmatogenous retinal detachment associated with choroidal detachment and received 23 G vitrectomy at the Eye Hospital of Wenzhou Medical University during January 2012 and January 2015 were enrolled. Twenty-three eyes were treated with subtenon injection TA 5 d before the planned 23 G vitrectomy (TA group). Twenty-five eyes were treated with dexamethasone 3 to 5 d before the planned vitrectomy (Dex group). Type-B ultrasonic, intraocular pressure, best corrected visual acuity examinations were conducted for all eyes on admission day, preoperatively and at 1 month, 3 month postoperatively, and during the last visit. The rate of reattachment, change of height of choroidal detachment, intraocular pressure, best corrected visual acuity, and the complication of the eyes between the two groups were compared. All patients were followed up at least half a year after the repair surgery. Results: The intraocular pressure of the TA group was higher than the Dex group[(8.58±3.83)mmHg vs. (6.70±2.49)mmHg (1 mmHg=0.133 kPa), (t=2.032)], and the height of choroidal detachment was lower in TA group [0.90(0.00, 3.84)mm vs. 4.03(1.05, 5.38)mm, Z=-2.569, P<0.05]. There is no statistic difference between the reattachment rate of the two groups [95.7%(22/23) vs. 76.0%(19/25), χ(2)=2.304, P=0.129], but it seems it was better in TA group. The best corrected visual acuity results of the last visit was better in TA group than Dex group [(0.91±0.54) vs. (1.25±0.62), t=-2.034, P=0.048]. The rate of hypertention was higher in TA group than Dex group at 1 month, 3 month postoperatively(χ(2)=2.304, 5.648, P<0.05), while there was no statistic difference of hypertention rate during last visit between the two groups (χ(2)=0.006, P=0.941). Conclusions: The treatment of 23 G vitrectomy combined with subtenon injection of triamcinolone acetonide can improve the intraocular pressure, reduce the height of choroidal detachment, and improve the best corrected visual acuity after the surgery, but it may cause heyertenion. (Chin J Ophthalmol, 2018, 54: 252-257).

Differential patterns of performance impairment result from changed reinforcer efficacy or distracting stimulation in a two-choice rodent spatial signal detection task

Measures of the discriminabililty of stimuli in signal detection tasks can be influenced by alterations of motivational state. In the present study, rats performed an operant signal detection procedure that required the completion of a fixed number of responses before a stimulus was presented at one of two front cue lamps to separately measure the motivation to respond from the ability to respond accurately. One manipulation, presession water access, affected the speed and frequency that trials were initiated, but did not affect response accuracy. In contrast, a flashing houselight during the session, and i.p. ((5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d,] cyclohepten-5,10-imine (dizocilpine or MK-801), a glutamate N-methyl-D-aspartate receptor antagonist, impaired response accuracy in a stimulus duration-dependent manner. These results suggest that it is possible to procedurally isolate the motivation to respond to stimuli from accuracy of detection, and thereby protect attending from side effects of drugs that influence the motivation to respond.

Long-term potentiation of the human blink reflex

The trigeminal reflex blink is an ideal system to investigate whether stimulus paradigms that produce long-term potentiation (LTP) in vitro modify motor learning in humans. Presentation of 12 trains of low-intensity, high-frequency stimuli (HFS) to the supraorbital branch of the trigeminal nerve (SO) modified subsequent reflex blinks of human subjects. When HFS occurred concurrently with reflex blinks, the procedure potentiated subsequent blinks for >1 hr. Combining HFS with feedback from the lid movement was critical for this facilitation because presenting HFS immediately after the blink did not alter subsequent blinks. When HFS preceded the blink, however, this treatment suppressed subsequent blinks for 30 min. These effects appear to occur within the trigeminal reflex blink circuits rather than at motoneurons, because stimulation of the previously HFS-treated SO evoked altered blinks in both eyelids, whereas stimulation of the untreated SO elicited unaltered blinks in both eyelids. The modified blink amplitude resulted from altering the response to A-fiber inputs to the trigeminal nerve because all stimuli were too weak to activate C-fibers. The data suggest that HFS produce LTP- and long-term depression (LTD)-like effects on wide dynamic range neurons in the trigeminal reflex blink circuit. The data also support the hypothesis that LTP and LTD mechanisms play a role in adaptive modification of human reflex blinks.

Microinjection of GABA-A agonist muscimol into the dorsal but not the ventral hippocampus impairs non-mnemonic measures of delayed non-matching-to-position performance in rats

Anatomical studies of afferent and efferent connections suggest that the hippocampus may have more than one information processing role that varies along the septo-hippocampal axis. The present study was conducted to test whether a distinct functional specialization for the dorsal versus ventral extents of the hippocampus could be detected. The effects of a GABA-A receptor agonist, muscimol, microinjected into either the dorsal or ventral hippocampus on an operant, spatial delayed non-matching-to-position (DNMTP) task were measured. A decrease in the number of trials completed per session and disruption of several DNMTP discrimination parameters were produced by muscimol microinjection into the dorsal hippocampus but not into the ventral hippocampus. Muscimol injected into either site did not impair the measure of working memory, delayed choice accuracy. These results are consistent with the view that hippocampal function varies along the septo-temporal axis, and that the dorsal hippocampus is relatively more critical to visual discrimination performance than the ventral hippocampus.

Differential effects on delayed non-matching-to-position in rats of microinjections of muscarinic receptor antagonist scopolamine or NMDA receptor antagonist MK-801 into the dorsal or ventral extent of the hippocampus

Glutamatergic NMDA and cholinergic muscarinic receptors are thought to contribute to cognitive processes mediated by the hippocampus. Evidence from lesion studies suggests that, despite cytoarchitectural uniformity within the hippocampus, information processing may not be uniform along the septo-temporal axis. The present study examined whether blockade of NMDA or muscarinic receptors in hippocampal subregions produced regional dissociations in the disruption of performance on an operant, spatial delayed non-matching-to-position (DNMTP) paradigm that also assessed vigilance. Rats were extensively pretrained on DNMTP, then bilaterally cannulated into either the dorsal or ventral hippocampus. Following retraining, scopolamine or MK-801 were administered prior to sessions. MK-801 administered into dorsal hippocampus produced delay-independent deficits in DNMTP delayed choice. Neither scopolamine administered into the dorsal or ventral hippocampus, nor MK-801 administered into the ventral hippocampus, produced significant disruption of DNMTP delayed choice. However, some dissociations were evident in other measures of vigilance. Scopolamine into the dorsal and ventral hippocampus increased errors of omission, scopolamine into the ventral hippocampus decreased sample response accuracy, and MK-801 into the dorsal hippocampus decreased sample response accuracy and increased response bias. These results are consistent with the suggestion that subregions of the hippocampus may be involved in different aspects of information processing and also suggest that the cholinergic inputs to the hippocampus may be functionally independent of NMDA receptor-mediated neurotransmission.