The prevention and management of ocular surface infections is still one of the great challenges for ophthalmologists. The spread of antimicrobial resistance makes it necessary to use antiseptic substances with a broad antimicrobial spectrum. Polyhexamethylene biguanide hydrochloride (Polyhexanide, PHMB) is a broad-spectrum antiseptic with excellent tolerance and a low-risk profile. Its physicochemical action on the phospholipid membrane and DNA replication or repair mechanism, prevents or impedes the development of resistant bacterial strains. PHMB revealed its effective against numerous organisms like viruses, Gram-negative and Gram-positive bacteria, and fungi. Polyhexanide is commonly used as preservative in commercially available disinfecting solutions for contact lens care and in ophthalmic formulations at different concentrations ranging from 1 µg/ml to 50 µg/ml. The administration of 0.02% (200 µg/ml) PHMB is often the first-line therapy of Acanthamoeba keratitis. However, to date, only one close-out randomized controlled study tested the efficacy of 0.02% PHMB in Acanthamoeba keratitis and a phase III study is still ongoing. This paper reviews the antiseptic agent PHMB, focusing on biochemical mechanisms, safety profile and applications in ophthalmology.

Macular peeling combined or followed by intravitreal dexamethasone implant (DEX-i) was recommended as an efficacy approach for tractional diabetic macular edema (tDME). Knowing the synergistic effect of cataract surgery and DEX-i one month earlier in eyes with DME, we compared Epiretinal Membrane/Inner Limiting Membrane (ERM/ILM) peeling preceded by DEX-i one month before versus ERM/ILM peeling alone for the treatment of tDME. A retrospective study on patients affected by tDME who underwent ERM/ILM peeling one month after DEX-i (n = 11; Group A) or ERM/ILM peeling alone (n = 10; Group B) was performed. Longitudinal comparison of best-correct visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP) between the time of surgery (T0) and each time point (months 1,3,5,6) within and among the groups were assessed. To evaluate the repeated measurements of BCVA, CRT, and IOP, a linear mixed-effects model was used. In Group A, DEX-i significantly improved mean BCVA and CRT (P < 0.001) just after 1 month (T0). After ERM/ILM peeling, mean BCVA and CRT significantly improved from month 1 in Group A and month 3 in Group B. Mixed model revealed a significant difference in BCVA (P ≤ 0.0001) and CRT (P ≤ 0.02) at different time-points among the groups with better results in Group A. Neither complications nor uncontrolled IOP increase was detected. ERM/ILM peeling confirmed its effectiveness in treating tDME. DEX-i performed one month before surgery seemed to be a safe approach and ensured a greater and faster recovery considering functional and tomographic parameters.

Purpose To report morphologic and functional changes after topography-guided trans-epithelial photorefractive keratectomy (PRK) combined with phototherapeutic keratectomy (PTK) for recalcitrant recurrent corneal erosions in Lattice Corneal Dystrophy (LCD). Methods One case report. Results A 78-year-old man presented us with decreased visual acuity [20/100 in right eye (RE), and 20/400 in left eye (LE)], and redness with foreign body sensation in both eyes. Clinical examination revealed epithelial erosions, and linear stromal opacities involving the center of the cornea in both eyes, supporting the diagnosis of LCD. Several medical approaches including autologous serum, amniotic membrane extract, and nerve growth factor eye drops allowed a temporary improvement in symptoms. A single-step topography-guided trans-epithelial PRK combined with PTK (CIPTA ® 2 software, iVis Technologies) was performed in both eyes. After surface ablation using PRK, PTK was performed using masking agents (1% hydroxy-methylcellulose) to smooth the ablated surface. Subsequently, 0.02% Mitomycin C was applied over the ablated surface. At the 3-month follow-up, a resolution of corneal erosions, and stromal opacities were observed in both eyes, with a visual improvement to 20/25 in the RE and 20/50 in the LE. Furthermore, spherical equivalent, keratometric astigmatism, and corneal morphological irregularity index improved. Conclusion Recalcitrant corneal erosions and stromal opacities in LCD may be successfully treated using combined topography-guided trans-epithelial PRK and PTK.

Background: An intravitreal dexamethasone implant (DEX-I) was found to be effective and safe for the treatment of cystoid macular edema (CME) after vitrectomy for rhegmathogenous retinal detachment (RRD) and in silicone oil (SO)-filled eyes. We aimed to investigate the efficacy and safety of DEX-I at the time of SO removal for the treatment of recalcitrant CME after successful RRD repair. Methods: A retrospective review of the medical records was performed on 24 consecutive patients (24 eyes) with recalcitrant CME after RRD repair who were treated with a single 0.7-mg DEX-I at the time of SO removal. The main outcome measures were changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT). A regression model was performed to assess the relationship between BCVA and CMT at 6 months and independent variables. Results: In all 24 patients, CME occurred after RRD repair and remained despite topical therapy. The mean time of CME onset was 27.4 ± 7.7 days after vitrectomy. The mean time between vitrectomy and DEX-I was 106.8 ± 10.1 days. The mean CMT was significantly decreased from 429.6 ± 59.1 µm at baseline to 294 ± 46.4 µm at month 6 (p < 0.0001). The mean BCVA significantly improved from 0.99 ± 0.3 at baseline to 0.60 ± 0.3 at month 6 (p < 0.0001). An elevation of intraocular pressure was observed in one (4.1%) eye, which was medically managed. A univariate regression model revealed a relationship between month-6 BCVA after DEX-I and gender (β = −0.27; p = 0.03) and macular status (β = −0.45; p = 0.001) when RRD occurred. No relationship between month-6 CMT and independent variables was found. Conclusions: DEX-I at the time of SO removal had an acceptable safety profile and achieved favorable outcomes in eyes affected by recalcitrant CME that occurred after RRD repair. RRD-related macular status is significantly associated with visual acuity after DEX-I.