Statistical analysis plan for the phaco TIp position during clear corneal Phacoemulsification Surgery (TIPS) randomized controlled trial

BACKGROUND

Cornea is the most important refractive media in the eye, and damage to the corneal endothelium is one of the most common causes of poor visual outcome following cataract surgery, particularly in those with predisposing factors. The role of phaco tip position during phacoemulsification on corneal endothelial damage is ambiguous, and there is no consensus regarding the most cornea-friendly phaco tip position (bevel-up or bevel-down). The objective of the trial is to compare the effect of phaco tip position (bevel-up vs. bevel-down) during phacoemulsification using direct chop technique on corneal endothelial cell count.

METHODS AND DESIGN

TIPS is a randomised, multicentre, parallel-group, triple-masked (participant, outcome assessor, and statistician) trial with 1:1 allocation ratio. A total of 480 eligible participants, aged > 18 years with immature cataract, will be randomly allocated into bevel-up and bevel-down groups at two centres. Randomisation will be stratified according to the cataract grade. The primary outcome is postoperative endothelial cell count at 1 month. Secondary outcomes are central corneal thickness on postoperative days 1, 15, and 30 and difference in intraoperative complications.

CONCLUSION

In this paper, we describe the detailed statistical analysis plan (SAP) for the TIPS trial, which was prepared prior to database lock. The SAP includes details of planned analyses and unpopulated tables, which will be reported in the publications. We plan to lock the database in July 2023 and publish the results later in the same year. SAP Version 0.1 (dated: 28 April 2023) Protocol version:2.0 TRIAL REGISTRATION: Clinical Trial Registry of India CTRI/2019/02/017464. Registered on 5 February 2019; https://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=29764&EncHid=&userName=2019/02/017464.

Safety of intracameral application of moxifloxacin and dexamethasone (Vigadexa®) after phacoemulsification surgery

BACKGROUND

Intracameral antibiotics, such as moxifloxacin and cefuroxime, are safe to corneal endothelial cells and effective prophylaxis of endophthalmitis after cataract surgery. Corneal endothelial cells decrease in density after cataract surgery. Any substance used in the anterior chamber may affect corneal endothelial cells and lead to a greater decrease in density. This study wants to determine the percentage of endothelial cell loss after cataract extraction by phacoemulsification with off-label intracameral injection of moxifloxacin and dexamethasone (Vigadexa®).

METHODS

An observational retrospective study was performed. The clinical records of patients undergoing cataract surgery by phacoemulsification plus intracameral injection of Vigadexa® were analyzed. Endothelial cell loss (ECL) was calculated using preoperative and postoperative endothelial cell density. The relation of endothelial cell loss with cataract grade using LOCS III classification, total surgery time, total ultrasound time, total longitudinal power time, total torsional amplitude time, total aspiration time, estimated fluid usage, and cumulative dissipated energy (CDE) was studied using univariate linear regression analysis and logistic regression analysis.

RESULTS

The median loss of corneal endothelial cells was 4.6%, interquartile range 0 to 10.4%. Nuclear color and CDE were associated with increased ECL. ECL>10% was associated with age and total ultrasound time in seconds.

CONCLUSIONS

The endothelial cell loss after the intracameral use of Vigadexa® at the end of cataract surgery was similar to the reported in other studies of cataract surgery without the use of intracameral prophylaxis for postoperative endophthalmitis (POE). This study confirmed the association of CDE and nuclear opalescence grade with postoperative corneal endothelial cell loss.

Mechanical protective effect of lens anterior capsule disc on corneal endothelial cells during femtosecond laser-assisted cataract surgery in a rabbit model

PURPOSE

To evaluate the effects of a novel technique using an isolated lens anterior capsule disc (LACD) to protect corneal endothelial cells in rabbit eyes during femtosecond laser-assisted cataract surgery.

METHODS

Experimental study. 40 rabbits were divided into endothelium-protected (experimental) and control groups, with 20 rabbits in each group. In the experimental group, after femtosecond laser capsulotomy, the isolated capsule disc was lifted to the corneal endothelium by an ophthalmic viscosurgical device. The endothelium was damaged for 1 min with an ultrasonic probe. The control group underwent the same surgery, except that the disc was removed immediately after capsulorhexis. Corneal endothelioscopy was performed preoperatively and on postoperative days (PODs) 3 and 7 to observe endothelial cell counts (ECC) and endothelial cell loss rate. Central corneal thickness (CCT) was measured before and at PODs 1, 3 and 7.

RESULTS

There were 3.59%±1.88% (p < 0.001) and 2.92%±2.14% (p < 0.001) loss of ECC in experimental group at POD3 and POD7, respectively, while those in the control group were 11.62%±7.43% and 10.34%±5.77%, respectively. On POD 1, the difference in central corneal thickness was significant(P = 0.019) between the two groups. At POD 3 and POD 7, CCT was not significantly different (P = 0.597;0.913) between the two groups.

CONCLUSIONS

The isolated LACD technique significantly reduced damage to the endothelium caused by ultrasonic energy and protects corneal endothelial cells during phacoemulsification.

Long-Term Endothelial Safety Profile With iStent Inject in Patients With Open-Angle Glaucoma

PURPOSE

To report 5-year postoperative safety data of iStent inject, including overall stability, endothelial cell density (ECD), and endothelial cell loss (ECL) in patients with mild-to-moderate primary open-angle glaucoma (POAG).

DESIGN

In this 5-year follow-up safety study of the 2-year iStent inject pivotal randomized controlled trial, patients receiving iStent inject placement and phacoemulsification or phacoemulsification alone were studied for the incidence of clinically relevant complications associated with iStent inject placement and stability.

METHODS

Corneal endothelial endpoints were mean change in ECD from screening and proportion of patients with >30% ECL from screening, from analysis of central specular endothelial images by a central image analysis reading center at several timepoints through 60 months postoperatively.

RESULTS

Of 505 original randomized patients, 227 elected to participate (iStent inject and phacoemulsification group, n = 178; phacoemulsification-alone control group, n = 49). No specific device-related adverse events or complications were reported through month 60. No significant differences were observed in mean ECD, mean percentage change in ECD, or proportion of eyes with >30% ECL between the iStent inject and control groups at any timepoint; mean percentage decrease in ECD at 60 months was 14.3±13.4% in the iStent inject group and 14.8±10.3% in the control group (P = .8112). The annualized rate of ECD change from 3 to 60 months was neither clinically nor statistically significant between groups.

CONCLUSIONS

Implantation of iStent inject during phacoemulsification in patients with mild-to-moderate POAG did not produce any device-related complications or ECD safety concerns compared to phacoemulsification alone through 60 months.

Does the phaco TIp position during clear corneal Phacoemulsification Surgery adversely affect corneal endothelium? TIPS study protocol for a randomised, triple-masked, parallel-group trial of bevel-up versus bevel-down phacoemulsification

Introduction: Globally, at least 30 million cataract surgeries are required annually to prevent cataract-related blindness. Corneal endothelial decompensation is one of the most common causes of poor visual outcome following cataract surgery, particularly in those with predisposing factors. The increasing ageing population and reduced visual impairment threshold for cataract surgery have resulted in rising cataract surgical rates and hence, an increase in corneal endothelial decompensation is expected. The role of phaco tip position on corneal endothelial damage is ambiguous. Previous studies have reported contradictory results and were also underpowered to detect a significant difference due to small sample sizes. With no consensus regarding the most cornea-friendly phaco tip position (bevel-up versus bevel-down) during phacoemulsification, we propose a randomised clinical trial with a robust design using direct chop phaco-technique. Objective: To compare the effect of phaco tip position (bevel-up vs. bevel-down) on corneal endothelial cell count during phacoemulsification. Methods: A randomised, multicentre, parallel-group, triple-masked (participant, outcome assessor, and statistician) trial with 1:1 allocation ratio is proposed. By adopting stratified randomisation (according to cataract grade), we will randomly allocate 480 patients aged >18 years with immature cataract into bevel-up and bevel-down groups at two centres. History of significant ocular trauma, previous intraocular surgery, shallow anterior chamber, low endothelial cell count, pseudoexfoliation syndrome, intraocular inflammation, and corneal endothelial dystrophy are the key exclusion criteria. The primary outcome is postoperative endothelial cell count at one month. Secondary outcomes are central corneal thickness on postoperative days 1, 15, and 30, and intraoperative complications. Trial registration: Clinical Trial Registry of India CTRI/2019/02/017464 (05/02/2019).

The Biologic Character of Donor Corneal Endothelial Cells Influences Endothelial Cell Density Post Successful Corneal Transplantation

Purpose

Corneal endothelial cell density (ECD) gradually decreases after corneal transplantation by unknown biologic, biophysical, or immunologic mechanism. Our purpose was to assess the association between donor corneal endothelial cell (CEC) maturity in culture and postoperative endothelial cell loss (ECL) after successful corneal transplantation.

Design

Prospective cohort study.

Participants

This cohort study was conducted at Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. It included 68 patients with a 36-month follow-up period who had undergone successful Descemet stripping automated endothelial keratoplasty (DSAEK) or penetrating keratoplasty.

Methods

Human CECs (HCECs) from remaining peripheral donor corneas were cultured and evaluated for maturity by surface markers (CD166⁺, CD44^-/dull, CD24^-, and CD105^-) using fluorescence-activated cell sorting. Postoperative ECD was assessed according to the mature-differentiated HCEC contents: high-maturity group: > 70%, middle-maturity group: 10% to 70%, low-maturity group: < 10%. The successful rate of ECD maintained at 1500 cells/mm² at 36 months postoperative was analyzed using the log-rank test.

Main Outcome Measures

Endothelial cell density and ECL at 36 months postoperative.

Results

The 68 included patients (mean [standard deviation] age 68.1 [13.6] years, 47.1% women, 52.9% DSAEK). The high, middle, and low-maturity groups included 17, 32, and 19 eyes, respectively. At 36 months postoperative, the mean (standard deviation) ECD significantly decreased to 911 (388) cells/mm² by 66% in the low-maturity group, compared with 1604 (436) by 40% and 1424 (613) cells/mm² by 50% in the high and middle-maturity groups (P < 0.001 and P = 0.007, respectively) and the low-maturity group significantly failed to maintain ECD at 1500 cells/mm² at 36 months postoperative (P < 0.001). Additional ECD analysis for patients who underwent DSAEK alone displayed a significant failure to maintain ECD at 1500 cells/mm² at 36 months postoperative (P < 0.001).

Conclusions

The high content of mature-differentiated HCECs expressed in culture by the donor peripheral cornea was coincident with low ECL, suggesting that a high-maturity CEC content predicts long-term graft survival. Understanding the molecular mechanism for maintaining HCEC maturity could elucidate the mechanism of ECL after corneal transplantation and aid in developing effective interventions.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

[CyPass microstent trimming with special cutting forceps : Video article]

OBJECTIVE OF SURGERY

A CyPass®-microstent (Alcon, Fort Worth, TX, USA) extending too far into the anterior chamber should be trimmed as close as possible to the scleral spur to avoid progression of endothelial cell reduction.

INDICATIONS

After CyPass implantation, if there is a significant loss of corneal endothelial cells due to the Cypass microstent extending too far into the anterior chamber, trimming or removal of the CyPass stent is necessary.

CONTRAINDICATIONS

There are no contraindications.

SURGICAL TECHNIQUE

As shown in our video, which is available online, a special cutter (19 Gauge Ahmed Micro Stent Cutter, MicroSurgical Technology Inc, Redmond, WA, USA) is inserted into the anterior chamber via a 1.5-mm wide corneal paracentesis made directly opposite to the CyPass stent. It is then possible to trim the anterior part of the stent. The severed fragment is removed using the head of the forceps. Finally, the previously inserted viscoelastic agent can be aspirated and the paracentesis can be hydrated.

POSTOPERATIVE TREATMENT

After the surgery vision testing as well as control of intraocular pressure and location of the stent are carried out. Antibiotic eye drops and ointment are postoperatively applied.

EVIDENCE

There is still no standardized protocol for the procedure to trim the CyPass stent. Performing the trimming in our clinic using the procedure described here has so far not led to any complications. Long-term data about the development of the endothelial cell measurement after CyPass trimming are not yet available.

Endothelial cell loss 5 years after Preserflo MicroShunt implantation: About two cases

Purpose

Preserflo MicroShunt is a minimally-invasive glaucoma drainage micro-tube used to shunt aqueous humor from the anterior chamber to the subtenon space. The safety of the procedure was considered satisfactory with a majority of minor side effects.

Observation

We describe the 5 year endothelial cell loss after Preserflo implantation in 2 primary open angle glaucoma patients. The case 1 presented a device-cornea touch after a backward migration of the device. The case 2 presented a modified aspect of the device compatible with an inflammatory reaction. Both cases were explanted.

Conclusion

As described in Ahmed glaucoma valve, Xen gel stent and Cypass, Preserflo MicroShunt can lead to endothelial cell loss in some cases. A long-term prospective study with pre and postoperative endothelial cell count and AS-OCT or UBM evaluation of the device positioning would be of great interest to assess the real impact of Preserflo MicroShunt and risk factors for endothelial cell loss.

Corneal Endothelial Cell Loss After PRESERFLO™ MicroShunt Implantation in the Anterior Chamber: Anterior Segment OCT Tube Location as a Risk Factor

INTRODUCTION

To analyze the effects of PRESERFLO on corneal endothelial cell density (ECD).

METHODS

Forty-six eyes that underwent PRESERFLO implantation were followed up for 12 months. Specular microscopy was performed preoperatively and at 1, 3, 6, and 12 months postoperatively to measure central ECD and mean monthly reduction (MMR). Anterior segment optical coherence tomography (AS-OCT) was applied to measure the tube-endothelium (TE < 200 μm, 201-500 μm, > 500 μm) distance. The relationship between TE distance and ECD was analyzed with a linear mixed-effects model.

RESULTS

Central ECD decreased significantly at 1 year (7.4%, p = 0.04), with an MMR of -15 ± 25 cells/mm². Regarding TE distance groups, there was an 18% ECD reduction in the < 200 μm group vs. 1% in the > 500 μm group (p = 0.08). Endothelial cell loss was related to TE distance (mean 482.9 ± 238 μm), with a higher rate at 1 month in comparison to 12 months for the same tube position in the anterior chamber (-174.8 ± 65.2 cells/mm² at 1 month vs. 30.2 ± 11.3 cells/mm² at 12 months, p < 0.01). From month 6, tubes located > 600 μm from the endothelium showed EC loss close to zero.

CONCLUSIONS

The PRESERFLO implant is associated with a loss of EC from the immediate postoperative period that continues over time at lower rates. A shorter TE distance appears to cause more severe ECD loss.

[Phacovitrectomy-Influence of the timing of intraocular lens implantation on the corneal endothelium]

BACKGROUND AND PURPOSE

In phacovitrectomy the cataract is usually operated on first including implantation of the intraocular lens (IOL) before beginning vitrectomy but the IOL can also be implanted following vitrectomy. This variation avoids optical impairments from corneal opacities and the lens rim, improves the visualization of the retina during surgery and might thereby reduce intraoperative complications, such as peripheral retinal tears or IOL subluxation. It might, however, increase stress on the corneal endothelium. The aim of this study was, therefore, to compare postoperative corneal endothelial cell loss for the standard procedure of phacovitrectomy and the surgical variation.

METHODS

In this retrospective study 41 eyes were each assigned to group I (standard phacovitrectomy) or group II (variation of phacovitrectomy). The primary endpoint was the absolute and relative corneal endothelial cell loss appearing 5 ± 1 weeks postoperatively with reference to the preoperative number of endothelial cells. Secondary endpoints included visual acuity, intraocular pressure, coefficient of variation of endothelial cell area (CV), proportion of hexagonal endothelial cell forms (6A), pachymetry, intraoperative and postoperative complications.

RESULTS

The absolute and relative endothelial cell loss in group I (-108 ± 146; -4.1 ± 5.7%) did not differ significantly from that in group II (-73 ± 122; -3.1 ± 5.3%, p = 0.299; p = 0.388). The secondary endpoints also showed no significant differences.

CONCLUSION

The presented variation of phacovitrectomy expands the surgical options and does not show a significantly different postoperative corneal endothelial cell loss compared to the standard procedure.

Efficacy and safety of iris-supported phakic lenses (Verisyse) for the treatment of high myopia: 5-year results

PURPOSE

Evaluating efficacy and safety of iris-supported phakic lenses (Verisyse) for high myopia treatment.

METHODS

Patients treated with Verisyse (Abbott Medical Optics, Santa Ana, CA, USA) intraocular lens (IOL) implants were evaluated retrospectively. Patients with follow-up periods of more than 5 years were included in the study. Pre- and postoperative fifth-year spheric equivalent (SE) of manifest refraction values, uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), and endothelial cell density (ECD) values were recorded. Complications were evaluated.

RESULTS

Forty-seven eyes of 31 patients were included in the study. Pre- and postoperative fifth year mean SE was - 12.50 ± 3.51D and - 0.72 ± 0.40D, respectively. Pre- and postoperative fifth-year UDVA was 1.56 ± 0.22 and 0.33 ± 0.18 logMAR (p < 0.001), respectively. The safety index (pre- and postoperative CDVA) was 1.39 ± 0.63 at the 5-year follow-up (p > 0,05). The efficacy index (ratio of mean postoperative UDVA to mean preoperative CDVA) of the patients was 1.14 ± 0.60. The mean postoperative endothelial cell loss at 5 years was -7.42%. None of the patients had lost 25% of their preoperative endothelial cells at 5-year follow-up. The mean postoperative endothelial cell loss was -3.05% at 1 year, -1.23% between years one and three, -1.02% between the third and fifth years.

CONCLUSION

Verisyse IOL implantation is an effective and safe for high myopia surgical treatment. However, the 5-year follow-up period is not sufficient to evaluate the safety profiles in terms of endothelial cells.

Corneal endothelial cell changes in diabetics versus age group matched nondiabetics after manual small incision cataract surgery

Purpose:

To assess and compare the endothelial cell changes after manual small incision cataract surgery (SICS) in diabetic patients versus age group matched non-diabetic patients.

Methods:

This comparative prospective observational follow-up study included 54 diabetic patients and 52 control patients without diabetes who underwent manual SICS. Preoperative, one day, one week, one month and three months post-surgery assessments of corneal endothelial cell changes were done using specular microscopy. Data analysis was performed using SPSS software (version 20.0, SPSS, Inc.). Mann–Whitney U test was used to compare the data between the test group and control group.

Results:

There was drop in the endothelial density in both the groups postoperatively, with the mean percentage of endothelial loss at three months post- surgery being 27.5% in diabetics and 18.3% in controls. There was also a significant increase in central corneal thickness and coefficient of variance in diabetics as compared to controls at every follow up one day, one week, one month and three months. The percentage of hexagonality was statistically significant at post-operative three months.

Conclusion:

The diabetic endothelium was found to be under greater metabolic stress and had less functional reserve after manual SICS than the normal corneal endothelium.

Safety and efficacy of hypertonic saline solution (5%) versus placebo in the treatment of postoperative corneal edema after uneventful phacoemulsification: a randomized double-blind study

PURPOSE

To evaluate safety and efficacy of hypertonic saline solution administration after uneventful cataract surgery.

DESIGN

Prospective double-blind randomized study METHODS: In total, 183 eyes of 183 patients undergoing phacoemulsification were randomly allocated into two equal groups. Treatment group (TG) subjects received single-dose hypertonic (NaCl 5%) solution 4 times daily for 14 days, while placebo group (PG) received single dose of normal saline solution (0.9%) at the same frequency in addition to ordinary postoperative treatment. All patients underwent assessment of central corneal thickness (CCT), endothelial cell density (ECD), best-corrected visual acuity (BCVA), clinical staging of postoperative corneal edema and questionnaire regarding the procedure success and impact on patient's life. Measurements were taken at baseline and 1, 4, 9 and 30 days following surgery.

RESULTS

CCT increased by 134.67 ± 94.51 μm (25.1 ± 19.4%) on postoperative day 1, without any difference between study groups (p = 0.58). Corneal edema showed a significant recession in TG compared to PG on day 4, in terms of both pachymetry (10.73% vs 7.39%, p = 0.004), BCVA (BCVA_TG = 0.64 ± 0.24 [logMAR_TG = 0.25 ± 0.3], BCVA_PG = 0.56 ± 0.23 [logMAR_PG = 0.33 ± 0.3], p = 0.04) and clinical staging (p = 0.02). Similar results were recorded on postoperative day 9 in subjects demonstrating marked corneal edema on the first postoperative day. Endothelial cell loss showed no statistically significant difference between study groups (p = 0.48). No adverse events were recorded in relation to treatment. More patients in the TG (92.4% vs 57.1% in the PG) reported a subjectively clear vision 1 week postoperatively (p = 0.04).

CONCLUSION

The use of 5% hypertonic saline solution is found to be a safe and effective adjunct in the management of postoperative corneal edema after uneventful phacoemulsification, achieving rapid corneal clearance and expediting a good visual outcome, especially in cases with marked postoperative edema.

Stepwise Decreasing of Vitreous Pressure by Anterior Vitrectomy: A Novel Method for Preventing Positive Vitreous Pressure During Penetrating Keratoplasty

BACKGROUND

This study evaluates the clinical effects of the stepwise anterior vitrectomy on the prevention of positive vitreous pressure (PVP) during penetrating keratoplasty (PKP).

METHODS

PKP in conjunction with stepwise anterior vitrectomy was performed on 15 eyes of 15 patients under retrobulbar anesthesia. A preset vitrectomy trocar-cannula was inserted into the vitreous cavity before PKP. During the opening of the anterior chamber, intermittent vitrectomy and corneal incision expansion were performed alternately to keep the lens or artificial intraocular lens (IOL) and iris flat until the entirety of the pathological cornea had been dissected. The main outcome measures include visual acuity, crystalline lens rise (CLR), corneal curvature and diopter, and corneal endothelial cell loss.

RESULTS

All surgical procedures were performed successfully without any PVP-related intraoperative complications. The mean time of the stepwise vitrectomies was 3.1 ± 0.7 s, the duration of each vitrectomy was 8.1 ± 5.3 s, and the duration of the total surgery was 60.5 ± 5.3 min. The anterior segment reaction was mild and the shape of the pupil remained normal 1 day after surgery. The mean preoperative and mean 3-month postoperative CLR values were 0.48 ± 0.09 mm and - 0.16 ± 0.04 mm, respectively (p < 0.0001). The mean preoperative endothelial cell density in donor buttons was 2570 ± 171 cells/mm², and the mean 6- and 12-month postoperative endothelial cell density in donor buttons was 2207 ± 127 cells/mm² and 2000 ± 198 cells/mm², respectively.

CONCLUSIONS

The novel and stabilized PKP procedure, performed in conjunction with the stepwise anterior vitrectomy, effectively avoided the PVP during open-sky surgery.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900021227.

Supracapsular phacoemulsification: Description of the "Garde à vous" technique and comparative clinical results

Phacoemulsification techniques can be divided into 2 categories: endocapsular and supracapsular techniques. Supracapsular techniques involve phacoemulsification of the nucleus outside and above the capsular plane. The "Garde-à-vous" technique described in this manuscript is a modified and improved version of the supracapsular procedure with up-to-date technology in micro-coaxial surgery. It maintains the known advantages of supracapsular techniques such as faster surgical times and lower rates of capsular tears and brings a standardized technique with well-defined surgical steps in order to achieve tilting of the nucleus in a vertical or oblique position in almost 100% of cases by performing a double-wave hydro-dissection. The authors also give the results of a non-randomized prospective study, comparing the "Garde-à-vous" technique and the standard "cracking" technique in 2856 cases. The results show that for the "Garde-à-vous group", the patients were significantly younger (P<0.001), the power of ultrasound used was greater (P<0.001) for lower UST (ultrasound time or average phacoemulsification time APT) and EPT (effective phacoemulsication time) (P<0.001), the duration of the procedure was shorter (P<0.001), patient discomfort was less (P<0.001), and the power of the implants used was lower (P<0.01). With regard to the gender of the patients, the percentage of topical anesthesia and the rate of intraoperative complications (posterior capsular rupture), there was no statistically significant difference.

Ocular Complications from Retained Intraocular Ointment Discovered 33 Months after Cataract Surgery

Topical antibiotic and steroid ointments are sometimes used topically at the conclusion of intraocular surgery, and inadvertent entry into the eye has been reported. Dispersed ointment droplets or consolidated globules in the anterior chamber (AC) can sometimes be visualized on exam. Occasionally, intraocular ointment is found incidentally without apparent toxic effect, but retained ointment usually presents with early or delayed intraocular inflammation, pressure rise, macular edema, or corneal edema. The usual treatment for toxicity from retained ointment is removal of the ointment. While the complication of ointment-induced cystoid macular edema has been reported, there is paucity of literature on the anatomical response and eventual visual outcome of patients who have been treated for long-standing edema from retained ointment. We present a case of a patient who presented with history of poor vision since the time of cataract surgery 33 months prior, who had cystoid macular edema, reduced endothelial cell count, and apparent Maxitrol ointment (neomycin, polymyxin B sulfate, and dexamethasone in paraffin vehicle; Novartis Pharmaceuticals UK) floating in the AC. The patient was treated with AC washout and sub-Tenon injection of triamcinolone. His vision, retinal architecture by optical coherence tomography, endothelial cell count, and pachymetry has been followed for 9 months following this treatment.

Comparison of clinical outcomes between femtosecond laser-assisted versus conventional phacoemulsification

Background

To compare femtosecond laser-assisted versus conventional phacoemulsification in terms of visual and refractive outcomes, cumulative dissipated energy, anterior chamber inflammation and endothelial cell loss.

Methods

In this retrospective cohort study, records of eyes that underwent femtosecond laser-assisted cataract surgery (FLACS) or conventional phacoemulsification (CP) were reviewed. The Victus femtosecond laser (Bausch and Lomb, Germany) was used to carry out corneal incisions, anterior capsulotomy, and lens fragmentation in FLACS procedures. Manifest refraction spherical equivalence (MRSE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), cumulative dissipated energy (CDE), postoperative cells and flare and endothelial cell count data were collected. Subgroup analysis of the visual acuity tests was performed based on the type of intraocular lens implanted (monofocal, monofocal toric, multifocal, multifocal toric, accommodating).

Results

A total of 735 eyes were included in the study (296 eyes for the FLACS group and 439 eyes for the CP group). At one year follow-up, 120 eyes comprised the FLACS group and 265 eyes for the CP group. MRSE in the FLACS group was - 0.16 ± 0.58 D and - 0.20 ± 0.52 D in the CP group (P = 0.50). UDVA in the FLACS group was 20/25 (mean logMAR 0.12 ± 0.13) and 20/25 (mean logMAR 0.11 ± 0.13) in the CP group (P = 0.48). CDVA was 20/20 (mean logMAR 0.03 ± 0.07) in the FLACS group and 20/20 (mean logMAR 0.02 ± 0.06) in the CP group (P = 0.15). No statistically significant trend was seen for FLACS versus CP by intraocular type for visual acuity. CDE for the different cataract grades ranged from 6.97 ± 5.74 to 29.02 ± 16.07 in the FLACS group and 7.59 ± 6.42 to 35.69 ± 18.30 in the CP group. The FLACS group was significantly lower for post-operative central corneal edema (P = 0.05), cells and flare (P = 0.01), and endothelial cell loss (P = 0.04).

Conclusions

Femtosecond laser-assisted cataract surgery and conventional phacoemulsification had similar refractive and visual outcomes. Phacoemulsification energy, anterior chamber inflammation and corneal endothelial cell loss were less in the femtosecond laser group.

Intra-correlations between cataract density based on Scheimpflug image, phacodynamics, surgery duration, and endothelial cell loss after phacoemulsification

Purpose

To assess intra-correlations between lens density based-on Scheimpflug Imaging System, power used during surgery, surgery duration, and endothelial cell loss in eyes with nuclear cataract.

Setting

Department of Ophthalmology, King Fahd Hospital of the University, Alkhobar, Saudi Arabia.

Design

Prospective cross-sectional observational study.

Methods and material

The objective lens density and endothelial cell density were measured using the Scheimpflug system and specular microscopy, respectively. Intra-operatively, all phacodynamic parameters and duration of the surgery were documented.

Results

This study of 62 patients (71 eyes) with a mean age of 58.56 ± 10.4 years. The mean Scheimpflug-measured lens density was 13.93 ± 3.27. The mean phacodynamic parameters, namely, power, ultrasound time, and elliptical motion were 13.63 ± 6.38, 1.27 ± 1.12, and 50.56 ± 50.06, respectively. There were a positive linear correlations between the Scheimpflug-measured lens density and phacodynamic parameters, power (AVG %), ultrasound time, and elliptical motion (r = 0.501, r = 0.620, and r = 0.641, respectively; all P < .001), amount of endothelial loss (r = 0.445, P < .001), and surgery duration (r = 0.346; P < .01). Phacodynamic parameters were positively correlated with degree of endothelial loss (P < .01). The length of the surgery failed to show any correlation with damage happened to the endothelium (r = 0.210, P > .05).

Conclusion

A positive correlations were observed between Scheimpflug-measured lens density with phacodynamic parameters, surgery duration, and endothelial loss. A strong correlation was observed between the degree of endothelial cell loss and phacodynamic parameters but not with the length of the procedure.

Computation of the temperature rise at the corneal endothelium during cataract surgery by modeling of heat generation inside the anterior chamber

The corneal endothelium sustaining the transparency of the cornea is a vulnerable cell layer. Thermal exposure during phacoemulsification is considered to be a potential cause of post-operative cell loss. Knowledge of the temperature rise and particularly of its dependence on region and system settings could deliver useful information about a potential correlation with cell damage. However, there exists a lack of understanding of the process and location of heat generation. Analytical calculations and experiments enabled the quantification of different mechanisms acting as heat sources during phacoemulsification. Heat generation caused by viscous friction was estimated using both an analytical approach and a numerical simulation. In contrast to absorption of sound and self-heating of the probe, this effect was ascertained to be the main heat source. Calorimetric measurement of the power input verified this modeling. On the basis of these results, the local temperature distribution inside a porcine eye was computed time dependently using the finite-element method. Two different amplitude settings were compared with respect to the temperature increase at the corneal endothelium. Various conclusions on the mitigation of thermal exposure during treatment can be drawn from this finite-element simulation.