Advanced epithelial mapping for refractive surgery.

One of the leading challenges in refractive surgery today is the presence of underlying subclinical early-stage keratoconus (KC), which can lead to iatrogenic post laser in situ keratomileusis ectasia. Timely detection of this condition could aid the refractive surgeons in better decision-making. This includes being able to defer refractive surgery in subclinical cases as well as providing treatment for the same in the form of appropriate corneal collagen crosslinking treatments. Corneal topography is considered the gold standard for the diagnosis of corneal ectatic disorders. However, there is a likelihood that topographers are overlooking certain subclinical cases. The corneal epithelium is known to remodel, which may mask underlying stromal irregularities. Imaging and analyzing corneal epithelium and stroma independently will undoubtedly open newer avenues to supplement our understanding of postrefractive surgery outcomes and KC. This review encapsulates the various Optical coherence tomography-based epithelial mapping devices particularly RTVue (Optovue, Fremont, USA) and MS-39 (Costruzione Strumenti Oftalmici, Florence, Italy) in terms of their utility in these conditions. It will help guide the clinician on how including an epithelial mapping in clinical practice can aid in diagnosis, management, and interpretation of outcomes both for refractive surgery as well as KC.

Preferred practice patterns for photorefractive keratectomy surgery.

Over the past two decades, excimer laser-based refractive surgery procedures have been successfully established for their safety and satisfactory visual outcomes. Surface ablation procedures or photorefractive keratectomy (PRK) are practised commonly for the correction of refractive errors including myopia, astigmatism and hyperopia. Satisfactory visual outcomes are achieved in majority of cases, although a very small percentage have issues related to corneal haze, regression, and its associated visual disturbances. To ensure optimal outcomes and to minimize complications, certain keys to success have been designed on the basis of the current review of literature on surface ablation procedures.

UV-Visible spectroscopic effect on Haemoglobin & DNA degradation: A forensic approach.

In forensic casework, sample degradation is a largely an unsolved problem that exists due to poor preservation protocols. In Indian subcontinent, the forensic blood stains are commonly exposed to different ecological conditions for months before they are collected and transferred to the forensic laboratory for analysis. Under such conditions, the question of haemoglobin (Hb) & nucleic acid stability is of utmost importance. The biological evidence, especially the blood sample that underwent extreme conditions should further be retained in an appropriate storage facility until processed for the forensic serology/DNA testing. The present study provides the spectroscopic approach of analyzing Hb and DNA degradation of forensic blood samples preserved under varied conditions (tabulated and graphically). These samples were further subjected to and DNA analysis to assess the quality of sample based on different preservation conditions. At last, this study suggests the effective and appropriate preservation protocol of sample soon after its collection.

Pain management after photorefractive keratectomy.

PURPOSE: To evaluate the effect of a bandage contact lens soaked in ketorolac ophthalmic 0.45% solution (Acuvail) on pain modulation in patients having transepithelial photorefractive keratectomy (PRK). DESIGN: Prospective case series. SETTING: Narayana Nethralaya Superspeciality Eye Hospital, Bangalore, India. METHODS: Eyes of patients were divided into 2 groups. After transepithelial PRK, a regular soft bandage contact lens was placed in Group 1 and a ketorolac-soaked bandage contact lens was placed in Group 2. The patients were matched for age and sex in the 2 groups. Postoperative pain was compared using the validated Wong-Baker pain scale. Before placement of a ketorolac-soaked bandage contact lens in patients' eyes, the safety of the procedure was checked using cultures from the bandage contact lens and measuring the quantity of the drug adsorbed and the elution profile over time with ultra-high-performance liquid chromatography (UHPLC). RESULTS: Each group comprised 35 eyes of 35 patients. The mean pain score was 7.95 ± 2.12 (SD) in Group 1, which was significantly higher than in Group 2 (2.76 ± 0.85), which received the ketorolac-soaked bandage contact lens. The UHPLC results showed that the soaked bandage contact lens acted as a depot for ketorolac, which was released onto the ocular surface over time, providing postoperative pain relief without causing adverse events. CONCLUSION: A bandage contact lens soaked in ketorolac 0.45% solution can act as a potential drug depot that can reduce pain after transepithelial PRK.

Corneal tomographic features of postrefractive surgery ectasia.

The purpose of this study was to evaluate the tomographic features of postrefractive surgery eyes. This was a retrospective evaluation of clinical data. Three patients with post-LASIK (laser-assisted in situ keratomileusis) and two patients with post-SMILE (small incision lenticule extraction) ectasia were imaged with Scheimpflug imaging (SI, Pentacam) and optical coherence tomography (OCT, RTVue). Curvature and wavefront aberrations of the air-epithelium interface (A-E) and epithelium-Bowman's layer interface (E-B) were derived. OCT of normal and keratoconic eyes from an earlier study were compared with the data of the ectasia eyes. Curvature and aberrometry of the A-E interfaces were statistically similar between SI and OCT. However, OCT revealed a steeper and more aberrated E-B interface than A-E though correlation between them was inferior to the correlation for keratoconic eyes. Furthermore, the magnitude of differences between the A-E and E-B interfaces was greater in the ectasia eyes than the keratoconic eyes. OCT could possibly assist better in selecting appropriate treatment plan for postrefractive surgery ectasia eyes than conventional tomographers.

Impact of the Learning Curve on Intraoperative Surgical Time in Femtosecond Laser-Assisted Cataract Surgery.

PURPOSE: To analyze the impact of learning curve on operating room (OR) times, femtosecond laser times, procedure time (time for laser and non-laser steps combined), and surgical time (procedure time minus transfer and preoperative times) during transition to femtosecond laser-assisted cataract surgery (FLACS) and comparison with conventional phacoemulsification. METHODS: In this retrospective, comparative case series, patients undergoing FLACS by an experienced surgeon between November 2012 and June 2014 were reviewed using the Catalys Precision Laser system (Abbott Medical Optics, Santa Ana, CA). The cohort was divided into five sequential groups of roughly equally sized cohorts (n = 33 for groups 1 to 4, n = 34 for group 5) and temporal change in surgical times was compared. For controls, 50 consecutive patients who underwent phacoemulsification concurrently were reviewed. RESULTS: There were 166 eyes evaluated that underwent FLACS. Femtosecond laser time shortened through the first three groups (group 1: 4.37 minutes vs group 3: 3.37 minutes, P < .05) but plateaued thereafter (group 4: 3:43 minutes, group 5: 3:35 minutes, P > .05). Total FLACS OR time reduced through sequential groups (group 1: 44 minutes vs group 5: 34 minutes, P < .001). Procedure time reduced from 33 (group 1) to 23 (group 5) minutes (P < .001). However, surgical and total OR time for group 5 (0:17 ± 0.02 and 0:34 ± 0:04 minutes, respectively) remained longer than phacoemulsification (0.14 ± 0:04 and 0:29 ± 0:05 minutes, respectively, both P < .05). CONCLUSIONS: Despite significant reduction in OR times with increasing surgeon experience, FLACS required longer overall procedure times and surgical times compared to phacoemulsification, even when approaching 200 cases. Surgeons and institutions should budget for increased surgical times and associated costs when transitioning to FLACS. [J Refract Surg. 2016;32(5):311-317.].

Epithelial Ingrowth Following Endothelial Keratoplasty.

PURPOSE: To present a large case series of epithelial ingrowth or implantation following endothelial keratoplasty (EK) with the purpose of identifying the common causes as well as the various clinical presentations. We aim to determine the typical clinical course and the most effective treatment for this rare but serious complication. METHODS: This is a retrospective study of 13 patients who developed epithelial ingrowth or implantation post-EK. Slit lamp photographs were independently examined along with other diagnostic imaging and histopathology to confirm the diagnosis. Patient medical records including operative reports were reviewed to determine the number of surgeries that occurred before EK and details of surgical technique, for example, whether venting incisions were performed. Records from follow-up visits were reviewed to determine the natural progression and management of these cases. The literature was reviewed and a meta-analysis was performed. RESULTS: The patients were divided into 5 groups according to the type of epithelial presentation. Eight patients had involvement within the interface away from the visual axis. One patient had ingrowth in the interface within the visual axis, 2 had retrocorneal involvement, and 1 had anterior chamber involvement. One had both retrocorneal and anterior chamber involvement. Venting incisions were performed in 8 patients, but only 1 had ingrowth related to the venting incision. Nine patients were observed without evidence of significant progression. Four patients had surgical treatment to remove the epithelium. CONCLUSIONS: Epithelial ingrowth or implantation occurs most commonly within the interface away from the visual axis and typically does not progress. The presentation of a homogeneous gray-white interface opacity is characteristic. Ingrowth can result from venting incisions, but rarely does. Other causes are eccentric trephination or loose donor or host epithelium being dragged into the eye at the time of surgery.