Ophthalmic viscosurgical devices

A Prospective, Randomized, Controlled Clinical Investigation Comparing the Efficacy and Safety of Sodium Hyaluronate-Based Ophthalmical Viscosurgical Devices FIDIAL PLUS and IAL®-F in Cataract Surgery

Purpose: To protect the corneal endothelium, various ophthalmical viscoelastic devices (OVDs) are used during cataract surgery. In this study, we compared two sodium hyaluronate-based OVD, the bacteria-derived FIDIAL PLUS OVD (test) with the animal-derived IAL®-F OVD (reference) during the surgical procedure. Methods: Fifty patients with bilateral cataract participated in the study: 50 eyes randomly received FIDIAL PLUS and 50 eyes received IAL®-F (ratio 1:1). Noninferior efficacy of FIDIAL PLUS compared with reference OVD (first objective) was evaluated using a paired t-test comparing the mean percent loss of corneal endothelial cells (CECs) with FIDIAL PLUS against the mean percent loss with IAL®-F. Corneal endothelial protection during cataract surgery with FIDIAL PLUS without significant (≥30 mmHg) postoperative intraocular pressure (IOP) increase (main secondary objective) was assessed using a repeated measures logistic model comparing the incidence of significant postoperative IOP elevation between the two groups. Safety, tolerability, and efficacy were also evaluated by assessing secondary endpoints before and after surgery. Results: FIDIAL PLUS showed a statistically noninferior efficacy compared with IAL®-F; there was no significant increase in IOP in either group or different trends of the secondary endpoints were observed between the OVD groups. The safety profile was similar in both OVD groups and no adverse device effects were reported. Conclusions: This study demonstrates the equivalent efficacy, tolerability, and safety of the bacteria-derived FIDIAL PLUS compared with the animal-derived IAL®-F, confirming the clinical value of this product.

Intraocular Pressure Spike Following Stand-Alone Phacoemulsification in the IRIS® Registry (Intelligent Research in Sight)

PURPOSE

To evaluate risk factors for intraocular pressure (IOP) spike after cataract surgery using the IRIS® Registry (Intelligent Research in Sight).

DESIGN

Retrospective clinical cohort study.

PARTICIPANTS

Adults with IRIS Registry data who underwent stand-alone phacoemulsification from January 1, 2013, through September 30, 2019.

METHODS

Intraocular pressure spike was defined as postoperative IOP of > 30 mmHg and > 10 mmHg from the baseline within the first postoperative week. Odds ratios (ORs) for demographic and clinical characteristics were calculated with univariable and multivariable logistic regression analyses.

MAIN OUTCOME MEASURES

Incidence and OR of IOP spike.

RESULTS

We analyzed data from 1 191 034 eyes (patient mean age, 71.3 years; 61.2% female sex; and 24.8% with glaucoma). An IOP spike occurred in 3.7% of all eyes, 5.2% of eyes with glaucoma, and 3.2% of eyes without glaucoma (P < 0.0001). Multivariable analyses of all eyes indicated a greater risk of IOP spike with higher baseline IOP (OR, 1.57 per 3 mmHg), male sex (OR, 1.79), glaucoma (OR, 1.20), Black race (OR, 1.39 vs. Asian and 1.21 vs. Hispanic), older age (OR, 1.07 per 10 years), and complex surgery coding (OR, 1.22; all P < 0.0001). Diabetes (OR, 0.90) and aphakia after surgery (OR, 0.60) seemed to be protective against IOP spike (both P < 0.0001). Compared with glaucoma suspects, ocular hypertension (OR, 1.55), pigmentary glaucoma (OR, 1.56), and pseudoexfoliative glaucoma (OR, 1.52) showed a greater risk of IOP spike and normal-tension glaucoma (OR, 0.55), suspected primary angle closure (PAC; OR, 0.67), and PAC glaucoma (OR, 0.81) showed less risk (all P < 0.0001). Using more baseline glaucoma medications was associated with IOP spike (OR, 1.18 per medication), whereas topical β-blocker use (OR, 0.68) was protective (both P < 0.0001).

CONCLUSIONS

Higher baseline IOP, male sex, glaucoma, Black race, older age, and complex cataract coding were associated with early postoperative IOP spike, whereas diabetes and postoperative aphakia were protective against a spike after stand-alone phacoemulsification. Glaucomatous eyes demonstrated different risk profiles dependent on glaucoma subtype. The findings may help surgeons to stratify and mitigate the risk of IOP spike after cataract surgery.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Corneal endothelial cell loss and intraocular pressure following phacoemulsification using a new viscous-cohesive ophthalmic viscosurgical device

PURPOSE

To compare results of two ophthalmic viscosurgical devices (OVDs)-Viscoat (a dispersive OVD, Alcon) and FR-Pro (a viscous-cohesive OVD, Rayner), in phacoemulsification surgery.

METHODS

A prospective randomized controlled study. Patients undergoing phacoemulsification were randomly assigned to receive one of the two OVDs. Exclusion criteria were age under 40, preoperative endothelial cell count (ECC) below 1,500 cells/mm2 and an eventful surgery. The primary outcome was change in ECC from baseline to postoperative month one and month three. Secondary outcomes were the difference between ECC at postoperative month one and month three, changes in IOP and occurrence of an IOP spike ≥ 30 mmHg after surgery.

RESULTS

The study included 84 eyes-43 in the Viscoat group and 41 in the FR-Pro group. Mean cell density loss at month one and month three was 17.0 and 19.2%, respectively, for the Viscoat group and 18.4 and 18.8%, respectively, for the FR-Pro group, with no statistically significant difference between the groups (p = 0.772 and p = 0.671, respectively). The mean ECC difference between the month one and month three visits was 50.5 cells/mm2 and was not statistically significant (p = 0.285). One eye in each group had an IOP spike ≥ 30 mmHg, both normalized by postoperative week one.

CONCLUSIONS

Viscoat and FR-Pro have comparable results following phacoemulsification surgery, suggesting that while FR-Pro is not a dispersive OVD, its endothelial cell protection may be comparable to one, perhaps due to the addition of sorbitol. Furthermore, a one-month follow-up of ECC seems sufficient in such trials.

Physical Characteristics, Clinical Application, and Side Effects of Viscoelastics in Ophthalmology

Purpose

To explain the physical properties of ophthalmic viscoelastic devices (OVDs), covering their structural units, optimal features, existing viscoelastic materials, clinical applications, and potential side effects.

Methods

This is a narrative review on the OVDs. A literature review was conducted in PubMed, Google Scholar, and Scopus databases. Studies that investigated physical characteristics, clinical applications, OVD commercial products, and their complications were included.

Results

We included 42 articles from 2010 and discussed physical characteristics, properties of a desirable OVD, structural units of common OVDs, OVD commercial products, clinical applications, and also complications of OVDs.

Conclusions

Today, viscoelastics hold a distinct and crucial role in intraocular surgery due to their remarkable properties. These materials safeguard the endothelium and epithelium, uphold anterior chamber depth, manage intraocular bleeding, ease tissue handling, and aid intraocular lens placement. Currently, the American market features 12 prevalent viscoelastic types, including 7 sodium hyaluronate derivatives (Healon, Healon-Greater Viscosity, Healon-5, Amvisc, Amvisc Plus, Advanced Medical Optics Vitrax, and Provisc), 2 hydroxypropyl methylcellulose 2% derivatives (OcuCoat and Cellugel), and 3 combinations of sodium hyaluronate and chondroitin sulfate (Viscoat, DisCoVisc, and DuoVisc). Despite the introduction of new viscoelastic materials annually, no single material encompasses all desired properties. Surgeons must select and employ suitable viscoelastics based on surgical conditions and patient requirements. Advancements in material development and understanding of physical properties and clinical applications continue to refine viscoelastic selection.

Polysaccharides in contact lenses: From additives to bulk materials

As the number of applications has increased, so has the demand for contact lenses comfort. Adding polysaccharides to lenses is a popular way to enhance comfort for wearers. However, this may also compromise some lens properties. It is still unclear how to balance the variation of individual lens parameters in the design of contact lenses containing polysaccharides. This review provides a comprehensive overview of how polysaccharide addition impacts lens wear parameters, such as water content, oxygen permeability, surface wettability, protein deposition, and light transmittance. It also examines how various factors, such as polysaccharide type, molecular weight, amount, and mode of incorporation into lenses modulate these effects. Polysaccharide addition can improve some wear parameters while reducing others depending on the specific conditions. The optimal method, type, and amount of added polysaccharides depend on the trade-off between various lens parameters and wear requirements. Simultaneously, polysaccharide-based contact lenses may be a promising option for biodegradable contact lenses as concerns regarding environmental risks associated with contact lens degradation continue to increase. It is hoped that this review will shed light on the rational use of polysaccharides in contact lenses to make personalized lenses more accessible.

Intraocular Pressure Changes Following Stand-Alone Phacoemulsification: An IRISɌ Registry Analysis

PURPOSE

To describe real-world intraocular pressure (IOP) changes following stand-alone cataract surgery by comparing postoperative IOP to phakic fellow eyes.

DESIGN

Retrospective clinical cohort study.

METHODS

A total of 1,334,868 patients (336,060 with glaucoma and 998,808 without glaucoma) in the IRIS® Registry (Intelligent Research in Sight) underwent stand-alone phacoemulsification from 1 January 2013 to 30 September 2019 with a fellow eye that had subsequent cataract surgery. Postoperative daily mean IOP was compared between surgical and control eyes from postoperative day 1 to 90. A generalized linear model determined when the postoperative daily mean IOP stabilized to calculate a final mean IOP, which was then compared to baseline IOP.

RESULTS

Postoperative daily mean IOP was initially greater for surgical than for control eyes because of an early postoperative IOP spike. By postoperative day 13, postoperative daily mean IOP was significantly lower for surgical than for control eyes every day through postoperative day 90 (P < .001). There was a mean (SD) decrease from baseline to final mean IOP of 1.55 (3.52) mm Hg or 7.79% for all surgical eyes, 1.91 (3.93) mm Hg or 8.89% for surgical eyes with glaucoma, and 1.37 (3.28) mm Hg or 7.24% for surgical eyes without glaucoma, respectively. There was a statistically significant decrease from baseline to the final mean IOP for all surgical eyes, surgical eyes without glaucoma, and all categories of pre-glaucoma and glaucoma (P < .0001 for all, excluding uveitic glaucoma [P = .0016]).

CONCLUSIONS

Eyes both with and without glaucoma that underwent stand-alone phacoemulsification had a significant decrease in IOP through the 90-day postoperative period compared to baseline and phakic fellow eyes.

Advances in biomaterials as a retinal patch for the repair of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is the most common retinological emergency that can cause blindness without surgical treatment. RRD occurs when liquefied vitreous accumulates between the neurosensory retina and the retinal pigment epithelium via retinal breaks, which are caused by the separation of the vitreous from the retina with aging. Currently, the main treatment option is pars plana vitrectomy, which involves surgical removal of the vitreous and laser photocoagulation around retinal breaks to generate firm chorioretinal adhesion, as well as subsequent filling of the vitreous cavity with long-lasting substitutes (expansile gas or silocone oil) to prevent the connection between the subretinal space and the vitreous cavity via the breaks before the chorioretinal adhesion firm enough. However, the postoperative face-down position and the not very satisfactory first retinal reattachment rate place a heavy burden on patients. With the development of technology and materials engineering, researchers have developed biomaterials that can be used as a retinal patch to seal retinal breaks and prevent the connection of subretinal space and vitreous cavity via breaks, thus replacing the long-lasting vitreous substitutes and eliminating the postoperative face-down position. Preclinical studies have demonstrated that biomaterial sealants have enough biocompatibility and efficacy in the in vitro and in vivo experiments. Some sealants have been used in clinical trials on a small scale, and the results indicate promising application prospects of the biomaterial sealants as retinal patches in the repair of RRD. Herein, we review the recent advances in biomaterials as retinal patches for the repair of RRD, focusing on the biomaterial categories, methods, and procedures for sealing retinal breaks, as well as their biocompatibility and efficacy, current limitations, and development perspectives.

Evaluation of posterior capsular opacification and neodymium-doped yttrium aluminum garnet capsulotomy rates in patients with hydrophilic intraocular lens implantation with and without ocular viscoelastic device

Purpose

To study the effect of intraocular lens (IOL) implantation with and without ocular viscoelastic device (OVD) on posterior capsular opacification (PCO) in eyes with phacoemulsification.

Methods

This prospective, comparative, and randomized case series included 70 patients (140 eyes) with senile cataracts scheduled for phacoemulsification and IOL implantation in a tertiary eye c are center. One eye of each patient was randomized to one of the two groups, namely, control and OVD. After phacoemulsification, the IOL was placed in the capsular bag under balanced salt solution (BSS) in the control group, whereas the IOL was placed under OVD in the OVD group. PCO was analyzed by an independent observer at 6, 12, and 18 months under slit-lamp illumination.

Results

The mean age of the participants in the two groups was 61.2 (±9.9) years. Of the total participants, 68 (48.5%) were men and 72 (51.5%) were women. The mean keratometry (K1, K2) values of the OVD (44.26 ± 1.43, 44.93 ± 1.66) and control (44.51 ± 1.74, 44.69 ± 1.49) groups were similar. The mean IOL powers of the control and OVD groups were 21.25 (±1.94) and 21.53 (±1.86), respectively (P = 0.463). The mean best-corrected visual acuity (BCVA) of the control group at 6-, 12-, and 18-month follow-ups were 0.622 (±0.253), 0.315 (±0.203), and 0.063 (±0.163), respectively, whereas those of the OVD group were 0.592 (±0.253), 0.336 (±0.169), and 0.066 (±0.118), respectively (P = 0.922). None of the patients had postoperative raised intraocular pressure (IOP), uveitis, or endophthalmitis. Three and four eyes in the control and OVD groups, respectively, required neodymium-doped yttrium aluminum garnet (ND: YAG) capsulotomy at study termination (P = 0.999).

Conclusion

The hydroimplantation technique of the placement of hydrophilic IOL did not reduce the PCO rate in the 18-month follow-up period. The ND: YAG capsulotomy rate did not differ between the groups.

Clinical observations of EVO-ICL implantation and changes in corneal astigmatism using a modified technique

Background

Implantable collamer lens (ICL) surgery techniques are constantly progressing. The purpose of this study was to investigate the application effect of the modified technique and its impact on the change in corneal astigmatism in EVO-ICL surgery.

Methods

The analysis of retrospective cohort data included 153 eyes of 81 patients with myopia from July 2018 to May 2020. An EVO-ICL was inserted by modified surgical skills, including a single 3.0 mm corneal incision and no ophthalmic viscosurgical device (OVD) before the insertion of the ICL (modified technique group: 41 cases, 80 eyes) and standard procedure (standard technique group: 40 cases, 73 eyes). Early postoperative intraocular pressure (IOP) was monitored at 2 and 24 h. IOP, corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), vault, and anterior chamber depth (ACD) were measured 1, 6, and 12 months following the initial examination. The corneal endothelial cell density (ECD) was monitored at 6 and 12 months after the operation. Surgically induced astigmatism (SIA) in the total, anterior, and posterior corneal surfaces was analysed 1 month after the operation.

Results

No serious complications were detected. The two groups had no difference in visual outcomes, ICL vaults, or ACD at any time point (P > 0.05). Two hours postoperatively, IOP was significantly lower in the modified technique group (16.22 ± 2.22 vs. 18.37 ± 1.92 mmHg, P < 0.05) than in the standard technique group. IOP decreased gradually after 24 h to preoperative levels. The postoperative IOP remained stable over a 12-month period. The ECD at 6 and 12 months was not significantly different between the groups (P > 0.05). SIA in the total, anterior, and posterior corneal surfaces were assumed to have no clinically meaningful differences between groups at one month after operation (P > 0.05).

Conclusions

The modified technique is efficient and safe, producing comparable visual and structural outcomes without adversely affecting ECD, and reduces fluctuations in IOP at the early postoperative stages. The auxiliary incision in the standard technique does not increase corneal SIA, which is also a factor to consider for inexperienced surgeons.

Evaluation of the Rheological Properties, Preclinical Safety, and Clinical Effectiveness of a New Dispersive Ophthalmic Viscoelastic Device for Cataract Surgery

Purpose

To evaluate the rheological properties of the ophthalmic viscoelastic device (OVD) PRO-149, its preclinical safety, and its effectiveness when used during cataract surgery in patients with age-related cataract.

Material and Methods

Control (HEC) and test (PRO-149) OVDs were compared through rheological measures, by two preclinical safety studies in rabbits, and under normal-use conditions during cataract removal and lens implantation in a parallel randomized clinical trial.

Results

Rheological properties were determined. Preclinical studies did not find any evidence of safety issues or toxicity. In the clinical trial, 36 subjects were included. After 29 days, there were no statistically significant differences in mean percentage of endothelial cell count change or in the postoperative intraocular pressure between groups. There were no significant differences between OVDs for any safety parameter studied. Finally, PRO-149 showed a statistically significant improvement in surgeon rating for ease of use during extraction (p < 0.05).

Conclusion

PRO-149 is a dispersive OVD. The rabbit models did not find evidence of clinical alterations or toxicity. The results of the clinical study support that the two studied OVDs were clinically similar in terms of safety and effectiveness for cataract surgery.

Trial Registration

The trial is registered at Clinical Trials.gov at NCT04702802 (21–01-11).

Dealing with floppy iris syndrome

PURPOSE OF REVIEW

The aim of this study was to review and summarize recent findings and advancements regarding intraoperative floppy iris syndrome (IFIS). Although many improvements have been made for the management of IFIS, it remains a challenging condition for surgeons. An understanding of the syndrome as well as the multitude of tools to mitigate risk of complication is important for surgeons operating on high-risk patients.

RECENT FINDINGS

A variety of management approaches have been modified and improved or further supported with new data, such as intracameral compounds, intraoperative devices and surgical techniques.

SUMMARY

An understanding of risk factors is important for the identification of at-risk patients. A variety of approaches can greatly reduce incidence of IFIS complications. Multiple management strategies should be utilized to further reduce risk during these difficult surgeries.

Safety of EVO ICL Implantation With an Ophthalmic Viscosurgical Device-Free Technique in the Early 24 h After Surgery

Purpose: To compare the safety of the non-ophthalmic viscosurgical device (OVD) technique with that of the minimum OVD technique in EVO Implantable Collamer Lens (EVO-ICL) implantation.

Methods: A total of 180 eyes of 90 consecutive patients were enrolled in the study, of which 100 eyes of 50 patients were treated with non-OVD technique, with a 55% success rate. The remaining 80 eyes of 40 patients were treated with min-OVD technique, so they were classified into the min-OVD group. Preoperative and postoperative intraocular pressure (IOP) measurements were collected and analyzed at 1, 2, 3, and 24 h. Visual acuity, corneal endothelial cell density (ECD), and corneal densitometry 24 h postoperatively were evaluated.

Results: No significant difference was found in visual outcomes (P = 0.54) or ECD (P = 0.78) between the two groups. The operation time was significantly shorter in the non-OVD group (P < 0.0001). The IOP was significantly higher at 1 h (P < 0.0001), 2 h (P < 0.0001) and 3 h (P = 0.0045) postoperatively in the min-OVD group. The non-OVD group had significantly lower IOP than the min-OVD group at 1 h (P = 0.01) and 2 h (P = 0.013) postoperatively. The temporal corneal densitometry in the non-OVD group were significantly lower than those in the minimum group (P = 0.0063) 1 day after surgery.

Conclusion: The non-OVD technique is safe and efficient for ICL implantation. It can be a safer method of ICL implantation in that it completely eliminates ophthalmic viscoelastic devices related complications without causing additional complications in short term.

Pure ICL Implantation: A Novel Ophthalmic Viscosurgical Device-Free Method

PURPOSE

To assess the clinical efficiency of a novel ophthalmic viscosurgical device-free (OVD-free) method for intraocular collamer lens (EVO-ICL) implantation in myopic eyes.

METHODS

In this study, 40 patients underwent ICL implantation for both eyes: one eye underwent traditional ICL implantation, and the other eye underwent OVD-free (pure) ICL implantation. Preoperative and postoperative UDVA, BCVA, equivalent spherical degree (SE), IOP, visual quality index, subjective visual quality scale, corneal endothelial cell density (ECD), operation time, and complications were compared between and within the traditional and pure ICL implantation groups.

RESULTS

Increased IOP >22 mmHg 2 h after surgery was noted in 8 eyes (20%) in the traditional group, but not in the pure group (0%, P < 0.001). Increased IOP relative to baseline was significantly higher at 2 h after surgery for the traditional group compared with the pure group (P < 0.001). UDVA, BCVA, and SE were significantly improved in the pure group compared with those in the traditional group 1 day (P < 0.001, P=0.003) after implantation, but not 1 week or 3 months after. Modulation transfer function cut-off frequency (MTF cut-off), Strehl ratio (SR), and OV20% were significantly better in the pure group than in the traditional group 1 day after implantation (P=0.013, P=0.009, and P=0.004). No significant difference in ECD changes within or between groups was observed (P > 0.05). The operation time for the pure group (2.897 ± 0.346 min) was significantly shorter than that for the traditional group (4.444 ± 0.656 min; P < 0.001). No complications were reported for either group during the observation period, except early IOP elevation in the traditional group.

CONCLUSIONS

The pure ICL implantation method was associated with faster visual acuity recovery, shorter operation time, and more stable intraocular pressure. Pure ICL represents a safe and convenient method for ICL implantation compared with the traditional method, completely eliminating OVD-related complications without causing additional complications.

Experimental evaluation of the injection force exerted in intraocular lens delivery with syringe-type injectors

The process of intraocular lens (IOL) delivery within the capsular bag during cataract surgery is crucial, as the integrity of the IOL, the injector and the ocular structures should be preserved at all times. This study aims to obtain the main parameters that affect the injection force exerted in the ejection of an intraocular lens (IOL) through syringe-type injectors. For that purpose, ejection tests were carried out in vitro, measuring the resistance force throughout the entire delivery process. The effect of IOL material, haptic design, IOL thickest area and ophthalmic viscosurgical device (OVD) was studied by ejecting seven IOLs with four syringe-type injectors of different sizes, 3.0, 2.2 and 1.8 mm. In all injectors, plate hydrophilic IOLs present the lowest resistance forces; hydrated C-loop hydrophobic IOLs present higher forces and the C-loop hydrophobic IOL in dry conditions presents the highest resistance forces. All IOLs could be properly delivered with an injector size of 2.2 mm, making injector sizes of 3.0 mm outdated. The injector size of 1.8 mm damaged several IOLs. IOL material and cartridge nozzle size were the most influential parameters in IOL delivery. IOL thickest area was also relevant but in a lesser extent whereas IOL haptic design was not as relevant.

Corneal endothelial damage in phacoemulsification using an anterior chamber maintainer compared with using an ophthalmic viscosurgical device

PURPOSE

To compare the effects of phacoemulsification surgery (PE) using an anterior chamber maintainer (ACM) and conventional PE using an ophthalmic viscosurgical device (OVD) on corneal endothelial cells.

SETTING

Department of Ophthalmology, Celal Bayar University, Manisa, Turkey.

DESIGN

Prospective randomized controlled trial.

METHODS

Eyes in the OVD group (n = 50) underwent conventional PE, whereas eyes in the ACM group (n = 50) underwent PE using an ACM. Endothelial cell density (ECD), coefficient of variation (CV), hexagonality (HEX), and noncontact central corneal thickness (CCT) measurements were performed by specular microscopy before and at 1 month, 3 months, and 6 months after PE.

RESULTS

This study included 100 eyes of 97 patients undergoing PE. The mean age was 64.7 ± 10.6 years in the OVD group, 64.0 ± 12.6 years in the ACM group (P > .05). The groups did not differ significantly in preoperative ECD, CV, HEX, and CCT or total PE time (P > .05 for all). ECD was significantly lower in the ACM group compared with the OVD group at postoperative 1 month, 3 months, and 6 months (P = .002, P = .002, and P = .001, respectively). Similarly, ECD loss compared with preoperative value was greater in the ACM group at all postoperative timepoints (P = .003, P = .001, and P = .001, respectively). CV increased and HEX decreased in both groups postoperatively (P > .05 for both). CCT showed a transient increase of less than 10 μm at postoperative 1 month in both groups (P = .296).

CONCLUSIONS

PE with ACM was associated with greater corneal ECD loss compared with conventional PE. ACM should not be used during PE in patients with limited corneal endothelial reserve.

Comparison of clinical outcomes of implantable collamer lens implantation with and without use of an ophthalmic viscosurgical device

PURPOSE

To compare the clinical efficacy of posterior chamber phakic implantable collamer lens (ICL) implantation with and without the use of an ophthalmic viscosurgical device (OVD).

SETTING

Onnuri Eye Hospital, Jeonju, Jeollabuk-do, South Korea.

DESIGN

Retrospective case series.

METHODS

Included were patients who underwent ICL implantation with the use of an OVD (OVD group) and patients who underwent ICL implantation without the use of an OVD (hydro group). Refractive error, endothelial cell density (ECD), intraocular pressure (IOP), vault, and adverse events were evaluated at 1 day, 1 week, 1 month, and 3 months postoperatively. The IOP and vault were checked 1 hour postoperatively, and the surgical time was recorded.

RESULTS

The OVD group comprised 54 eyes of 27 patients and the hydro group 49 eyes of 25 patients. There were no significant preoperative differences between the 2 groups. At 1 hour postoperatively, the IOP was significantly higher in the OVD group (P < .001); however, there was no significant difference in IOP between the 2 groups at other follow-up timepoints. Surgical time was significantly shorter for the hydro group (P = .032). There was no statistically significant difference in vault, ECD, or refractive error between the 2 groups during the 3-month follow-up period. No adverse events were observed.

CONCLUSIONS

ICL implantation without the use of an OVD was safe and effective. The advantages of this technique included a short surgical time, prevention of early postoperative IOP spikes, and cost savings due to OVD elimination.

A primer on ocular viscosurgical devices

PURPOSE

To provide pharmacists with an overview of ocular viscosurgical devices (OVDs) and a comprehensive resource describing characteristics of commercially available agents.

SUMMARY

OVDs are substances that are injected into the eye during ophthalmic procedures, such as cataract surgery, to reduce injury to the endothelium that may result from surgical manipulation. Currently available OVDs are composed of one or more of the following active ingredients: sodium hyaluronate, sodium chondroitin sulfate, and hydroxypropylmethylcellulose. Rheologic properties of OVDs, such as viscosity, elasticity, pseudoplasticity, and cohesion, affect the products' function and performance. Based on rheologic properties, OVDs can be generally classified as cohesive or dispersive. Given each products' unique characteristics, OVDs are not interchangeable. An understanding of OVD characteristics and role in practice allows for improved product selection, which varies based on patient characteristics and procedure. Availability of OVD information and literature is generally lacking since OVDs are regulated by the US Food and Drug Administration (FDA) as medical devices. This primer includes an overview of relevant ophthalmic surgical practices and the landscape of comparative efficacy and safety literature to assist in formulary decision-making. This review also provides a comprehensive guide to commercially available OVDs and a discussion on practical considerations for the pharmacist.

CONCLUSION

Pharmacists may be tasked with handling OVDs in institutional settings. Knowledge about OVD rheologic properties, product characteristics, role in practice, and available literature is necessary for managing formularies and ensuring optimal product selection.

Hydroxypropyl methylcellulose: Physicochemical properties and ocular drug delivery formulations

Hydroxypropyl methylcellulose (HPMC) is a cellulose ether widely used in drug formulations due to its biocompatibility, uncharged nature, solubility in water and thermoplastic behavior. Particularly for ocular and ophthalmic formulations, HPMC is applied as viscosity enhancer agent in eye drops, gelling agent in injections, and polymeric matrix in films, filaments and inserts. The different therapeutic approaches are necessary due to the complex anatomic structure of the eye. The natural ocular barriers and the low drug permeation into the circulatory system make the drug administration challenging. This review presents the eye anatomy and the usual local routes of drugs administration, which are facilitated by the physicochemical properties of HPMC. The relationship between chemical structure and physicochemical properties of HPMC is displayed. The different types of formulations (local application) including HPMC for ocular drug delivery are discussed with basis on recent literature reports and patents.

Corneal Endothelial Health after Phacoemulsification Cataract Surgery without Viscoelastic Substance

Purpose:

To evaluate corneal endothelial health after cataract surgery without viscoelastic substance (VS).

Methods:

A prospective, non-randomized, case-series study was developed, and phacoemulsification cataract surgery without VS was performed on 1324 eyes between September 2015 and September 2018. As main outcomes, mean endothelial cell density (ECD) and mean central corneal thickness (CCT) were assessed before surgery and then 6 and 12 months after surgery. Data are summarized as mean, standard deviation (SD), and 95% confidence intervals (CI).

Results:

A total of 1324 eyes were operated, and 31 were excluded by intraoperative complications. The mean ECD baseline was 2506 cells/mm² (SD = 215, CI = 2494–2518); 6 months after surgery, it was 2328 cells/mm² (SD = 213, CI = 2316–2340); and 1 year after surgery, it was 2265 cells/mm² (SD = 214, CI = 2253–2277). In terms of percentage differences, the mean ECD decrease was 9.4% after 1 year. The mean preoperative CCT was 531.6 μm (SD = 34.8, CI = 529.7–533.5); 6 months after surgery, it was 537.7 μm (SD = 38.2, CI = 535.6–539.8); and 1 year after surgery, it was 537.9 μm (SD = 37.9, CI = 535.8–540.0). The mean CCT increased 1.2% 1 year after surgery.

Conclusions:

Phacoemulsification cataract surgery can be completely performed without VS, with very low intraoperative complications. The postoperative ECD and CCT changes occurred primarily during the first 6 months, and the changes decreased during the second semester.

Dropless cataract surgery: modernizing perioperative medical therapy to improve outcomes and patient satisfaction

PURPOSE OF REVIEW

Advances in pharmacology offer freedom from topical medical therapy without compromise of anti-inflammatory and antimicrobial coverage in the perioperative period. In this review, we describe the basis for dropless cataract surgery with the goal of improving outcomes and the patient experience.

RECENT FINDINGS

Phacoemulsification outcomes depend largely on surgeon skill but also on adherence to a complex multidrug regimen of perioperative anti-inflammatory and antimicrobial therapy to prevent sight-threatening complications such as cystoid macular edema or endophthalmitis. Successful administration of this regimen can be limited by noncompliance, difficulty administering eye drops, bioavailability, and side effects, among others. The recent development of sustained-release formulations of dexamethasone - one an intracanalicular insert and the other an intraocular suspension - can provide sustained tapering doses of dexamethasone while reducing or eliminating the need for anti-inflammatory eye drop therapy. Similarly, mounting evidence compellingly demonstrates that intracameral antibiotic use intraoperatively is at least as effective as topical antibiotics in preventing endophthalmitis.

SUMMARY

Sustained-release dexamethasone coupled with intracameral antibiotics at the time of phacoemulsification can provide antimicrobial and anti-inflammatory prophylaxis without the need for topical eye drop medications. This approach has the potential to improve compliance with therapy, visual acuity outcomes, and the overall patient experience.

Intraoperative Evaluation of Phacoemulsification Cataract Surgery with and without the Use of Ophthalmic Viscosurgical Devices

PURPOSE:

The purpose of this study was to compare the efficacy and safety of cataract surgery by the phacoemulsification technique with and without the use of ophthalmic viscosurgical devices (OVDs).

SETTING:

This study was conducted at a tertiary eye care center in a rural area of Central India.

DESIGN:

This was a prospective, randomized, observational study.

METHODS:

In this study, 220 patients underwent phacoemulsification for cataract surgery with OVDs (OVD group) or without OVDs (BSS group) (n = 110 in each group). Patients with operable, nuclear Grade 2–4 cataracts were included in the study. The study was conducted from June 2017 to September 2018. The frequency of intraoperative complications, surgical time, and ease of the surgical procedure (easy, difficult, or very difficult) were recorded.

RESULTS:

There was no statistically significant difference in the nuclear opalescence, axial length, and intraocular lens (IOL) power between the two groups. Capsulorhexis extension was seen in two eyes in the OVD group and none of the eyes in the BSS group. The problems that occurred during IOL implantation included flip (OVD group, 2; BSS group, 1), haptic breakage (OVD group, 1; BSS group, 1), sulcus implantation (OVD group, 0; BSS group, 2), and stuck haptic (OVD group, 1; BSS group, 3). The total surgical time was almost equal in the two groups (OVD group, 9.2 min ± 3; BSS group, 9.5 min ± 3.5; P = 0.521). None of the patients had iris trauma or posterior capsular rupture.

CONCLUSIONS:

OVD-less phacoemulsification surgery is a safe and effective technique for treating age-related cataracts that requires no additional instrumentation and saves the cost of the OVD.

A novel ophthalmic viscosurgical device-free phakic intraocular lens implantation makes myopic surgery safer

Purpose

To assess the efficacy and safety of a novel ophthalmic viscosurgical device-free (OVD-free) method for posterior chamber phakic intraocular lens (PIOL) implantation in myopic eyes.

Methods

In this retrospective cohort study, the medical records of myopic eyes that underwent PIOL (Implantable Collamer Lens, ICL) implantation for myopia correction at the Eye Hospital of Wenzhou Medical University between May 2015 and March 2017 were reviewed. A total of 49 eyes with complete data that met follow up requirements (2 h, 1 day, 1 week, 3 months postoperatively) were recruited. Based on the surgical techniques used, the eyes were divided into the OVD-free method group and the standard method group. The clinical data, including intraocular pressure (IOP), corrected distance visual acuity (CDVA) and spherical equivalent (SE), at each follow-up were collected for comparison. Endothelial cell loss and complications were also investigated.

Results

Twenty-one eyes received the standard method, and 28 eyes received the OVD-free method. A rise in IOP > 22 mmHg at 2 h was noted in 14 eyes (66.7%) in the standard group and none (0%) in the OVD-free group (p < 0.001). The rise in IOP from baseline was significantly higher at 2 h in the standard group (10.5 ± 5.2 mmHg vs. 2.2 ± 3.3 mmHg, difference: 8.3, 95% CI 5.8 to 10.8; p < 0.001). There was a significant difference in the time course of LogMAR CDVA changes between the two groups (p = 0.047). The LogMAR CDVA was significantly better in the OVD-free method group compared to the standard group at 1 day (− 0.076, 95% CI − 0.134 to − 0.018; p = 0.012), 1 week (− 0.071, 95% CI − 0.135 to − 0.007; p = 0.03), but not at 3 months (− 0.046, 95% CI − 0.107 to 0.015; p = 0.134). There was no significant difference in the time course of SE changes between the two groups (p = 0.471; p = 0.705). In the OVD-free group, mean endothelial cell loss was 4.6% at 3 months (2522 ± 281 vs. 2407 ± 226 cells/mm², difference: -115, 95% CI − 295 to 65; p = 0.187). No complications were reported in both groups except for the early IOP elevation in the standard group during the observation period.

Conclusions

The OVD-free method is safe and efficient for ICL implantation. It can be a safer method of ICL implantation compared to the standard method in that it completely eliminates ophthalmic viscoelastic devices-related complications without causing additional complications.

Early postoperative intraocular pressure elevation following cataract surgery

PURPOSE OF REVIEW

The aim of this review was to assess the risk factors and course of postoperative intraocular pressure (IOP) increase in order to determine the optimal the treatment.

RECENT FINDINGS

Early postoperative IOP elevation following cataract surgery is a frequent adverse event, and might represent 88% early postoperative complications. The risk factors for IOP elevation following phacoemulsification cataract surgery include residual viscoelastic material, resident performed surgery, glaucoma, pseudoexfoliation syndrome, axial length over 25 mm, tamsulosin intake, topical steroid application in steroid responders. A day-1 postoperative follow-up might be questioned, even in glaucoma patients, as in IOP spikes the topmost IOP elevation occurs 3-4 h postoperatively.

SUMMARY

Several IOP-lowering agents have been evaluated, but none has completely prevented the occurrence of IOP spikes. We recommend applying a combination of dorzolamide/timolol and brinzolamide topically in high-risk patients, particularly with preexisting optic nerve damage. Corticosteroid cessation usually results in a reduction of the IOP to normal levels in steroid responders. Additional studies are required to assess the optimal treatment, especially in glaucoma patients.

Combined use of an iris hook and pupil expansion ring for femtosecond laser-assisted cataract surgery in patients with cataracts complicated by insufficient mydriasis and an ectopic pupil

We developed a surgical technique that combines use of an iris hook and a pupil expansion ring in femtosecond laser-assisted cataract surgery complicated by insufficient mydriasis and an ectopic pupil. With this technique, the surgery, including femtosecond laser assistance, phacoemulsification, and intraocular lens implantation, can be accomplished successfully prior to iris repair.

FINANCIAL DISCLOSURE

Dr. Malyugin receives travel grants from Alcon Laboratories, Inc. and Novartis Corp.; he receives royalties from Microsurgical Technology, Inc. None of the other authors has a financial or proprietary interest in any material or method mentioned.

[Mechanical pupillary dilatation using rings in small pupils during cataract surgery : Video article]

OBJECTIVE

The purpose of mechanical pupillary dilatation in small pupils is a sufficient visualization of the lens to be able to perform capsulorhexis, phacoemulsification and intraocular lens implantation.

INDICATIONS

The indications for mechanical dilatation are fulfilled in patients where a sufficient pharmacological preoperative pupil dilatation is not possible.

SURGICAL TECHNIQUE

During routine cataract surgery specific foldable rings can be employed to dilate the pupil with the appropriate injector under viscoelastic substances. These rings are carefully placed at the pupillary margin until circular pupillary dilatation up to 6-7 mm is achieved. After intraocular lens implantation and before removing the viscoelastic substance the rings are slowly folded into the injector and then removed. The surgical technique is demonstrated in detail with the help of a video of the operation, which is available online.

RESULTS

Mechanical pupillary dilatation was possible in all patients studied (n = 14), which allowed uncomplicated phacoemulsification and intraocular lens implantation. For both ring systems studied the mean pupillary dilatation was 6.6 mm. At the end of surgery, the pupillary diameter was 4.89 mm using a Malyugin ring (MST, Redmond, Washington, USA) and 4.93 mm with an I‑ring (Visitec, Waltham, MA, USA; P > 0.05). Small lesions at the pupillary margin or pigment dispersion during implantation or explantation depended mostly on the individual patient situation and not on the ring used.

CONCLUSION

Mechanical pupillary dilatation with rings allows sufficient dilatation to perform cataract surgery. Both the Malyugin ring and the I‑ring achieved smooth and atraumatic pupillary dilatation.

Phaco capsulotomy: a technique to prevent the Argentinean Flag Sign

The Argentinean Flag Sign is a complication that occurs during capsulorhexis construction, in which the capsulorhexis extends to the periphery due to lens intumescence. Phaco capsulotomy is a technique in which the phacoemulsification tip is used to simultaneously create the initial tear in the anterior capsule and remove a portion of the intumescent lens, thereby debulking and relieving pressure from the lens and capsule, and preventing the Argentinean Flag Sign. A detailed description of the phaco capsulotomy technique is provided, including applications and potential complications.

Sealed implantation of foldable intraocular lenses

PURPOSE

To evaluate the safety and efficacy of sealed implantation, a simple technique for implanting foldable intraocular lenses (IOLs).

METHODS

This was a retrospective study including consecutive patients who underwent phacoemulsification cataract using the sealed implantation technique. Sealed implantation is a technique in which a single-piece, foldable IOL is implanted without an intraocular ophthalmic viscosurgical device (OVD) or continuous infusion (hydroimplantation) of balanced saline solution (BSS). Forty consecutive patients who underwent clear corneal incision cataract surgery with IOL implantation using this technique were included. A 3-step 2.75-mm incision was performed approximately 0.5 mm anterior to the limbus with a 1.50 to 1.75 mm length as well as a 0.9 mm side port incision. Prior to the insertion of the IOL, the capsular bag and anterior chamber are filled with BSS. Hydroxypropyl methylcellulose 2% is applied external to the main corneal incision. The foldable IOL injector tip is introduced into the main incision in one quick jabbing motion and the IOL injected. The IOL is dialed with a standard irrigating Simcoe cannula. The main outcomes were intraoperative complications and postoperative hypotony.

RESULTS

Of 50 charts reviewed, sealed implantation was attempted in 40 (80%), with success in all cases. The injection of the IOL was performed without anterior chamber loss in 92% of the cases (n = 36) and no complications were recorded. There were no events of postoperative hypotony or wound leakage.

CONCLUSIONS

Sealed implantation is a safe and efficient alternative to hydroimplantation without the need for OVDs in suitable cases.

Toxic Anterior Segment Syndrome Outbreak after Cataract Surgery Triggered by Viscoelastic Substance

PURPOSE:

The purpose of this study is to present toxic anterior segment syndrome (TASS) outbreak at our clinic and discuss possible causes of TASS.

MATERIALS AND METHODS:

Thirty-four eyes of 34 patients developed TASS in a consecutive 2 weeks period were included in this study. Both anterior segment and fundus examinations were performed before and after uncomplicated cataract surgery. During the follow-up period, clinical features and all possible causes were evaluated including perioperative products and processing such as sterilization technique of surgical instruments, irrigating solutions, drugs, viscoelastic substance (VES), and intraocular lens.

RESULTS:

Patients had corneal edema, anterior chamber reactions, and decreased vision. No patient had purulent secretion, chemosis, lid involvement, and pain. At first 2 postoperative days, patients treated as infectious endophthalmitis by topical and oral antibiotics and then TASS was suspected, and patients treated completely with topical steroids. Suspected cause for TASS was VES substance, 2% sodium hyaluronate which had newly been used as VES product in phacoemulsification surgery. No new case has occurred after stopped usage of this VES product.

CONCLUSION:

As far as we know, this is the largest report of TASS outbreak in the shortest period from the same clinic caused by VES. Suboptimal products of surgical materials can be the cause of TASS. Close monitoring of each surgical step and elimination of causative agent can prevent the outbreaks of TASS.

Safety and efficacy of phacoemulsification and intraocular lens implantation through a small pupil using minimal iris manipulation

Purpose

The aim of this study was to compare the results of phacoemulsification through a small pupil using minimal iris manipulation versus phacoemulsification through a well-dilated pupil.

Methods

This prospective randomized control (comparative) study comprised 78 patients (group I) with a maximally dilated pupil size of ≤4.00 mm and 45 patients (group II) with dilated pupil size of ≥7.00 mm. In group I patients, only viscodilation and minimal push-and-pull iris stretching with two collar-button iris-retractor hooks were utilized without iris manipulation. Phacoemulsification was performed by two senior surgeons and the technique used consisted of either stop and chop or quick chop, infusion/aspiration of lens cortex, capsular bag refill with ocular viscoelastic devices, and implantation of an acrylic foldable intraocular lens. Patients were examined on the first day and 1 month postoperatively.

Results

Forty-six eyes of group I patients had pseudoexfoliation syndrome, eleven eyes had previous glaucoma surgery, 14 eyes had angle-closure or open-angle glaucoma, and seven eyes had posterior synechiae with iritis. In group I patients, the mean pupil size measured under an operating microscope was 3.2 mm preoperatively, 4.3 mm after viscoelastic and mechanical pupil dilation, and 4.1 mm at the end of a surgical procedure. Rupture of the zonular fibers occurred in six patients of group I and the intraocular lens was implanted in the sulcus. Small iris-sphincter rupture and small hemorrhages occurred in four eyes during pupillary manipulation, but they were not evident at the end of the surgery. In group II patients, no intraoperative complications occurred. Signs of significant corneal edema and iritis were observed more frequently in group I eyes (26 eyes and 20 eyes, respectively) on the first postoperative day in comparison with group II eyes (ten eyes and six eyes, respectively). Intraocular pressure was <20 mmHg in all eyes of both groups. One month postoperatively, the pupil was round and reactive to light, the anterior chamber was quiet, and the cornea was clear in all eyes. The best-corrected visual acuity on Snellen chart was 20/40 (Monoyer’s scale) or better in both groups.

Conclusion

Phacoemulsification through a small pupil using minimal iris manipulation can be safe and exhibits the same results as those obtained with phacoemulsification through normal pupils.

Intraocular lens implantation without the use of ophthalmic viscosurgical device

The purpose of this study was to determine whether single-piece hydrophilic acrylic intraocular lens can be safely implanted without the use of ophthalmic viscosurgical devices. This retrospective study comprised 100 eyes having phacoemulsification and intraocular lens implantation without the use of ophthalmic viscosurgical device. 80 eyes with the use of a viscosurgical device are used as control group. In this intraocular lens implantation technique, the anterior chamber was maintained with an irrigation cannula and intraocular lens was implanted with a lens injector. Visual acuity, corneal clarity and edema, intraocular pressure, and corneal endothelial cell count were evaluated preoperatively and postoperatively at days 1, 7, and 30. Corneal endothelial cell count was repeated 2 weeks after surgery. Complications of this technique were also evaluated. No significant complications of this intraocular lens implantation technique, such as posterior capsule rupture, intraocular lens buttonholing, zonular dialysis, Descemet's tear/detachment, occurred. On the seventh postoperative day, 90 % of eyes achieved 20/20 or better vision. There was no difference in corneal endothelial cell loss between viscoelastic device-used and not-used cases (p = 0.356). When implanting intraocular lens without the use of ophthalmic viscosurgical device, significant intraoperative complications did not occur. The possible advantages are shortened surgery time, avoidance of postoperative IOP spike from ocular viscosurgical device (OVD) remnant, and reduced cost.

Changes in corneal endothelium cell characteristics after cataract surgery with and without use of viscoelastic substances during intraocular lens implantation

PURPOSE

To evaluate whether the use of balanced salt solution (BSS) or an ophthalmic viscoelastic device (OVD) during hydrophilic acrylic intraocular lens (IOL) implantation variously impacts corneal endothelial cell characteristics in eyes undergoing uneventful phacoemulsifications.

METHODS

Prospective nonrandomized observational clinical trial. Patients were assigned either to the BSS plus(®) or to the OVD Z-Celcoat™ group depending on the substance used during IOL implantation. Corneal endothelium cell characteristics were obtained before, 1 week, and 6 weeks after surgery. Intraoperative parameters (eg, surgery time, phacoemulsification energy) were recorded.

RESULTS

Ninety-seven eyes were assigned to the BSS plus and 86 eyes to the Z-Celcoat group. Preoperative corneal endothelium cell density (ECD) and endothelium cell size were 2,506±310 cells/mm(2)/2,433±261 cells/mm(2) and 406±47 µm(2)/416±50 µm(2) (P=0.107/P=0.09). After 1 and 6 weeks, ECD decreased and endothelium cell size increased significantly in both groups (each P<0.001) without significant differences between both groups (each P>0.05). Irrigation-aspiration suction time (30.3±16.6 versus 36.3±14.5 seconds) and overall surgical time (7.2±1.2 versus 8.0±1.4 minutes) were significantly longer in the OVD Z-Celcoat group (each P<0.001). No complications or serious side effects occurred.

CONCLUSION

Implantation of a hydrophilic acrylic IOL under BSS infusion seems to be a useful and faster alternative in experienced hands without generating higher ECD loss rates.

Femtosecond laser-assisted cataract surgery without OVD: a prospective intraindividual comparison

PURPOSE

To compare femtosecond laser-assisted cataract surgery without the use of ophthalmic viscosurgical device (OVD) with standard phacoemulsification using OVD.

METHODS

This was a prospective, randomized, single-center trial of 37 patients (74 eyes) diagnosed as having significant cataract in both eyes. Randomly, one eye underwent standard phacoemulsification with OVD (the OVD group); this group acted as controls. The other eye was treated with the femtosecond laser; the subsequent manual part of the procedure was performed without OVD (non-OVD group). Time of surgery, amount of fluid used during phacoemulsification, central corneal thickness, intraocular pressure, endothelial cell count, and visual acuity were documented over the 6-month follow-up.

RESULTS

There were no major complications and no significant difference in overall surgery time (non-OVD: 375 ± 81 seconds; OVD: 362 ± 43 seconds; P = .713) and in the quantity of fluid passing through the eye (non-OVD: 187 ± 35 mL; OVD: 186 ± 27 mL; P = .952) between groups. Endothelial cell loss after 6 months was not significantly different between groups (non-OVD: -2.4%; OVD: -2.7%; P = .880). Central corneal thickness was not different at 1 week postoperatively between groups (non-OVD: 575 ± 45 µm; OVD: 573 ± 46 µm; P = .820). Three patients in the OVD group and one patient in the non-OVD group experienced intraocular pressure greater than 25 mm Hg at 1 day postoperatively. There were no significant differences in corrected distance visual acuity between groups (logMAR non-OVD: 0.024; OVD: 0.038; P = .461).

CONCLUSIONS

Femtosecond laser-assisted treatment allows the cataract surgeon to perform phacoemulsification and intraocular lens implantation without the use of OVD at no additional risk to the corneal endothelium. Furthermore, there was a tendency toward fewer increases in intraocular pressure in patients treated with the femtosecond laser.

The use of ophthalmic viscosurgical devices during donor's corneal harvesting

PURPOSE OF THE STUDY

To evaluate the protective effect of Biolon (sodium-hyaluronate 1%) use on corneal endothelium, during donor's corneal harvesting.

MATERIALS AND METHODS

A prospective, randomized, double blind, comparative study was performed on 120 corneas donated from 60 donors. One cornea from each donor (n = 60) was harvested using intracameral injection of ophthalmic viscosurgical device (OVD), and the fellow cornea with no use of OVD (n = 60, control group). Endothelial cell density (ECD) values were obtained at the center of each corneal graft with a specular microscope one day after harvesting.

RESULTS

ECD in the OVD group were 2839 ± 412.5 cells/mm(2) and in the control group 2748 ± 429.7 cells/mm(2). (p = 0.03). Distribution curve of the difference in ECD between the OVD and no OVD eyes showed that 47% of the donors had > 100 cells/mm2 difference, and 32% of donors had >200 cells/mm(2) difference in favor of the OVD group.

CONCLUSIONS

Intracameral OVD injection during corneal graft harvesting may protect the endothelium from the mechanical damage induced during the procedure. Further investigation is needed before routine the use of intracameral OVD should be considered in this setting.

Non-steroidal drug-induced glaucoma

Numerous systemically used drugs are involved in drug-induced glaucoma. Most reported cases of non-steroidal drug-induced glaucoma are closed-angle glaucoma (CAG). Indeed, many routinely used drugs that have sympathomimetic or parasympatholytic properties can cause pupillary block CAG in individuals with narrow iridocorneal angle. The resulting acute glaucoma occurs much more commonly unilaterally and only rarely bilaterally. CAG secondary to sulfa drugs is a bilateral non-pupillary block type and is due to forward movement of iris-lens diaphragm, which occurs in individuals with narrow or open iridocorneal angle. A few agents, including antineoplastics, may induce open-angle glaucoma. In conclusion, the majority of cases with glaucoma secondary to non-steroidal medications are of the pupillary block closed-angle type and preventable if the at-risk patients are recognized and treated prophylactically.

Viscoat versus Visthesia during phacoemulsification cataract surgery: corneal and foveal changes

Background

Ophthalmic viscosurgical devices (OVDs) are widely used in phacoemulsification cataract surgery to maintain adequate intraocular space, stabilize ocular tissue during the operation and decrease the possible damage of the corneal endothelium. Our study has the purpose to compare the corneal and foveal changes of Viscoat and Visthesia in patients undergoing uneventful phacoemulsification cataract surgery.

Methods

Participants in our study were 77 consecutive patients, who were randomized into two groups based on type of OVD used during phacoemulsification: Viscoat or Visthesia. All patients underwent a complete ophthalmological examination i.e., measurement of best corrected visual acuity (BCVA) by means of Snellen charts, intraocular pressure examination by Goldmann tonometry, slit lamp examination, fundus examination, optical coherence tomography, specular microscopy and ultrasound pachymetry preoperatively and at three time points postoperatively (day 3, 15, 28 postoperatively). The differences in baseline characteristics, as well as in outcomes between the two groups were compared by Mann-Whitney-Wilcoxon test and Student's t-test, as appropriate.

Results

Intraoperatively, there was no statistically significant difference in the duration of the ultrasound application between the two groups, while Viscoat group needed more time for the operation performance. It is also worthy to mention that Visthesia group exhibited less intense pain than patients in Viscoat group. Postoperatively, there was a statistically significant difference in central corneal thickness, endothelial cell count and macular thickness between the two groups, but BCVA (logMAR) did not differ between the two groups.

Conclusions

Our study suggests that Viscoat is more safe and protective for the corneal endothelium during uneventful phacoemulsification cataract surgery, while Visthesia is in superior position regarding intraoperative pain. Patients of both groups acquired excellent visual acuity postoperative. Finally, this is the first study comparing OVDs in terms of macular thickness, finding that Visthesia cause a greater increase in macular thickness postoperatively than Viscoat, although it reaches normal ranges in both groups.