Anant Sharma

Efficacy and safety assessment of a novel ultraviolet C device for treating corneal bacterial infections

Background:  A prototype solid‐state Ultraviolet‐C (UVC) LED device may be useful in the treatment of corneal microbial infections, as UVC is commonly used for eradicating bacteria, fungi and viruses in other settings. This study assessed the efficacy of 265 nm UVC from this LED, on four different bacterial strains, and investigated the consequences of corresponding exposures on human corneal epithelial cells in vitro.

Endoscopic visualisation to aid deep anterior lamellar keratoplasty.

AbstractAims The aim of this study was to assess the value of endoscopy during deep anterior lamellar keratoplasty (DALK) by visualising the posterior cornea. This allows the surgeon to determine whether air injection had succeeded in stripping Descemets membrane and endothelium from the posterior corneal stroma.Methods Four whole globes for research were obtained from the Florida eye bank with consent. A 2 mm incision was placed at the limbus and the endoscope was introduced through this into the anterior chamber. A 26-gauge needle was introduced into the cornea with the bevel positioned as deep as possible and air injected into the corneal stroma. Air was injected until the whole cornea became opaque and repeated air injections were made even after an opaque cornea was noted. The endoscopic camera was used to visualise the posterior corneal surface during this procedure.Results The view of the posterior corneal surface was clear and introduction of the probe did not interfere with the air dissection. In all four eyes, despite ease of air injection and diffuse corneal air infiltration, no large air bubble dissection of Descemets membrane from adjacent stroma occurred. Instead multiple blistering of the posterior corneal surface could be seen.Conclusions Endoscopy provides an effective tool to visualise the posterior corneal surface during DALK, using air dissection. This technique may become a standard adjunctive procedure during DALK.

Effects of some ophthalmic medications on pupil size: a literature review

Ophthalmological pharmacology is a rapidly expanding field aimed at achieving the safest and most effective treatment results. Physicians must be aware of the side-effect profiles, both beneficial and harmful, of medications currently used. This review highlights the available data on the effect of some ophthalmic medications on pupil size; it was limited to all reports or studies describing topical ophthalmic agents not originally designed or indicated to alter pupil diameter. This awareness will protect patients from unwanted drug-induced side effects and will improve clinical management and patient care.

P63 Expression in Conjunctival Proliferative Diseases: Pterygium and Laryngo-Onycho-Cutaneous (LOC) Syndrome

Purpose: Compare expression of p63 in pterygium and laryngo-onycho-cutaneous (LOC) syndrome with normal conjunctiva. Methods: P63 immunohistochemical detection was carried out in normal, pterygium, and LOC conjunctival tissue. In vitro, growth of normal conjunctival biopsy specimens, pterygium, and LOC in growth tissue was compared. Results: In normal conjunctiva, p63 was poorly expressed in the infranasal quadrant, with 36% of cells stained vs. 55 to 59% in other quadrants (p < 0.05). In pterygium, p63 was overexpressed (59% cells stained) compared to normal supranasal (55%) and normal infranasal conjunctiva (36%, p < 0.05). In LOC, p63 was only expressed in 39% of cells vs. 58% in normal supratemporal conjunctiva (p < 0.05). Cytokeratin 19 was expressed by all cells cultured from normal conjunctival tissue. Conclusions: This study emphasizes the importance of using control tissue explanted from the correspondent conjunctival quadrant when studying proliferative disorders. Different pathogenesis may account for the differences in p63 expression between pterygium and LOC.

Man versus Machine: Software Training for Surgeons—An Objective Evaluation of Human and Computer-Based Training Tools for Cataract Surgical Performance

This study aimed to address two queries: firstly, the relationship between two cataract surgical feedback tools for training, one human and one software based, and, secondly, evaluating microscope control during phacoemulsification using the software. Videos of surgeons with varying experience were enrolled and independently scored with the validated PhacoTrack motion capture software and the Objective Structured Assessment of Cataract Surgical Skill (OSACCS) human scoring tool. Microscope centration and path length travelled were also evaluated with the PhacoTrack software. Twenty-two videos correlated PhacoTrack motion capture with OSACCS. The PhacoTrack path length, number of movements, and total procedure time were found to have high levels of Spearmans rank correlation of −0.6792619 (p = 0.001), −0.6652021 (p = 0.002), and −0.771529 (p = 0001), respectively, with OSACCS. Sixty-two videos evaluated microscope camera control. Novice surgeons had their camera off the pupil centre at a far greater mean distance (SD) of 6.9 (3.3) mm, compared with experts of 3.6 (1.6) mm (p ≪ 0.05). The expert surgeons maintained good microscope camera control and limited total pupil path length travelled 2512 (1031) mm compared with novices of 4049 (2709) mm (p ≪ 0.05). Good agreement between human and machine quantified measurements of surgical skill exists. Our results demonstrate that surrogate markers for camera control are predictors of surgical skills.

Documentation of corneal epithelial defects with fluorescein‐enhanced digital fundus camera photography

The advent of digital photography in the ophthalmic setting has provided not only a means of documenting pathology, but with instantaneous results, it is possible to aid clinical diagnosis and management. This study was designed to demonstrate the ability to image corneal epithelial lesions stained with fluorescein, with a digital fundus camera set on fluorescein angiography settings. The contrast of this technique demonstrated both gross and subtle corneal epithelial lesions better than traditional methods. The results obtained demonstrated the high sensitivity and high contrast images this technique can facilitate in every ophthalmic practice equipped with a fundus camera with digital fluorescein angiography capability.

Difficulties Imaging Herpes Simplex Keratitis With Fluorescein Isothiocynate-Labeled Anti-HSV-1 Antibodies in an Ex Vivo Model

Aim: The aim of this study was to attempt to visualize herpes simplex keratitis in an ex vivo model using currently available ophthalmological equipment and anti-herpes simplex virus 1 (HSV-1) fluorescein isothiocynate-labeled antibody. Methods: Sixteen donor human corneas were included in this study. Eight corneas were infected with HSV-1, whereas 8 remained uninfected. Abrasions were made on 2 infected and 2 uninfected corneas to assess a possible nonspecific absorption of antibodies in the sites of corneal epithelial defects. Corneas were examined before and after antibody application using a slit lamp, the fluorescein enhancing filter settings of fundus camera, and Confoscan 3. All corneas were further imaged using multiphoton laser confocal microscopy. Results: Before anti-HSV-1 antibody application, no fluorescence was detected in donor corneas with the blue light of the slit lamp and fundus camera at fluorescein enhancing filter settings. Examination with the fundus camera after antibody application detected increased background fluorescence in all the corneas with more highlighted areas of epithelial defects in abraded infected and uninfected corneas. Confoscan 3 did not show a significant difference between the appearances of HSV-1-infected and control corneas with and without application of the antibody. However, specific staining was confirmed by multiphoton laser confocal microscopy in all infected corneas. Conclusion: Further refinement of currently available ophthalmological tools is required to aid in vivo visualization of herpes simplex keratitis using fluorescein isothiocynate-labeled antibodies.

Scaling the punctum and canaliculus in patients undergoing punctoplasty surgery: A prospective cohort study

ABSTRACT Optical Coherence Tomography (OCT) is a safe and non-invasive method of high-resolution cross-sectional imaging of tissue microstructures using infrared radiation. This study investigates how the appearance of the punctum and proximal canaliculus differs pre- and post-operatively in patients undergoing punctoplasty surgery. Patients with symptomatic punctal stenosis warranting punctoplasty surgery were prospectively invited to enrol from a single centre. Spectral OCT images of the lower punctae were captured with a Topcon 3D OCT 2000 machine pre- and post-operatively (at their follow-up appointment). Measurements were made of the maximal punctal diameter, canalicular diameter and canalicular depth. Pre- and post-operative measurements were compared using a paired t-test. Twenty-three punctae of 18 patients with punctal stenosis were included in the study. They were 10 males and 8 females with a median age 71.0 (SD 12.1). Mean canalicular cross-sectional area was 56.9 × 10-3 mm2 pre-operatively and 267.2 × 10-3 mm2 post-operatively, showing a statistically significant increase (p = 0.0004). There was an increase in both mean canalicular width (0.253 to 0.524mm (p = 0.0001)) and depth (0.433 to 0.852mm (p = 0.0001)) from pre- to post-operatively. There was a significant improvement in symptoms from pre- to post-operatively, as measured subjectively by the Lac-Q questionnaire (p = 0.021). This study describes the change in the appearance of the punctum and proximal canaliculus in patients undergoing punctoplasty operations, by using spectral OCT to capture in vivo high-resolution images. It demonstrates that punctal OCT can be successfully applied to quantify the morphological changes of the punctum and canaliculus pre- and post-punctoplasty.

Fingerprick autologous blood for dry eyes and persistent epithelial defects.

Autologous serum has been used effectively to treat severe dry eye syndrome1 (DES) and persistent epithelial defects2 (PED). However, difficulty obtaining funding and delays in production often make it unfeasible for acute cases. The authors report on finger prick autologous blood (FAB)3 as an alternative treatment option. Patients cleaned a finger with an alcohol steret. Next, they produced a drop of blood using a diabetic lancet and applied it to their lower fornix. They repeated this technique to apply FAB four times per day to each eye. A different finger was used for each eye to reduce any risk of cross-infection.

Reply: Comments on surgical iridotomy technique

Comments on surgical iridotomy technique We congratulate Athanasiadis et al. for documenting the surgical iridotomy technique. We have used this technique in several clinical scenarios and have a few observations to make. One advantage of the technique is the ease of placing an iridotomy in the superior iris so it is covered by the upper lid. A large number ofmodern cataract surgeries are performed using a temporal clear corneal section. It is virtually impossible to make a superior iridectomy using a scissors in this situation. It is cosmetically as well as optically undesirable to place an iridotomy in the temporal iris. When the main section is at the temporal limbus, one can easily use the side port (used for the second instrument) in the case of the right eye to create an iridotomy. In the left eye, a paracentesis can be created at the superior limbus tomake an iridotomy with the microvitreoretinal (MVR) blade. However, as opposed to the other methods of surgical iridectomy (using a scissors or a vitrectomy cutter), there is no countertraction to the posterior force when the MVR blade is used. This is especially