Biomedical subjects

Thomas Kuriakose

Publications and source records attributed to Thomas Kuriakose.

6 recordsLinked to original sources

PubMed2006

The effect of Gonioscopy on keratometry and corneal surface topography.

BACKGROUND: Biometric procedures such as keratometry performed shortly after contact procedures like gonioscopy and applanation tonometry could affect the validity of the measurement. This study was conducted to understand the short-term effect of gonioscopy on corneal curvature measurements and surface topography based Simulated Keratometry and whether this would alter the power of an intraocular lens implant calculated using post-gonioscopy measurements. We further compared the effect of the 2-mirror (Goldmann) and the 4-mirror (Sussman) Gonioscopes. METHODS: A prospective clinic-based self-controlled comparative study. 198 eyes of 99 patients, above 50 years of age, were studied. Exclusion criteria included documented dry eye, history of ocular surgery or trauma, diabetes mellitus and connective tissue disorders. Auto-Keratometry and corneal topography measurements were obtained at baseline and at three follow-up times - within the first 5 minutes, between the 10th-15th minute and between the 20th-25th minute after intervention. One eye was randomized for intervention with the 2-mirror gonioscope and the other underwent the 4-mirror after baseline measurements. t-tests were used to examine differences between interventions and between the measurement methods. The sample size was calculated using an estimate of clinically significant lens implant power changes based on the SRK-II formula. RESULTS: Clinically and statistically significant steepening was observed in the first 5 minutes and in the 10-15 minute interval using topography-based Sim K. These changes were not present with the Auto-Keratometer measurements. Although changes from baseline were noted between 20 and 25 minutes topographically, these were not clinically or statistically significant. There was no significant difference between the two types of gonioscopes. There was greater variability in the changes from baseline using the topography-based Sim K readings. CONCLUSION: Reversible steepening of the central corneal surface is produced by the act of gonioscopy as measured by Sim K, whereas no significant differences were present with Auto-K measurements. The type of Gonioscope used does not appear to influence these results. If topographically derived Sim K is used to calculate the power of the intraocular lens implant, we recommend waiting a minimum of 20 minutes before measuring the corneal curvature after gonioscopy with either Goldmann or Sussman contact lenses.

Aged↗

PubMed2006

Role of frequency doubling technology perimetry in screening of diabetic retinopathy.

PURPOSE: To study the ability of frequency-doubling technology perimetry (FDT) to detect sight-threatening diabetic retinopathy. METHOD: Fifty-eight eyes of fifty-eight patients with established diagnosis of diabetes mellitus with diabetic retinopathy, fifty-five eyes of fifty-five diabetic patients without retinopathy and forty-one eyes of forty-one normals underwent FDT and dilated stereo-biomicroscopic fundus examination. The sensitivity and specificity of FDT in identification of "sight-threatening retinopathy" (severe and very severe nonproliferative diabetic retinopathy and proliferative diabetic retinopathy) and clinically significant macular edema (CSME) were determined. RESULTS: For the detection of sight-threatening retinopathy, two abnormal adjacent points depressed to any level on the 20-1 screening program had a sensitivity of 90.5% and specificity of 97.6%. At (assuming a) 10% prevalence of sight-threatening retinopathy in a diabetic clinic, two abnormal adjacent points anywhere in the field depressed to any level has a positive predictive value (PPV) of 48% with a negative predictive value of 98.8%. Sensitivity and specificity for the detection of CSME was poor. CONCLUSIONS: The 20-1 screening program of the FDT is useful in the detection of sight-threatening diabetic retinopathy (PPV 48%). A normal 20-1 test rules out sight-threatening retinopathy. FDT was not useful in the detection of CSME.

Adult↗

PubMed2005

Amplitude of accommodation and its relation to refractive errors.

AIMS: To evaluate the relationship between amplitude of accommodation and refractive errors in the peri-presbyopic age group. MATERIALS AND METHODS: Three hundred and sixteen right eyes of 316 consecutive patients in the age group 35-50 years who attended our outpatient clinic were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 6/6 J1 in both eyes were included. The amplitude of accommodation (AA) was calculated by measuring the near point of accommodation (NPA). In patients with more than +/- 2 diopter sphere correction for distance, the NPA was also measured using appropriate soft contact lenses. RESULTS: There was a statistically significant difference in AA between myopes and hypermetropes (P < 0.005) and between myopes and emmetropes (P < 0.005) in the 35-39 year age group. In the 40-44 year age group, there was a significant difference in AA between emmetropes and hypermetropes (P < 0.0001), emmetropes and myopes (P < 0.01) and hypermetropes and myopes (P < 0.0001). In patients above 45 years of age there was no significant difference (P > 0.5). CONCLUSION: Our study showed higher amplitude of accommodation among myopes between 35 and 44 years compared to emmetropes and hypermetropes.

Accommodation, Ocular↗

PubMed2003

The incidence of vitreous loss and visual outcome in patients undergoing cataract surgery in a teaching hospital.

PURPOSE: To determine the incidence of vitreous loss in patients undergoing cataract surgery and the visual outcome in a tertiary teaching hospital. METHODS: Hospital records of 2095 consecutive patients undergoing cataract surgery between July 1999 and June 2000 were reviewed in this non-concurrent cohort study. Incidence and visual outcome of vitreous loss managed using standard vitrectomy techniques were assessed for different cataract surgical techniques (extracapsular, Blumenthal technique and phacoemulsification) as well as at different levels of surgical training. The outcome was compared with matched cases without vitreous loss (controls). RESULTS: Vitreous loss occurred in 160 of 2095 eyes (7.63%; CI -7 to 9.3): 8.3% for ECCE, 8.1% for the Blumenthal technique and 5% with phacoemulsification. Vision > or = 6/18 was achieved in 85% of cases and 95% of controls. For experienced surgeons, 95% of the cases and controls had vision > or = 6/18. 5.8% of cases and 0.7% of controls had vision < 6/60. One patient in each group was blind following cataract surgery; both had operable cataracts in the fellow eye. CONCLUSIONS: The vitreous loss rate in this tertiary teaching hospital is relatively high. This complication, managed with standard surgical techniques, is compatible with good visual outcome. In eyes with vitreous loss, the final visual acuity achieved by experienced surgeons was similar to that in uncomplicated cases.

Adult↗

PubMed2002

Role of choroidal drainage in therapeutic keratoplasty.

PURPOSE: To discuss the role of choroidal drainage in the management of positive vitreous pressure during therapeutic keratoplasty for patients with perforated corneal ulcers. METHODS: Over a 2-year period, 8 of 36 (22%) consecutive patients with therapeutic grafts presented with a shallow anterior chamber during or immediately after surgery. These patients underwent choroidal drainage for formation of the anterior chamber. In 5 of them choroidal drainage was done intraoperatively when there was significant positive vitreous pressure and the anterior chamber could not be formed. Three patients had drainage within a week postoperatively for persistent shallow anterior chamber when ultrasonogram showed choroidal detachment. RESULTS: Of the eight cases, seven drained fluid and the chamber could be reformed well. One was a dry tap and the chamber did not reform completely. CONCLUSION: Choroidal detachment (CD) is a previously unpublished cause for positive vitreous pressure in therapeutic keratoplasty for perforated corneal ulcers. In these situations suprachoroidal drainage can be considered as an option for the reformation of the anterior chamber. We recommend that a preoperative B-scan ultrasound be included in the workup of all corneal perforations and that intraoperative drainage of the fluid is considered in cases with significant positive vitreous pressure and confirmed CD.

Anterior Chamber↗

PubMed2002

Intracameral amphotericin B injection in the management of deep keratomycosis.

PURPOSE: To report the use of intracameral amphotericin B in the management of deep keratomycosis. METHODS: Four patients with deep keratomycosis unresponsive to conventional medical treatment underwent repeated intracameral injections of 5 microg amphotericin B in 0.1 mL 5% dextrose through a paracentesis. Three to 13 intracameral injections were given to each patient over 6 to 36 days. RESULTS: Three of the four patients had complete resolution of the ulcer. The fourth patient perforated and required evisceration. CONCLUSION: Preliminary experience suggests that intracameral injections of amphotericin B may have a role in the management of deep keratomycosis.

Adult↗