RESUMO
AIM: To determine the anatomic and visual outcomes of prophylactic juxtapapillary laser photocoagulation treatment alone in the prevention of retinal detachment (RD) in a cohort of pediatric patients diagnosed with morning glory syndrome (MGS). METHODS: A total of 24 eyes of 22 consecutive patients aged 0-15y diagnosed with MGS treated with prophylactic juxtapapillary laser photocoagulation alone were reviewed. Data including demographics, ocular examination, anatomic and visual outcomes, following treatment and complications were collected. RESULTS: Two patients had bilateral laser treatment and 20 had monocular laser treatment. The age at treatment of 13 (59.1%) patients was less than 12mo. The presenting symptoms included strabismus (6/22, 27.3%), decreased vision (2/22, 9.1%), and routine fundus screening (14/22, 63.6%). Fifteen (68.2%) patients underwent cranial magnetic resonance imaging (MRI) examinations, and 3 of those 15 (20.0%) had abnormal findings in the nervous system. Based on preoperative wide-field fundus photography and B-scan echography, all (100.0%) eyes had no obvious RD. On postoperative 1mo and 6mo and the following follow-ups, the anatomic outcomes of all eyes remained stable. The mean follow-up duration was 27.7±17.5mo. No severe complications were found. Preoperative visual acuity acquired from 2 (9.1%) patients ranged from light perception to 20/200. Postoperative acuity acquired from 11 (50.0%) patients ranged from light perception to 20/125. CONCLUSION: The preliminary anatomic and visual outcomes of prophylactic juxtapapillary laser treatment alone in pediatric MGS patients are relatively stable in a short-term follow-up. Further long-term clinical observation will be needed to confirm its efficacy and safety.
RESUMO
In recent years, some researchers paid their attention to the interaction between toxic phytoplankton and zooplankton. Their studies showed that the mechanism of food selection in zooplankton is still immature and when different algae of the same species (toxic and nontoxic) coexist, some zooplankton may not be able to distinguish between toxic and nontoxic algae, and even show a slight preference for toxic strains. Thus, in this article, a fractional order mathematical model with time delay is constructed to describe the interaction of nutrient-phytoplankton-toxic phytoplankton-zooplankton. The main purpose of this paper is to study the influence of fractional order and time delay on the ecosystem. The sufficient conditions for the existence and local stability of each equilibrium are obtained by using fractional order stability theory. By choosing time delay as the bifurcation parameter, we find that Hopf bifurcation occurs when the time delay passes through a sequence of critical values. After that, some numerical simulations are performed to support the analytic results. At last we make some conclusion and point out some possible future work.