Diagnosis of Dry Eye Syndrome Using Ocular Surface Disease Index, Tear Film Break-up Time, and Schirmer Test.

OBJECTIVE: To evaluate the subjects of possible ocular surface dysfunction in dry eye syndrome (DES) by using Ocular Surface Disease Index (OSDI) questionnaire and correlating it with the tear film break-up time (TBUT) test and Schirmer test. STUDY DESIGN: Cross-sectional, observational study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), National University of Medical Sciences (NUMS), Rawalpindi, Pakistan, from March to August 2022. METHODOLOGY:  Demographics and detailed ophthalmological examinations were carried out for all the patients using slit lamp biomicroscopy. The questionnaire for OSDI was filled to calculate the OSDI score, Schirmer test, and TBUT test were performed for all patients. For statistical analysis, the mean test score of both eyes was used. Correlations between tests were drawn and reported. RESULTS: This study was conducted on ninety-seven adult participants with mean age of 31.3 ± 10.7 years, comprising of forty-five (46.4%) females and fifty-two (53.6%) males. The mean score for OSDI, TBUT, and Schirmer test was found to be 16.03 ± 14.22 (range 0 - 62.5), 9.63 ± 4.54 seconds (range 2.5 - 22.5), and 24.6 ± 10.85 mm (range 4.5 - 35.5), respectively. An inverse correlation was found between the OSDI and Schirmer, and OSDI and TBUT test scores which was also statistically significant. Schirmer and TBUT test scores also showed significant correlation. CONCLUSION: The OSDI is quick, precise, feasible for self-assessment, and non-invasive standardised tool for evaluating symptoms of dry eye disease, hence it can aid in the diagnosis of DES. KEY WORDS: Dry eye syndrome, Ocular surface, Tear flim break-up time, Schirmer test.

Refractive Outcome of Femtosecond Assisted Laser in situ Keratomileusis in 1564 cases of Myopia and Compound Myopic Astigmatism.

OBJECTIVE: To determine the outcomes of Femtosecond Assisted Laser in situ Keratomileusis (Femto LASIK) on eyes with myopia and compound myopic astigmatism in terms of efficacy, safety, accuracy, predictability, and stability of the procedure. STUDY DESIGN: Quasi-experimental study. Place and Duration of the Study: Refractive Surgical Department, Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, from January 2014 to August 2019. METHODOLOGY: Participants aged 18 years and above with upto -12D (dioptre of myopia, underwent preoperative detailed work-up with history, ocular examination, subjective refraction and assessment on topography, tomography, and aberrometry. Suitable candidates underwent Femto LASIK and were re-evaluated at 1st postoperative day, end of 1st week, 1 month, 3 months, 6 months and 1 year. Results were analysed and represented in form of standard graphs for refractive surgery.  Results: Postoperative UDVA (uncorrected distance visual acuity) of 20/40 was achieved in 99% of patients. Efficacy index was 1.02 + 0.15. Safety index was 1.04 + 0.199. None of the patients lost more than one line in postoperative CDVA (corrected distance visual acuity) when compared to preoperative CDVA. All the eyes (100%) were accurately treated within +1.0 DS of intended spherical equivalent (SEQ) range. Mean SEQ showed stability with 1% eyes recorded to have more than 0.5D change or more over 12 months. CONCLUSION: Femto LASIK is an effective, safe, accurate, predictable, and stable procedure for correction of myopia and compound myopic astigmatism. KEY WORDS: Femtosecond, Laser in situ Keratomileusis, Refractive surgery, Myopia, Compound myopic astigmatism, Uncorrected distance visual acuity.

Mechanical Epithelial Debridement versus Transepithelial Phototherapeutic Keratectomy Followed by Accelerated Corneal Collagen Crosslinking for Progressive Keratoconus.

OBJECTIVE: To compare the visual and topographic outcomes between mechanical epithelial debridement followed by accelerated corneal collagen cross linking (CXL) vs. transepithelial phototherapeutic keratectomy followed by accelerated CXL for treatment of progressive keratoconus. STUDY DESIGN: Quasi experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), National University of Medical Sciences, Rawalpindi, Pakistan, from December 2020 to December 2021. METHODOLOGY: On the basis of surgical technique used, patients were divided into two groups, Group A comprising of twenty eyes that underwent mechanical epithelial removal followed by accelerated CXL, and Group B comprising of twenty-two eyes that underwent transepithelial phototherapeutic keratectomy (t-PTK) followed by accelerated CXL. All variables were recorded preoperatively and 6 and 12 months postoperatively and included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), MRSE (manifest refraction spherical equivalent), and keratometric indices (flat K, steep K, Kmax , mean K, thinnest pachymetry, KPI, K prob, CLMIaa, and I-S). RESULTS: Forty-two eyes of twenty-nine patients were included in the study and were divided into two groups; Group A (mechanical epithelial removal followed by accelerated CXL) and Group B (t-PTK followed by accelerated CXL). The visual acuity improved in both the groups at 6 and 12 months, with more significant improvement in Group B in both UCVA (p=0.005) and CDVA (p=0.004) parameters. Keratometric outcomes showed significant differences in median values for flat K (p=0.048) and thinnest pachymetry (p=<0.001) in Group A, while significant difference in Kmax (p=0.024) and thinnest pachymetry (p=<0.001) in Group B. At 6 and 12 months, the CLMIaa, PPK, and I-S values were significantly lower in Group B (p=0.002 for all three indices). CONCLUSION: Transepithelial PTK followed by accelerated CXL yielded better outcomes regarding visual acuity and keratomertic indices as compared to mechanical epithelial removal followed by accelerated CXL and did not show any significant decrease in corneal pachymetry. KEY WORDS: Mechanical, Corneal Collagen Crosslinking (CXL), Transepithelial, Phototherapeutic keratectomy, Keratoconus.

Intraocular Pressure Changes in Myopic Patients Undergoing Laser In-Situ Keratomileusis and Photorefractive Keratectomy.

OBJECTIVE: To assess the variation in intraocular pressure measurements between Ocular Response Analyzer (ORA) and Goldmann Applanation Tonometer (GAT) in myopic patients undergoing laser assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). STUDY DESIGN: Quasi-experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), National University of Medical Sciences, Rawalpindi, Pakistan, between September 2020 and 2021. METHODOLOGY: Myopic patients undergoing LASIK and PRK during the study period were selected. Baseline examinations and postoperative follow-ups were carried out to measure intraocular pressure at 1, 3, and 6 months after LASIK or PRK, using Goldmann Applanation Tonometer (GAT) and Ocular Response Analyzer, corneal compensated IOP (ORA IOPcc). RESULTS: One hundred and thirteen eyes underwent myopic refractive surgery, LASIK (n = 60) or PRK (n = 53). Mean age of patients was 23.6 ± 4.11 years in the PRK group and 24.4 ± 5.94 years in LASIK group. For the PKR group, the GAT IOP value increased at 1-month (p <0.001), decreased at 3-month (p <0.001) and further decreased at 6-month (p <0.001) follow-up postoperatively. In the LASIK group, the GAT IOP value decreased at all time points (p <0.001). In both groups, the mean ORA IOPcc value increased at 1 month (p <0.001), decreased at 3-month (p <0.001) and further decreased at 6-month (p <0.001) follow-up postoperatively. The IOP mean values were generally found to be higher when measured using ORA as compared with GAT. CONCLUSION: Corneal refractive surgery markedly decreased IOP. This decrease in IOP was observed more after LASIK than after PRK. ORA was less likely to underestimate the intraocular pressure than GAT. KEY WORDS: Myopia, Laser in-situ keratomileusis, Photorefractive keratectomy, Tonometery ocular, Intraocular pressure.

Changes in Corneal Biomechanical Properties after Laser-Assisted in situ Keratomileusis and Photorefractive Keratectomy in Myopia.

OBJECTIVE: To compare changes in corneal biomechanical properties after laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in low and moderate myopia by Ocular Response Analyzer. STUDY DESIGN: Quasi-experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, between September 2020 and April 2022. METHODOLOGY: Myopic correction was done in forty-six eyes of twenty-three patients by PRK, and forty-seven eyes of twenty-four patients by LASIK. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using Ocular Response Analyzer (ORA), pre-operatively, and then 1, 3, and 6 months, postoperatively. The relationship between the amount of myopia treated and biomechanical properties was also studied. RESULTS: CRF and CH were decreased significantly after LASIK and PRK. A significantly larger decrease in CRF was observed after LASIK as compared to PRK at 6 months (Mann-Whitney U test: CRF, p = 0.02); however, decrease in CH was not statistically significant between LASIK and PRK at 6 months period (Mann-Whitney U test: CH, p = 0.388). A significant correlation was observed between the changes in biomechanical properties and extent of myopic correction after LASIK and PRK. CONCLUSION: Biomechanical strength of the cornea was significantly reduced by PRK and LASIK, which was also dependent on the spherical equivalent (SEQ) of myopic correction. A significantly larger change in CRF was observed after LASIK as compared to post PRK. KEY WORDS: Myopia, Laser in situ keratomileusis, Photorefractive keratectomy, Cornea, Biomechanics.

Comparison of Higher Order Aberrations between Wavefront Optimized Photorefractive Keratectomy and Laser in situ Keratomileusis in Myopic Patients.

OBJECTIVE: To compare the higher order aberrations (HOA) between wavefront optimized (WFO) laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in myopic patients. STUDY DESIGN: Quasi-experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan, from December 2021 to December 2022. METHODOLOGY: Forty-four patients underwent wavefront optimized PRK and fifty-seven patients underwent wavefront optimized LASIK. All variables were recorded before the procedure and at 1, 3, 6, and 12 months postoperatively and included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), root mean square (RMS) of HOAs, spherical aberration (SA), and coma aberration (CA). RESULTS: A total of 101 eyes of 51 patients were considered in the final analysis. Patients were divided into two groups. Group A comprised of 44 (43.6%) eyes of 22 patients who underwent PRK while group B comprised of 57 (56.4%) eyes of 29 patients who underwent LASIK. UCVA significantly improved postoperatively at 3 and 6 months in both PRK and LASIK groups (p<0.001 for both groups). In this study, the increase in root mean square (RMS) of higher order aberrations from baseline value was 77% after PRK and 28% after LASIK, similar ratio was observed in spherical aberration (SA). The trend of rise in Coma aberrations was more in LASIK group 66.49% as compared to 46.2% in PRK group. CONCLUSION: Both Wavefront Optimized PRK and LASIK are safe and have elicited comparable results of post-procedure visual recovery. There was a marked increase in RMS of HOAs in PRK group as compared to WFO LASIK group while coma aberration increased more in LASIK as compared to PRK postoperatively. KEY WORDS: LASIK, PRK, RMSh, HOAs, Spherical aberration, Coma, Myopia.

Correlation Between Corneal Keratometry, Central Corneal Thickness and Anterior Chamber Depth as Measured by Wavelight OB 820 Biometer and Wavelight Oculyzer II in Preoperative Cataract Surgery Patients.

OBJECTIVE: To compare and correlate corneal keratometry (K), central corneal thickness (CCT), and anterior chamber depth (ACD) using a partial coherence interferometry device and a Scheimpflug camera system device in patients planned for cataract surgery. STUDY DESIGN: Comparative cross-sectional study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology, from December 2021 to June 2022. METHODOLOGY: Patients planned for cataract surgery underwent measurement of central corneal thickness (CCT), anterior chamber depth (ACD), and keratometric values (K) by Wavelight OB 820 biometer and Allergo Oculyzer II, preoperatively. Correlation and inter-device agreement were assessed between two devices. RESULTS: There were 115 patients with a mean age of 64.23 ± 9.26 years. All anterior segment parameters showed excellent agreement and high degree of correlation between the two optical devices. Correlation coefficient (r) for central corneal thickness was r = 0.958 (p<0.001) while correlation coefficient for anterior chamber depth was r = 0.965 (p<0.001), r = 0.966 (p<0.001) for flat K, and r = .0969 (p<0.001) for steep keratometry, respectively. CONCLUSION: Ophthalmic parameters assessed by both devices were comparable and are recommended to be used in the clinical practice of keratorefractive and cataract surgeries interchangeably. KEY WORDS: ACD, CCT, Keratometry, Cataract, OB 820 biometer, Oculyzer II.

Assessment of Refractive Outcome of Photo Refractive Keratectomy in Myopia and Myopic Astigmatism.

OBJECTIVES: To determine the refractive outcomes of wavefront optimized photo refractive keratectomy (PRK) in patients having myopia and myopic astigmatism in terms of efficacy, safety, accuracy, stability and predictability of the procedure. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Refractive Surgical Unit, Armed Forces Institute of Ophthalmology, National University of Medical Sciences, Rawalpindi, Pakistan, from October 2013 to August 2018. METHODOLOGY: Patients having myopia and myopic astigmatism, consented to be a part of the study, underwent meticulous screening consisting of detailed medical history, ocular examination and investigations. Each case was compiled and evaluated. Those who satisfied the criteria for refractive surgery were subjected to PRK procedure. Postoperative follow-up was carried out and parameters were recorded at designated intervals of 1 week, 1, 3, 6 and 12 months. RESULTS: This study included 208 eyes of 106 patients with mean age of 25.33 + 5.196 years. At the end of one year, 97% (202 out of 208) eyes had uncorrected distance visual acuity (UDVA) better than 20/25 with efficacy index of 1.009 ± 0.132 and safety index of 1.019 ± 0.126. None of the eyes lost two or more lines. In this study, 207 out of 208 eyes remained within + 0.50 diopter (D) of intended spherical equivalent (SEQ). Results showed 100% accuracy of procedure since all the study patients achieved SEQ within + 1D. CONCLUSION: PRK is an effective, predictable, and safe treatment procedure for correcting myopia and myopic astigmatism. Key Words: Photorefractive keratectomy, Myopia, Refractive surgery, Myopic astigmatism, Uncorrected distance visual acuity.

Microsporidial Keratitis - First Case Series of a Rare Pathogen in the Wake of Flood Disasters of 2022 in Pakistan.

The recent monsoon rains in Pakistan were unprecedented and caused flooding all over Pakistan, especially in Sindh and Balochistan. Following this national disaster, various water-borne and contagious diseases started erupting all over the country. In such a calamity-struck city of Jacobabad, we started receiving cases with a peculiar set of ocular complaints mimicking viral keratoconjunctivitis. Failure to respond to traditional treatment and the unique appearance of these corneal opacities led to a rare diagnosis of Microsporidial Keratoconjunctivitis, which was later confirmed by microscopy and staining of corneal scrapings of the most affected case. In line with published literature, all cases were treated with topical fluoroquinolone and topical anti-fungal therapy, following which the disease was cleared within a week. The disease has seen an upward trend the world over, especially among Asia. To the best of our knowledge, no such cases have been reported in Pakistan as yet. In this case series, we highlight the strong correlation of emergence of microsporidial keratitis in patients following exposure to pooled water bodies after the monsoon rainy season and floods. Moreover, this report will help create awareness in eye professionals regarding the prevention, timely diagnosis and treatment of these rare and emerging cases. Key Words: Keratitis, Spores, Water-borne diseases, Microsporidia.

Assessment of Refractive Outcomes of Femtosecond-assisted Laser in Situ Keratomileusis (LASIK) for Hyperopia.

OBJECTIVE: To determine the effect of refractive treatment in terms of safety, efficacy, stability, accuracy, and predictability with Wavefront Optimized Laser-assisted in situ keratomileusis (LASIK) on hyperopia. STUDY DESIGN: Descriptive, analytical study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology, National University of Medical Sciences, Rawalpindi, Pakistan from August 2013 to June 2018.  Methodology: Participants were selected after detailed history, careful ocular examination and meticulous relevant assessment on refractive scans. Preoperative measurements were recorded. Refractive strategy was designed, considering individual requirements for each patient. Postoperative readings were taken at 1 day, 1 week, 1, 3, 6 and 12 months. RESULTS: A total of 54 patients participated with mean age of 28.07 + 8.13 years. Out of the 54 patients, 33 (61%) were males and 21 (39%) were females. Uncorrected distance visual acuity (UDVA) and Spherical equivalent (SEQ), which is algebraic sum of sphere and half of cylinder, were recorded pre- and postoperatively. These parameters were changed significantly at 12 months (p <0.001). SEQ reduced from 2.146 + 2.027 to 0.079 ± 0.269 Diopter (D) (p <0.001). UDVA improved from 0.672 ± 0.270 (20/93) to 0.153 ± 0.182 (20/28) (p <0.001). A total of 48 (out of 54) patients had uncorrected vision better than 20/40; and 49 patients showed either same or gain of Snellen lines when pre- and postoperative corrected distance visual acuity (CDVA) was compared. Two patients showed loss of two or more lines. All the patients had postoperative SEQ within + 1.0 D range. CONCLUSION: LASIK, performed to correct hyperopia, demonstrated satisfactory outcomes in terms of safety, efficacy, stability, accuracy, and predictability. LASIK is an effective treatment option for moderate (<6 D) hyperopia. Key Words: LASIK, Refractive surgery, Hyperopia, Spherical equivalent, Uncorrected distance visual acuity.

Screening Thresholds for the Corneal Tomography in Hyperopic Pakistani Population.

OBJECTIVE: To evaluate key corneal tomography parameters for screening mixed astigmatism and hyperopic males and females for refractive surgery and to compare the data to a previously studied myopic group in Pakistani population. STUDY DESIGN: Cross-sectional, observational study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology AFIO, National University of Medical Sciences, Rawalpindi, Pakistan, from August 2013 to August 2018. METHODOLOGY: WaveLight Allegro Oculyzer II diagnostic device was used to examine eyes of 106 adult hyperopic patients in order to determine normal values of 20 parameters, which are considered most clinically applicable for refractive surgery screening. Kolmogorov-Smirnov test was used to evaluate normality of data. Results for outliers were displayed as 2.5%, 5%, 95% and 97.5% percentiles. RESULTS: Two hundred and nine eyes were examined; 110 men and 99 women with overall mean age of 31+11.7 years. Normal mean anterior segment values included: flat simulated keratometry (K1) 42.1±1.84 diopters (D), steep K2 43.8 ± 1.93 D, K maximum 44.4 ± 1.93 D, K mean 42.9 ± 1.75 D, astigmatism -1.3 ± 1.75 D, pachymetry at thinnest point 546.9 ± 33.3 um, front elevation at thinnest point 5.2 ± 3.47 um, and at the back was 14.1 ± 6.60 um, Ambrosio relational thickness maximum 472.0 ± 88.73, progression index (PI) maximum 1.2 ± 0.18, and anterior chamber depth (ACD) 2.7 ± 0.35 mm. CONCLUSION: Hyperopic patients had greater front and back elevation and pachymetry but lesser keratometry, anterior chamber depth and chamber volume as compared to myopic patients in Pakistani population. Front and back elevation data in this hyperopic study population was slightly higher than previously published studies. Key Words: Refractive surgery, Corneal tomography, Screening, Hyperope.

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.

Agreement between Keratometric readings by VERION image guided System, Galilei G4 and Pentacam.

OBJECTIVE: To study Agreement between Keratometric readings by VERION image guided System, Galilei G4 and Pentacam. METHODS: The quasi experimental study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from August 2016 to December 2016. Twenty five patients fulfilling the inclusion criteria participated in the study. All Patients were subjected to Keratometric assessment using Galilei G4 Dual Scheimpflug analyzer (Ziemer, Switzerland), Wavelight Oculyzer II (Pentacam, Germany) and Verion image guided system (Alcon). Steep and flat meridian and diopter of astigmatism by three systems were recorded and endorsed. All readings were taken by the same observer. Statistical Program for Social Sciences (SPSS) version 22.0 was used for statistical analysis. Results analyzed for significance by t-tests and Interclass correlation analysis. In t tests, P values of <0.05 was considered statistically significant while interclass coefficient of >0.7 was considered acceptable. RESULTS: Fifty eyes of twenty-five patients (22 male, 28 female) with mean age of 29.50 ± 3.46 years were studied. Flat K, steep K and dioptric power of astigmatism were measured with verion, pentacam and Galilei G4. Interclass correlation analysis showed agreement between individual variables measured by the three devices, while one sample t test showed no significant difference between dioptric power of astigmatism between Verion-Pentacam and Verion- Galilei group. (p 0.178 for former and 0.622 for later group). CONCLUSION: Verion image guided system is comparable to other instruments used currently for keratometry. Verion can be interchangeably used with Pentacam and Galilee G4 in assessing corneal astigmatism.

Safety Of High Intensity Accelerated Corneal Collagen Cross-Linking In Keratoconus Patients On Basis Of Endothelial Cell Density.

BACKGROUND: This study was conducted to evaluate the safety of accelerated corneal collagen crosslinking (CXL) in keratoconus patients on basis of endothelial cell density measurements. METHODS: We studied 24 patients (42 eyes) with diagnosed keratoconus who underwent accelerated CXL with 9 Mw/cm2 UVA irradiance for 10minutes. All patients underwent detailed examination and video keratography (VKG) for classification and confirmation of keratoconus. Patients with central corneal thickness (CCT) of ≥400µ were included in the study. Specular microscopy was done to note endothelial cell density (ECD) preoperatively and then at the end of 1st, 4th and 12th weeks' post-operative period. RESULTS: The study included 24 patients (42 eyes) from October 2016 to June 2017. Among these 13 were females and 11 males with mean age of 20.15±6.73 years. Eighteen patients underwent the procedure in both eyes while 6 had the procedure in one eye. The pre-operative ECD mean±SD of right eye was 2743.97±542.77/mm2 and left eye was 2763.35±532.57/mm2. The post-operative ECD mean±SD of right and left eyes at the end of 12th post-op weak were 2806.34±520.11/mm2 and 2823.30±628.57/mm2 respectively. The pre and post-op ECD comparison showed p-values at first week post-op are 0.474 and 0.683 for right and left eyes respectively. Similarly, the p-values at 4th and 12 weeks post-op for right eye are 0.266 and 0.280 respectively. The p-values at 4th and 12th weeks for left eye are 0.913 and 0.404 respectively. CONCLUSIONS: Accelerated CXL protocols is safe and effective procedure and did not lead to significant change in ECD in our study population in three months post-procedural follow up. However further research is required to determine the effect of high intensity UVA radiation on other ocular structures with larger group of patients and long-term follow up.

Comparison of analgesic effect of preoperative topical Diclofenac versus Ketorolac on postoperative pain after Corneal Collagen Cross Linkage.

OBJECTIVE: To compare post-operative pain relieving effect of topical diclofenac 0.1% versus ketorolac 0.5% in Corneal Collagen Cross Linking (CXL) for patients diagnosed with keratoconus. METHODS: This randomized controlled trial was carried out for six months from October 2016 to March 2017. We included young patients having keratoconus with k-readings greater than 47D and central corneal thickness more than 400 microns. All the patients received single dose one drop of topical diclofenac 0.1% to (Group-A) and ketorolac 0.5% to (Group-B) 30 minutes in advance of the corneal collagen cross linking (CXL) procedure. The CXL was performed with topical 0.1% riboflavin eye drops in 20% dextran as a photo sensitizer. After 36 hours of the CXL procedure, the postoperative intensity of pain was assessed verbally by patients with the help of visual analog scale (VAS) numbers from zero to five where 0 designated no pain & 5 symbolized worst pain. RESULTS: The study comprised sixty eyes of forty one patients. Out of total 16 were male while 25 female patients. The mean age of the patients was 24.27 ± 2.93 years (range 20 to 29 years). In the conclusive analysis, diclofenac 0.1% was used on 30 patients in Group-A and ketorolac 0.5% on 30 subjects in Group-B. Pain relieving scores in Group-A (diclofenac 0.1%) was 2.57 ± 0.67 while in Group-B (ketorolac 0.4% treated arm) was 3.20 ± 0.61. CONCLUSION: Topical diclofenac 0.1% is statistically comparable to topical ketorolac 0.5% in precluding severity of pain after corneal collagen cross linkage operation.

Effect of Femtosecond Laser-Assisted Cataract Surgery (FLACS) on Endothelial Cell Count.

OBJECTIVE: To compare the change in endothelial cell count after femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification. STUDY DESIGN: Randomized controlled clinical trial. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from January 2016 to August 2017. METHODOLOGY: Patients with senile cataract and age ranging from 40 to 80 years were included in the study. Patients with any other cause of endothelial cell loss, history of trauma, documented diabetes millitis, hypertention and glaucoma were excluded. Preoperative detailed ocular examination, including both anterior and posterior examination, was carried out. Patients were distributed into two groups. Group GP were planned for conventional phacoemulsification, while group GF underwent FLACS. All the surgeries were performed under local anesthesia by same ophthalmic surgeon. Specular microscope (Topcon specular microscope sp-3000p) was utilized to measure the endothelial cell count (ECC) before and 4 weeks after the surgery. RESULTS: Fifty eyes (25 in each group) of 48 patients underwent cataract surgery by phacoemulsification or FLACS. Twenty-five (52.08%) out of the total were females while 23 (47.91%) were males. Median age of the participants in phacoemulsification group was 55 years (IQR 20.50), while in FLACS group it was 54 years (IQR 8). The median change in endothelial cell count was 228 (IQR 532) in Phaco group, while 23 (IQR 35) in FLACS group. (p<0.05 Mann Whitney U-test). CONCLUSION: FLACS is a safe and effective modality for cataract treatment and it induces significantly less endothelial cell loss than conventional phacoemulsification.

Transepithelial corneal crosslinking in treatment of progressive keratoconus: 12 months' clinical results.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of transepithelial corneal collagen cross linking (TE-CXL) with modified riboflavin and accelerated UVA irradiance in thin corneas with pachymetry less than 400 microns at thinnest point, untreatable by epithelium off corneal collagen cross linking (CXL) in adult Pakistani population with progressive keratoconus. METHODS: This quasi experimental study included twenty six eyes of 26 patients with progressive keratoconus who underwent accelerated transepithelial CXL in Armed forced institute of ophthalmology with 12 months follow up. Modified riboflavin, ParaCel ((riboflavin 0.25%, Benzalkonium chloride, EDTA, Trometamol, hydroxypropyl methylcellulose) and vibeX Xtra (riboflavin 0.25%) (Avedro, USA)) were applied to cornea in two stages. Uncorrected and Corrected Distant Visual Acuities (UDVA, CDVA), spherical equivalent (SE), astigmatism, pachymetry at thinnest point (Pachy thin), apex keratometry (Kmax), simulated and steep keratometry (Sim K, steep K) were measured at baseline and at 3, 6 and 12 months post operatively. The cornea was then exposed to accelerated UVA irradiance of 9mW/cm2 for 10 min (total dose 30 mW/cm2). RESULTS: The mean age of the patient was 24.54±5.16 years. UDVA, CDVA, SE, astigmatism significantly improved at all postoperative test points (p=0.000, 0.004, 0.000, 0.004 respectively). Kmax and pachy thin were significantly reduced over baseline at 1 year (p=0.000, 0.004 respectively). Topographic indices Sim K and steep K did not show significant changes. No intra or post-operative complications were reported. CONCLUSION: Transepithelial accelerated CXL with modified riboflavin is a safe and effective procedure which halt disease progression in thin corneas with progressive keratoconus.

TNF-α Genetic Predisposition and Higher Expression of Inflammatory Pathway Components in Keratoconus.

Purpose: To date keratoconus (KC) pathogenesis is undefined; however, the involvement of inflammatory pathways in disease development is becoming apparent. In the present study, we investigated the role of a promoter region polymorphism rs1800629 (-308G>A) in the inflammatory pathway component TNF-α and its effects on the expression of TNF-α and downstream molecules tumor necrosis factor receptor 1 and 2 (TNFR1 and TNFR2), v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA), and interleukin 6 (IL-6) in KC development. Methods: TNF-α promoter polymorphism rs1800629 (-308G>A), was genotyped in 257 sporadic KC patients and 253 healthy controls. Enzyme-linked immunosorbent assay (ELISA) was performed to assess for the -308G>A genotypes. Quantitative polymerase chain reaction (qPCR) was carried out to compare the mRNA expression of TNF-α, TNFR1, TNFR2, RELA, and IL6 in the corneal tissues of 20 KC patients and 20 donor controls. Results: The -308G>A genotype GA was found to be significantly associated with KC development (dominant model [odds ratio (OR) = 6.67 (95% confidence interval [CI] = 4.28-10.42), P < 0.001]) and allele-A (OR = 4.30, 95%CI = 2.93-6.34, P < 0.001). TNF-α serum levels were significantly raised in patients with GA genotype (196.5 ± 69.5 pg/mL) compared to reference genotype GG (21.7 ± 8.2 pg/mL) (P < 0.0001). There was a significant overexpression of TNF-α (P = 0.002), TNFR2 (P = 0.0001), RELA (P = 0.0117), and IL6 (P = 0.0007) in the KC corneal tissues as compared to the control. Conclusions: The GA genotype of the TNF-α -308G>A polymorphism is a significant genetic risk factor for the pathogenesis of KC. Moreover, this single nucleotide polymorphism (SNP) was observed to be associated with deregulated expression of downstream molecules, thus further reinforcing the role of the inflammatory pathway components in the development of KC.

Comparison of Clinical Characteristics of Rhegmatogenous Retinal Detachment in Pseudophakic and Phakic Eyes.

OBJECTIVE: To compare the clinical profile, systemic risk factors, and characteristics of rhegmatogenous retinal detachment (RRD) in pseudophakic and phakic eyes. STUDY DESIGN: Cross-sectional comparative study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology, Rawalpindi from August 2013 to August 2015. METHODOLOGY: A total of 164 eyes (96 pseudophakic patients and 68 phakic patients) with RRD were analyzed. Demographic data and associated known risk factors of study population were acquired. Retinal examination was done by single experienced retinal surgeon using indirect ophthalmoscopy for type of retinal break, location and number of retinal breaks, status of macula, morphological extent of RRD and retinal degenerations. All the findings were endorsed on a pre-devised proforma. RESULTS: Mean age of patients in pseudophakic and phakic groups was 61.18 ±10.39 and 59.27 ±9.57 years, respectively. Frequency of male patients in pseudophakic and phakic groups was 74% and 57.4%, respectively. Mean axial length in pseudophakic and phakic groups was 23.13 ±2.18 mm and 21.9 ±2.01 mm, respectively. Difference in axial length and gender distribution between two groups was statistically significant (p < 0.05). Difference in frequency of patients with history of hypertension and myopia between two groups was statistically significant (p < 0.05). Characteristics of RRD (type, location and number of retinal breaks, macula status, and extent of RRD) between groups were not statistically significant. CONCLUSION: RRD is more common in pseudophakic patients with male gender, increased axial length, myopia, and hypertension.

Visual outcome of retinal vein occlusion in patients residing at high altitude.

OBJECTIVE: To study visual outcome in patients of high altitude retinopathy presenting with retinal venous occlusion. METHODS: The randomised clinical trial study was conducted at the Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan, from January 2013 to December 2015, and comprised eyes of lowlanders. Patients staying at high altitude (>8,000 feet above sea level) as part of their service duty and presented with retinal venous occlusive disease were included. Patients with history of diabetes, hypertension, glaucoma, any pre-existing retinal disease or age-related conditions responsible for decreased vision were excluded. Detailed ocular as well as systemic examination was carried out to establish the diagnosis of retinal venous occlusion. Patients were divided into two groups. First group was observed over a period of 6 months and labelled as control group, whereas the second group was treated with intravitrealbevacizumab and labelled as intervention group. Complete ocular examination was carried out in all patients at 4 weeks, 3 months and 6 months. SPSS 21 was used for data analysis. RESULTS: A series of 32 eyes of 28 male patients were included. The overall mean age was 31.40±3.40 years. The mean altitude of their temporary stay was 4,120±941 metres above sea level and the mean duration of stay was 6.80±4.13months. Besides, 21(75%) subjects were smokers. Moreover, 26(81.25%) eyes had central retinal vein occlusion while branch retinal vein occlusion was seen in 6(18.75%) eyes. The mean visual acuity in the control group was 0.70±0.56 on Logarithm of the Minimum Angle of Resolution chart at the presentation while it was 0.26±0.87, 0.20±0.32 and 0.15±0.23 after 4 weeks, 3 months and 6 months, respectively. The mean best corrected visual acuity in intervention group was 0.68 ± 0.46 before treatment and 0.15±0.11, 0.12±0.11 and 0.10±0.08 at 4 weeks, 3 months and 6 months, respectively. Significant post-intervention change was observed in best corrected visual acuity at 6 months (p<0.05) in patients who presented with severe visual loss. CONCLUSIONS: Treatment with intravitrealbevacizumab may be considered in patients with severe visual loss at presentation.