Ritu Arora

Comparative Analysis of Refractive and Topographic Changes in Early and Advanced Keratoconic Eyes Undergoing Corneal Collagen Crosslinking.

Purpose: To compare the refractive and topographic changes at 1 year in eyes with early and advanced keratoconus undergoing corneal collagen crosslinking (CXL). A prospective, nonrandomized comparative clinical intervention study. Methods: Thirty eyes of patients with keratoconus underwent CXL. They were divided into 2 groups based on their mean central keratometry: group A [mean central K ⩽ 53 diopters (D)] and group B (mean central K > 53 D). Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refraction, topography, pachymetry, and endothelial cell counts were evaluated at baseline and at 1, 3, 6, and 12 months of follow-up. Results: The mean baseline logarithm of the minimum angle of resolution (logMAR) UCVA and logMAR BCVA in group A was 1.007 ± 0.30 and 0.566 ± 0.21, respectively. The values improved to 0.727 ± 0.29 (P = 0.001) and 0.306 ± 0.15 (P = 0.001) at 1-year post CXL. The mean baseline logMAR UCVA and logMAR BCVA in group B were 1.040 ± 0.24 and 0.641 ± 0.25, respectively. It changed to 0.953 ± 0.26 (P = 0.054) and 0.633 ± 0.27 (P = 0.891) at 1 year. The improvement in the UCVA and BCVA was statistically significant in group A as compared with that in group B. The mean baseline flattest, steepest, central, and apical keratometry in group A were 48.7 ± 2.5 D, 54.9 ± 3.3 D, 49.5 ± 1.4 D, and 57.3 ± 2.3 D, respectively. At 12 months, the values changed to 47.8 ± 2.4 D, 54.1 ± 3.0 D, 48.8 ± 1.8 D, and 56.2 ± 2.7 D, the change being statistically significant for mean flat and apical K only (P < 0.05). All the 4 indices did not show any statistically significant difference at 12 months in group B (P > 0.05). Conclusions: Corneal CXL is more effective in improving the refractive and topographical parameters at 1 year when it is performed early in the course of the disease.

Temporary conduction block of optic nerve after retrobulbar anesthesia.

Three patients who experienced temporary visual loss after retrobulbar anesthesia with 2% lidocaine (Xylocaine) are described. Visual evoked potentials (VEPs) consistently increased in latency and decreased in amplitude. Abnormal VEPs such as these recorded for humans after retrobulbar anesthesia are, to our knowledge, reported here for the first time.

Peribulbar anesthesia and optic nerve conduction

ABSTRACT Serial recordings of distance visual acuity and visually evoked potentials (VEPS) after peribulbar anesthesia in three patients are reported. Visual acuity was not markedly affected but the latency and amplitude of VEPS were. This study concludes that optic nerve conduction is not significantly affected by peribulbar anesthesia.

Peribulbar Anesthesia in Retinal Reattachment Surgery

We prospectively evaluated the effectiveness of peribulbar anesthesia in retinal reattachment surgery. Of the 24 patients studied, 2 required retrobulbar supplementation during the latter part of the surgery. Our results show that peribulbar anesthesia can be effectively used for retinal reattachment surgery and probably should be the preferred form of local anesthesia for this surgery, since the eyes involved have a relatively high incidence of axial myopia and posterior staphyloma.

Comparative evaluation of higher-order aberrations and corneal asphericity between wavefront-guided and aspheric LASIK for myopia.

PURPOSE To compare visual outcome, higher-order aberrations, and corneal asphericity (Q value) between wavefront-guided and aspheric LASIK for myopia and myopic astigmatism. METHODS Forty patients were randomly selected to receive wavefront-guided LASIK (wavefront-guided group) or aspheric LASIK (aspheric group) (40 eyes of 20 patients in each group) using the Technolas 217z excimer laser platform (Bausch & Lomb, Rochester, NY). Flaps were created using the Zyoptix XP microkeratome (Bausch & Lomb). Preoperative and postoperative evaluation included uncorrected distance visual acuity (UDVA), corneal topography, wavefront aberrometry, and contrast sensitivity. Minimum follow-up period was 6 months. RESULTS At 6 months postoperatively, the aspheric group had significantly better UDVA (logMAR 0.04 ± 0.04 [Snellen 20/16] [range: -0.079 to 0.000]) and lower mean residual spherical error (+0.10 ± 0.52 diopters [D] [range: -1.12 to 1.25 D]) than the wavefront-guided group (logMAR UDVA 0.00 ± 0.07 [range: -0.079 to 0.176]; MRSE -0.35 ± 0.47 D [range: -1.5 to 0.62 D]) (P = .003 and < .001, respectively). Mean change in higher-order aberration root mean square at 6 months postoperatively (6-mm pupil) was 0.16 ± 0.17 µm after aspheric LASIK and 0.27 ± 0.28 µm after wavefront-guided LASIK (P = .02). Aspheric LASIK induced minimal change in spherical aberrations postoperatively (0.03 ± 0.12 µm, P = .09), unlike wavefront-guided LASIK (0.23 ± 0.17 µm, P < .01). Change in Q value was significantly less in the aspheric group (0.53 ± 0.31) than the wavefront-guided group (0.91 ± 0.30) (P < .01). The aspheric group had significant improvement in contrast sensitivity at all spatial frequencies (P < .01), whereas the wavefront-guided group showed a slight decrease at higher spatial frequency (18 cycles per degree). CONCLUSIONS Aspheric LASIK induced significantly less change in higher-order aberrations and maintained corneal asphericity better than wavefront-guided LASIK. The visual outcome and contrast sensitivity was better in the aspheric group at 6 months postoperatively.

Eye casualty department

A retrospective analysis of all new patients attending our eye casualty department was carried out during the 1 year period, from January to December 1987. During this time the casualty unit saw and treated 4905 new patients. Of these 40.61% were traumatic in origin, 30.52% comprised various ocular infections and the remaining 28.87% had miscellaneous ocular problems. On average, 13 new patients and seven consultations from other departments were seen and treated daily. Apart from the management of ocular emergencies, other functions provided by our department included glaucoma screening, donor eye collection, attending to referrals from other departments and eye health education.

Black corneal ulcer.

Purpose To discuss the etiology of an unusual finding of black color in a corneal ulcer. Method Smear examination and culture of the corneal scraping were undertaken. Result The causative organism was found to be Aspergillus niger. Conclusion Black color in the corneal ulcer is attributed to Aspergillus niger.

Operculina turpethum extract inhibits growth and proliferation by inhibiting NF-κB, COX-2 and cyclin D1 and induces apoptosis by up regulating P53 in oral cancer cells

OBJECTIVES Herbal drugs are popularly emerging as complementary and alternative medicines in cancer patients because of their cost effectiveness and minimal side-effects. The extract of Operculina turpethum (OT) is known to have antipyretic, anti-inflammatory and purgative properties. Since it is popularly known have antiinflammatory activity, we investigated its anti-tumor activity on four oral squamous cell carcinoma cell lines (OSCC) namely, (SCC-4, KB, SCC-9 and SCC-25). DESIGN Antitumor activities of Operculina turpathum extract (OTE) was investigated by MTT and clonogenic assay, effect on cell cycle and apoptosis induction by Annexin-V/propidium iodide (PI) staining and flow cytometry and invasive potential of the tumor was determined by matrigel assay. The expression of various proteins involved in these mechanisms was analysed by western blotting. RESULTS OTE specifically inhibited the growth and colony formation of OSCC cells in a dose-dependent manner via inhibiting NF-κB and its downstream target COX-2. It further arrested cell cycle at G0/G1 phase by inhibiting cyclin-D1 and induced early apoptosis by up-regulating P53 in OSCC cells. It also limits the invasion capacity of OSCC cells by up to 55-60%. CONCLUSIONS OTE shows antitumor activities in OSCC cells by inhibiting NF-κB, COX-2 and cyclin D1 and upregulation of p53 expression. It may be developed as a safe and promising alternative chemopreventive/chemotherapeutic agent for oral cancer.

Unique fixed point theorems for α–ψ-contractive type mappings in fuzzy metric space

Abstract Fixed point theory is one of the most powerful tools in nonlinear analysis. The Banach contraction principle is the simplest and most versatile elementary result in fixed point theory. The principle has many applications and was extended by several authors. In this paper, we introduce a concept of α–ψ-contractive type mappings and establish fixed point theorems for such mappings in complete fuzzy metric spaces. Starting from the Banach contraction principle, the presented theorems are the extension, generalization, and improvement of many existing results in the literature. Some example and application to ordinary differential equations are given to illustrate the usability of obtained results.

Refractive outcome of wavefront guided laser in situ keratomileusis and wavefront guided photorefractive keratectomy in high pre-existing higher order aberration

PURPOSE To compare visual outcome and higher order aberrations (HOA) between wavefront-guided LASIK (WF-LASIK) and wavefront guided PRK (WF-PRK) in patients with high preoperative HOA. METHODS Randomized prospective interventional study. Conducted at Guru Nanak Eye Centre, Maulana Azad Medical College, Delhi, India. Eighty myopic eyes of forty patients were included. INCLUSION CRITERIA age more than 21 years, best corrected visual acuity of 20/20 or better, a stable refraction, to be off soft contact lens for minimum 14 days prior to preoperative examination, preoperative RMS HOA more than 0.35 μ, preoperative central corneal thickness at least 500 μm, estimated residual stromal bed thickness of at least 275 μm in patients undergoing WF-LASIK and 350 μm in patients undergoing WF-PRK. Exclusion criteria were severe dry eye, blepharitis, corneal disease and warpage, uveitis, posterior segment abnormalities involving the macula or optic nerve and systemic diseases. Patients were randomly divided into two groups. They underwent either WF-LASIK (group A) or WF-PRK (group B) over 2 years (40 eyes each). Patients were followed up for 6 months. Main outcome measures were efficacy, safety, stability, predictability and HOA. RESULTS At 6 months mean uncorrected visual acuity (logMAR) in group A was -0.01 ± 0.04 and group B was 0.00 ± 0.07 (P = 0.23). HOA RMS (6mm pupil) in group A was 0.61 ± 0.24 μm and group B was 0.55 ± 0.25 μm. The increase was statistically significant in both the groups (P < 0.05). Both the groups showed similar efficacy, predictability and safety. CONCLUSION WF-LASIK and WF-PRK have similar efficacy, safety and predictability, though WF-PRK induces less HOA.