Human amniotic membrane for the treatment of large and refractory macular holes: a retrospective, multicentric, interventional study

Background

The purpose of the current study is to report the anatomical and functional results of off-label human amniotic membrane graft as primary intervention to repair large to giant macular holes and in reoperations when wide internal limiting membrane peeling was unsuccessful.

Methods

Retrospective chart review was carried out in five different centers to identify all cases that had undergone off-label human amniotic membrane graft for the treatment of large or failed macular holes (MH). Data collected included age, gender, other concomitant diagnosis, symptoms duration, lens status, number of previous surgeries, macular hole measurements (minimum and base linear diameters), mean post-operative follow-up (months), and pre- and post-operative best corrected visual acuity (BCVA). Main outcome measures were anatomical MH closure rates and final BCVA (in logMAR). Nonparametric Wilcoxon rank-sum test was used because the data was not normally distributed, a P values < 0.05 were considered statistically significant.

Results

Nineteen eyes of 19 patients were identified and included in the study. Mean age was 66.21 ± 14.96 years and predominantly females (84%). All eyes had successfully closed MH with a single intervention with no recurrences during a mean of 9 ± 3.87 months follow-up. The median BCVA in logMAR preoperative was 1.30 ± 0.44 (0.80–2.0), approximately 20/400 on Snellen chart and the median BCVA in logMAR postoperative was 1.0 ± 0.72 (0.4–3.0) approximately 20/200 (p < 0.0001) with median of three lines of visual improvement.

Conclusion

The use of human amniotic membrane graft seems to be a viable and effective alternative for the treatment of large and persistent macular holes. However, further larger prospective controlled studies are necessary to confirm our preliminary results of this new surgical technique.

Peripheral nerve surgery: the role of high-resolution MR neurography

High-resolution MRN is becoming increasingly available due to recent technical advancements, including higher magnetic field strengths (eg, 3T), 3D image acquisition, evolution of novel fat-suppression methods, and improved coil design. This review describes the MRN techniques for obtaining high-quality images of the peripheral nerves and their small branches and imaging findings in normal as well as injured nerves with relevant intraoperative correlations. Various microsurgical techniques in peripheral nerves, such as neurolysis, nerve repairs by using nerve grafts, and conduits are discussed, and MRN findings of surgically treated nerves are demonstrated.

Refractive status of indigenous people in the northwestern Amazon region of Brazil

PURPOSE

The purpose of this study was to investigate the refractive status of the illiterate indigenous people of the upper Rio Negro region of the Amazon rain forest in northwestern Brazil.

METHODS

From an overall sample of 486 people, 259 indigenous people and 78 Brazilians between 12 and 59 years of age with no compromising optical opacities were refracted with cycloplegic retinoscopy. Subjects were categorized as indigenous if they had at least three generations of indigenous ancestry with no folklore suggesting other ancestors.

RESULTS

Myopia was rare among the indigenous population. Only 2.7% of eyes showed myopia of -1.00 D or more and 1.6% (four people) had bilateral myopia of -1.00 D or more. Half of this small group were the only educated indigenous people examined. The prevalence of astigmatism and anisometropia equal to or >1.00 D was 15.5% and 8.2%, respectively. Most of the astigmatism in the indigenous people had an against-the-rule axis. Age was not associated with the refractive errors of the indigenous people. Brazilians from the small city in which the study was performed had higher rates of myopia (6.4% of eyes and 5.1% of subjects bilaterally). Older preeducation adults also had a very low prevalence of myopia (3.2% of eyes and 2.0% of subjects), whereas the younger, slightly educated Brazilians had a higher prevalence of myopia (11.3% of eyes and 9.7% of subjects).

CONCLUSION

The low prevalence of myopia in the illiterate indigenous people is consistent with other studies and suggests that myopia is related to literacy. The generational change among the local mixed race Brazilians further supports this conclusion. The relatively high rates of astigmatism and anisometropia in the indigenous people were unusual for a predominantly emmetropic sample.

Differential effects of glycosylated and non-glycosylated porcine prolactin on estradiol and progesterone secretion by rat granulosa cells in culture

BACKGROUND

The objective was to better understand the interactions between prolactin and ovarian function.

METHODS

The effects of two variants of porcine prolactin (pPRL) on estradiol (E2) and progesterone (P4) production by rat granulosa cells in culture were studied using granulosa cells obtained from large preovulatory follicles of pregnant mare serum gonadotropin (PMSG)-treated immature Sprague-Dawley rats. Cultures were performed in the absence or presence of hCG (0.1 IU/ml) and different concentrations of either glycosylated and non-glycosylated (g-pPRL and ng-pPRL, respectively) pPRL.

RESULTS

Dose-response studies showed that maximal stimulation occurred in all instances with g-pPRL at the dose of 10 ng/mL during the 72-h treatment period. In the case of E2, the maximal response was obtained in hCG-stimulated cultures, whereas the response of P4 was higher in cultures stimulated with g-pPRL in the absence of hCG. In a similar manner, the non-glycosylated form of pPRL increased, although to a lesser extent, the secretion of P4 only in those cultures incubated in the absence of hCG. In contrast to these observations, ng-pPRL was about twice as active than the glycosylated form on the stimulation of growth of Nb2 lymphoma cells.

CONCLUSIONS

These data point out that glycosylation is involved in the differential effects of pPRL on ovarian steroidogenesis and support the role of carbohydrates in the structural-functional polymorphic nature of the hormone.

Modulation of stimulatory action of follicle stimulating hormone (FSH) and inhibitory action of epidermal growth factor (EGF) on aromatase activity in Sertoli cells by calcium

Aromatization of testosterone by cultured Sertoli cells isolated from immature rats was stimulated more than 7-fold by follicle stimulating hormone (FSH) or dcAMP. The effects of FSH and dcAMP could be partly inhibited by epidermal growth factor (EGF) in a dose-dependent manner (ID500.5 nM). The phorbol ester 4 beta-phorbol-12-myristate-13-acetate (PMA) could also inhibit aromatase activity in a fashion similar to EGF. When 3 mM EGTA was present in the culture medium, the inhibitory effect of EGF was abolished but the stimulatory effect of FSH or dcAMP was magnified. These results suggest that EGF exerts a negative control on aromatase via calcium and protein kinase C. The abolishment of the inhibitory effect of EGF and the enhancement of the stimulatory effect of FSH or dcAMP by a calcium deficiency may be an indication that growth factors produced by Sertoli cells negatively controls FSH-induced responses in an autocrine fashion.

Epidermal growth factor stimulates lactate production and inhibits aromatization in cultured Sertoli cells from immature rats

The addition of epidermal growth factor (EGF) at nanomolar concentrations to cultures of Sertoli cells from 16-day-old rats induced more than a 2-fold stimulation of lactate production after 12 h of incubation. The effects of EGF, insulin and FSH on lactate production were very similar and the concentrations that produced half maximal stimulation were 11, 22 and 25 ng/ml or, in molar terms, 1.8, 3.5 and 0.6 nM for EGF, insulin and FSH, respectively. No synergistic or additive effects of these hormones on lactate production could be demonstrated. In contrast, EGF inhibited FSH-stimulated oestradiol synthesis by more than 50%. Insulin had no effect on FSH-stimulated aromatization.

Chromatographic pattern of circulating prolactin in ovulatory hyperprolactinemia

Hyperprolactinemia is a major cause of anovulation and female infertility. However, we found 22 hyperprolactinemic patients with preserved ovarian function as assessed by midluteal plasma progesterone levels greater than 7 ng/ml. We performed a gel chromatography on the plasma of six of those patients to study the circulating pattern of prolactin (PRL). In all six patients we found that the vast majority of circulating PRL corresponds to big,big and big PRL, with only a small proportion of monomeric biologically active PRL. This finding might explain the preserved luteal function in those women and might have therapeutic implications.