Screening thresholds for the corneal tomography in a myopic Pakistani population

Objective: To evaluate key corneal tomography parameters for screening refractive surgery patients in Pakistani population

Study Design: Cross-sectional, observation study

Place and Duration of Study: Armed Forces Institute of Ophthalmology AFIO, National University of Medical Sciences, Rawalpindi, Pakistan, from August 2013 to December 2016

Methodology: Myopic patients were evaluated by two separate observers on Allegro OculyzerII [Wavelight] for normal ocular examination. A total of 20 tomographic parameters, used for pre-refractive surgical evaluation, were included. Normality of data was evaluated using Kolmogorov-Smirnov test. Results for outliers were displayed as 2.5%, 5%, 95% and 97.5% percentiles

Results: The sample of 451 patients [895 eyes], comprised of 61% [n=277] females and 39% [n=174] males [39%]. The mean age was 26 +6.4 years [range of 18-62 years, M=F]. Normal mean anterior segment values included; flat simulated keratometry [K1] 42.9 +/-1.44 diopters [D], steep K2 43.9 +/-1.52 D, K mean 43.4 +/-1.43 D, K maximum 44.6 +/-1.56 D, astigmatism -0.96 +/-0.97 D, anterior chamber depth [ACD] 3.19 +/-0.28 mm, front elevation at the thinnest point 4.11 +/-2.44 um, and that at the back was 7.56 +/-4.52 um progression index [PI] maximum 1.14 +/-0.17, Ambrosio relational thickness maximum [ART max] 487.5 +/-89.0 and pachymetry at thinnest point 542.2 +/- 31.1 um

Conclusion: The study demonstrates key corneal tomography parameters, which can be useful for screening refractive surgery patients in Pakistani population

Healthcare in Pakistan-A systems perspective

Health system in Pakistan has witnessed evolution and dates back to the medieval, traditional health care, health for all approach, primary health care approach and health systems strengthening approach for better health outcomes. The main objectives of health system are improvement in health, fairness in distribution of risk and finances and responsiveness to the non medical needs of the population. With decreasing expenditure on health care, booming private health sector and flourishing pharmaceutical industry, government can only reduce catastrophic health expenditures by the poor and impoverished through an efficient, effective, accessible and responsive public health system. Inter sectoral collaboration, community participation, social protection, equitable distribution of resources, people centric health policy, health work force development, evidence based health information system and quality assurance of essential medicines will strengthen health system in Pakistan

Intravitreal triamcinolone alone versus combined intravitreal triamcinolone and bevacizumab on central macular thickness in diabetic macular edema

Objective: To compare the effect of intravitreal triamcinolone [IVT] alone with combined intravitreal triamcinolone [IVT] and intravitreal bevacizumab [IVB] on central macular thickness [CMT] in patients of diabetic macular edema [DME]

Study Design: Randomized control trial

Place and Duration of Study: Armed Forces Institute of Ophthalmology, Jun 2013 to Dec 2013

Material and Methods: Eighty patients were included in the study through non probability consecutive sampling and were randomized to IVT alone or IVT + IVB group using random number table. Pre and post injection [12 weeks] CMT were recorded and intra and inter group comparison was performed

Results: Both groups showed statistically significant reduction in mean CMT at 12 weeks [p<0.05]. In Group A, mean CMT reduction at 12 weeks was 64.33 microns [SD=15.17] while in Group B it was 75.18 [SD=20.82]. On comparison, IVT + IVB group was more effective in reducing CMT with statistically significant difference [p=0.009]

Conclusion: Intravitreal triamcinolone used in combination with IVB is more effective in reducing central macular thickness in diabetic macular edema [DME] than intravitreal triamcinolone alone

Comparison of rapid and conventional corneal collagen cross linking in patients having Keratoconus

To compare the effect of rapid and conventional methods of corneal collagen cross linking [CXL] on visual acuity [VA] and corneal parameters in Keratoconus. Randomized control trial. Armed Forces Institute of Ophthalmology, Feb 2012 to Apr 2013. Thirty patients, fifteen in each group, were randomized by non probability consecutive sampling to rapid or conventional CXL group. Pre and post operative [6 months] best corrected visual acuity [BCVA], anterior and posterior keratometric [K] values and pachymetry were recorded. Intra and inter group comparison of all these parameters were statistically analyzed. All thrty patients showed either stabilization or improvement in BCVA. Both groups showed comparable results in terms of improvement BCVA [p = 0.682], reduction in the corneal thickness at thinnest point [p = 0.062], anterior flat and steep K [p = 0.633, p = 0.443 respectively] and posterior flat and steep K values [p = 0.130, p = 0.068] at six months duration. Conventional and rapid methods of CXL are comparable in terms of their effect on VA and corneal parameters

Comparison of higher order aberrations in patients with various refractive errors

To compare the mean root mean square [RMS] of total higher order aberrations [HOAs], coma and spherical aberrations in individuals with myopia, hypermetropia and myopic astigmatism. This prospective analytical study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from Jan 2014 to Dec 2014. Two hundred eyes of 121 patients with age ranging from 18-40 years were included in the study. Patients were divided into 4 group namely Low myopia, High myopia, Astigmatism and Hypermetropia on the basis of refractive error. Included were the patients who had refractive error more than +/- 0.5D and best corrected visual acuity [BCVA] of 0.00 or better. Patients who had history of surgery and / or eye disease were excluded from the study. Visual acuity [VA], Spherical equivalent [SE] of refractive error, RMS value of total HOAs, coma and spherical aberrations were evaluated. HOAs were measured with aberrometer [Wavelight analyzer version 1073] at 6 mm pupil size. Age of the patients ranged from 18 years to 40 years with mean age of 29.10 +/- 10.6 years. Seventy one [35.5%] were males and 129 [64.5%] were female. Mean RMS value of HOAs, coma and spherical aberrations was calculated in all four groups. RMS of total HOAs and spherical aberrations in hypermetropia was 0.96 +/- 0.96 and 0.30 +/- 0.42 respectively and it was higher than other three groups. In overall comparison the mean RMS of total HOAs and spherical aberrations was significantly increased in hypermetropia group and there was a statistically significant negative correlation of SE of hypermetropia with RMS of total HOAs and spherical aberration

Effect of wavefront optimized LASIK on higher order aberrations in myopic patients

To determine mean change induced in root mean square value of higher order aberrations in myopic patients undergoing wavefront optimized laser assisted in situ keratomileusis. This quasi experimental study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from Jan 2014 to Dec 2014. Sixty eyes of 35 myopic patients were included in the study. All patients underwent wavefront optimized [WFO] laser assisted in situ keratomileusis [LASIK] using femtosecond laser [FM 200Wavelight technologies] and excimer laser [Ew SOOWavelight technologies]. Higher order aberrations [HOAs] were measured with aberrometer [Wavelight allegro analyzer version 1073] during preoperative assessment and one month after surgery. All 35 patients ranged from 20 to 32 years with a mean age of 24 +/- 3.41 years. Refractive error ranged from -1.00 to -9.50 DS with a mean spherical equivalent [SE] of -3.73 +/- 1.95 before surgery and - 0.36 +/- 1.50DS one month after LASIK. Uncorrected visual acuity [UCVA] was improved to 0.00 or better in all 60 eyes. An increase of 1.56 fold was observed in RMS of total HOAs. Among the HOAs, a statistically significant positive correlation was observed between spherical aberrations [4[th] order aberration] and preoperative spherical equivalent. In spite of excellent improvement in refractive error, significant amount of higher order aberrations were induced after WFO LASIK

Association of vitamin d deficiency with tuberculosis in adult patients reporting to a tertiary care hospital of Rawalpindi

To compare the mean vitamin D levels in pulmonary tuberculosis patients and healthy controls and to find out the frequency and association of vitamin D deficiency in patients with tuberculosis. Study Design: Case control study. Pulmonology department, Military Hospital Rawalpindi from Jan 2013 to Dec 2013. Patients and Methods: Fifty two incident outdoor pulmonary tuberculosis patients were selected with 52 age and gender matched controls. Tuberculosis was diagnosed by the sputum examination through gene Xpert technique from National Institute of Health [NIH], Islamabad. Serum 25-hydroxvitamin D level <50 nmol/1 [electrochemiluminescene assay] was taken as vitamin D deficiency. Mean vitamin D was much lower [20.688 +/- 14.065 nmol/1] in cases as compared to the controls [57.917 +/- 18.197 nmol/1] which was statistically significant [p<0.001]. Forty nine [94%] cases and 18 [34.6%] controls were found to be vitamin D deficient. [Odd's Ratio = 3.8, 95% CI = 2.423-5.999, p>0.00l]. Sensitive tuberculosis patients had mean vit D levels of 18.55 +/- 9.99 nmol/1 while multi-drug resistant tuberculosis patients had the mean serum vitamin D levels of 22.38 +/- 16.60 nmol/1 but the difference was statistically insignificant [p > 0.05]. Significant vitamin D deficiency was seen in newly diagnosed TB patients. It was found that vitamin D deficiency is associated with tuberculosis, but its causal role has not been established