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- Avaliação do endotélio corneano através de microscopia especular em participantes com edema macular diabéticoPublication . Sabino, Bárbara; Pinto, Joana; Branco, Tiago; Batista, Ricardo; Pereira, Bruno; Camacho, PedroIntrodução: Apesar da integridade morfológica e funcional do endotélio corneano, essencial para a transparência corneana, ser afetada com a Diabetes Mellitus (DM) a sua relação com severidade de retinopatia diabética e presença de edema macular diabético não é clara. Objetivos: Avaliar as características morfológicas do endotélio corneano em doentes com Diabetes Mellitus Tipo 2 (DMT2) com diferentes perfis de resposta terapêutica ao edema macular diabético (EMD). Métodos: Com uma abordagem transversal, 24 participantes com DMT2 foram divididos em 2 grupos (sem EMD e com EMD). Posteriormente, o grupo com EMD foi subdividido de acordo o tipo de resposta terapêutica (respondedor e persistente). Parâmetros obtidos através da microscopia especular (densidade de células endoteliais, coeficiente de variação, hexagonalidade e espessura central da córnea) e da tomografia de coerência ótica (espessura mínima da fóvea, espessura no 1mm central, a espessura da camada de células ganglionares macular, e a espessura da camada de fibras nervosas peripapilar) foram analisados e comparados nos diferentes grupos. Resultados: Não foram encontradas alterações significativas do endotélio corneano entre os grupos com e sem EMD (p>0,05). No entanto, foram encontradas diferenças na densidade de células endoteliais (p=0,04) nos participantes com diferentes EMD persistente (1900,3 ± 270,1) comparativamente ao EMD respondedor (2307,9 ± 121,2) e grupo de controlo (2191,7 ± 165,5). Conclusão: Os diferentes parâmetros do endotélio corneano não mostraram diferenças entre participantes com e sem EMD. No entanto, o tipo de resposta terapêutica ao EMD parece estar associada à diminuição da densidade de células endoteliais.
- Foveal avascular zone area measurement in diabetic patients: superficial, deep or combined retinal vascular complex?Publication . Pereira, Bruno; Faria, Ross; Domingues, Cátia; Barros, Ana; Varandas, Teresa; Henriques, José; Nascimento, João; Carolino, Elisabete; Camacho, PedroPurpose: To compare differences in the foveal avascular zone (FAZ) area, measured in the Superficial Vascular Complex (SVC), Deep Vascular Complex (DVC), and a combined analysis of both (SDVC), using two Spectral Domain OCT angiography (OCT-A) protocols, High Speed (HS) and High Resolution (HR). Methods: A total of 26 eyes of diabetic patients, with and without macular oedema, were examined with two different fovea-centered OCT-A volume scans. The two protocols were HS and HR volume scans, and the foveal avascular zone was manually measured in the SVC, DVC, and SDVC slabs by two masked investigators. Inter and intraoperator variability was analysed using Intraclass Correlation Coefficient (ICC) and differences were compared between the HR and HS acquisitions throughout the different vascular slabs. Results: Intraoperator variability was low in all slabs (ICC > 0.9) and interoperator variability was lower for HR (ICC 0.835-0.911) compared to HS (ICC between 0.604 and 0.865). Comparing HS and HR measurements for the same slab, the correlation was only moderate in SVC and DVC (ICC was 0.640 and 0.568 respectively) but was good in the SDVC (ICC = 0.823). FAZ area measurement in SDVC also showed the smallest bias (mean difference 0.009 mm2) and the narrowest limits of agreement (-0.175 to 0.193 mm2). Conclusions: Even in cases of diabetic macular oedema, when measuring the FAZ area, the reproducibility was better between HS and HR protocols when using the SDVC slab, compared to the SVC or DVC slabs alone. Further studies should evaluate the use of the combined SDVC slab for the FAZ assessment, compared to the SVC and DVC slabs alone, in detecting and progressing different retinal diseases.
- The potential of DNA methylation as a biomarker for age-related macular degeneration: a systematic reviewPublication . Ghannai, Salema; Ribeiro, Edna; Pereira, Bruno; Brito, Miguel; Camacho, PedroAge-related macular degeneration (AMD) is a multifactorial disease influenced by genetic and environmental factors, yet its pathogenesis remains incompletely understood. DNA methylation, increasingly recognized as a disease indicator, has been linked to AMD and may represent a promising biomarker or therapeutic target. This systematic review, conducted according to PRISMA 2020 guidelines, analyzed 13 studies addressing DNA methylation in AMD populations (2012-2025). Results revealed that 25% reported hypermethylation, 8% hypomethylation, and 41% both patterns, while 15% found no significant differences. Notably, one study described downregulation of DNA methyltransferases in advanced stages compared with early or intermediate AMD. Despite the limited evidence, findings support the relevance of methylation in AMD prognosis and therapy. Further research with robust methodologies is essential to clarify the role of epigenetic mechanisms in disease progression and to explore their potential for guiding targeted therapeutic strategies