Intraocular Lens Power and Corneal Topographic Change After Pterygium Surgery: Pterygium Effects on IOL Power Calculation.

PURPOSE: To investigate the impact of pterygium excision on intraocular lens (IOL) power calculation and corneal astigmatism. DESIGNS: Prospective cohort study METHODS: We enrolled 30 eyes with primary pterygium that underwent pterygium excision with a conjunctival autograft. IOL power calculation and keratometry using the IOL Master 700, along with topographic parameters using the Pentacam Scheimpflug topography system, were performed preoperatively and at 1, 3, 6, and 12 months postoperatively. We analyzed correlations between pterygium length/area and IOL power, as well as corneal topographic changes. RESULTS: The mean pterygium length was 2.08 ± 0.58 mm, and the mean area was 6.05 ± 2.41 mm2. One year after pterygium surgery, the calculated IOL power values using all formulas were lower than the preoperative values. Pterygia with a horizontal length of 1.73 mm and an area of 4.45 mm2, and those with a horizontal length of 2.25 mm and an area of 6.95 mm2 created 0.5 D and 1.0 D errors in calculated IOL power, respectively (p<0.001). The calculated IOL power values changed significantly from preoperative to six months postoperatively but did not change significantly from six to 12 months postoperatively. Pterygia with a horizontal length greater than 1.83 mm (p<0.001) and an area greater than 5.1 mm2 (p < 0.001) created a 2.0 D error in anterior corneal astigmatism. CONCLUSIONS: Pterygium causes errors in IOL power calculation, with greater pterygium length/area exerting a larger effect. Cataract surgery with IOL implantation is recommended at least six months after pterygium surgery. In combined case, calculated IOL power should be decreased by 0.5-1.5 D based on the pterygium length/area.

Pattern of uveitis in a referral ophthalmology center in Northeastern Thailand.

PURPOSE: To report the characteristics and epidemiology of uveitis in a university-based referral center in northeastern Thailand and review the uveitis patterns present in various regions worldwide. METHODS: A retrospective review of all medical records for new patients visiting the uveitis clinic at Srinagarind hospital, Khon Kaen University, between August 2016 and June 2021, was conducted. RESULTS: A total of 522 uveitis patients were included in this study. Disease etiologies were categorized as non-infectious 35.8% (187/522), infectious 32.8% (171/522), and undetermined cause 31.4% (164/522). Specific diagnoses were established in 68.6% of cases. Vogt-Koyanagi-Harada (VKH) (14.2%) was identified as the most common specific diagnosis, and tuberculosis (6.7%) ranked highest among infectious causes. CONCLUSIONS: Although non-infectious uveitis is observed predominantly in this region, the proportion of infectious uveitis is relatively more common than in developed countries. We have found no cause for one-third of our patients despite the utilization of PCR and serology for diagnostic purposes.

Outcome of Therapeutic Penetrating Keratoplasty Using Glycerol-Preserved Donor Corneas in Infectious Keratitis.

PURPOSE: To report the surgical outcomes and complications of therapeutic penetrating keratoplasty (TPK) using glycerol-preserved corneas in infectious keratitis. METHODS: This is a retrospective, noncomparative case series of patients with severe infectious keratitis who received TPK using glycerol-preserved corneas from 2004 to 2014 in the Department of Ophthalmology, Srinagarind Hospital, Khon Kaen University. The medical records were reviewed for baseline characteristics, visual outcomes, recurrence rate, wound integrity, secondary glaucoma, and donor cornea storage times. RESULTS: Twenty-two eyes from 22 patients were included. Age ranged from 28 to 85 years and the donor cornea sizes ranged from 7.5 to 9.5 mm. The most common causative agents were fungi (16/22, 72.7%). Eleven patients (50.0%) developed secondary glaucoma and 7 patients (31.8%) had wound leakage. Recurrence of infection was observed in 15 patients (68.2%) and 9 patients (40.9%) received enucleation or evisceration. Thirteen globes (59.1%) were saved and the final visual acuites ranged from 1/60 to light perception. The storage times of donor corneas varied between 2 days and 62 months. The length of donor cornea storage did not affect the success rate of surgical outcome. CONCLUSIONS: TPK using glycerol-preserved corneas has a high rate of secondary glaucoma and recurrence of infection with unsatisfactory visual results. These corneas may be used as temporary emergency transplants in infectious keratitis when fresh corneas are unavailable to meet demands.

Effectiveness of hormone therapy for treating dry eye syndrome in postmenopausal women: a randomized trial.

BACKGROUND: The efficacy of hormone therapy (HT) on dry eye syndrome remains debatable. OBJECTIVE: To study the efficacy of HT on dry eye syndrome. MATERIAL AND METHOD: A randomized controlled, double blind, parallel group, community-based study in 42 post-menopausal patients was conducted. The patients had dry eye syndrome and were not taking any medications. They were assigned to one of two groups. Group A comprised 21 patients given transdermal 17 beta-estradiol (50 mg/day) and medroxy progesterone acetate (2.5 mg/day) continuously for three months and group B comprised 21 patients given both transdermal and oral placebo. Participants in the study were included for final analysis. The improvement of dry eye symptoms were measured by visual analog scale, tear secretion, intraocular pressure, corneal thickness, and tear breakup time determined before treatment and at 6 and 12 weeks of treatment. RESULTS: At 12 weeks, the number of patients who reported improvement of dry eye symptoms was greater in the HT group than that in the placebo group. However, the difference was not statistically significant (RR 0.25, 95% CI 0.04-2.80 and 0.60, 95% CI 0.33-2.03 in right and left eye, respectively). For other parameters, there was no significant difference between the two groups. CONCLUSION: According to the present study, there is no strong evidence to support the use of HT for treating dry eye syndrome. The limited number of participants included in the present study may have contributed to the insignificant effects.

Randomized double-blind study of phenylephrine 2.5% vs 10% on pupillary dilation.

PURPOSE: To compare the efficacy of phenylephrine 2.5% versus 10% on pupillary dilation, and also compare their side-effects. METHOD: Patients at the Eye Clinic Srinagarind Hospital were randomized into two groups. Patients in group 1 received 1% tropicamide and 10% phenylephrine, whereas those in group 2 received 1% tropicamide and 2.5% phenylephrine. Pupil diameter, blood pressure and heart rate were measured before and after eyedrop instillation. RESULTS: Five hundred and sixty four patients were randomized into 293 patients (group 1) and 271 patients (group 2), using simple random sampling method. Mean pupil diameters before instillation in group 1 were 4.43 +/- 1.13 mm in the right eye and 4.31 +/- 0.95 mm in the left eye, whereas those in group 2 were 4.45 +/- 1.0 mm in the right eye and 4.32 +/- 0.92 mm in the left eye. After the instillation, the mean pupil diameters in group 1 were 7.58 +/- 0.96 mm in the right eye and 7.60 +/- 1.03 mm in the left eye, whereas those in group 2 were 7.17 +/- 1.04 mm in the right eye and 7.07 +/- 1.06 mm in the left eye. The difference was statistically significant (P < 0.05). There was no significant difference in mean systolic and diastolic blood pressure after instillation between the two groups. However, the mean heart rate after instillation in group 1 was greater than the value in group 2 with statistically significant difference. CONCLUSION: Pupillary dilation with 1% tropicamide and 10% phenylephrine is more effective than 1% tropicamide and 2.5% phenylephrine with statistically significant difference. After single dose instillation, there was no significant difference in the mean blood pressure between the two groups.