Nicole R. Fram

Femtosecond laser-assisted cataract incisions: Architectural stability and reproducibility

There is considerable interest in the potential relationship between postoperative endophthalmitis and clear corneal tunnel incisions for cataract surgery. Earlier work from Ernest et al. clearly demonstrated that incisions that are square in surface architecture are significantly more resistant to deformation and leakage than those that are rectangular. The purpose of this preliminary investigation was to determine whether corneal tunnel incisions could be constructed with femtosecond laser technology and in a manner that would preclude deformation and leakage at any intraocular pressure (IOP).

Pseudophakic negative dysphotopsia: Surgical management and new theory of etiology

PURPOSE: To evaluate the benefit of various surgical methods to address pseudophakic negative dysphotopsia. SETTING: Private practice, Los Angeles, California, USA. DESIGN: Interventional case series. METHODS: The following 4 surgical methods were used to treat negative dysphotopsia: secondary piggyback intraocular lens (IOL) implantation, reverse optic capture, in‐the‐bag IOL exchange, and iris suture fixation. Ultrasound biomicroscopy (UBM) was used to analyze posterior chamber anatomy. The primary outcome was partial or complete resolution of the negative dysphotopsia symptoms 3 months postoperatively. RESULTS: Twelve eyes of 11 patients with negative dysphotopsia had surgical treatment. All 10 patients who had piggyback IOL implantation or reverse optic capture had partial or complete resolution of symptoms by 3 months. No patient who had in‐the‐bag IOL exchange (n = 3) or iris suture fixation of the capsular bag–IOL complex (n = 1) improved despite alteration of IOL material or edge design in the case of IOL exchange or UBM confirmation of posterior chamber collapse in the case of iris suture fixation of the capsular bag–IOL complex. CONCLUSIONS: Consistent with a new hypothesis, resolution of negative dysphotopsia symptoms depended on IOL coverage of the anterior capsule edge rather than on collapse of the posterior chamber alone. Furthermore, negative dysphotopsia was not attributed to a particular IOL material or edge design. Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Comparison of Intraoperative Aberrometry, OCT-Based IOL Formula, Haigis-L, and Masket Formulae for IOL Power Calculation after Laser Vision Correction

PURPOSE To compare the accuracy of intraoperative aberrometry technology and the Fourier-domain optical coherence tomography (OCT)-based intraocular lens (IOL) formula for IOL power calculation in eyes undergoing cataract surgery after previous laser vision correction (LVC) compared with established methods. DESIGN Retrospective consecutive case series. PARTICIPANTS Patients undergoing cataract surgery with a history of LASIK or photorefractive keratectomy. METHODS The IOL power was estimated preoperatively using the IOLMaster 500 (Carl Zeiss Meditec, Dublin, CA) to calculate the Haigis-L and Masket regression formulae (when prior data were available), and the Optovue RTVue (Optovue Inc, Fremont, CA) spectral domain OCT was used to obtain the Fourier-domain OCT-based IOL formula. The Optiwave Refractive Analysis (ORA) System (WaveTec Vision Systems Inc, Aliso Viejo, CA) wavefront aberrometer measured aphakic refractive measurements intraoperatively and calculated the IOL power with a modified vergence formula. Comparative analysis was done for predictive accuracy of IOL power determination using 2 conventional methods and 2 new technologies: the Haigis-L formula, Masket regression formula, ORA intraoperative aberrometry, and Optovue RTVue Fourier-domain OCT-based IOL formula. Patients without historical data (N = 39) were compared using 3 methods (Haigis-L, ORA, and Optovue), and patients with historical data (N = 20) were compared using all methods (Masket regression formula, Haigis-L, ORA, and Optovue). MAIN OUTCOME MEASURES Median absolute error (MedAE), mean absolute error (MAE), and percentage of eyes within ±0.25, ±0.50, ±0.75, and ±1.00 diopters (D) of refractive prediction error. RESULTS A total of 39 eyes of 29 patients without historical data were analyzed separately from 20 eyes of 20 patients with historical data. In the group without historical data (N = 39), 49% of eyes were within ±0.25 D, 69% to 74% of eyes were within ±0.50 D, 87% to 97% of eyes were within ±0.75 D, and 92% to 97% of eyes were within ±1.00 D of targeted refractive IOL power prediction error. The MedAE was 0.26 D for Haigis-L, 0.29 D for ORA, and 0.28 D for Optovue. The MAE was 0.37 D for Haigis-L, 0.34 D for ORA, and 0.39 D for Optovue. In the group with historical data (N = 20), 35% to 70% of eyes were within ±0.25 D, 60% to 85% of eyes were within ±0.50 D, 80% to 95% of eyes were within ±0.75 D, and 90% to 95% of eyes were within ±1.00 D of targeted refractive IOL power prediction error. The MedAE was 0.21 D for the Masket regression formula, 0.22 D for the Haigis-L formula, 0.25 D for ORA, and 0.39 for Optovue. The MAE was 0.28 D for the Masket regression formula, 0.31 D for the Haigis-L formula, 0.37 D for ORA, and 0.44 D for Optovue. There was no statistically significant difference among the methods. CONCLUSIONS Newer technology to estimate IOL power calculations in eyes after LVC shows promising results when compared with established methods.

Randomized comparison of postoperative use of hydrogel ocular bandage and collagen corneal shield for wound protection and patient tolerability after cataract surgery

PURPOSE: To compare the safety and efficacy of a hydrogel bandage and a collagen corneal shield in providing wound protection and relief of pain/discomfort in the acute period after uneventful unilateral clear corneal phacoemulsification cataract surgery with foldable intraocular lens (IOL) implantation. SETTING: Seventeen investigational sites in the United States. DESIGN: Prospective randomized single‐masked parallel study. METHODS: The study comprised patients scheduled to have unilateral clear corneal cataract surgery with posterior chamber intraocular lens implantation. The patients were examined preoperatively and frequently for 30 days postoperatively. The design was a noninferiority study of the 2 primary endpoints, device performance and maximum reported postoperative pain. RESULTS: The device performance success was 78.6% (228/290) for the hydrogel bandage and 26.5% (26/98) for the corneal shield (P<.0001 for noninferiority). Analyses indicated that the hydrogel bandage was superior to the corneal shield in device performance (P<.001; difference = 52.1%; 95% confidence interval, 41.6%‐61.4%). The maximum postoperative pain/discomfort score of the hydrogel bandage (mean 1.3 ± 1.8 [SD]; scale 0 to 10) was noninferior to that of the corneal shield (1.1 ± 1.6) in the first 4 hours after surgery (P<.001). Adverse events in the cataract surgeries were reported in 22.2% (70/316) and 36.5% (38/104) of hydrogel bandage patients and corneal shield patients, respectively (P = .0045). CONCLUSION: The hydrogel bandage was safe and effective for ocular surface protection and relief of pain/discomfort when applied topically to clear corneal incisions used in cataract or IOL implantation surgery. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Use of a calibrated force gauge in clear corneal cataract surgery to quantify point-pressure manipulation

Purpose To develop and evaluate a calibrated force gauge designed to simulate the effect of patient‐induced manipulation of the eye with resultant elevation of intraocular pressure (IOP) and use the device to determine the stability of cataract incisions. Setting Three private practice study sites. Design Clinical trials. Methods A calibrated force gauge was developed to apply controlled and quantifiable amounts of force to the eye. In study 1, the calibrated force gauge was used to evaluate the change in IOP during application of 1 oz of external force in a group of healthy volunteers. In studies 2 and 3, the calibrated force gauge was used to assess wound leakage of clear corneal incisions that were subjected to stromal hydration or sutures, respectively. Results In study 1, with the application of 1.00 oz of external force, the mean IOP rose from a baseline of 17.49 mm Hg to 43.44 mm Hg. In study 2 (stromal hydration) using up to 1.00 oz of force, the leak rate was 67% for the main incision. The overall leak rate for study 3 (sutures) using up to 1.00 oz of force was 23.8%. No adverse events or serious adverse events occurred during these studies. Conclusions Study 1 confirmed that 1.00 oz of force is a realistic approximation of the amount of force a patients eye may experience during rubbing. After clear corneal cataract surgery, the application of 1.00 oz of force to the ocular surface for approximately 2 to 3 seconds may simulate the propensity for postoperative wound leak resulting from patient manipulation. Financial Disclosure Drs. Masket, Hovanesian, and Raizman are consultants to Ocular Therapeutix. Dr. Masket is also a medical monitor for Ocular Therapeutix. Drs. Hovanesian and Masket are shareholders in Ocular Therapeutix. Drs. Wee and Fram have no financial disclosures.

Dysphotopsia and oval intraocular lenses

Post-cataract dysphotopsia represents undesired optical imagery other than entoptic phenomena from vitreoretinal traction. Patients might present with negative dysphotopsia, a dark crescent in the temporal field of vision, or positive dysphotopsia, light streaks, arcs, flashes or starbursts, or both negative dysphotopsia and positive dysphotopsia. Although the cause of negative dysphotopsia remains speculative and is likely multifactorial, the literature supports several theories, including a penumbra related to intraocular lens (IOL) material and design as well as the interaction between the anterior surface of the IOL and the edge of the overlapped anterior continuous tear capsulotomy. Although the term was coined later, positive dysphotopsia was first described in 1993 as undesirable central and peripheral light streaks emanating from oblique light with ovoid IOLs; it was determined by reflectometry and ray tracing that the squared truncated edges induced internal reflection. Positive dysphotopsia has also been associated with high index-of-refraction acrylic IOLs that have a relatively flat anterior radius of curvature. Management of both persistent negative dysphotopsia and positive dysphotopsia might require secondary surgery. A new oval-optic IOL, the Softec HDO (Lenstec, Inc.) (Figure 1) was introduced to prevent negative dysphotopsia based on its large profile, measuring 6.50 mm by 5.75 mm. However, 2 patients with the IOL were referred for management of intense positive dysphotopsia symptoms; both required IOL exchange.

Safety-basket suture for management of malpositioned posterior chamber intraocular lens

&NA; The safety‐basket suture technique is used during surgical management of a malpositioned or subluxated posterior chamber intraocular lens (IOL) in post‐vitrectomy eyes. The purpose of the safety suture is to prevent posterior dislocation of the IOL during repositioning. The technique has been used in 32 cases to date with no occurrence of IOL posterior luxation. The only complication was transient vitreous hemorrhage in 2 eyes. This technique provides increased safety in the management of malpositioned IOLs and can be used for secondary IOL implantation by suture or intrascleral fixation. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.

Influence of ophthalmic viscosurgical devices on intraoperative aberrometry.

Purpose To determine whether the presence of an ophthalmic viscosurgical device (OVD) in the anterior chamber influences intraoperative aberrometry and the suggested intraocular lens (IOL) power. Setting Advanced Vision Care, Los Angeles, and Specialty Surgery Center, Beverly Hills, California, USA. Design Prospective interventional case series. Method Eyes scheduled for routine phacoemulsification and were divided into 6 equal groups, with each having 1 of 6 OVDs. After cataract removal, carefully controlled aberrometry was performed with the anterior chamber filled with balanced salt solution (BSS). Immediately thereafter, the BSS was replaced by 1 of the OVDs and the aberrometry repeated. The IOL power was selected from the BSS reading, and clinical manifest refraction was performed 3 weeks after surgery. The mean absolute error (MAE) was determined and compared with the extrapolated refraction had the IOL power been selected from the aberrometry reading under OVD. Results The study comprised 120 eyes, 20 in each group. The IOL power determination was lower with OVD filling the chamber. For Discovisc and Amvisc Plus, the MAE determinations were statistically different because the suggested IOL power was approximately 0.50 diopter less than with a BSS fill. For the remaining OVDs (Amvisc, Healon, Healon GV, and Provisc), the MAE differences were insignificant. The strong correlation between differences in the index of refraction between BSS and specific OVDs appeared to be causal. Conclusion Surgeons should be aware of the influence of OVDs on the accuracy of intraoperative aberrometry because specific agents can alter the optical results and suggested IOL power. Financial Disclosure Dr. Masket is a consultant to Wavetec Vision Systems, Inc., and Alcon Laboratories, Inc., and has a research grant from Alcon Laboratories, Inc. Dr. Fram has a research grant from Wavetec Vision Systems, Inc. Dr. Holladay is a consultant to Wavetec Vision Systems, Inc.

Spontaneous dislocation of posterior chamber intraocular lenses (PC IOLs) in patients with retinitis pigmentosa – Case series

PURPOSE To report the outcomes of intraocular lens (IOL) dislocation management in 6 cases with Retinitis Pigmentosa (RP). SETTING Private practice, Los Angeles, USA. DESIGN Retrospective interventional case series. METHODS The medical reports of six eyes of four RP patients with capsule bag fixated posterior chamber IOL dislocation were retrospectively reviewed. Pre-operative data included demographics, systemic or ocular disorders, history of trauma, previous intraocular surgery and pre-operative visual acuity. Outcome measures included the type of surgery, surgical complications, elevation of intraocular pressure (IOP), ocular inflammation, cystoid macular edema (CME) and IOL dislocation at 3 months or greater post-operatively. RESULTS The medical records of six eyes of four patients operated on between December 2009 and May 2011 were evaluated. In four cases, dislocated PC IOL implants were sutured to the sclera. In two eyes of one patient anterior chamber IOLs (AC IOLs) were implanted after PC IOLs were explanted. One eye developed CME during the follow-up period. Despite modest tilt in one case and modest decentration in another, stability and centration of the IOLs was excellent during the follow-up period. No eyes had intraocular inflammation requiring long term medical treatment, new onset glaucoma or retinal detachment. Mean follow-up time was 6.9 months (range 3-20). CONCLUSIONS Cataract surgeons should be aware of the increased risk for decentration and malposition of PC IOLs in patients with RP. Satisfactory results can be achieved by fixation of the PC IOL or AC IOL implantation.