Reproducibility, Repeatability, and Correlation of Central Corneal Thickness Measurement with the Pentacam Scheimpflug System and Ultrasound Pachymetry.

BACKGROUND/AIM: The importance of an accurate determination of central corneal thickness (CCT) relies on its diagnostic and therapeutic implications in glaucoma, corneal ectasias, corneal edema and endothelial function monitoring, and refractive surgery suitability, among others. We aimed to analyze the repeatability, reproducibility, correlation, and laterality variations of CCT measurements performed with the Pentacam HR and the standard of care ultrasound A-scan (USP). METHODS: A cross-sectional study including CCT measurements of healthy individuals was performed by three independent examiners with the Pentacam HR and USP. Intra-observer and inter-observer variations were calculated with intra-class correlation coefficients (ICCs). Bland-Altman plots and 95% limits of agreement (95% LoA) were used to assess the agreement between devices. Linear correlation was calculated with Pearson's coefficient. RESULTS: Thirty individuals (60 eyes), including 10 (33.3%) men and 20 (66.6%) women, with a mean age of 30.0 ± 9.1 years, were studied. No statistical differences were found in CCT measurements between Pentacam HR (range 500 - 609 µm) and USP (range 498 - 628 µm). There was a high degree of correlation in repeatability and reproducibility of each independent device (ICC > 0.90). Pearson's correlation between 1 vs. 2, 2 vs. 3, and 3 vs. 1 Pentacam HR attempts were 0.914, 0.958, and 0.925, respectively (p < 0.001). Corresponding results for USP were 0.957, 0.957, and 0.943 (p < 0.001). The Pentacam HR tended to overestimate CCT by a mean difference of 3.77 µm (95% LoA, - 24.9 - 18.4). Right eyes were also overestimated (- 3.6 ± 14.1 µm) with the Pentacam HR device, whereas left eyes were underestimated (1.3 ± 11.1 µm). CONCLUSIONS: The Pentacam HR device provides reliable operator-independent estimates of CCT. Right eyes exhibited a tendency to overestimate with the Pentacam HR. We suspect this difference is due to USP underestimation related to patients' position while performing the study. In clinically relevant scenarios, performing a third measurement and cautiously measuring right eyes can provide higher accuracy.

Efficacy and safety of 0.1% lodoxamide for the long-term treatment of superior limbic keratoconjunctivitis.

PURPOSE: To report the therapeutic efficacy and safety of topical 0.1% lodoxamide in the long-term treatment of superior limbic keratoconjunctivitis. METHODS: Sixty-seven eyes of 34 patients with active SLK were studied. Therapeutic response was analyzed according to modified-Ohashi parameters. All eyes were treated with 0.1% lodoxamide twice daily, and those with moderate or severe inflammation received a short course (7-14 days) of 0.1% fluorometholone acetate at presentation and during a relapse. Patients were evaluated at regular intervals and followed up for ≥3 months on continuous therapy. Primary endpoints included inflammatory response; rates of inflammatory control and remission; relapses while on therapy or on remission; and therapeutic failure rate. RESULTS: The mean follow-up time on lodoxamide therapy was 15.3 months. The majority of eyes (82.0%) achieved control of inflammation in a mean time of 2.2 months. Of these, 42 (76.3%) eyes remained under control while on therapy for 13.8 months. There was a significant improvement of SLK-related signs by the third month on therapy (p < 0.05). A total of 24 (35.8%) eyes achieved remission. Relapses presented in 12 (18.0%) treated eyes and in 4 (16.6%) eyes on remission. Only 5 (7.4%) eyes failed to respond to therapy. In the majority of cases (95.3%), lodoxamide 0.1% was well tolerated and minor adverse effects not requiring stopping the medication were reported in only 4.7% of patients. CONCLUSIONS: Lodoxamide 0.1% is an efficacious therapeutic alternative for the treatment of active and chronic SLK. This medication has proved to be safe and well tolerated.

Knowledge and compliance with contact lens care: A population-based study at a referral center in Northeast Mexico.

OBJECTIVE: Despite the increasing prevalence of contact lens (CL) wear, knowledge and compliance with proper care remain suboptimal. This study aims to assess the level of knowledge and compliance with lens care practices in patients attending a third-level institution in Northeast Mexico. METHODS: A cross-sectional study using a self-administered online survey was conducted. Patients at the Instituto Tecnolgico de Monterrey were invited to participate. The questionnaire consisted of three sections: demographic data and CL information, CL practices, and CL care knowledge. Participants responding correctly to 6/7 questions from the second and third sections were classified as having good compliance and good knowledge, respectively. Predictive factors for good compliance and knowledge were calculated using a logistic regression model. RESULTS: A total of 287 users participated in the study. The median age was 25 (14-78) years with a female (n = 221, 77 %) predominance. Good knowledge was observed in 215 (74.9 %), whereas only 42 (14.6 %) presented good compliance. Failing to replace CL as prescribed (n = 199, 69.3 %) and sleeping with the devices (n = 198, 69 %) were the most frequent practices causing non-compliance. Whereas prohibition of swimming with CL was the least known practice (n = 74, 25 %). Users with recent (≤5 years) wearing experience were more likely to present good knowledge (OR 2.19, p = 0.014) and compliance (OR 3.15, p < 00.01). No statistical correlation was established between knowledge and compliance. CONCLUSION: Non-compliance and lack of knowledge of proper CL care were prevalent among in this population. Long-term CL users were at higher risk of non-compliance and lack of knowledge. Moreover, knowledge was not related to compliance; therefore, different strategies must be implemented to reduce CL misconduct.

COVID-19 and the eye: a review.

BACKGROUND: To provide a review for general practitioners and medical specialists about the most common eye complaints and ocular manifestations in a COVID-19 patient. METHODS: Reviewed 50 articles referenced in 4 databases from 20 December 2019 to 16 September 2020. RESULTS: Of the 50 articles reviewed, 26 met the criteria for analysis and were included in the study. Among them were 5 reviews, 6 case series, 7 case reports, 4 cross-sectional studies, 2 systematic reviews, 1 cohort study and 1 correspondence. We found that the prevalence of ocular manifestations in patients during the course of COVID-19 varied between 0.8% and 31.6%, depending on the study design. Symptoms of acute conjunctivitis were the most frequent clinical findings. Acute phase reactants were also correlated to ocular manifestations and the severity of the systemic disease in many reports. CONCLUSIONS: Ocular manifestations are not uncommon in COVID-19 patients and have been associated with higher levels of acute phase reactants as well as a higher degree of severity of the systemic disease. We recommend that all physicians consider COVID-19 as a differential diagnosis in the presence of acute conjunctivitis with or without systemic symptoms.

Comparison of postoperative pain in patients following photorefractive keratectomy versus advanced surface ablation.

PURPOSE: To compare postoperative pain associated with advanced surface ablation versus traditional photorefractive keratectomy (PRK). SETTING: Codet-Aris Vision Institute, Tijuana, Mexico. METHODS: This prospective double-masked randomized study included 56 eyes of 28 myopic patients who received traditional PRK in 1 eye and advanced surface ablation in the contralateral eye. For advanced surface ablation, removal of corneal epithelium was performed by incubating the cornea with 18% ethanol. Subsequently, the epithelium was removed by a surgical microsponge. For eyes treated by PRK, mechanical debridement of corneal epithelium was performed with a surgical blade. Excimer laser corneal ablation was performed using the Nidek EC-5000 excimer laser in all eyes. On postoperative days 1 and 3, patients were instructed to rate their pain via 3 pain measuring tools: (1) a global subjective rating; (2) a 100 mm visual analog scale (VAS); and (3) an 11-point numerical rating scale. RESULTS: All 28 patients completed postoperative questionnaires on day 1 and day 3. On postoperative day 1, all reported pain in both eyes. Using the global assessment rating, patients reported statistically significant more pain in eyes treated by advanced surface ablation (P = .0037; confidence interval [CI], 59%-92%). Furthermore, based on the 11-point numerical rating scale, mean pain scores were significantly higher in the advanced surface ablation treated eyes (P = .0121), while the VAS mean pain scores were marginally significantly higher (P = .0822). On postoperative day 3, 23 patients reported the presence of some pain, at least in 1 eye. Using the global assessment rating, 70% of the those who had pain reported more pain in the advanced surface ablation-treated eye (advanced surface ablation 16/23 versus PRK 7/23) (P = .0931; 95% CI, 47%-87%). In addition, on postoperative day 3, advanced surface ablation-treated eyes demonstrated slightly higher mean pain scores based on the 11-point numerical rating scale and on the VAS; however, mean differences were not statistically significant (P = .3494 and P = .3337, respectively). CONCLUSIONS: Advanced surface ablation was associated with statistically significantly more postoperative pain than PRK on postoperative day 1. A greater percentage of patients reported more pain in the advanced surface ablation-treated eyes on day 3. Refractive surgeons should consider the postoperative pain associated with advanced surface ablation when deciding on the type of epithelial debridement for their patients.

A new method for measuring progression in patients with ocular cicatricial pemphigoid.

OBJECTIVES: To describe a method to measure the progression of ocular cicatricial pemphigoid and to compare its facility with traditional methods used to measure the progression of the disease. METHODS: The proposed method consists of measuring (in millimeters) the total relative inferior conjunctival surface available in 3 gaze positions. This method was used to monitor 7 eyes of 4 patients with ocular cicatricial pemphigoid over 2 years. The changes in the conjunctival measurements from baseline were compared with the changes documented by traditional methods. RESULTS: During the study, 2 eyes remained stable (changes, <3 mm), 2 had a decrease of 10 mm or more, and 3 had a change in measurements between 4 and 9 mm. With the proposed method, we demonstrated the detection of more subtle changes in the conjunctiva of all patients. Patients who had changes between 4 and 9 mm easily underwent staging by the traditional systems when the new technique was used as a reference. CONCLUSION: The proposed method offers an objective variable that can be used in consecutive visits to detect subtle progression or disease control in patients with ocular cicatricial pemphigoid.