Gagandeep Singh Brar

Corneal collagen crosslinking using riboflavin and ultraviolet-A light for keratoconus

PURPOSE: To evaluate changes in corneal curvature, corneal elevation, corneal thickness, lens density, and foveal thickness after corneal collagen crosslinking with riboflavin and ultraviolet‐A (UVA) light in eyes with progressive keratoconus. SETTING: Grewal Eye Institute, Chandigarh, India. METHODS: Subjective refraction, best corrected visual acuity (BCVA), Scheimpflug imaging, and optical coherence tomography were performed preoperatively and 1 week, 1, 3, and 6 months, and 1 year after crosslinking. RESULTS: There were no significant differences (P > 0.05) in mean values between preoperatively and 1 year postoperatively, respectively, in BCVA (0.22 ± 0.10 and 0.20 ± 0.10), spherical equivalent (−6.30 ± 4.50 diopters (D) and −4.90 ± 3.50 D), or cylinder vector (1.58 × 7° ± 3.8 D and 1.41 × 24° ± 3.5 D). There was no significant difference in mean measurements between preoperatively and 1 year postoperatively, respectively, for central corneal thickness (458.9 ± 40 μm and 455.2 ± 48.6 μm), anterior corneal curvature (50.6 ± 7.4 D and 51.5 ± 3.6 D), posterior corneal curvature (−7.7 ± 1.2 D and −7.4 ± 1.1 D), apex anterior (P = .9), posterior corneal elevation (P = .7), lens density (P = .33), or foveal thickness (175.7 ± 35.6 μm and 146.4 ± 8.5 μm; P = .1). CONCLUSIONS: Stable BCVA, spherical equivalent, anterior and posterior corneal curvatures, and corneal elevation 1 year after crosslinking indicate that keratoconus did not progress. Unchanged lens density and foveal thickness suggest that the lens and macula were not affected after UVA exposure during crosslinking.

Correlation of nuclear cataract lens density using Scheimpflug images with Lens Opacities Classification System III and visual function.

PURPOSE To calculate the average lens density (ALD) and nuclear lens density (NLD) using Scheimpflug images and to determine their correlation with logarithmic minimal angle resolution (logMAR) best-corrected visual acuity (BCVA), contrast sensitivity (CS), and lens grading based on the Lens Opacities Classification System (LOCS) III. DESIGN Cross-sectional observational study. PARTICIPANTS One hundred ten patients with age-related nuclear cataract. METHODS The logMAR BCVA was recorded using Early Treatment Diabetic Retinopathy Study charts and photopic contrast-sensitivity using CSV-1000LV (Vector Vision, Greeneville, OH). Fifty Scheimpflug images (Pentacam, Oculus, Germany) covering 360 degrees of the lens were obtained for 1 eye of each patient after dilation. All Scheimpflug images were exported to ImageJ software (NIH, Bethesda, MD) for analysis wherein the ALD and NLD (using a mask applied to the lens nuclear area) were calculated in pixel-intensity units. Repeatability was determined using coefficient of variation (CoV) and intraclass correlation coefficient (ICC). Lens opacity on slit-lamp images was graded using LOCS III for nuclear opalescence (NO) and nuclear color (NC). MAIN OUTCOME MEASURES We evaluated ALD and NLD on Scheimpflug images and their correlation with NO and NC LOCS III grading, BCVA, and photopic CS. RESULTS The ICC for ALD and NLD were 0.983 and 0.99, respectively; the CoV were 3.92+/-1.76% and 2.57+/-0.74%, respectively. The ALD correlated with NO (r = .774; P<0.001), NC (r = .732; P<0.001), BCVA (r = 0.696; P<0.001), and CS at 3 cycles per degree CPD (P = 0.011), 6, 12, and 18 CPD (P<0.001). The NLD correlated with NO (r = .859; P<0.001), NC (r = .81; P<0.001), BCVA (r = .760; P<0.001), CS at 3 CPD (P = 0.002), 6, 12, and 18 CPD (P<0.001). The NLD had a significantly stronger correlation with BCVA (P<0.05), NO (P<0.01), NC (P<0.01), and CS at 6 CPD (P<0.01) and 12 CPD (P<0.005) compared with ALD. CONCLUSIONS Repeatable 360 degrees lens density measurements were obtained using Scheimpflug imaging. A stronger correlation was observed between NLD and LOCS III grading, BCVA, and photopic CS than with ALD. The NLD is an objective and repeatable method for assessment of lens density, which could be helpful in longitudinal studies monitoring nuclear cataracts.

Effect of in-the-bag intraocular lens fixation on the prevention of posterior capsule opacification

Purpose: To compare the incidence of posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) and phacoemulsification and to evaluate the role of posterior chamber intraocular lens (PC IOL) haptic fixation and biomaterial/design in reducing the incidence. Setting: Postgraduate Institute of Medical Education and Research, Chandigarh, India; Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: This study comprised 278 eyes of 263 patients having ECCE and 318 eyes of 297 patients having phacoemulsification with PC IOL implantation. Posterior capsule opacification leading to a decrease in Snellen visual acuity of 2 or more lines was considered visually significant. The presence of PCO and IOL haptic fixation were evaluated postoperatively using slitlamp biomicroscopy. Haptic position was noted as in‐the‐bag (B‐B), 1 haptic in the bag and 1 in the sulcus (bag‐sulcus [B‐S]), or both haptics out of the bag (sulcus‐sulcus [S‐S]). In addition, the rate of visually significant PCO was compared among 3 IOL biomaterials: poly(methyl methacrylate), silicone, and hydrophobic acrylic. Results: Visually significant PCO occurred in 42.45% of eyes having ECCE and 19.18% of eyes having phacoemulsification (P < .001, chi‐square test) after a mean follow‐up of 2.4 years ± 0.7 (SD). In both groups, visually significant PCO was significantly less in eyes with B‐B fixation than in those with B‐S or S‐S fixation (P < .001). The rate of visually significant PCO in all eyes in the phacoemulsification group with B‐B fixation was low (11.90%) and was significantly lower in eyes with a hydrophobic acrylic IOL (2.22%; P < .05, chi‐square test). Conclusions: In‐the‐bag PC IOL fixation is required to consistently reduce the incidence of PCO. Thorough removal of lens substance, including hydrodissection‐assisted cortical cleanup, and in‐the‐bag PC IOL fixation seem to be the most important factors in reducing PCO, regardless of surgical procedure or IOL type used. Intraocular lens biomaterial and design also help prevent PCO.

Role of posterior capsulotomy with vitrectomy and intraocular lens design and material in reducing posterior capsule opacification after pediatric cataract surgery

Purpose: To study the effect of primary posterior capsulotomy with anterior vitrectomy (PPC + AV) and intraocular lens (IOL) design and material on the development of posterior capsule opacification (PCO) after pediatric cataract surgery. Setting: Tertiary care institution in India. Patients: Sixty‐four eyes of 52 children ranging in age from 3 months to 12 years who had cataract extraction with IOL implantation were prospectively evaluated for a minimum postoperative period of 2 years. Methods: Thirty‐two eyes received a hydrophobic acrylic lens with a truncated, square edge and 32, a single‐piece poly(methyl methacrylate) (PMMA) lens that was not heparin surface modified. Sixteen eyes in each IOL group had PPC + AV; in the remaining 16 eyes in each group, the posterior capsule was left intact. Results: Postoperatively, 25 eyes in the intact capsule group and 5 in the PPC + AV group developed PCO; the difference between groups was significant (P<.05). Of eyes with an intact capsule, 12 with an acrylic IOL and 13 with a PMMA IOL developed PCO (P>.05). In the PPC + AV group, 2 eyes with an acrylic IOL and 3 with a PMMA IOL developed PCO (P>.05). Overall, 14 eyes with an acrylic lens and 16 eyes with a PMMA lens developed PCO (P>.05). After surgery, there was a significant short‐term delay in the development of PCO in the acrylic group (14 eyes; mean 6.66 months ± 1.57 [SD]) compared to the PMMA group (16 eyes; mean 3.16 ± 0.83 months) (P<.05). Conclusions: It is the management of the posterior capsule rather than IOL design and material that influences the incidence of PCO after cataract surgery in children. Development of PCO in the postoperative period was delayed with a hydrophobic acrylic IOL with square edges compared with a PMMA lens without square edges.

Intracameral amphotericin B: initial experience in severe keratomycosis.

Purpose. Fungal keratitis is a significant cause of ocular morbidity in India. The most commonly implicated fungi are Aspergillus spp. Patients often present with hypopyon, which usually contains fungal elements. The treatment is difficult owing to poor intraocular penetration of most available antifungal agents. This study evaluated the results of intracameral injection of amphotericin B in natamycin resistant cases of severe keratomycosis. Methods. Three patients of culture proven Aspergillus flavus corneal ulcer with hypopyon not responding to topical natamycin 5%, amphotericin B 0.15%, and oral itraconazole were administered intracameral amphotericin B. The first case received 7.5 &mgr;g in 0.1 mL followed by two subsequent injections of 10 &mgr;g in 0.1 mL each, the second case received two injections of 10 &mgr;g in 0.1 mL, and the third patient received a single dose of 10 &mgr;g in 0.1 mL. Culture of the aqueous sample also grew A. flavus in all three cases. Results. All three cases responded favorably, with the ulcer and hypopyon clearing completely. There was no clinical evidence of corneal or lenticular toxicity in any patient. Conclusions. Intracameral amphotericin B may be a useful modality in the treatment of severe keratomycosis not responding to topical natamycin. It ensures adequate drug delivery into the anterior chamber and may be especially useful to avoid surgical intervention in the acute stage of the disease.

Assessment of central corneal thickness in normal, keratoconus, and post-laser in situ keratomileusis eyes using Scheimpflug imaging, spectral domain optical coherence tomography, and ultrasound pachymetry.

PURPOSE: To compare the central corneal thickness (CCT) in normal eyes, eyes with keratoconus, and eyes after laser in situ keratomileusis (LASIK) using 3 methods. SETTING: Cornea Clinic, Grewal Eye Institute, Chandigarh, India. METHODS: In this study, CCT was measured by sequential Scheimpflug imaging, spectral‐domain anterior segment optical coherence tomography (AS‐OCT), and ultrasound (US) pachymetry. RESULTS: Each of the 3 groups comprised 50 eyes. There were no differences between the 3 groups in age, sex, or intraocular pressure. In normal eyes, CCT was statistically significantly higher by US pachymetry (mean 525.8 μm ± 41.4) [SD] than by Scheimpflug imaging (mean 519.4 ± 40.9 μm) and AS‐OCT (mean 517.9 ± 41.5 μm) (both P<.001). In keratoconus eyes, CCT by US pachymetry (mean 446.4 ± 57.9 μm) was statistically significantly higher than by Scheimpflug imaging (mean 439.6 ± 62.1 μm) (P = .002) and AS‐OCT (mean 441.8 ± 58.4 μm) (P = .007). In post‐LASIK eyes CCT by US pachymetry (mean 462.4 ± 44.7 μm) was significantly higher than by Scheimpflug imaging (mean 457.9 ± 33.6 μm) (P = .012) and AS‐OCT (mean 455.4 ± 43.2 μm) (P<.001). In all groups, CCT measured by Scheimpflug imaging and AS‐OCT was similar. CONCLUSIONS: There was a statistically significant difference between Scheimpflug imaging and US pachymetry and AS‐OCT, with US pachymetry measurements being consistently thicker. Thus, CCT should be interpreted in the context of the instrument used. Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Visual results and postoperative complications of capsular bag and ciliary sulcus fixation of posterior chamber intraocular lenses in children with traumatic cataracts.

PURPOSE To evaluate the visual results and postoperative complications of capsular bag and ciliary sulcus fixation of posterior chamber intraocular lenses (IOLs) for traumatic cataracts in children. SETTING Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. METHODS Twenty children (20 eyes) with traumatic cataracts had extracapsular cataract extraction (ECCE) and posterior chamber IOL implantation. They were randomly divided into 2 groups. Capsular bag fixation was performed in 10 children (Group A) and ciliary sulcus fixation in the other 10 (Group B). Traumatic cataracts associated with large corneal lacerations (10.0 mm or more), hyphema, angle recession, or posterior segment involvement were excluded. The best corrected visual acuity (BCVA) as well as early and delayed postoperative complications were prospectively evaluated in both groups. RESULTS The BCVA was 6/12 or better in 9 eyes (90%) in Group A and 8 eyes (80%) in Group B at the end of the mean follow-up (24.6 months +/- 10.6 [SD]). Amblyopia (1 eye in Group A) and corneal scar and commotio retinae (1 eye each in Group B) accounted for a visual acuity of worse than 6/12. The residual refractive error did not exceed 3.50 diopters in either group. The incidences of fibrinous anterior uveitis and pupillary capture were significantly higher in Group B (P < .05, Fisher exact test). CONCLUSION Capsular bag fixation of posterior chamber IOLs provided visual results similar to those with ciliary sulcus fixation but was associated with fewer postoperative complications, particularly uveitis and pupillary capture. This represents another important reason to attempt in-the-bag fixation in cases of traumatic cataract.

Postoperative complications and visual results in uniocular pediatric traumatic cataract.

BACKGROUND AND OBJECTIVES This study was prospectively carried out to evaluate the postoperative complications and visual results following posterior chamber intraocular lens (PCIOL) implantation in children with unilateral traumatic cataract. PATIENTS AND METHODS We prospectively evaluated 40 children, 12 years or younger, with traumatic cataract (blunt trauma, n = 22 eyes, repaired penetrating eye injury, n = 18 eyes) undergoing PCIOL implantation with a minimum follow-up period of one year. Children with posterior segment ocular injury were excluded. RESULTS The postoperative complications were significantly higher in the penetrating eye injury group as compared to blunt trauma group (ie, pupillary capture 44.44% vs 9.09%, posterior capsulotomy rate 83.33% vs 40.90% and IOL decentration 27.77% vs 4.54%). The final visual acuity was 6/12 or better in 38.8% and 86.36% of eyes with penetrating eye injury and blunt trauma, respectively. CONCLUSION Extracapsular cataract extraction (ECCE) with PCIOL implantation in traumatic cataract following blunt trauma results in better visual outcome and fewer complications compared to penetrating eye injury if the posterior segment is not involved.

Pentacam Tomograms : A Novel Method for Quantification of Posterior Capsule Opacification

PURPOSE To develop and validate a method to quantify posterior capsule opacification (PCO) in eyes after cataract surgery and intraocular lens implantation using Scheimpflug Pentacam tomograms and compare its validity with slit lamp retroillumination image analysis. METHODS One hundred twenty-four pseudophakic eyes of 124 patients were divided into two groups. Group 1 consisted of 40 eyes with visually significant PCO, and group 2 consisted of 84 eyes without visually significant PCO. Pentacam Imaging was performed after full mydriasis using the 50-scan acquisition protocol, and high-resolution tomograms were reconstructed and analyzed using ImageJ freeware. Retroillumination photographs were captured for group 1 eyes using the Topcon digital slit lamp, and these were analyzed using POCOman software to calculate an aggregate severity grade and percentage PCO value. Correlation coefficients were calculated for PCO values obtained using POCOman and ImageJ. RESULTS Mean PCO percentage value obtained using POCOman software was 23.34 +/- 6.25 U, mean aggregate PCO severity grade was 0.46 +/- 0.28 U, and mean pixel-intensity value using ImageJ was 31.071 +/- 8.26 U. There was a significant positive correlation between the percentage PCO (P = 0.000; r = 0.864) and PCO severity grade (P = 0.001; r = 0.490) obtained for group 1 eyes using slit lamp retroillumination images and PCO pixel intensity obtained using Pentacam tomograms. CONCLUSIONS Retroillumination photographs are the standard for quantifying PCO. Pentacam tomograms are easier to obtain and are free of flash reflections, and they allow for a more objective analysis. The correlation between the two methods demonstrates that ImageJ analysis of Pentacam tomograms is a viable tool for PCO analysis.

Neodymium:YAG capsulotomy rates following phacoemulsification with implantation of PMMA, silicone, and acrylic intraocular lenses

BACKGROUND AND OBJECTIVE Posterior capsular opacification (PCO) is the most common visually disabling sequela of modern cataract surgery. Methods of reducing its incidence include the development of newer surgical techniques and intraocular lens (IOL) materials and designs. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a polymethylmethacrylate (PMMA), silicone, or acrylic IOL. PATIENTS AND METHODS The data of 340 consecutive patients who underwent phacoemulsification and implantation ofa PMMA, silicone, or acrylic intraocular lens were analyzed. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a PMMA, silicone, or acrylic IOL. RESULTS The incidence of PCO was found to be significantly less in the acrylic group (6.5% as compared to 21.74% and 26.6% in the PMMA and silicone groups, respectively; P = 0.01297 and 0.0039). Most patients (65%) exhibiting PCO in the PMMA group developed it within the first six months. In the silicone group, development of PCO was delayed. In 60% of patients, it appeared 18 months after surgery. Neodymium:YAG capsulotomy was required in 45% and 60% of patients developing PCO in the PMMA and silicone groups, respectively, while it was required in only 1 of the 4 patients developing PCO in the acrylic group. CONCLUSION This study indicates that implantation of an acrylic IOL helps reduce the incidence of PCO as well as the need for Nd:YAG capsulotomy. PMMA IOLs require Nd:YAG capsulotomy earlier in the postoperative period as compared to silicone IOLs.