Tear proteome profile in eyes with keratoconus after intracorneal ring segment implantation or corneal crosslinking.

Purpose: Keratoconus (KC) is a corneal ectasia characterized by structural changes, resulting in progressive thinning and biomechanical weakening that can lead to worsening visual acuity due to irregular astigmatism. Corneal collagen Crosslinking (CXL) and Intracorneal Ring Segment (ICRS) are widely used treatments in KC disease, but the alterations they cause in biomechanical mediators are still poorly understood. The aim of this study was to analyze the tear proteome profile before and after treatments to identify biomarkers altered by surgery. Materials and methods: An observational, prospective, case-control pilot study was conducted, analyzing tear samples from KC patients by nano-liquid chromatography-mass spectrometry (nLC-MS/MS). Data are available via ProteomeXchange with identifier PXD035655. Patients with KC who underwent ICRS surgery (n = 4), CXL (n = 4), and healthy subjects (Ctrl, n = 4) were included in this study. Clinical parameters were measured and tear samples were collected before and 18 months after surgery. Proteins with ≥2 expression change and p-value < 0.05 between groups and times were selected to study their role in post-operative corneal changes. Results: These analyses led to the identification of 447 tear proteins, some of which were dysregulated in KC patients. In comparisons between the two surgical groups and Ctrls, the biological processes that were altered in KC patients at baseline were those that were dysregulated as a consequence of the disease and not of the surgical intervention. Among the biological processes seen to be altered were: immune responses, cytoskeleton components, protein synthesis and metabolic reactions. When comparing the two treatment groups (ICRS and CXL), the process related to cytoskeleton components was the most altered, probably due to corneal thinning which was more pronounced in patients undergoing CXL. Conclusion: The changes observed in tears after 18 months post-operatively could be due to the treatments performed and the pathology. Among the deregulated proteins detected, A-kinase anchor protein 13 (AKAP-13) deserves special attention for its involvement in corneal thinning, and for its strong overexpression in the tears of patients with more active KC and faster disease progression. However, it should be kept in mind that this is a pilot study conducted in a small number of patients.

Anterior capsule opacification after femtosecond laser-assisted cataract surgery: Clinical classification versus Scheimpflug device densitometry values.

PURPOSE: To compare the clinical classification of anterior capsule opacification (ACO) after femtosecond laser-assisted cataract surgery with the mean density values of ACO provided by rotating Scheimpflug device (Pentacam HR) densitometry software and to determine which densitometry method correlates best with the clinical classification. SETTING: Ophthalmology Department, Donostia University Hospital, Donostia-San Sebastian, Spain. DESIGN: Prospective comparative study. METHODS: Femtosecond laser-assisted cataract surgery was performed using the Victus platform between June 2014 and March 2015. Inclusion criteria were age between 55 years and 85 years, a pupil diameter larger than 6.0 mm in full mydriasis, no intraoperative complications, a curvilinear anterior capsulotomy without tears, and an intraocular lens in the correct intracapsular position at the end surgery. The ACO was measured by a clinical classification ranging from 0 to 4. In addition, ACO density was measured with the Scheimpflug device using 3 densitometry methods (area, linear, and peak). RESULTS: The study comprised 32 eyes of 32 patients. Area and linear densitometry values provided by the Scheimpflug device had a strong correlation with the values obtained by clinical classification, whereas peak densitometry values had a very weak correlation at 6 months (area densitometry: Spearman ρ = 0.78; P < .0005; linear densitometry: ρ = 0.73; P < .0005; peak densitometry ρ = 0.21; P = .2). CONCLUSION: The Scheimpflug device provided an objective measurement of ACO after cataract surgery. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.

Objective optical quality analysis using double-pass technique in pterygium surgery.

PURPOSE: To analyze objective optical quality changes after pterygium surgical excision using the Optical Quality Analysis System. METHODS: Forty eyes with primary pterygium suitable for surgical treatment were included. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), objective scattering index (OSI), and cutoff frequency of the modulation transfer function (MTFcutoff) were recorded preoperatively and at 1 and 6 months postoperatively. Slit-lamp measurement of pterygium size was performed to classify them: small in group 1 and medium size/large in group 2. A paired comparative study of all data that included preoperative with 1-month results (comparison A), preoperative with 6-month results (comparison B), and 1 month with sixth-month results (comparison C) was performed. RESULTS: In global analysis, uncorrected distance visual acuity and OSI showed significant changes in comparison A, all parameters in comparison B, and CDVA, OSI, and MTFcutoff in comparison C. When subdividing into groups, in group 1, there was significant improvement between preoperative uncorrected distance visual acuity value and those at 1 and 6 months. Significant improvement in CDVA, OSI, and MTFcutoff values were observed in comparisons B and C. In group 2, MTFcutoff values significantly improved in comparisons B and C. The comparison of mean values between each group at each evaluation showed a lower value for MTFcutoff at 1 month after surgery. A comparative analysis of the evolution between both groups based on pterygium size did not reveal significant differences. CONCLUSIONS: Pterygium can undermine visual quality, and its excision provides significant improvement even at 6 months after surgery. Optical Quality Analysis System proved useful for postoperative outcomes.

Rotational stability and visual quality in eyes with Rayner toric intraocular lens implantation.

PURPOSE: To assess astigmatic reduction and rotational stability of Rayner T-flex toric intraocular lenses (IOL) (573T and 623T; Rayner Intraocular Lenses Ltd) in a series of cataract surgery patients with corneal astigmatism >1.50 diopters (D). METHODS: This prospective, observational study included 27 eyes from 22 consecutive patients with pre-operative regular corneal astigmatism ≥1.50 D in which Rayner T-flex toric IOL implantation was performed after phacoemulsification. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), residual refractive sphere, residual keratometric and refractive cylinder, and deviation from attempted toric IOL axis were measured. RESULTS: Mean UDVA 3 months after surgery was 0.1042±0.1290 with 20/40 or better in 96% of eyes and 20/25 or better in 52% of eyes. Mean refractive postoperative sphere was 0.25±0.37 D and mean refractive postoperative cylinder was 0.52±0.63 D. Vector analysis of attempted versus achieved visual correction showed that 100% of eyes were within ±1.00 D and 87% of eyes were within ±0.50 D. Mean change in keratometric astigmatism was 0.54±1.33 for J(0) and -0.24±1.17 for J(45) (P>.05). Twenty-five (92.6%) eyes had IOL rotation <10°. CONCLUSIONS: Rayner T-flex toric IOL implantation is an effective and reliable option to correct preexisting astigmatism in cataract surgery.