[Expected effect of retinal thickness after focal photocoagulation in diabetic macular oedema]. / Efecto esperado del grosor retiniano después de fotocoagulación focal en edema macular diabético.

BACKGROUND: Macular oedema is a form of diabetic retinopathy that can be treated with photocoagulation. The expected effect of treatment varies, and may depend on the previous characteristics of retinal thickening. OBJECTIVE: To determine whether the change in retinal thickness after focal photocoagulation for diabetic macular oedema varies due to the presence of anatomical features that may justify a separate assessment. MATERIAL AND METHODS: Non-experimental, comparative, retrospective, longitudinal study. The mean percentage change in macular volume was compared in eyes with diabetic macular oedema, 3 weeks after focal photocoagulation. The analysis was stratified according to the presence of central and perifoveal temporal thickening (Mann-Whitney U). A regression analysis was performed to identify the contribution of the anatomical variables before photocoagulation to the change in macular volume. RESULTS: A total of 72 eyes were evaluated. The mean change of macular volume in the sample was -0.68±3.84%. In the multiple regression analysis, the changes of perifoveal temporal (beta 0.54, p<0.001) and central field thickness (beta 0.3, p =0.01) contributed to the change of macular volume (R=0.64). Macular volume decreased by a mean of -2.1±4.3% in eyes with temporal perifoveal thickening, and increased by 0.5±2.8% (p =0.007) in eyes with no thickening. CONCLUSION: Perifoveal temporal thickening before photocoagulation changes the expected effect of this therapy on macular volume in eyes with focal diabetic macular oedema. It is recommended to evaluate the effect separately, and according to the perifoveal temporal thickness.

[Association between visual improvement after photocoagulation and the use of angiotensin converting enzyme inhibitors in diabetic macular oedema]. / Asociación entre la mejoría visual y el uso de inhibidores de la enzima convertidora de angiotensina, en edema macular diabético.

BACKGROUND: Angiotensin converting enzyme inhibitors are effective in delaying the progression of diabetic retinopathy. It is unknown if their use is associated with a better visual outcome in patients with diabetic macular oedema. MATERIAL AND METHODS: A non-experimental, comparative, longitudinal and retrospective study was performed on patients with diabetic macular oedema treated by focal photocoagulation, and with systemic arterial hypertension treated with angiotensin converting enzyme inhibitors (Group 1), and without hypertension (Group 2). The dependent variable was the proportion with visual improvement, operatively defined as the gain of one or more lines of vision three weeks after photocoagulation. The independent variable was the use of angiotensin converting enzyme inhibitors. The proportion of eyes with visual improvement after treatment was compared between groups using the Chi squared (χ(2)) test. RESULTS: A total of 33 eyes (51.6%) were assigned to group 1, and 31 (48.2%), to group 2. The mean of visual acuity improved after three weeks, compared with baseline (p=0.002). The proportion of eyes with visual improvement did not differ between patients treated with angiotensin converting enzyme inhibitors (45.5%) and those that did not use them (51.6%, p=0.4). CONCLUSIONS: There was no statistical difference in the proportion of eyes with visual improvement between patients treated with angiotensin converting enzyme inhibitors and in those where they were not used. There is no support for the inhibition of angiotensin II in addition to photocoagulation for improving the outcome in patients with diabetic macular oedema.

[Lack of correlation between retinal variables before treatment and poor functional response after focal photocoagulation in diabetic macular oedema]. / Falta de asociación entre las características retinianas previas al tratamiento y la mala respuesta funcional a la fotocoagulación focal, en edema macular diabético.

BACKGROUND: Although photocoagulation reduces the incidence of moderate visual loss in eyes with focal diabetic macular oedema, some eyes may lose some vision after treatment. The proportion of eyes with poor functional response after photocoagulation, and whether any retinal variable is associated with this, is unknown. OBJECTIVE: To determine the proportion of eyes with diabetic macular oedema that have a poor functional response after focal photocoagulation, and their associated features. MATERIAL AND METHODS: A non-experimental, longitudinal, comparative and retrospective study was conducted. The proportion and 95% confidence intervals (CI) of diabetics with macular oedema that had a poor functional response after focal photocoagulation (any visual loss after 6 weeks) were identified. The means of retinal variables before treatment were compared between eyes with and without a poor functional response using the Student t test for independent means. RESULTS: The study included 115 eyes of patients aged 59.3 (SD 9.24) years. Visual acuity was greater than or equal to 0.5 in 63 eyes (54.8%). A total of 33 eyes had a poor functional response after photocoagulation (28.7%, 95% CI: 13.3 to 44.1). The comparison between retinal variables and visual acuity before treatment did not show any differences between eyes with or without a poor functional response and eyes. CONCLUSION: Retinal thickening and visual acuity improved or did not change in 71.3% of eyes with diabetic macular oedema with a single photocoagulation procedure. Retinal variables that are usually evaluated were unable to identify the remaining 28.7%, which could lose vision after that treatment, and would require additional interventions.

[Features associated with retinal thickness extension in diabetic macular oedema]. / Características relacionadas con la extensión del engrosamiento retiniano en edema macular diabético.

BACKGROUND: Clinically significant macular edema has features that are associated with a major risk of visual loss, with thickening that involves the centre of the macula, field 7 or visual deficiency, although it is unknown if these features are related to retinal thickness extension. MATERIAL AND METHODS: An observational, analytical, prospective, cross-sectional and open study was conducted. The sample was divided into initial visual acuity ≥0.5, central field thickness, center point thickness, field 7 and macular volume more than the reported 2 standard deviation mean value in eyes without retinopathy. The extension was determined by the number of the central field area equivalent thickening and these features were compared with by Student's t test for independent samples. RESULTS: A total of 199 eyes were included. In eyes with visual acuity of ≥0.5, the mean extension was 2.88±1.68 and 3.2±1.63 in area equivalent in eyes with visual acuity <0.5 (p=0.12). The mean extension in eyes with less than 2 standard deviation of central field thickness, center point thickness, field 7 and macular volume was significantly lower than in eyes with more than 2 standard deviations (1.9±0.93 vs. 4.07±1.49, 2.44±1.47 vs. 3.94±1.52, 1.79±1.07 vs. 3.61±1.57 and 1.6±0.9 vs. 3.9±1.4, respectively, p<0.001). CONCLUSIONS: The extension of retinal thickness is related with the anatomical features reported with a greater risk of visual loss, but is not related to initial visual deficiency.

Retinal thickness after focal photocoagulation for diabetic macular edema with and without temporal perifoveal thickening.

BACKGROUND: Visual improvement after focal photocoagulation in diabetic macular edema is more common in eyes without temporal perifoveal thickening. This feature is related to a lower macular volume before treatment; the higher proportion of visual improvement could be associated with a shorter need of volume reduction. OBJECTIVE: To compare macular volume before and after focal photocoagulation in eyes with diabetic macular edema, with and without temporal perifoveal thickening. METHODS: Non-experimental, retrospective, longitudinal, comparative study in diabetics with macular edema treated with focal photocoagulation. Macular volume measured with optical coherence tomography, and best corrected visual acuity were compared between eyes with (group 1) and without temporal perifoveal thickening (group 2, independent samples Student's t test). The comparison was also performed after stratifying the groups by baseline visual acuity. RESULTS: One hundred and twenty eyes, 65 eyes from group 1 (54.2%) and 55 from group 2 (45.8%). Mean volume before and after treatment and mean absolute and percentage changes were lower in group 2 (p < 0.001) regardless of visual acuity. Macular volume decreased significantly in eyes of group 1; only eyes in group 2 with visual acuity < 0.5 before treatment increased their visual function (p < 0.001). CONCLUSIONS: Eyes without temporal perifoveal thickening had visual improvement, although their volume did not change statistically. The significant volume reduction in eyes with temporal perifoveal thickening was not associated to visual improvement. The anatomical change was not enough to explain the functional improvement.

[Comparison of macular volume change after photocoagulation, in eyes with diabetic macular edema, with and without visual improvement]. / Comparación del cambio del volumen macular entre ojos con y sin mejoría visual después de fotocoagulación en edema macular diabético.

OBJECTIVE: To compare the changes in macular volume after photocoagulation between eyes with diabetic macular edema with and without visual improvement. METHODS: Non-experimental, retrospective, longitudinal, comparative study in eyes with diabetic macular edema; the sample was divided in groups: eyes with visual improvement three weeks after photocoagulation (group 1) and eyes without it (group 2). The means of macular volume changes (potential, absolute and percentage) were compared between groups (Student's t test). RESULTS: 115 eyes, 50 from group 1 and 65 from group 2; mean macular volume before and after photocoagulation and mean potential, absolute, and percentage volume changes did not differ between groups. 13.9% of the sample had visual improvement and a significant volume reduction; the proportion of the latter did not differ between groups (p = 0.3). Macular volume and visual acuity decreased significantly in eyes without previous visual deficiency (p = 0.012); it was more common to find eyes without visual improvement with a non-significant volume reduction, than finding eyes with visual improvement and a significant macular volume reduction. CONCLUSION: The reduction of macular volume was not enough to explain visual improvement. Optimizing the outcome in patients with diabetic macular edema requires the identification of functional features with a prognostic value.

[Retinal sensitivity in diabetic macular edema, with and without decreased visual acuity]. / Sensibilidad retiniana en el edema macular diabético con y sin disminución de la agudeza visual.

OBJECTIVE: To compare retinal sensitivity in diabetics with macular edema, with and without decreased visual acuity. METHODS: An observational, prospective, cross-sectional comparative study in eyes with diabetic macular edema. The sample was divided into two groups: eyes with visual acuity ""≥ 0.5 (group 1) and < 0.5 (group 2). Foveal sensitivity was compared between groups (Mann-Whitney´s U), stratified according to the center point thickness. Correlations between visual acuity and retinal sensitivity and between visual acuity and macular volume were identified. RESULTS: 81 eyes, 59 from group 1 and 22 from group 2. The mean of retinal sensitivity in group 2 (24.4 ± 6.9 dB) was significantly lower than in group 1 (30.8 ± 3.4; p < 0.001). The correlation between visual acuity and retinal sensitivity was 0.49 (r2 = 0.25), and it was 0.37 in eyes with center point thickness within one standard deviation above the mean and 0.40 in eyes within two standard deviations (p < 0.001). The correlation between visual acuity and macular volume was -0.108 (r2 = 0.026). CONCLUSIONS: Retinal sensitivity in eyes with clinically significant macular edema and decreased visual acuity before treatment was significantly lower than in eyes with normal visual acuity; the difference did not change as center point thickness increased.

[Impact of follow-up loss over visual deficiency in open-globe ocular trauma]. / Impacto de la pérdida de seguimiento sobre la deficiencia visual en trauma ocular con globo abierto.

INTRODUCTION: Open-globe ocular trauma causes visual deficiency; calculating the magnitude of the latter often misses the estimation in patients without follow-up. AIM: to identify the modification of the postoperative proportion of visual deficiency in open-globe ocular trauma, which would introduce considering the proportion estimated in patients without follow-up. METHODS: Non-interventional, retrospective, longitudinal, analytical study. Visual outcome in eyes with open-globe trauma, with and without follow-up, was calculated using the Ocular Trauma Score. The observed postoperative proportion of visual deficiency was identified in eyes with follow-up; in eyes without follow-up, the postoperative proportion of visual deficiency was estimated using an analysis of scenarios: best (Ocular Trauma Score), mean (that of eyes with follow-up) and worst (last observation/no visual improvement). The estimated proportion of visual deficiency was added to that observed in eyes with follow-up, and the resulting proportion was compared with that expected in the sample, using the Ocular Trauma Score (χ(2)). RESULTS: 104 eyes, 70 without follow-up and 34 without it. In eyes with follow-up the expected proportion of visual deficiency was 58.6%, and the observed one was 71.4% (p = 0.1); the estimated proportion of visual deficiency in eyes without follow-up was 76.5%. The resulting postoperative proportion of visual deficiency in the sample would be 73.1%, which would overcome that expected by the Ocular Trauma Score (59.6%, p = 0.04). CONCLUSIONS: In open-globe ocular trauma, the efficacy of surgery to reduce the proportion of visual deficiency would decrease with regard to the standard expected by the Ocular Trauma Score, if the deficiency estimated in eyes without follow-up were considered.