ABSTRACT
Objective: To study the clinical characteristics of patients attending the contact lens clinic at Siriraj Hospital. Methods: Retrospective chart indicates characteristics of new patients who attended the contact lens clinic at Siriraj Hospital from January 2008 to December 2009. Results: One hundred and thirty three eyes were collected from 85 patients (50 females and 35 males) with the mean age of 31.87 years: 40 eyes were low refractive error, 23 eyes were high myopia, 22 eyes were high hyperopia, 18 eyes were high astigmatism, 18 eyes were high myopia and high astigmatism and 12 eyes were keratoconus. The mean pre-fitting visual acuity in all groups was 0.79LogMAR (range 0 to 2.6LogMAR). Soft sphere contact lenses were mostly prescribed in low refractive error patients while PMMA contact lenses were mostly prescribed in keratoconus patients. The mean final visual acuity with contact lenses in all groups was 0.2LogMAR (range 0 to 1LogMAR). No serious contact lens related complications were found in the follow up visit. Conclusion: Many types of contact lenses can be used in different indications. Contact lenses can improve visual acuity substantially in high hyperopia patients. To wear contact lenses is a less invasive option for moderate keratoconus patients to improve vision. Patient’s education for contact lens caring is important and should be emphasized to prevent irreversible contact lens related complications.
ABSTRACT
Objective : To define normal values of Electroretinogram [ERG] and Visual Evoked Potential [VEP] in different age groups using Viking Select Master Software V7.1. Methods: ERG and VEP values were measured using Viking Select Master Software V7.1 in selected subjects without history of ocular and/or systemic diseases that affect ERG and VEP values. Results were studied in three groups of age: less than 10 years old, 11 to 40 years old and over 40 years old. Results: There were 26 eyes in the first group with age range from 6-10 years old [mean 7.8 + 1.52 years old]. In ERG : the normal values of photopic amplitude of ; a-wave was> 18.57 microvoltage [ตV] and b-wave was> 23.82 ตV, flickering amplitude of b-wave was > 21.93 ตV, scotopic amplitude of b-wave was> 39.12 ตV, mesopic amplitude of ; a-wave was > 60.44 ตV and b-wave was > 96.84 ตV. In VEP : transient flash amplitude was> 20.58 ตV and latency was < 94.10 millisecond[ms], transient pattern size 2 amplitude was > 8.61 ตV and latency was < 100.00 ms. There were 75 eyes in the second group with age range from 11-38 years old [mean 26.8 + 7.35 years old]. The values of photopic amplitude of ; a-wave was > 22.56 ตV and b-wave was > 20.14 ตV, flickering amplitude of b-wave was > 19.35 ตV, scotopic amplitude of b-wave was > 32.29 ตV, mesopic amplitude of ; a-wave was > 45.05 ตV and b-wave was> 78.97 ตV, VEP- transient flash amplitude was > 11.64 ตV and latency was < 96.78 ms, transient pattern size 2 amplitude was > 4.82 ตV and latency was < 88.49 ms. There were 77 eyes in the third group with age range from 41-81 years old [mean 60.1 + 11.54 years old]. The values of photopic amplitude of; a-wave was > 19.12 ตV and b-wave was > 24.59 ตV, flickering amplitude of b-wave was > 18.76 ตV, scotopic amplitude of b-wave was > 35.60 ตV, mesopic amplitude of ; a-wave was > 40.90 ตV and b-wave was > 94.09 ตV, VEP- transient flash amplitude was > 10.07 ตV and latency was < 102.10 ms, transient pattern size 2 amplitude was > 5.34 ตV and latency was < 96.00 ms. Conclusion: We established normal ERG and VEP values in different age group using Viking Select Master Software V7.1 at Siriraj Hospital to distinguish between normal and pathological patients. The values are affected in relation to machine and environmental setting in different laboratory. It is essential for individual laboratories to set their own normal values.
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Objective: To demonstrate clinical manifestations and treatment outcomes in dissociated strabismus complex patients. Methods: Charts of patients who attended the Muscle Clinic at Siriraj Hospital from July 1998 to June 2002 were reviewed. Information regarding the patient’s age, sex, eye deviation, visual acuity, binocular function, head posture, degree of dissociated vertical deviation (DVD), dissociated horizontal deviation (DHD), dissociated torsional deviation (DTD), inferior oblique overaction (IOOA) and the treatments were obtained. Results: Seventy-three subjects from 1,335 strabismic patients were included in the study (5.5% of all strabismic patients attended the Muscle Clinic during the study time). The mean age of DSC patients was 8 years old. Among all DSC patients, 65.8% had esodeviation; 23.2% had exodeviation; and, 11% had isolated DSC. Latent nystagmus was found in 11% of the patients. Abnormal head posture was found in 16.4% of the patients. About fifteen percent of DSC patients had binocular function. All DSC patients had DVD but only 5 patients had DHD; no DTD was found. The treatment of DHD was correction of the horizontal deviation that coexisted with vertical deviation. As for DVD, there were many surgical procedures for correction such as superior rectus muscle (SR) recession, inferior oblique muscle (IO) recession, inferior oblique muscle anteriorization and inferior rectus muscle (IR) resection. Both unilateral and bilateral surgeries were performed. Regardless of the procedures, the total success rate was 78.4% (the residual of hyperdeviation was 10 prism diopters (PD) or less).The group of patients, who had surgical correction in only one eye, had a significant deviation in the non-operated eye after the surgical treatment. Conclusions: DSC was composed of DVD, DHD, DTD and latent nystagmus. DVD was the predominant manifestation in most cases of DSC. DSC was usually bilateral and was seen in subnormal binocular function patients. Esotropia was the most common deviation associated with DSC patients. Many surgical procedures were used to correct DVD such as bilateral large SR recession or IO anteriorization. In unilateral surgery, the manifestation of the deviation in the non-operated eye was always be found. Bilateral surgery was suggested but may be performed in asymmetrical degree. In this study, the overall success rate was 78.4%.
ABSTRACT
OBJECTIVE: To evaluate the change in intraocular pressure (IOP) measurement by Goldmann applanation tonometer after Laser in Situ Keratomileusis (LASIK) for myopia and myopic astigmatism, and to assess the correlation between the changes of lOP reading and the reduction of central corneal thickness (CCT) after LASIK in Thai patients. STUDY DESIGN: Prospective correlational study. MATERIAL AND METHOD: LASIK was performed on 65 eyes of 33 patients for correction of myopia and myopic astigmatism. IOP was measured by Goldmann applanation tonometer before and 3 months after LASIK. The correlation between the change in IOP reading and the change in central corneal thickness were evaluated. RESULTS: IOP reading was significantly reduced by mean of 2.9 +/- 2.5 mmHg (p = 0.0001). The authors used Pearson analysis to study the correlation between the change in IOP and the reduction of CCT. In subgroup analysis the patients were divided by degree of myopia: group 1, myopia less than -3 diopters (D) (n = 14); group 2, myopia -3 to -6 D (n = 31); group 3, myopia greater than -6 D (n = 20)). The result showed more correlation in higher myopia group (Pearson; r = 0.158 in group 3, r = -0.098 in group 2 and r = -0.102 in group 1). CONCLUSION: Goldmann applanation tonometry underestimates the IOP in thin cornea. Variability in CCT is a potent confounder of this tonometry technique. Therefore, it has important implications for considering CCT measurement incorporated with Goldmann applanation tonometry for glaucoma diagnosis especially in myopic patients who undergo LASIK surgery.