Shameema Sikder

Artisan iris-supported phakic IOL implantation in patients with keratoconus: a review of 16 eyes.

PURPOSE To evaluate the clinical outcomes of Artisan phakic intraocular lens (PIOL; Ophtec BV) implantation in patients with stable keratoconus. METHODS In a prospective, nonrandomized case series, 14 Artisan PIOLs and 2 toric Artisan PIOLs were implanted in 13 patients (16 eyes) with stable keratoconus who had contact lens intolerance. Pre- and postoperative data were collected. RESULTS Mean follow-up was 14.2 ± 7.8 months. Preoperative uncorrected distance visual acuity (UDVA) was counting fingers in all patients. Mean final logMAR (Snellen equivalent) UDVA and corrected distance visual acuity (CDVA) were 0.15(20/28) ± 0.13 and 0.11(20/26) ± 0.10, respectively. The improvements in UDVA and CDVA were statistically significant (P<.0001 and P<.002, respectively). All patients achieved a final UDVA of 20/40 or better, and 84.6% had a final CDVA of 20/32 or better. No postoperative complications occurred except for two cases of sterile uveitis. CONCLUSIONS Implantation of the Artisan PIOL is effective in improving visual acuity in patients with stable keratoconus. Long-term safety remains to be established as no postoperative endothelial cell counts were performed.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. Results: At 6 months, mean values for UDVA (logMAR) were −0.043 ± 0.668 and −0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK): analysis of visual outcomes and higher order aberrations

Purpose To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms. Methods In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing. Results Mean values for UDVA (logMAR) were −0.067 ± 0.087 and −0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism. Conclusion Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.

Noninvasive mitochondrial imaging in live cell culture.

Abstract The observed distribution of mitochondria in a cell can vary with environmental influence, degree of differentiation and disease. Differences in the distribution of mitochondrial autofluorescence may be used to distinguish these different cellular states.

Surgical management of traumatic LASIK flap dislocation with macrostriae and epithelial ingrowth 14 years postoperatively

Fourteen years after uneventful laser in situ keratomileusis (LASIK), a 59-year-old woman presented after suffering blunt trauma to her left eye 5 weeks earlier. The injury resulted in traumatic flap dislocation, epithelial ingrowth, and significant macrostriae. Following epithelial removal, the flap was hydrated with sterile water, facilitating reduction of the macrostriae and reapproximation without the need for suture placement. The postoperative course was uneventful, and at 1 month, the epithelial ingrowth and macrostriae had resolved and the uncorrected distance visual acuity was 20/30. This case represents the longest documented interval from LASIK surgery to traumatic flap dislocation. We describe our surgical approach to the management of this type of injury and present a video illustrating the technique.

Surgical simulators in cataract surgery training

Background Virtual simulators have been widely implemented in medical and surgical training, including ophthalmology. The increasing number of published articles in this field mandates a review of the available results to assess current technology and explore future opportunities. Method A PubMed search was conducted and a total of 10 articles were reviewed. Results Virtual simulators have shown construct validity in many modules, successfully differentiating user experience levels during simulated phacoemulsification surgery. Simulators have also shown improvements in wet-lab performance. The implementation of simulators in the residency training has been associated with a decrease in cataract surgery complication rates. Conclusions Virtual reality simulators are an effective tool in measuring performance and differentiating trainee skill level. Additionally, they may be useful in improving surgical skill and patient outcomes in cataract surgery. Future opportunities rely on taking advantage of technical improvements in simulators for education and research.

Prospective, randomized, fellow eye comparison of WaveLight Allegretto Wave Eye-Q versus VISX CustomVueTM STAR S4 IRTM in photorefractive keratectomy: analysis of visual outcomes and higher-order aberrations.

Background The purpose of this study was to compare differences in visual outcomes, higher-order aberrations, contrast sensitivity, and dry eye in patients undergoing photorefractive keratectomy using wavefront-guided VISX CustomVue™ and wavefront-optimized WaveLight® Allegretto platforms. Methods In this randomized, prospective, single-masked, fellow-eye study, photorefractive keratectomy was performed on 46 eyes from 23 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Three-month postoperative outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive error, root mean square of total and grouped higher-order aberrations, contrast sensitivity, and Schirmer’s testing. Results Mean values for uncorrected distance visual acuity (logMAR) were −0.03 ± 0.07 and −0.06 ± 0.09 in the wavefront-optimized and wavefront-guided groups, respectively (P = 0.121). Uncorrected distance visual acuity of 20/20 or better was achieved in 91% of eyes receiving wavefront-guided photorefractive keratectomy, and 87% of eyes receiving wavefront-optimized photorefractive keratectomy, whereas uncorrected distance visual acuity of 20/15 was achieved in 35% of the wavefront-optimized group and 64% of the wavefront-guided group (P ≥ 0.296). While root mean square of total higher-order aberration, coma, and trefoil tended to increase in the wavefront-optimized group (P = 0.091, P = 0.115, P = 0.459, respectively), only spherical aberration increased significantly (P = 0.014). Similar increases were found in wavefront- guided root mean square of total higher-order aberration (P = 0.113), coma (P = 0.403), trefoil (P = 0.603), and spherical aberration (P = 0.014). There was no significant difference in spherical aberration change when comparing the two platforms. The wavefront-guided group showed an increase in contrast sensitivity at 12 cycles per degree (P = 0.013). Conclusion Both VISX CustomVue and WaveLight Allegretto platforms performed equally in terms of visual acuity, safety, and predictability in photorefractive keratectomy. The wavefront-guided group showed slightly improved contrast sensitivity. Both lasers induced a comparable degree of statistically significant spherical aberration, and tended to increase other higher-order aberration measures as well.

A surgical technique for donor tissue harvesting for descemet membrane endothelial keratoplasty.

Purpose: To create a reproducible and effective technique in donor tissue harvesting for Descemet membrane (DM) endothelial keratoplasty. Methods: A new method has been developed for the harvest of donor DM and endothelium. This method involves placement of a human corneoscleral rim in an artificial anterior chamber with removal of the anterior stroma with a Moria One microkeratome (Moria USA, Doylestown, PA). The residual stromal bed over the central cornea is removed by blunt dissection using a Barraquer sweep. A thin rim of posterior residual stroma permits easy donor button trephination and tissue manipulation. The risk of tearing through DM is minimal and may not preclude use in transplantation. This method allows relatively easy assessment of endothelial integrity before trephination. Results: Optical coherence tomography evaluation revealed minimal stroma overlying DM and endothelium. Endothelial cell integrity of the harvested DM by this new harvest method was assessed using specular microscopy and demonstrated minimal loss after DM harvest. Conclusions: We presented a manual tissue harvest method for DM endothelial keratoplasty.

Evaluation of Irradiated Corneas Using Scatterometry and Light and Electron Microscopy

Objective: To determine if sterilization of donor corneas by irradiation alters optical, histologic, or ultrastructural tissue characteristics. Methods: Blinded assessment of 10 irradiated and 10 nonirradiated donor corneas by a scatterometer used to objectively measure backscattered corneal light. Light and electron microscopy were performed on samples from both groups. Results: The mean scattering of the nonirradiated (control) corneas was significantly lower (0.0060 ± 0.0034, mean ± SD) than the scattering of the irradiated corneas (0.023 ± 0.0078; P = 0.0001). There was no statistical difference between ages, days in storage, or central corneal thickness of the 2 groups. Light microscopic evaluation revealed attenuation of the irradiated corneal epithelium with superficial stromal clefting. Transmission electron microscopy demonstrated similar fibril diameter in the nonirradiated and irradiated corneas. Although the mean interfibrillar distance was similar between the nonirradiated and irradiated groups, the interfibrillar distance in the superficial stroma was increased in the nonirradiated compared with the irradiated groups (15.4 ± 2.4 vs. 11.8 ± 0.98 nm; P ≤ 0.05). Conclusions: Our data quantitatively support increased light scatter after irradiation, which cannot be attributed to increased corneal thickness. Irradiation alters the histology of the epithelium and the ultrastructure of the superficial corneal stroma. Increased light scatter because of epithelial changes would not be expected to impact postoperative visual function. However, increased light scatter because of stromal changes may affect postoperative visual function if used for optical corneal rehabilitation. Further investigation is warranted to determine whether attenuated epithelium or superficial stromal changes are the cause of increased light scatter in the irradiated corneal tissue.

Comparing resident cataract surgery outcomes under novice versus experienced attending supervision

Purpose To determine whether supervision by an attending who is new to surgical teaching, or an experienced attending measurably influences intraoperative complications rates or outcomes in phacoemulsification performed by ophthalmology residents. Setting Single tertiary hospital. Design Retrospective cohort study. Methods Resident-performed phacoemulsification cases supervised by one novice attending (N=189) and experienced attending (N=172) over 1 year were included. Data included: resident year, patient age, sex, preoperative risk factors (4+ on the four point scale for dense/white/brunescent cataracts, Flomax, zonular dialysis, pseudoexfoliation, glaucoma risk, post-vitrectomy), intraoperative risk factors (Trypan blue, iris hooks), and intraoperative complications (capsule tears, vitreous loss, zonular dialysis, zonular dehiscence, burns, nuclear fragment loss, Descemet’s tear). Experienced attending data were compared against those of the novice attending. Results Regarding preoperative risks, experienced attending cases more likely involved 4+ cataract (P=0.005), Flomax (P<0.001), or glaucoma risk (P=0.001). For intraoperative risks, novice attending cases more likely involved Trypan blue (P<0.001). Regarding complications, novice attending cases were associated with vitreous loss (P=0.002) and anterior capsule tears (P<0.001). When comparing total complications, the novice attending was more likely to have both increased number of cases with complications and total complications than the experienced attending. The novice attending’s overall complication rate trended downward (rate from 28% in first 25 cases to 6.67% in last 15). Conclusion Early cases for the novice attending were accompanied by greater complications (vitreous loss and anterior capsule tear), likely due to a learning curve. Surgical judgment in the operating room likely develops with experience. Training programs may focus on these specific areas to aid new instructors.