Dry eye and cataract surgery: Narrative review and recommendations for management.

Cataract surgery is the most frequently performed surgical procedure in the elderly in Western countries and patients' expectations for postoperative outcomes are very high.Dry eye disease (DED) is a common multifactorial symptomatic disease of the ocular surface with a complex etiopathogenesis and a prevalence significantly increasing with age.Cataract surgery and DED have a complex relationship, which needs to be acknowledged, understood, and properly managed, as suggested by daily clinical experience and growing scientific evidence. The surgical procedure can have a relevant impact on the tear film and the ocular surface, and it can, usually transiently, induce or exacerbate DED symptoms. Moreover, preoperative DED can affect surgical refractive outcomes, while postoperative DED symptoms can significantly worsen patients reported outcomes and satisfaction.At the end of this narrative review summarizing the evidence on this topic, the "Dry Eye and Cataract Surgery" subcommittee of the DROPS workshop formulated some recommendations for ocular surface and DED management pre-, intra-, and post-cataract surgery.

Partial-thickness corneal tissue restoration after a chemical burn.

PURPOSE: We describe a case of full-thickness corneal restoration after an acute corneal burn with an acid agent. METHODS: A 32-year-old male reported painful discomfort, redness, photophobia, and a decrease in visual acuity in the left eye after a unilateral burn with an acid agent. Slit-lamp examination revealed massive corneal melting involving necrotic sequestrum of the entire corneal surface. Surgical approach was carried out in order to preserve residual ocular tissues. RESULTS: Extensive corneal-conjunctival layer curettage of the necrotic tissue was performed showing perfectly clear undamaged deep lamellar corneal layers. The patient underwent multilayered amniotic membrane transplantation and total capsular-conjunctival flap in order to preserve ocular tissue from further melting or corneal perforation. A complete and spontaneous "restitutio ad integrum" of the corneal layers was shown during the follow-up. The cornea was perfectly clear with restored normal anatomical architecture. CONCLUSION: In this case, a spontaneous full-thickness corneal tissue restoration occurred after an acute chemical burn. Studies about the mechanisms whereby different cells interact and replicate within the stroma may unveil the biology behind corneal regeneration and transparency.

Aging and corneal layers: an in vivo corneal confocal microscopy study.

PURPOSE: To describe age-related changes of different corneal layers using a quantitative analysis of in vivo corneal confocal microscopy. DESIGN: Descriptive observational cross-sectional study. METHODS: A total of 108 healthy corneas of 108 subjects, distributed in four age categories, underwent in vivo corneal confocal microscopy. The effect of aging on the main features of corneal epithelium, sub-basal nerve plexus, stroma, and endothelium was investigated. RESULTS: Mean diameter of superficial epithelial cells increases with age (0.05 µm per year; p < 0.0001). Mean cell density of basal epithelium does not change with age (p = 0.37). The sub-basal nerve plexus fiber number, density, and the number of beadings do not statistically change with age (p = 0.14, p = 0.10 and p = 0.17, respectively). Keratocyte density significantly reduces with age in each stromal layer (p < 0.0001). Endothelial cell count decreases by 10.92 cells/mm(2) per year (p < 0.0001). Endothelial polymegathism index and pleomorphism index do not change with age (p = 0.79 and p = 0.39, respectively). CONCLUSIONS: Corneal confocal microscopy allows a non-invasive examination of the living cornea, analyzing the microstructure of each corneal layer. Aging significantly influences the corneal confocal microscopy parameters of individual corneal layers, except sub-basal nerve plexus and basal epithelium.

Cytostatic and cytotoxic effects of 5-fluorouracil on human corneal epithelial cells and keratocytes.

PURPOSE: To investigate the effects of various 5-fluorouracil (5-FU) concentrations, exposure times, and application techniques on in vitro-cultured human corneal cells. METHODS: Human corneal epithelial cell (HCEC) and human corneal keratocyte (HCK) cultures were exposed to different 5-FU concentrations (0.025%-1%) and incubation durations (5 minutes to 2 hours). The cytostatic effect was evaluated as the percentage of inhibition of migration relative to the control. The evaluation of cytotoxic effect included both phase contrast microscopic observations and viability measures performed using an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] colorimetric assay. The results are expressed as ratio of optical density (OD) reduction 24 hours after exposure. RESULTS: The cytostatic effect was time and dose dependent. The 50% inhibiting dose was 0.55% after 1 hour of incubation for HCECs and was 0.5% after 2 hours of incubation for HCKs. A 100% inhibitory effect was never observed at any concentration or incubation duration. No cytotoxic changes were observed using an 5-FU concentration of <1%; 1% 5-FU showed time-dependent cytotoxic changes in HCEC cultures only. MTT analysis showed no OD reduction at 5-FU concentrations of <1%, whereas 1% 5-FU showed OD reduction <50% at any tested exposure time. HCECs showed higher reduction in OD than HCKs. CONCLUSIONS: 5-FU formulations topically used in clinical practice showed limited toxicity in normal cultured corneal epithelial cells and keratocytes.

Wavefront-optimized surface ablation with the Allegretto Wave Eye-Q excimer laser platform: 12-month visual and refractive results.

PURPOSE: To evaluate the wavefront-optimized algorithm of the Allegretto Wave Eye-Q (Wavelight AG) 400-Hz excimer laser platform. METHODS: Three hundred three eyes of 303 patients treated with advanced surface ablation were evaluated prospectively. Topical mitomycin C (MMC) was used when ablation was ≥80 µm. Efficacy, safety, and predictability at 12 months were quantified with subjective refraction, visual acuity (logMAR), and slit-lamp examination. RESULTS: Mean postoperative uncorrected distance visual acuity (UDVA) was 20/20.5 (0.01±0.05 logMAR). Postoperative UDVA was equal or better than preoperative corrected distance visual acuity (CDVA) in 94.7% of eyes. Efficacy index was 1.05. Corrected distance visual acuity was maintained (93.7%) or improved (5.9%) in 99.6% of treated eyes. No patient lost ≥2 lines. Safety index was 1.05. Haze at 12 months was grade ≤0.5 in 98% of treated eyes and grade ≤1 in 100% of treated eyes. Mean postoperative manifest refraction spherical equivalent (MRSE) was -0.03±0.15 diopters (D). Postoperative MRSE was within ±0.50 D in 99% of eyes. Overcorrection was documented in 0.66% and undercorrection in 0.33% of eyes. CONCLUSIONS: The wavefront-optimized algorithm of the Allegretto Wave Eye-Q excimer laser platform showed good efficacy, safety, and predictability in advanced surface ablation, with or without MMC intraoperative use.