Clinical outcomes of the light adjustable lens in eyes with a history of prior corneal refractive surgery.

PURPOSE: This study aimed to evaluate the visual and refractive outcomes in eyes with a history of laser corneal refractive surgery implanted with the second-generation light-adjustable lens (LAL). SETTING: Private Practice, Sioux Falls, South Dakota, US. DESIGN: Retrospective, consecutive case series. METHODS: Eyes with a history of prior corneal refractive surgery that underwent cataract surgery with implantation of the LAL and were targeted for plano were included. Data on the type and number of prior refractive surgeries were collected, in addition to the timing and number of postoperative adjustments. The primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and the percentage (%) of eyes within ±0.25 diopter (D), ±0.50D, and ±1.00 D of their refractive target. RESULTS: 76 eyes from 70 patients were included. A total of 45 eyes with a history of one prior refractive surgery and 31 eyes with a history of ≥2 refractive surgeries were included. 74% (n=56) of all eyes achieved UDVA of 20/20 or better, 88% (n=67) achieved 20/25 UDVA or better and 93% (n=71) were correctable to 20/20 or better postoperatively. For refractive outcomes, 66% of eyes (n=50) were within ±0.25 D and 86% (n=65) were within ±0.50 D of refractive target. CONCLUSIONS: Patients with a history of laser corneal refractive surgery achieved favorable visual and refractive outcomes with the LAL. This intraocular lens (IOL), which affords postoperative adjustability, is a promising option for patients with a history of corneal refractive surgery who maintain high expectations for functional uncorrected acuity following cataract surgery.

Varenicline Solution Nasal Spray for the Treatment of Dry Eye Disease Following LASIK.

INTRODUCTION: The purpose of this study is to evaluate the use of a varenicline solution nasal spray (VNS) for reducing the signs and symptoms of dry eye following laser in situ keratomileusis (LASIK). METHODS: Subjects electing to undergo LASIK were randomized to VNS (study group) or placebo/vehicle (control group) and initiated treatment with the nasal spray twice daily 28 days prior to surgery with continued treatment for 84 days following LASIK. After initiation of treatment, subjects were seen on the day of surgery and postoperatively on Days 1, 7, 28, 84 (3 months) and 168 (6 months). The primary outcome measure was the mean change in NEI-VFQ-25, a 25-item dry eye questionnaire, from baseline to 3 months. The second primary outcome measure was the mean change in corneal fluorescein staining. Secondary outcome measures included evaluation of tear break-up time, Schirmer testing, tear osmolarity and eye dryness score (EDS). RESULTS: Twenty subjects were enrolled in each group and successfully underwent LASIK. Both groups demonstrated an improvement in the National Eye Institute Visual Function Questionnaire (NEI-VFQ) at 3 months. The study group demonstrated improved corneal staining scores at months 1 and 3. Similarly, the study group demonstrated improvement in tear osmolarity scores versus the placebo group at the same time points. Although the study group was numerically greater than placebo for each time point for both corneal staining and tear osmolarity, the differences were not statistically significant for any primary or secondary outcome measures. CONCLUSION: VNS is a dry eye treatment option for patients following LASIK and may have potential benefit for patients hoping to avoid additional topical medications. The results were not statistically significant compared to placebo in this trial, and further investigation of the use of VNS following LASIK in a larger trial would be beneficial.

Laser in situ keratomileusis (LASIK) is a very successful refractive surgery option for patients hoping to reduce or eliminate their need for spectacles. Signs and symptoms of dry eye disease are very common after LASIK owing to the transection of corneal nerves that occurs during the procedure, and many patients are advised to manage it with frequent instillation of artificial tears. This study evaluated the use of a varenicline solution nasal spray, a recently introduced pharmacologic option that stimulates natural tear production through activation of the trigeminal nerve pathway. This is the first study to evaluate the use of the varenicline solution nasal spray in patients after refractive surgery and demonstrates that it could represent a favorable, ocular surface-sparing option for patients to minimize the signs and symptoms of dry eye following LASIK, a procedure known to trigger symptoms of dry eye disease.

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction.

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Evaluating the safety and efficacy of epi-off corneal cross-linking in patients with thin corneas due to keratectasia.

Background: Corneal cross-linking (CXL) is a safe and effective procedure for slowing keratectasia progression in eyes with a corneal thickness of at least 400 µm. Limited research has evaluated the safety and efficacy of epi-off CXL in corneas thinner than 400 µm. Objective: To evaluate the safety and efficacy of CXL to slow keratectasia progression in eyes with <400 µm preoperative corneal thickness. Design: Retrospective chart review. Methods: This retrospective chart review included 37 eyes who underwent epi-off, iso-osmolar riboflavin corneal CXL with a preoperative thinnest point of the cornea <400 µm and had at least 6-12 months of follow-up. Preoperative and postoperative uncorrected visual acuity, best-corrected visual acuity (BCVA), thinnest point of the cornea, flat keratometry, steep keratometry, maximum keratometry (Kmax), need for penetrating keratoplasty, and cases of endothelial failure were recorded. Data were collected at baseline and months 3, 6, 9, and 12 post-CXL. Results: Following cross-linking, 18 eyes (47%) had improved BCVA, 13 (35%) had an unchanged BCVA, and 6 eyes (16%) had a worse BCVA (p = 0.05). The mean postoperative BCVA was 20/81 (0.61 LogMAR) compared to 20/121 (0.78 LogMAR) preoperatively (p = 0.06). Kmax decreased an average of 1.1 D at 3-month (p = 0.53) and 3.4 D at the furthest follow-up (p = 0.10). At the farthest follow-up, 22.7% of eyes had >1 D of Kmax steepening. No patients required keratoplasty and there were no cases of endothelial failure in the follow-up period. Conclusion: This research supports the safety and efficacy of epi-off, iso-osmolar CXL in eyes with <400 µm baseline corneal thickness with no patients requiring penetrating or endothelial keratoplasty, a trend toward improvement in BCVA, and Kmax flattening. In the future, prospective studies would be helpful to confirm these findings.

Radial keratotomy and cataract surgery: A quest for emmetropia.

A 75-year-old man with an ocular history of 8-cut radial keratotomy (RK) in both eyes presented for cataract surgery evaluation. He was previously correctable in spectacles in years prior despite his irregular corneas to 20/25 in the right eye and 20/30 in the left eye. He recently noticed a change in his overall visual function with significant nighttime glare and difficulty reading despite spectacle correction. Of note, he was unable to tolerate contact lenses and was resistant to refitting despite additional encouragement. Cataract surgery was delayed for many years, given he was correctable in spectacles and the concern of uncovering a highly aberrated cornea after removing his cataracts (Figures 1 and 2JOURNAL/jcrs/04.03/02158034-202308000-00021/figure1/v/2023-07-21T030437Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202308000-00021/figure2/v/2023-07-21T030437Z/r/image-tiff). Of note, the patient was interested in returning to the spectacle independence he enjoyed in the past. Ocular examination revealed a corrected distance visual acuity (CDVA) of 20/30 in the right eye and 20/60 in the left eye, with a manifest refraction of +4.50 -0.50 × 177 in the right eye and +5.75 -1.75 × 14 in the left eye. Glare testing was 20/50 in the right eye and 20/100 in the left eye, with retinal acuity meter testing of 20/25 in each eye. Pupils, confrontation visual fields, and intraocular pressures were normal. Pertinent slitlamp examination revealed corneal findings of 8-cut RK with nasal-gaping arcuate incisions in both eyes and lens findings of 2+ nuclear sclerosis with 2+ cortical changes in the right eye and 3+ nuclear sclerosis with 3+ cortical changes in the left eye. Cup-to-disc ratios of the optic nerves measured 0.5 with temporal sloping in the right eye and 0.6 with temporal sloping in the left eye. The dilated fundus examination was unremarkable. What intraocular lens (IOL) options would you offer this patient and how would you counsel regarding realistic expectations? What additional diagnostic testing would be helpful in your assessment? How would you calculate the IOLs?

Negative Pressure Application via a Multi-Pressure Dial to Lower IOP in Patients with Suspected Glaucoma or Open Angle Glaucoma.

PRCIS: The multi-pressure dial applies localized periocular negative pressure to safely and effectively lower IOP and represents the first non-invasive, non-pharmacologic device for IOP reduction. OBJECTIVE: To evaluate the safety and effectiveness of the Multi-Pressure Dial (MPD) system, a device that applies periocular negative pressure to lower intraocular pressure (IOP). SETTING: 6 investigational sites, United States. DESIGN: Prospective, assessor-masked, randomized controlled trial. METHODS: Subjects with suspected glaucoma, ocular hypertension (OHTN), and open angle glaucoma (OAG) with baseline IOP ≥13 mmHg and ≤32 mmHg were enrolled. One eye of each subject was randomized to receive negative pressure application; the fellow eye served as a control. The study eye negative pressure setting was programmed for 60% of the baseline IOP. The primary effectiveness endpoint was the proportion of study eyes versus control eyes achieving an IOP reduction ≥20% at Day 90. Secondary endpoints included the proportion of eyes achieving an IOP reduction ≥25% at Day 90 as well as the proportion of eyes achieving an IOP reduction ≥20% at Days 30 and 60. RESULTS: 116 eyes of 58 subjects completed the study. At the Day 90 visit, 89.7% ( n =52) of study eyes versus 3.4% ( n =2) of control eyes achieved an IOP reduction ≥20% ( P <0.001). At Day 90, 77.6% ( n =45) of study eyes achieved a ≥25% IOP reduction compared to 1.7% ( n =1) of control eyes ( P <0.001). The most commonly reported adverse events were lid (17.2% study eye, 7.8% control eye) and periorbital edema (14.1% study eye, 10.9% control eye). CONCLUSIONS: This trial demonstrates that the MPD safely and effectively lowers IOP in a group of patients that included glaucoma suspects, OHTN, and patients with OAG.

Clinical Outcomes of a Non-Diffractive Extended Depth-of-Focus IOL in Eyes with Mild Glaucoma.

Purpose: To evaluate the clinical outcomes of a non-diffractive, wavefront-shaping extended depth-of-focus (EDOF) intraocular lens (IOL) in eyes with mild open-angle glaucoma (OAG). Setting: Private practice; Sioux Falls, South Dakota. Design: Prospective, open-label, interventional study. Methods: In total, 52 eyes of 26 patients with mild OAG were enrolled and completed the study. All patients were bilaterally implanted with a non-diffractive, wavefront-shaping EDOF IOL. Seventy-seven percent of the patients were implanted with a trabecular microbypass stent at the time of surgery. Primary outcome measures included binocular corrected and uncorrected distance visual acuity (CDVA and UDVA), uncorrected intermediate and near visual acuity (UIVA and UNVA) and contrast sensitivity as measured by a Pelli-Robson chart. A subjective questionnaire was also administered to patients. Results: At 4 months postoperative, the mean binocular UDVA and CDVA was 0.03 ± 0.12 and -0.06 ± 0.07, respectively. The mean UIVA and UNVA were 0.18 ± 0.12 and 0.31 ± 0.18, respectively. Eighty-five percent of the subjects achieved ≥20/25 UDVA and 77% of the subjects achieved ≥20/32 UIVA at 4 months postoperative. The mean binocular mesopic contrast sensitivity was 1.76 ± 0.16 at a spatial frequency of 1 cycle-per-degree (cpd). Eighty-five percent of the subjects reported they would choose the same lens and 1 subject reported they would choose a different IOL if it meant reduced spectacle independence. Conclusion: The non-diffractive, wavefront-shaping EDOF IOL can be safely implanted in eyes with mild, pre-perimetric open-angle glaucoma with favorable uncorrected distance and intermediate visual acuity. The contrast sensitivity measurements were favorable and the subjective questionnaire revealed satisfactory spectacle independence and patient satisfaction.

Intraocular Pressure Measurement with Pneumatonometry and a Tonometer Tip Cover During Negative Pressure Application.

Purpose: This is a 2-part study to investigate the agreement between pneumatonometry and direct pressure transducer intraocular pressure (IOP) measurements in a perfusion organ culture (POC) model where (1) the perfusion fluid column is open to atmospheric pressure, holding IOP constant to permit evaluation of the impact of negative pressure (NP) on IOP measurements, and (2) the perfusion fluid column is a closed system, allowing IOP to vary with NP application. Methods: The first part incorporated a fluid column open to atmospheric pressure, maintaining IOP constant to permit evaluation of the effect of applied NP on IOP measurement accuracy. In the second part, the POC column was closed, allowing IOP to vary with NP application and permit evaluation of agreement between pneumatonometry and pressure transducer measurements. In each part, four perfused tissues were used in thirteen paired pre-set IOP (10, 20, 25, 30 mmHg) and NP (0, 5, 10, 15, 20 mmHg) combinations, resulting in a total of 1040 paired measurements (520 per study). The difference in IOP measurements (Δ IOP = Excursion tonometry - pressure transducer) was calculated at each paired configuration. Results: During the first part, the mean Δ IOP was -0.7 ± 1.6 mmHg across all measurements. During the second part, the mean Δ IOP across all measurements was +0.7 ± 1.4 mmHg. At NP settings of -5, -10, -15, and -20 mmHg, across all pre-set IOPs, the mean IOP reduction via Excursion tonometry was 3.1 ± 0.3, 5.6 ± 1.3, 8.5 ± 1.7 and 11.2 ± 1.8 mmHg, respectively. Conclusion: Measurement of IOP via Excursion tonometry yields results within the accuracy range of the pneumatonometry device (per manufacturer) and is minimally impacted by NP application. The IOP-lowering results are consistent with previous studies and further support the effectiveness of the Multi-Pressure Dial in lowering IOP relative to atmospheric pressure.

IOL power calculations after LASIK or PRK: Barrett True-K biometer-only calculation strategy yields equivalent outcomes as a multiple formula approach.

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculations performed using the biometer-embedded Barrett True-K formula vs a multiple formula approach using the ASCRS postrefractive calculator in eyes with previous myopic or hyperopic refractive surgery. SETTING: Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio. DESIGN: Retrospective, consecutive case series. METHODS: Patients who underwent cataract surgery with a history of corneal refractive surgery were included. For each formula, the IOL prediction error and refractive prediction error was calculated. Main outcome measures included mean absolute error (MAE) and the percentage of eyes within ±0.25 diopters (D), ±0.50 D, and ±1.00 D. RESULTS: 96 postmyopic eyes and 47 posthyperopic eyes were analyzed. In the postmyopic cohort, the Barrett True-K formula had the lowest MAE (0.36 D), followed by the Haigis-L formula (0.41 D). The Barrett True-K formula had a significantly higher percentage (44.8%) of eyes within ±0.25 D in comparison with the Haigis-L formula (34.4%), which had the second highest percentage ( P < .01). In the posthyperopic cohort, the Barrett True-K formula had the lowest MAE (0.41 D), followed by the ASCRS-mean (0.46). The Barrett True-K and ASCRS-mean formulas had the highest percentage of eyes within ±0.25 D (42.6% vs 38.3%, P = .16). CONCLUSIONS: The Barrett True-K formula built into the biometer performed equivalently to a multiple formula approach on the ASCRS online calculator in both postmyopic and posthyperopic eyes. This approach reduces the potential for transcription error from data entry for lens power calculation approaches that require manual data entry.

Acute Calcific Band Keratopathy as an Adverse Effect of Recombinant Human Nerve Growth Factor (Cenegermin): A Multicenter Case Series.

PURPOSE: Cenegermin, (OXERVATE) a recently Food and Drug Administration-approved topical formulation of recombinant human nerve growth factor, has been used for the treatment of neurotrophic keratopathy (NK). Corneal deposits have been previously reported as a potential adverse effect; however, the clinical characteristics, visual significance, and treatment options have not been fully described. The purpose of this article is to better characterize corneal deposits occurring during treatment with cenegermin for neurotrophic keratopathy. METHODS: This was a retrospective, multicenter consecutive case series. RESULTS: We identified 5 patients from 3 institutions who developed a white opacity in varying layers of the cornea, consistent with calcium deposition, during treatment with cenegermin. In all cases, the opacity occurred rapidly over the course of a few weeks after initiation of treatment. Histopathologic examination of the cornea from one corneal patient demonstrated extensive calcification of the stroma extending to 90% depth. Before treatment, all patients had stage 2 or 3 NK (Mackie classification). The deposits were visually significant in all patients and did not resolve after cessation of cenegermin. There were no differences in age, sex, etiology of the NK, corneal transplant status, or concurrent medications between the patients who developed a deposit and 15 other patients with stage 2 or 3 NK who did not. One patient was successfully treated with superficial keratectomy with ethylenediaminetetraacetic acid chelation, one patient underwent penetrating keratoplasty, and one patient received a Boston keratoprosthesis. CONCLUSIONS: We report the rapid onset of a corneal opacity after initiation of treatment with cenegermin in patients with stage 2 or 3 NK, consistent with acute calcific band keratopathy. This visually significant adverse finding has not previously been described. We could not identify any risk factors for development. We recommend close monitoring of patients receiving cenegermin therapy because the opacity may be irreversible and may require keratoplasty for visual rehabilitation.

The Effect of Periocular Negative Pressure Application on Intraocular and Retrobulbar Pressure in Human Cadaver Eyes.

INTRODUCTION: To investigate the effect of applying negative pressure (vacuum) to the periocular space on intraocular pressure (IOP) and retrobulbar pressure (RBP) by use of the Multi-Pressure Dial (MPD) system (Equinox Ophthalmic, Inc.). METHODS: Two eyes of two full body cadavers were studied. In each subject, the retrobulbar space, posterior segment and intra-goggle space were cannulated to provide direct IOP, RBP and intra-goggle pressure measurements via a pressure transducer data acquisition system. The goggles of the MPD system were placed over the eyes of each subject, and multiple test runs were performed, with negative pressure settings programmed to 5, 10 and 20 mmHg. IOP and RBP measurements were continuously obtained during each run and plotted against time for analysis. RESULTS: For both subjects, the mean reduction (± standard deviation) in IOP was 1.6 ± 0.9 (10%), 3.5 ± 1.8 (23%) and 5.6 ± 2.0 (37%) mmHg at programmed negative pressure levels of - 5, - 10 and - 20 mmHg, respectively. The overall mean change in RBP (mmHg) during negative pressure application was 0.02 ± 0.14 at - 5 mmHg, 0.03 ± 0.19 at - 10 mmHg and - 0.01 ± 0.18 at - 20 mmHg. In both subjects, the magnitude of RBP change during application of negative pressure fell below the uncertainty of the measurement system. CONCLUSIONS: The application of negative pressure to the periocular space with the MPD decreases IOP but does not affect RBP.

High-Dose Oral Posaconazole for the Treatment of Recalcitrant Fungal Keratitis.

PURPOSE: To report the successful treatment of 3 cases of recalcitrant fungal keratitis (FK) with high-dose oral posaconazole. METHODS: This is a series of 3 patients from a single academic center with a culture-positive FK who were treated with oral posaconazole after failing to respond to conventional treatments. RESULTS: All 3 patients had a history of contact lens wear. Two of the 3 cases were culture positive for Fusarium and the other for Paecilomyces . The infections of all 3 failed to respond to conventional antifungal therapies including varying combinations of topical, systemic, and intraocular antifungal therapies. All 3 cases rapidly responded to high-dose oral posaconazole ranging from 500 to 600 mg once daily. In 1 case, multiple courses of high-dose therapy were required to treat delayed recurrences of a latent infection. There were no significant adverse effects with the elevated dose, and treatment was administered with the guidance of an infectious disease specialist. CONCLUSIONS: In cases of recalcitrant FK failing to respond to conventional therapies, high-dose posaconazole, in the delayed-release tablet formulation, can be an effective treatment option.

Evaluation of Same-Day versus Next-Day Implantation of Intracanalicular Dexamethasone for the Control of Postoperative Inflammation and Pain Following Cataract Surgery.

PURPOSE: To evaluate the safety and efficacy of a sustained-release intracanalicular dexamethasone insert for postoperative inflammation and pain implanted in a clinical setting preoperatively or on postoperative day 1. METHODS: Single-site, retrospective, contralateral eye study of patients undergoing cataract surgery. Included were subjects with a dexamethasone intracanalicular insert implanted in the clinic immediately prior to surgery in one eye (same-day) and on postoperative day 1 (POD1) in the contralateral eye. The primary outcome measure was the resolution of anterior chamber inflammation at 1 week postoperative. Secondary outcome measures included proportion of eyes requiring additional therapy for pain and inflammation through 1 month as well as the number of eyes with IOP spikes above baseline. Safety measures included adverse events through 1 month postoperative. RESULTS: Sixty-two eyes of 31 subjects were included in the case series. At 1 week postoperative, 52% of the eyes (n = 16) achieved complete resolution of inflammation in the same-day group and 58% (n = 18) met this endpoint at 1 week in the POD1 group. One subject in the same-day group required additional therapy for rebound inflammation and no eyes required additional therapy in the POD1 group. There were no reports of pain at 1 week or 1 month in either group. There were no implant-related adverse events in either group. CONCLUSION: The favorable results of this study indicate that the sustained-release dexamethasone insert can be safely implanted in the clinic either preoperatively on the day of surgery or on postoperative day 1 for the control of pain and inflammation following cataract surgery.

Depth-resolved Corneal Biomechanical Changes Measured Via Optical Coherence Elastography Following Corneal Crosslinking.

Purpose: To evaluate depth-resolved changes of corneal biomechanical properties in eyes with corneal ectasia after corneal crosslinking (CXL) using optical coherence elastography. Methods: In a prospective pilot series of eyes with corneal ectasia, a custom high-speed swept source optical coherence tomography system was used to image the cornea before and 3 months after CXL during a low-speed applanating deformation while monitoring applanation force. Cross-correlation was applied to track frame-by-frame two-dimensional optical coherence tomography speckle displacements, and the slope of force versus local axial displacement behavior during the deformation was used to produce a two-dimensional array of axial stiffness (k). These values were averaged for anterior (ka) and posterior (kp) stromal regions and expressed as a ratio (ka/kp) to assess depth-dependent differences in stiffness. CXL was performed according to the Dresden protocol with a system approved by the U.S. Food and Drug Administration. Results: Four eyes from four patients with keratoconus (n = 3) or post-LASIK ectasia (n = 1) underwent optical coherence elastography before and 3 months after CXL. The mean ka/kp was 1.03 ± 0.07 before CXL compared with 1.34 ± 0.17 after the CXL procedure. All four eyes demonstrated at least a 20% increase in the ka/kp. Conclusions: Preferential stiffening of the anterior stroma with the standard CXL protocol was demonstrated with optical coherence elastography in live human subjects. Translational Relevance: Although ex vivo studies have demonstrated anterior stiffening effects after CXL using various destructive and nondestructive methods, this report presents the first evidence of such changes in serial live human measurements.

Optimized CorT Total to compare Scheimpflug vs dual Scheimpflug/Placido imaging devices.

PURPOSE: To compare the manufacturer-provided measures of total corneal power (TCP) generated by Scheimpflug and dual Scheimpflug/Placido imaging compared with corneal topographic astigmatism calculated on the basis of measured TCP data (CorT Total). SETTING: Emory University, Atlanta, Georgia, USA. DESIGN: Retrospective case series. METHODS: TCP values were exported from virgin 209 eyes that underwent imaging with both the Scheimpflug (Pentacam HR) and dual Scheimpflug-Placido (Galilei G4) imaging devices to compute an optimized CorT Total. The standard deviation of the ocular residual astigmatism (ORAsd), which serves as a value describing the vectoral difference between the corneal astigmatism measure and manifest refractive cylinder at the corneal plane, was evaluated for all eyes to compare manufacturer-provided measurements vs the optimized CorT Total. RESULTS: The Scheimpflug CorT Total had the lowest ORAsd (0.306 diopter [D]; spherical equivalent [SE] 0.018) of all the parameters evaluated, although the difference was not statistically significant (P = .22) from the dual Scheimpflug/Placido CorT Total (0.32 2 D; SE 0.017). For the Scheimpflug device, the CorT Total had a statistically significant lower (P < .05) ORAsd in comparison to the best measure on the device (total corneal refractive power apex zone 2 mm: 0.324 D; SE 0.021). For dual Scheimpflug/Placido measurements, the CorT Total had the lowest ORAsd (0.322 D; SE 0.017), but the difference was not statistically significant (P = .43) from the lowest manufacturer-provided measure (TCP 2). CONCLUSIONS: CorT Total generated with the Scheimpflug device corresponded better with the manifest refractive cylinder than all measures of total corneal astigmatism calculated by the software from both the Scheimpflug and the dual Scheimpflug/Placido devices.

Periodic normalization of the translaminar pressure gradient prevents glaucomatous damage.

The 24-hour intraocular pressure (IOP) rhythm is of interest to clinicians but its overall impact on glaucomatous progression remains unclear. Recent evidence has implicated the translaminar pressure gradient (TLPG), or imbalance between IOP and intracranial pressure, in the development of glaucoma. Evidence suggests that retinal ganglion cell death occurs as a result of decreased axonal transport only after a sustained, elevated TLPG. We hypothesize that periodic normalization of the TLPG prevents glaucomatous damage by enabling temporary resumption of axonal transport. Temporary resumption of axonal transport allows for delivery of critical metabolic cargoes with concomitant removal of metabolic waste which prevents apoptosis of the retinal ganglion cell.

Evaluation of negative pressure transfer through tissue in a benchtop cornea and eyelid model.

PURPOSE: A new glaucoma treatment device, known as the multi-pressure dial (MPD), has been introduced, which offers a novel approach to IOP reduction by delivering negative pressure to the periocular region. Clinical studies have demonstrated the IOP-lowering effect of the MPD via direct measurements using pneumatonometry. It remains unclear whether the eyelids, when closed, affect the transmission of negative pressure and subsequently affect IOP reduction. This study aimed to evaluate whether the transfer of negative pressure and subsequent decrease in IOP are altered by the presence of synthetic eyelid tissue. METHODS: A model with 13 different configurations controlling for eyelid material type, presence of slit/opening, and eyelid-cornea contact was employed. The slit modification was employed to mimic the physiologic separation that exists between the eyelids. Baseline IOP within an eye model was set at various levels ranging from 10 to 30 mmHg with applied negative pressure settings of 10, 15, and 20 mmHg utilized at each baseline IOP. The percentage of vacuum transfer was calculated by comparing baseline IOP to resultant IOP measurements following application of vacuum to the system. RESULTS: In the open configuration (without eyelid tissue), the mean % vacuum transfer was 98.7%. The sealed, full-contact configurations exhibited values of 97.4%, 98.8%, and 97.2%. The slit configurations, which closely mimic the physiologic eyelid, demonstrated a mean % vacuum transfer of 98.7% across all settings. CONCLUSIONS: The impact of eyelid tissue on transfer of negative pressure can be isolated and evaluated. The presence of eyelid tissue has an insignificant impact on the transfer of negative pressure, and the IOP reduction achievable with the MPD would not be altered with the eyelids closed.

Evaluation of the IOP-Lowering Effect of a Multi-Pressure Dial at Different Negative Pressure Settings.

Purpose: To evaluate the intraocular pressure (IOP)-lowering effect of a multi-pressure dial (MPD) at targeted negative pressure settings. Methods: Prospective, intrasubject controlled study of 65 healthy subjects randomized to receive no negative pressure for 60 minutes or negative pressure application at designated levels of 25%, 50%, and 75% of baseline IOP for 20 minutes each. The main outcome measure was mean IOP with application of negative pressure. Results: In the study eye group, from a baseline IOP of 15.8 ± 3.6 mm Hg, the mean IOP was 13.5 ± 3.4, 11.5 ± 3.1, and 10.2 ± 2.7 mm Hg with negative pressure settings of 25%, 50% and 75%, respectively. In the control eye group, from a baseline IOP of 15.5 ± 3.0 mm Hg, the mean IOP values at the same time points, without negative pressure, were 15.6 ± 3.0, 15.5 ± 2.5 and 15.3 ± 2.4 mm Hg. The difference between the mean IOPs of the two groups was significantly different at all negative pressure settings (P < 0.001) in comparison with baseline. There was one minor adverse event, a corneal abrasion, that was unrelated to device wear. Conclusions: Negative pressure application to the periocular space with a multi-pressure dial can produce titratable IOP reduction while the device is worn with active negative pressure. To our knowledge, this technology represents the first nonpharmacologic, nonlaser, nonsurgical method for IOP reduction. Translational Relevance: This represents the first study demonstrating the IOP-lowering ability of the multi-pressure dial, a device that uses a novel IOP-lowering strategy by delivering negative pressure to the periocular region.

Overnight Safety Evaluation of a Multi-Pressure Dial in Eyes with Glaucoma: Prospective, Open-Label, Randomized Study.

PURPOSE: To investigate the safety and tolerability of the multi-pressure dial (MPD) worn overnight for seven consecutive days. DESIGN: Prospective, open-label, randomized, single-site study. SUBJECTS: Twenty eyes of 10 subjects with open-angle glaucoma were fitted with an MPD and randomized to negative pressure application of -10 mmHg in one eye (study eye) worn overnight for 7 consecutive days. METHODS: Safety measures included best-corrected visual acuity (BCVA), intraocular pressure (IOP) changes from baseline during and after negative pressure application, slit lamp and dilated fundus exam findings, and rate of adverse events. Subjective assessments were completed daily by the subjects during the 7-day study period and immediately following the study period. RESULTS: Prior to the 7-day testing period, application of 10 mmHg negative pressure reduced mean IOP from 18.2 ± 3.8 mmHg to 14.0 ± 2.1 mmHg (p<0.01), a 22% reduction. After 7 days of consecutive nightly wear, repeat IOP measurements with the application of negative pressure showed a decrease in mean IOP from 16.9 ± 4.3 mmHg to 13.5 ± 3.7 mmHg. The observed IOP reduction was in addition to the subjects' current treatment regimen. There were no statistically significant changes in IOP, BCVA from baseline following the 7-day period of nightly wear with the application of negative pressure. The patient-reported outcomes were favorable. CONCLUSION: The MPD can safely and comfortably be worn overnight. The decrease in IOP of >20% in addition to current therapy is both clinically and statistically significant. The MPD shows promise as a potential new treatment option for nocturnal IOP control.

Short-Term Steady-State Pattern Electroretinography Changes Using a Multi-Pressure Dial in Ocular Hypertensive, Glaucoma Suspect, and Mild Open-Angle Glaucoma Patients: A Randomized, Controlled, Prospective, Pilot Study.

INTRODUCTION: This study evaluates the effects of the multi-pressure dial (MPD) on steady-state pattern electroretinography (ss-pERG) parameters. The study is a randomized, controlled, prospective, pilot trial in a private practice setting with ocular hypertensive (OHT), glaucoma suspect, and open-angle glaucoma (OAG) subjects. METHODS: This study included nine patients (64 ± 9.0 years, nine female) with OHT, glaucoma suspect, or mild OAG. One eye of each subject was randomized to receive negative periocular pressure, while the contralateral eye served as the intrasubject control through the goggle without negative pressure. The Diopsys High Contrast Sensitivity ss-pERG protocol was conducted on both eyes of each subject while wearing the MPD device. Application of negative periocular pressure was set at 50% of baseline intraocular pressure for each study eye. RESULTS: Following 2 h of negative periocular pressure application, the difference in MagnitudeD (MagD) from baseline for eyes randomized to receive negative periocular pressure (+ 0.17 versus - 0.26) was statistically significant (p = 0.023). Over the same period, the change in MagD/Magnitude (MagD/Mag ratio) from baseline for eyes randomized to receive negative periocular pressure was also higher (+ 0.14 versus - 0.16), compared to the control eyes, approached significance (p = 0.059). CONCLUSIONS: Following 2 h of MPD wear, the measured MagD and MagD/Mag ratio improved compared to control, suggesting that negative periocular pressure application to the anterior globe can lead to short-term improvement in one measure of retinal ganglion cell function.