Total keratometry in intraocular lens power calculations in eyes with previous laser refractive surgery.

IMPORTANCE: Intraocular lens (IOL) calculations in post-refractive cases remain a concern. Our study identifies improved options for surgeons. BACKGROUND: To evaluate and compare the prediction accuracy of IOL power calculation methods after previous laser refractive surgery using standard keratometry (SK), measured posterior corneal astigmatism (PCA) and total keratometry (TK). DESIGN: Retrospective consecutive cohort. PARTICIPANTS: A total of 50 consecutive patients (72 eyes) at a private institution who underwent cataract surgery with prior laser refractive procedures. METHODS: Methods using SK included ASCRS mean, Barrett True-K no history, Haigis-L and Shammas IOL formulae. Barrett True-K using posterior values (True K TK), Haigis and Holladay 1 Double-K methods using TK were also assessed. Post-surgery refraction was undertaken at minimum 3 weeks following surgery. MAIN OUTCOME MEASURES: Arithmetic and absolute IOL refractive prediction errors, variances in mean arithmetic IOL prediction error, and percentage of eyes within ±0.25D, ±0.50D, ±0.75D and ±1.00D of refractive prediction errors were compared. RESULTS: The Barrett True-K (TK) provided the lowest mean refractive prediction error (RPE) and variance for both prior myopes and hyperopes undergoing cataract surgery. The Barrett True-K (TK) exhibited the highest percentages of eyes within ±0.50D, ±0.75D and ±1.00D of the RPE compared to other formulae for prior myopic patients. CONCLUSIONS AND RELEVANCE: Accuracy of IOL power calculations in post-laser eyes can be improved by the addition of posterior corneal values as measured by the IOLMaster 700. The use of total keratometry may supplement outcomes when no prior refraction history is known.

Donation of discarded ocular tissue in patients undergoing SMILE laser refractive surgery: developing appropriate guidelines.

Tissue Biobanks represent an invaluable resource. Despite the majority of people supporting tissue donation, the actual rate remains low overall. Tissue discarded from surgical procedures represents a further avenue for collection for use in research. We aim to understand the information and consent requirements in a cohort of healthy, post-ophthalmic surgical subjects to optimise future tissue collection in living donors. Patients attending an ophthalmic clinic following refractive surgery for myopia (SMILE) were identified. Patient consent was implied with the completion of the provided survey. The questionnaire included gender, age range and education status. The majority of 31 subjects identified a benefit for future patients as the main motive for potential donation of discarded tissue (71%). Payment for the discarded tissue would not influence their decision in 77.4%. Explanation of the potential benefits of research was the most important information to consider before making a decision to donate. Only 12.9% of patients would have refused to include further information. Almost half of patients felt that the Biobank became the owner of tissue following donation. Current surgical patients may be more inclined to participate in research than the general public because of a sense of duty or an increased understanding of the role of research in evolving treatment. Despite minor uncertainty about the eventual use of the tissue and data, most subjects were positive to donation of discarded ocular tissue and de-identified information. Consent and education processes should be revised within an ophthalmic practice to minimise future patient anxiety.

Comparison of Hill-radial basis function, Barrett Universal and current third generation formulas for the calculation of intraocular lens power during cataract surgery.

IMPORTANCE: This study represents a novel comparison of recently introduced intraocular lens power calculation formulas. BACKGROUND: To compare current new generation formulas for calculating the intraocular lens power for a standard cohort of patients undergoing cataract and lens replacement surgery in a private group practice in Australia. DESIGN: Retrospective case series comparison. PARTICIPANTS: Postoperative results from 400 consecutive patients undergoing implantation of an SN60WF intraocular lens post cataract removal by 12 surgeons were used. METHODS: Refractive outcomes were compared with expected targets to determine the predicted refractive outcomes using the Hill-radial basis function, Barrett Universal II and readily available third or fourth generation intraocular lens power calculation formulas. MAIN OUTCOME MEASURE: Mean absolute predicted error. RESULTS: The mean absolute predicted difference ranged from 0.30 to 0.34 D. There was no overall significant difference in the predicted difference or variance between formulas. All formulas achieved greater than 78.3% of eyes within ±0.5 D of intended refraction. The Hill-radial basis function and Barrett formulas provided the lowest mean numerical error compared with existing formulas in short and long eyes, respectively. The Barrett Universal II formula had the lowest percentage of refractive surprises (>1 D from predicted error) across all axial lengths. CONCLUSIONS AND RELEVANCE: Acceptable outcomes can be achieved with optical biometry, consistent surgical technique and use of current intraocular lens power calculation formulas. The Barrett Universal II formula may provide the lowest risk of refractive surprise compared with other intraocular lens power calculation formulas.

Lacquer cracks developing after phakic intraocular lens implantation.

PURPOSE: To describe a case of lacquer cracks developing after phakic intraocular lens implantation. METHODS: Case report. RESULTS: A 46-year-old woman diagnosed as having extreme myopia and corrected distance visual acuity of 20/40 presented with decreased vision and a central scotoma less than 24 hours following phakic intraocular lens implantation. Dilated examination revealed the presence of a macular hemorrhage and possible lacquer crack formation. Documented preoperative imaging showed an absence of lacquer cracks in the eye that was operated on. The patient was treated with intravitreal bevacizumab. At 4 weeks postoperatively, imaging confirmed an almost complete resolution of the hemorrhagic pigment epithelial detachment with evidence of lacquer cracks. Uncorrected visual acuity was 20/50 and the patient was asymptomatic. CONCLUSIONS: This is the first reported case of macular crack formation immediately following phakic intraocular lens implantation. Possible contributing factors are discussed.

Tear levels of SFRP1 are significantly reduced in keratoconus patients.

PURPOSE: To measure secreted frizzled-related protein 1 (SFRP1) levels in human tears and to investigate tear SFRP1 as a potential biomarker for keratoconus (KC). METHODS: Tears were collected from control (n = 33) and KC patients (n = 33) using micropipette tubes. Total tear protein was measured using a FluoroProfile Protein Quantification kit. An in-house enzyme-linked immunosorbent assay (ELISA) was developed to measure SFRP1 in control and KC tears. Statistical analyses of age, gender, the association of SFRP1, and total tear protein with KC were conducted. RESULTS: Tear SFRP1 was significantly decreased in KC, compared to age-matched controls (3.41 ng/µl ± 3.12 versus 5.55 ng/µl ± 5.62, respectively; p = 0.039). Conversely, total tear protein was significantly increased in KC, compared to age-matched controls (12.38 µg/µl ± 4.76 versus 9.40 µg/µl ± 3.88, respectively; p = 0.038). The ratio of SFRP1/total tear protein was also found to be significantly decreased in the KC group (p = 0.007). No significant association between tear SFRP1 and total tear protein was detected. CONCLUSIONS: Tear SFRP1 was significantly decreased in age-matched KC versus control patients, and may be further reduced in moderate KC. Tear-SFRP1 levels alone do not provide an obvious biomarker for KC; however, our results provide further evidence that tear-protein profiles are altered in KC, and suggest the involvement of SFRPs in the pathogenesis of KC.

Surgical outcomes and safety of femtosecond laser cataract surgery: a prospective study of 1500 consecutive cases.

OBJECTIVE: To report the surgical outcomes and safety of femtosecond (FS) laser cataract surgery (LCS) with greater surgeon experience, modified techniques, and improved technology. DESIGN: Prospective, interventional case series. PARTICIPANTS: Fifteen hundred consecutive eyes undergoing FS laser cataract and refractive lens exchange surgery in a single group private practice. INTERVENTION: Femtosecond LCS. METHODS: All eyes undergoing LCS between April 2011 and March 2012 were included in the study. Cases underwent anterior capsulotomy, lens fragmentation, and corneal incisions with the Alcon/LenSx FS laser (Alcon/LenSx, Aliso Viejo, CA). The procedure was completed by phacoemulsification and insertion of an intraocular lens. The cases were divided into 2 groups: Group 1, initial experience consisting of the first 200 cases; and group 2, the subsequent 1300 cases performed by the same surgeons. MAIN OUTCOME MEASURES: Intraoperative complication rates and comparison between groups. RESULTS: Both groups were comparable for baseline demographic parameters. Anterior capsule tears occurred in 4% and 0.31% of eyes, posterior capsule tears in 3.5% and 0.31% of eyes, and posterior lens dislocation in 2% and 0% of eyes in groups 1 group 2, respectively (P<0.001 for all comparisons). Number of docking attempts per case (1.5 vs 1.05), incidence of post-laser pupillary constriction (9.5% vs 1.23%), and anterior capsular tags (10.5% vs 1.61%) were significantly lower in group 2 (P<0.001 for all comparisons). CONCLUSIONS: In the authors' experience, the surgical outcomes and safety of LCS improved significantly with greater surgeon experience, development of modified techniques, and improved technology.

Femtosecond cataract surgery: transitioning to laser cataract.

PURPOSE OF REVIEW: The introduction of the femtosecond laser to the field of cataract surgery offers many potential benefits. The femtosecond laser is able to perform three important steps in cataract surgery: capsulotomy, lens fragmentation and corneal incisions. Although evidence in support of its efficacy is accumulating, there is a surgical learning curve that needs to be addressed. This review outlines key issues to consider when contemplating the transition to laser cataract surgery in clinical practice. RECENT FINDINGS: Laser cataract surgery has been shown to be associated with an initial learning curve. Femtosecond lasers produce a more accurate and precise anterior capsulotomy, improve intraocular lens centration and reduce intraocular lens tilt. Visual and refractive outcomes, although in a limited number of studies, have been shown to be at least as good as those of conventional phacoemulsification. The impact of reduced phacoemulsification energy on the corneal endothelium is still being investigated. SUMMARY: The automation of key steps by the use of femtosecond lasers in cataract surgery has several potential advantages. Emerging literature supports the transition from conventional phacoemulsification to the laser cataract surgery.

Femtosecond laser cataract surgery: technology and clinical practice.

The recent introduction of femtosecond lasers to cataract surgery has generated much interest among ophthalmologists around the world. Laser cataract surgery integrates high-resolution anterior segment imaging systems with a femtosecond laser, allowing key steps of the procedure, including the primary and side-port corneal incisions, the anterior capsulotomy and fragmentation of the lens nucleus, to be performed with computer-guided laser precision. There is emerging evidence of reduced phacoemulsification time, better wound architecture and a more stable refractive result with femtosecond cataract surgery, as well as reports documenting an initial learning curve. This article will review the current state of technology and discuss our clinical experience.

Early experience with the femtosecond laser for cataract surgery.

OBJECTIVE: To describe the intraoperative complications and to evaluate the learning curve with femtosecond laser cataract surgery. DESIGN: Prospective, consecutive cohort study. PARTICIPANTS: The first 200 eyes undergoing femtosecond laser cataract surgery and refractive lens exchange in a single center. METHODS: The initial 200 eyes undergoing cataract surgery between April 2011 and June 2011 by 6 surgeons were included in the study. The cases underwent anterior capsulotomy, lens fragmentation, and corneal incisions with the femtosecond laser. The procedure was completed by phacoemulsification and insertion of an intraocular lens. Data were collected about patient demographics, preoperative investigations and intraoperative complications. The cases were divided into 4 groups-group 1 included the first 50 cases, group 2 included cases 51 through 100, group 3 included cases 101 through 150, and group 4 included cases 151 through 200-and were analyzed. MAIN OUTCOME MEASURES: Intraoperative complication rates. RESULTS: The mean age of patients included was 69.2±9.8 years. Of the 200 eyes, 74.5% underwent a complete procedure of laser capsulotomy, lens fragmentation, and corneal incisions. Five eyes had suction breaks during the laser procedure that led to the remainder of the laser procedure being aborted. Twenty-one (10.5%) eyes showed the presence of small anterior capsular tags. The number of eyes with free-floating capsulotomies was 35 (17.5%). The other complications during the study were anterior radial tears (n = 8; 4%), posterior capsular ruptures (n = 7; 3.5%), and dropped nucleus (n = 4; 2%). A significant difference was noted among the sequential groups with respect to the number of docking attempts (P<0.001), miosis after the laser procedure (P<0.001), and free-floating capsulotomies (P<0.001), suggesting an improving learning curve. The surgeons with prior experience with femtosecond lasers had fewer complications in the first 100 cases (P<0.001). No difference in complications was observed after the initial 100 cases. CONCLUSIONS: In this case series, there was a clear learning curve associated with the use of femtosecond lasers for cataract surgery. Adjustment to surgical technique and prior experience with a femtosecond laser seemed to flatten the learning curve.

Outcomes of femtosecond laser cataract surgery with a diffractive multifocal intraocular lens.

PURPOSE: To report the visual and refractive outcomes in an initial series of eyes undergoing femtosecond laser cataract surgery with implantation of a diffractive multi-focal intraocular lens (IOL). METHODS: The first 61 consecutive eyes undergoing femtosecond laser cataract surgery and ReSTOR (Alcon Laboratories Inc) +3.00-diopter (D) add IOL implantation between May and July 2011 were enrolled in the study (LCS group). The control group consisted of a retrospective consecutive cohort of 29 eyes that underwent manual phacoemulsification cataract surgery and ReSTOR +3.00-D add IOL implantation (MCS group) between December 2010 and April 2011. Visual and refractive parameters were collected pre- and postoperatively at 1 and 3 months. RESULTS: Mean postoperative spherical equivalent refraction was -0.01±0.35 D and -0.06±0.30 D in the LCS and MCS groups, respectively (P=.492). Mean absolute refractive prediction error (PE) was 0.26±0.25 D for the LCS group and 0.23±0.16 D for the MCS group (P=.489). Mean arithmetic refractive PE was 0.06±0.44 D and -0.02±0.30 D for the LCS and MCS groups, respectively (P=.388). No significant difference was noted in mean postoperative uncorrected distance visual acuity or uncorrected near visual acuity between groups. No eyes in either group had surgical complications or loss of corrected distance visual acuity in the follow-up period. CONCLUSIONS: Mean spherical equivalent refraction and visual acuity of our initial group of patients undergoing laser cataract surgery are comparable to the manual phacoemulsification cohort for the AcrySof ReSTOR +3.00-D add IOL.

Prevalence of tear film hyperosmolarity in 1150 patients presenting for refractive surgery assessment.

PURPOSE: To present an analysis of tear film hyperosmolarity in a large, consecutive population and evaluate the correlation of ocular and systemic conditions with tear film osmolarity (TFO). SETTING: Private practice, Sydney, Australia. DESIGN: Single-center, retrospective, consecutive cohort. METHOD: Patients undergoing screening for laser refractive surgery from October 2017 to October 2020 were retrospectively reviewed. 1404 patients (n = 1357 standard, n = 47 postrefractive) undergoing screening for laser refractive surgery from October 2017 to October 2020 were reviewed. Routine examination included TFO and Ocular Surface Disease Index (OSDI) questionnaire. TFO was conducted prior to further tests, and patients refrained from topical eyedrops minimum 2 hours before the appointment. RESULTS: 1404 patients (n = 1357 standards, n = 47 postrefractive) patients were reviewed. Mean highest TFO in the standard population was 299.12 ± 11.94 mOsm/L, with 82.3% of eyes <308 mOsm/L indicating normal tear film homeostasis. The mean intereye TFO difference was 8.17 ± 8.60 mOsm/L, with 65.2% of eyes ≤8 mOsm/L. Mean highest TFO in the postrefractive subgroup was 299.72 ± 11.00 mOsm/L, with a mean intereye difference of 9.02 ± 6.92 mOsm/L. Postrefractive surgery patients indicated higher mean OSDI values of 15.28 ± 14.46 compared with the remainder of the population 9.69 ± 10.56 (P = .012). Significant correlation was demonstrated between TFO scores and OSDI normal classification in the standard population only (P = .005, r = 0.077). The use of contact lens correlated inversely with TFO and OSDI scores (P = .000, r = -0.136, and P = .000, r = -0.152, respectively). CONCLUSIONS: To the authors' knowledge, this study represents the largest available cohort of TFO scores in a standard population presenting for refractive surgery. Although most patients were found to fall within normal ranges, a reasonable percentage were diagnosed with tear hyperosmolarity and therefore at risk for dry eye disease.

Visual and Refractive Efficacy of Panoptix Toric Intraocular Lens in a Clinical Setting.

Purpose: Trifocal Intraocular Lenses (IOLs) were developed to provide patients with effective near, intermediate and distance vision, thus minimizing spectacle dependency. Residual astigmatism has previously been shown to impact unaided visual acuity across all distances; therefore, to optimise the expected outcomes, consideration of preoperative corneal astigmatism is essential. The purpose of this study was to provide a real-world, multi-site review of visual and refractive outcomes in eyes undergoing implantation with the Panoptix Trifocal toric IOL platform. Patients and Methods: This study represents a two-fold approach. Patients who had previously undergone routine cataract removal and IOL insertion with the Panoptix Toric IOL were retrospectively analysed for routine efficacy and safety endpoints ("Retrospective Cohort"). Data was retrieved from the preoperative, surgical and postoperative visits (range 2-6 weeks). A further subset of patients undergoing lens removal and bilateral Panoptix Toric IOL insertion were identified at surgery ("Qualitative Cohort"). These patients underwent additional testing inclusive of quality of vision questionnaire and bilateral defocus curve. Results: A total of 466 eyes of 254 patients were included in the retrospective cohort. Between 91% and 98% of eyes, respectively, were within 0.50D and 1.00D of target. Mean absolute difference from Spherical Equivalent (SE) target was 0.22 ± 0.24Ds. Following surgery, 94% of eyes demonstrated a refractive astigmatism of 0.50D or less. Further, 61% eyes achieved uncorrected distance visual acuity (UDVA) of 20/20 or better, increasing to 94% achieving 20/32 or better. Seventy percent of eyes unilaterally achieved N5 unaided and 66.0% achieved N8 or better at intermediate. In the qualitative cohort, no patient described any symptom as significant or requested explant. Conclusion: In a real-world setting, the PanOptix toric trifocal IOL continues to demonstrate refractive accuracy and good visual performance at all focal distances. This IOL also exhibited good quality of vision, with minimally bothersome visual disturbances or photic phenomena.

Development of an In Situ Printing System With Human Platelet Lysate-Based Bio-Adhesive to Treat Corneal Perforations.

Purpose: Corneal perforation is a clinical emergency that can result in blindness. Currently corneal perforations are treated either by cyanoacrylate glue which is toxic to corneal cells, or by using commercial fibrin glue for small perforations. Both methods use manual delivery which lead to uncontrolled application of the glues to the corneal surface. Therefore, there is a need to develop a safe and effective alternative to artificial adhesives. Methods: Previously, our group developed a transparent human platelet lysate (hPL)-based biomaterial that accelerated corneal epithelial cells healing in vitro. This biomaterial was further characterized in this study using rheometry and adhesive test, and a two-component delivery system was developed for its application. An animal trial (5 New Zealand white rabbits) to compare impact of the biomaterial and cyanoacrylate glue (control group) on a 2 mm perforation was conducted to evaluate safety and efficacy. Results: The hPL-based biomaterial showed higher adhesiveness compared to commercial fibrin glue. Treatment rabbits had lower pain scores and faster recovery, despite generating similar scar-forming structure compared to controls. No secondary corneal ulcer was generated in rabbits treated with the bio-adhesive. Conclusions: This study reports an in situ printing system capable of delivering a hPL-based, transparent bio-adhesive and successfully treating small corneal perforations. The bio-adhesive-treated rabbits recovered faster and required no additional analgesia. Translational Relevance: The developed in situ hPL bio-adhesives treatment represents a new format of treating corneal perforation that is easy to use, allows for accurate application, and can be a potentially effective and pain relief treatment.