Influence of Sex on Neuroretinal Degeneration: Six-Month Follow-Up in Rats With Chronic Glaucoma.

Purpose: To evaluate differences by sex in the neuroretina of rats with chronic glaucoma over 24 weeks of follow-up, and to assess by sex the influence on neurodegeneration of different methods of inducing ocular hypertension. Methods: Forty-six Long-Evans rats-18 males and 28 females-with induced chronic glaucoma were analyzed. Glaucoma was achieved via 2 models: repeatedly sclerosing the episcleral veins (9 male/14 female) or by injecting poly(lactic-co-glycolic acid) microspheres measuring 20 to 10 µm (Ms20/10) into the anterior chamber (9 male/14 female). The IOP was measured weekly by tonometer; neuroretinal function was recorded by dark/light-adapted electroretinography at baseline and weeks 12 and 24; and structure was analyzed by optical coherence tomography using the retina posterior pole, retinal nerve fiber layer and ganglion cell layer protocols at baseline and weeks 8, 12, 18, and 24. Results: Males showed statistically significant (P < 0.05) higher IOP in both chronic glaucoma models, and greater differences were found in the episcleral model at earlier stages. Males with episclerally induced glaucoma showed a statistically higher increase in retinal thickness in optical coherence tomography recordings than females and also when comparing Ms20/10 at 12 weeks. Males showed a higher percentage of retinal nerve fiber layer thickness loss in both models. Ganglion cell layer thickness loss was only detected in the Ms20/10 model. Males exhibited worse dark/light-adapted functionality in chronic glaucoma models, which worsened in the episcleral sclerosis model at 12 weeks, than females. Conclusions: Female rats with chronic glaucoma experienced lower IOP and structural loss and better neuroretinal functionality than males. Sex and the ocular hypertension-inducing method influenced neuroretinal degeneration.

Influence of Chronic Ocular Hypertension on Emmetropia: Refractive, Structural and Functional Study in Two Rat Models.

Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (<20 mmHg) and an OHT cohort (>20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long-Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time.

Study of corneal biomechanical properties in patients with childhood glaucoma.

AIM: To study of corneal biomechanical properties and intraocular pressure (IOP) measured with Corvis Scheimpflug Technology (ST) in patients with childhood glaucoma (CG). METHODS: Cross-sectional study in which 89 eyes were included 56 of them with CG. Only one eye per patient was included. The following variables were obtained from the clinical history and the ophthalmological examination: age, sex, IOP, number of surgeries, and the cup/disc ratio (CDR). The following parameters were recorded using Corvis ST: corrected by biomechanics IOP (bIOP), not corrected IOP (nctIOP), central corneal thickness (CCT), maximum concavity [radius, peak distance (PD) and deformation amplitude], applanation 1 and 2 (length and velocity). The mean age was 23±14.55 and 33±19.5 years old for the control group and CG group, respectively. Totally 36 were males and 53 were females. In the CG group, 7 patients were controlled only with medical treatment. Sixteen had at least one previous goniotomy, 19 had at least one trabeculectomy, and 11 had an Ahmed implant. RESULTS: A significant and positive intraclass correlation coefficient was found between Goldman IOP and the IOP measured by Corvis in both groups. No differences were found between the IOP measured with Corvis and Goldman using a student t-test. Regarding biomechanical parameters, there were differences in the applanation length 2 (A-L2), in the applanation velocity 2 (A-V2) and in the PD. By sex, only the applanation length 1 (A-L1) was found to be different in control group. A positive and significant Pearson correlation was found between CDR and the A-L1. CONCLUSION: Corneal biomechanical properties have shown differences between CG and healthy subjects and also between men and women.

Treatment of recurrent corneal erosions using autologous serum.

PURPOSE: To study the effect of autologous serum in the treatment of recurrent corneal erosions. METHODS: Eleven eyes of 11 consecutive patients with acute macroform corneal erosions who had suffered several relapses despite receiving different types of treatment were analyzed from November 2000 to February 2002. All patients were treated with autologous serum for 3 months. RESULTS: Mean follow-up time was 9.4 +/- 3.7 months (range, 4-16). No side effects were noted in any of the treated patients. Treatments prior to the use of autologous serum had failed to avoid recurrences in all the patients, with the mean recurrence rate being 2.2 recurrences per month of follow-up. After the onset of serum treatment, only a single recurrence was recorded in three of the patients (0.028 recurrences per month of follow-up). CONCLUSION: The use of autologous serum for the treatment of patients with recurrent corneal erosion is effective and safe in reducing the number of recurrences experienced by patients.

Methodologic quality of studies on prognostic factors for primary open-angle glaucoma progression measured by visual field deterioration.

Glaucoma is a chronic, slowly progressing, and asymptomatic optic neuropathic disorder with a great variety of causes that involve gradual retinal ganglion cell axon loss. The disease is the second most common cause of blindness in the industrialized world. Once vision loss develops it is irreversible-although in many cases further loss can be slowed if adequate treatment is provided. If not treated, glaucoma can lead to complete vision loss in the affected eye. Primary open-angle glaucoma (POAG) is the most prevalent form of the disease in the industrialized countries, representing 94% of all glaucomas. In a Spanish study of 569 individuals, the prevalence of POAG was 2.1% (99% confidence interval 1.9%-2.3%) in the age range between 40 and 79 years. Assessing glaucomatous damage progression remains one of the most important and challenging aspects in glaucoma management. In addition, a better understanding of clinical risk factors for glaucoma worsening may help us to develop new strategies to improve glaucoma care. Over the past 2 decades, many studies have addressed the issue of risk factors associated with or predicting for glaucoma progression. Although many studies have attempted to identify the prognostic factors capable of predicting the course of POAG, the results have been varied and in some cases contradictory, and are thus of scant practical utility. This study was designed to evaluate the methodologic quality of the studies published in the literature on the prognostic factors for POAG progression measured by visual field deterioration.