Keratoconus in Thai population - a cross-sectional hospital-based study.

Background: Studies in the epidemiology of keratoconus are limited in Southeast Asia. A study on the prevalence and characteristics of keratoconus in the Thai population could give a general idea of its impact. Objectives: To study keratoconus prevalence in patients seeking refractive surgery and analyze the characteristics of keratoconus. Methods: Medical records from April 2015 to August 2018 were retrospectively reviewed. Keratoconus and keratoconus suspect prevalence in patients seeking laser vision correction were calculated. The characteristics of keratoconus patients were reviewed. The Amsler-Krumeich classification was used to determine the stages. Topographically, the types of cones were categorized into oval, nipple, pellucid marginal degeneration (PMD)-like, and astigmatic types. Results: Keratoconus and keratoconus suspect prevalence were 1.66% and 0.68%, respectively. Out of the affected patients, 73.8% were male. The mean age at diagnosis was 25.25 ± 8.35 years. The presenting symptoms were blurred vision (87%) and itching (47%). Stage 1 was predominant, found in 39% of patients (followed by stages 2, 4, and 3, respectively). Ocular findings comprised the Munson sign (14.63%), the Rizutti sign (6.94%), Fleischer ring (28.14%), Vogt striae (24.95%), corneal scar (8.63%), prominent corneal nerve (2.81%), and corneal staining (7.69%). Mean uncorrected visual acuity (logarithm of the minimum angle of resolution [logMAR]) was 0.88 ± 0.64. Mean corrected visual acuity (logMAR) was 0.40 ± 0.49. Mean Q-value was -0.92 ± 0.63. The thinnest pachymetry was 459.39 ± 56.96 microns. The mean keratometry was 49.7 ± 6.64 diopters. Topographically, the types of cones were oval (57%), astigmatic (33%), PMD-like (5%), and nipple type (4%). Conclusions: Keratoconus prevalence among Thai patients seeking refractive surgery was 1.66%. Most patients were male and presented with the disease at a mild bilateral stage in their second decade of life.

Effectiveness and Safety of Combined Application of Three Modes of 2940-nm Erbium:YAG and 1064-nm Neodymium:YAG Lasers in Treatment of Meibomian Gland Dysfunction.

PURPOSE: To study the effectiveness and safety of upper and lower eyelid treatment with combined application of three modes of 2940-nm erbium-doped yttrium aluminium garnet (Er:YAG) and 1064-nm neodymium-doped yttrium aluminium garnet (Nd:YAG) lasers in patients with baggy eyelids (formed by intraorbital fat herniation) who exhibited meibomian gland dysfunction (MGD). PATIENTS AND METHODS: In this prospective cohort study, patients with baggy eyelid who exhibited MGD received combined laser treatment at baseline, as well as at the 4-, 8-, and 12-week follow-ups. The primary endpoint was meibum quality score at 16- and 24-week follow-ups; secondary endpoints were ocular surface index scores, tear film lipid layer thicknesses, tear break up times (TBUTs), Oxford scheme grades, and meibography grades at 16- and 24-week follow-ups. Adverse events, uncorrected visual acuities, best-corrected visual acuities, and intraocular pressures were also recorded. RESULTS: Sixteen patients (four men and 12 women; mean age, 56.38 ± 8.64 years) were included. Meibum quality scores at the 16-week follow-up were significantly lower than scores at baseline (p=0.043) and at the 24-week follow-up (p=0.015). TBUT was significantly exacerbated at the 24-week follow-up, compared with baseline (p=0.001) and the 16-week follow-up (p=0.006). There were no significant changes in other parameters. All adverse events were mild and resolved without additional treatment. CONCLUSION: Combined application of three modes of 2940-nm Er:YAG and 1064-nm Nd:YAG lasers on upper and lower eyelids significantly improved meibum quality in patients with MGD; it ameliorated symptoms and signs of dry eye disease at 4 weeks after completion of laser treatment.

Efficacy and Safety of Intense Pulsed Light in Patients With Meibomian Gland Dysfunction-A Randomized, Double-Masked, Sham-Controlled Clinical Trial.

PURPOSE: To study the efficacy and safety of intense pulsed light (IPL) in patients with meibomian gland dysfunction (MGD). METHODS: This prospective randomized double-masked sham-controlled trial included 114 patients with MGD. Patients were randomized into the IPL or sham group. Either the IPL or sham procedure was performed on days 0, 15, and 45. Ocular Surface Disease Index (OSDI), visual analog scale, visual acuity, tear breakup time, meibum quality and expressibility, meibography grade, ocular surface staining, tear film lipid layer thickness, tear osmolarity, Schirmer test, tear interleukin-1 receptor agonist, and interleukin-6 levels were examined on days 0, 15, and 45 and at months 3 and 6. Subgroup analysis according to stage and the patient's compliance to conventional treatment were also analyzed. Any adverse events during the study were recorded. A multilevel mixed-effect linear regression model was used. P value less than 0.05 was considered statistically significant. RESULTS: At 6 months, tear breakup time, meibum quality grades, expressibility grades, and OSDI were better in the IPL group (5.23 ± 2.91 vs. 3.11 ± 0.99 seconds, P < 0.001; 8.74 ± 4.74 vs. 13.19 ± 5.01, P < 0.001; 0.50 ± 0.67 vs. 1.12 ± 0.70, P < 0.001; 24.29 ± 16.92 vs. 32.71 ± 20.07, P < 0.05). OSDI, meibum quality, and expressibility in the IPL group began to improve at day 15 (P < 0.001), whereas the results in the sham group began to improve at day 45 (P < 0001). No adverse event occurred after IPL. CONCLUSIONS: IPL is effective and safe for MGD treatment in all stages regardless of compliance.

Topometric Indices And Corneal Densitometry Change After Corneal Refractive Surgery Combined With Simultaneous Collagen Crosslinking.

PURPOSE: To show the alteration of tomography, topometric indices and corneal densitometry after corneal refractive surgery combined with collagen crosslinking. PATIENTS AND METHODS: All medical records of patients undergoing corneal refractive surgery with simultaneous collagen crosslinking during April 2015 and August 2018 were retrospectively reviewed. Corneal tomography, higher-order aberrations (HOA), topographic indices and corneal densitometry were evaluated. All the data at 1 month, 3 months and 6 months were compared to baseline value. All complications were noted. P value less than 0.05 was considered statistically significant. RESULTS: Medical records of fourteen patients (twenty-five eyes) were reviewed. HOA increased at all time points (p < 0.05). Keratoconus index and central keratoconus index decreased, whereas index of surface variance, index of vertical asymmetry, index of height decentration and the minimum of radius of curvature increased at all time points (p < 0.05). Index of height asymmetry increased at 3 and 6 months (p < 0.05). Corneal densitometry at anterior layer of 0-10 mm zone and center layer of 0-6 mm zone increased at 1 and 3 months (p < 0.05). At 6 months, the densitometry at 0-6 mm zone returned to baseline level. However, at 6 months, at anterior and center layer of 6-10 mm zone, the densitometry values were still more than preoperative values (p < 0.05). There was one case of bacterial keratitis. CONCLUSION: After the corneal refractive surgery combined with collagen crosslinking, the HOA and corneal densitometry increased. Topographic indices showed conflicting results.