Intraocular pressure and wound status in eyes immediately after scleral tunnel incision and clear corneal incision cataract surgery

Design of an endoscopic OCT probe based on piezoelectric tube with quartered outside electrodes

Introduction: Optical coherence tomography (OCT) is a pivotal imaging modality in ophthalmology for real-time, in vivo visualization of retinal structures. To enhance the capability and safety of OCT, this study focuses on the development of a micro intraocular OCT probe. The demand for minimal invasiveness and precise imaging drives the need for advanced probe designs that can access tight and sensitive areas, such as the ocular sclera. Methods: A novel OCT probe was engineered using a piezoelectric tube with quartered electrodes to drive Lissajous scanning movements at the end of a single-mode fiber. This design allows the probe to enter the eyeball through a scleral opening. Structural innovation enables the outer diameter of the endoscopic OCT probe to be adjusted from 13G (2.41 mm) to 25G (0.51 mm), accommodating various imaging field sizes and ensuring compatibility with different scleral incisions. Results: The fabricated micro intraocular OCT probe successfully performed preliminary imaging experiments on in vivo fingers. The Lissajous scanning facilitated comprehensive coverage of the target area, enhancing the imaging capabilities. Discussion: The integration of a piezoelectric tube with quartered outside electrodes into the OCT probe design proved effective for achieving precise control over scanning movements and adaptability to different surgical needs. The design characteristics and practical applications demonstrated the probe's potential in clinical settings.

Anaesthetic considerations for the surgical management of ocular hypotony in adults

Ocular hypotony can occur from many causes, including eye trauma, ophthalmic surgery and ophthalmic regional anaesthesia-related complications. Some of these patients require surgical intervention(s) necessitating repeat anaesthesia. While surgical management of these patients is well described in the literature, the anaesthetic management is seldom discussed. The hypotonous eye may also have altered globe anatomy, meaning that the usual ocular proprioceptive feedbacks during regional ophthalmic block may be altered or lost, leading to higher risk of inadvertent globe injury. In an 'open globe' there is a risk of sight-threatening expulsive choroidal haemorrhage as a consequence of ophthalmic block or general anaesthesia. This narrative review describes the physiology of aqueous humour, the risk factors associated with ophthalmic regional anaesthesia-related ocular hypotony, the surgical management, and a special emphasis on anaesthetic management. Traumatic hypotony usually requires urgent surgical repair, whereas iatrogenic hypotony may be less urgent, with many cases scheduled as elective procedures. There is no universal best anaesthetic technique. Topical anaesthesia and regional ophthalmic block, with some technique modifications, are suitable in many mild-to-moderate cases, whilst general anaesthesia may be required for complex and longer procedures, and severely distorted globes.

Preserving posterior capsular integrity in post-endothelial keratoplasty posterior capsular opacification

Endothelial keratoplasty (EK) with pseudophakia often presents with late-onset proliferative after-cataract with posterior capsule distension. We performed a modified technique of capsular bag lavage in 11 eyes with late-onset PCO after EK (4 cases: post-DSAEK, 7 cases: post-DMEK). Anterior capsular rim was separated from the underlying IOL optic using MVR blade. Circumferential relaxing radial nicks were made on the capsular rim to create space for the passage of irrigation-aspiration (IA) probes behind the IOL. Bimanual IA of the flocculent cortical material was performed without damaging the posterior capsule. Air was injected at end of surgery to ensure graft apposition. All cases gained 1-3 lines of Snellen’s acuity and no case developed graft failure, rejection, or endothelial decompensation. An intact posterior capsule is associated with better outcomes post a repeat graft, if required. Our technique helps avoid complications related to a disturbed anterior hyaloid phase and minimizes postoperative inflammation.

Short-Term Changes in Prediction Error after Cataract Surgery in Eyes Receiving 1 of 3 Types of Single-Piece Acrylic Intraocular Lenses

PURPOSE

To compare short-term changes in refractive prediction error (PE) after phacoemulsification among eyes receiving different types of single-piece acrylic intraocular lenses (IOLs).

DESIGN

Randomized clinical trial.

METHODS

A total of 195 eyes of 195 patients scheduled for implantation of a single-piece acrylic IOL were randomly assigned to receive 1 of 3 IOLs: 1) an Alcon model SN60WF, 2) a Hoya model XY-1, or 3) an AMO model ZCB00V. Manifest spherical equivalent (MRSE) value, PE, and changes in PE were examined at 1 day and at 1 and 2 months postoperatively and were compared among groups.

RESULTS

The mean MRSE and PE significantly changed toward myopia between 1 day and 2 months postoperatively in all groups (P < .0001). The MRSE and PE did not differ significantly among groups at 1 day and 1 month postoperatively and were significantly smaller in the SN60WF group than in the XY-1 and ZCB00V groups at 2 months (P ≤ .0006). The PE change between 1 day and 2 months postoperatively was significantly smaller in the SN60WF group than in the other groups (P = .0062). IOL type and changes in anterior chamber depth and corneal curvature independently correlated with PE changes.

CONCLUSIONS

The MRSE and PE showed a significant myopic change for 2 months postoperatively in eyes implanted with 1 of 3 types of single-piece acrylic IOLs and were significantly smaller in the SN60WF than in the XY-1 and ZCB00V groups. Changes in PE during the 2 postoperative months were smaller in the SN60WF IOLs than in the other IOLs, suggesting that postoperative refractive stability differs among single-piece acrylic IOLs.

Microscope-integrated Intraoperative Optical Coherence Tomography for Anterior Segment Surgical Maneuvers

Purpose

To evaluate the potential value of microscope-integrated optical coherence tomography (MI-OCT) in anterior segment surgical maneuvers.

Methods

Twenty-four ophthalmology residents, who were randomly and evenly divided into two groups, performed four anterior segment surgical maneuvers (corneal tunnel, scleral tunnel, simple corneal suture, and corneal laceration repair) on porcine eyes with (group B) or without (group A) real-time MI-OCT feedback. All residents performed the maneuvers again without MI-OCT.

Results

Compared with group A, group B (with MI-OCT) showed better accuracy in the length/depth of the corneal tunnel and the length of the scleral tunnel. However, both groups showed similar performances in the depth of both the simple corneal suture and the corneal laceration suture. When both groups performed the maneuvers again without MI-OCT, group B still showed better results than group A for the length of both the corneal and scleral tunnels.

Conclusions

Primary results suggest that real-time MI-OCT images are valuable for some anterior segment surgical maneuvers and could be helpful in surgical training.

Translational Relevance

MI-OCT systems can be valuable in improving accuracy and decision making during anterior segment surgery and will be useful in surgical training.

Corneal Sealants in Clinical Use: A Systematic Review

AIM

To review the use of clinical corneal sealants for the closure of full thickness corneal wounds.

METHODS

A systematic review was conducted across CENTRAL, Medline, PubMed, Embase, Scopus, mRCT and ICTRP for the keywords of 'cornea', 'full-thickness wound', 'sealant' and their synonyms. Only evidence level 2 of higher as graded by Oxford Centre of Evidence-based Medicine were included for this review.

RESULTS

Seven studies were included; three randomized controlled trials investigated ReSure® sealant, 2 OcuSeal®, 1 human fibrin glue vs cyanoacrylate and 1 human fibrin glue as an adjunct to sutures vs sutures alone in penetrating keratoplasty. ReSure® was superior to suture for sealing leaking corneal incisions after cataract surgery despite provocation. ReSure® sealant has not been tested on complex full thickness corneal wounds, perforated ulcers or penetrating keratoplasty. OcuSeal® was also able to seal full thickness cornea wound post-cataract surgery to prevent ingress of Trypan blue dye. Human fibrin glue and cyanoacrylate were similarly effective in treating corneal perforations <3 mm of mixed etiologies.

CONCLUSION

There are limited high-level evidence for corneal sealants. The currently available sealants with human data are ReSure®, OcuSeal®, human fibrin glue and cyanoacrylates. While ReSure® and OcuSeal® are effective post-cataract surgery, there are no data for perforations from other etiologies. Post-approval data from ReSure® registry report good tolerability and no apparent safety concerns.

Effect of Topical Hypotensive Medications for Preventing Intraocular Pressure Increase after Cataract Surgery in Eyes with Glaucoma

PURPOSE

To compare the effects of a topical intraocular pressure (IOP)-lowering medication for preventing an IOP increase after cataract surgery in eyes with glaucoma.

DESIGN

Randomized clinical study.

METHODS

A total of 165 eyes of 165 patients with primary open-angle glaucoma or pseudoexfoliation glaucoma scheduled for phacoemulsification were randomly assigned to 1 of 3 groups to receive each medication immediately postoperatively: 1) prostaglandin F_2α analog (travoprost), 2) β-blocker (timolol maleate), or 3) carbonic anhydrase inhibitor (brinzolamide). Intraocular pressure (IOP) was measured using a rebound tonometer at 1 hour preoperatively, at the end of surgery, and at 2, 4, 6, 8, and 24 hours postoperatively. The incidence of eyes exhibiting a marked IOP increase to greater than 25 mm Hg was compared among the groups.

RESULTS

At 1 hour preoperatively and at the end of surgery, mean IOP did not differ significantly among the groups. Mean IOP increased significantly between 4 and 8 hours postoperatively and then decreased at 24 hours postoperatively in all groups (P < .0001). Mean IOP was significantly lower in the brinzolamide group than in the travoprost or timolol group at 4, 6, and 8 hours postoperatively (P ≤ .0374) and did not differ significantly among groups at 2 and 24 hours postoperatively. The incidence of an IOP spike was significantly lower in the brinzolamide group than in the travoprost and timolol groups (P = .0029).

CONCLUSIONS

Brinzolamide reduces the short-term IOP increase after cataract surgery more effectively than travoprost or timolol in eyes with glaucoma, suggesting that brinzolamide is preferable for preventing an IOP spike.

CONSORT 2010 statement: extension checklist for reporting within person randomised trials

Evidence shows that the quality of reporting of randomised controlled trials (RCTs) is not optimal. The lack of transparent reporting impedes readers from judging the reliability and validity of trial findings and researchers from extracting information for systematic reviews and results in research waste. The Consolidated Standards of Reporting Trials (CONSORT) statement was developed to improve the reporting of RCTs. Within person trials are used for conditions that can affect two or more body sites, and are a useful and efficient tool because the comparisons between interventions are within people. Such trials are most commonly conducted in ophthalmology, dentistry, and dermatology. The reporting of within person trials has, however, been variable and incomplete, hindering their use in clinical decision making and by future researchers. This document presents the CONSORT extension to within person trials. It aims to facilitate the reporting of these trials. It extends 16 items of the CONSORT 2010 checklist and introduces a modified flowchart and baseline table to enhance transparency. Examples of good reporting and evidence based rationale for CONSORT within person checklist items are provided.

Intraocular pressure elevation after cataract surgery and its prevention by oral acetazolamide in eyes with pseudoexfoliation syndrome

PURPOSE

To examine whether intraocular pressure (IOP) increases immediately after cataract surgery in eyes with pseudoexfoliation (PXF) syndrome and to assess whether orally administered acetazolamide can prevent the IOP elevation.

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

DESIGN

Prospective case series.

METHODS

Patients with PXF syndrome scheduled for phacoemulsification were randomly assigned to 1 of 3 groups: (1) oral acetazolamide administered 1 hour preoperatively (preoperative administration group), (2) administered 3 hours postoperatively (postoperative administration group), and (3) not administered (no administration group). The IOP was measured using a rebound tonometer 1 hour preoperatively, upon completion of surgery, and at 1, 3, 5, 7, and 24 hours postoperatively.

RESULTS

The study comprised 96 patients (96 eyes). The mean IOP increased at 3, 5, and 7 hours postoperatively in all groups. At 1 hour and 3 hours postoperatively, the IOP was significantly lower in the preoperative administration group than in the postoperative group and no administration group (P ≤ .001). At 5, 7, and 24 hours postoperatively, the IOP was significantly lower in the preoperative group and postoperative administration group than in the no administration group (P ≤. 045). An IOP spike higher than 25 mm Hg occurred less frequently in the preoperative administration group than in the postoperative administration group and the no administration group (P = .038).

CONCLUSIONS

Intraocular pressure increased at 3, 5, and 7 hours after cataract surgery in eyes with PXF syndrome. Oral acetazolamide administered 1 hour preoperatively reduced the IOP elevation throughout the 24-hour follow-up; acetazolamide administered 3 hours postoperatively reduced the elevation at 5 hours postoperatively and thereafter.

Real-Time Monitoring of Post-Surgical and Post-Traumatic Eye Injuries Using Multilayered Electrical Biosensor Chip

Lack of current techniques for the early monitoring of bleb leaks and other post-traumatic or post-surgical ocular injury has posed an unmet clinical need for the development of new techniques. Present evaluation techniques use either subjective or nonquantitative approaches. At present, there are no FDA approved ocular devices that can directly measure ascorbic acid (AA) concentration levels for both tear film (TF) and aqueous humor (AH) at point-of-care (POC) level. Toward this aim, we present a novel POC quantitative assay, called the ocular biosensor device, which can be used to evaluate the integrity of the anterior surface of the eye by measuring the concentration of AA in TF and AH. Herein, we utilize a novel scientific engineering approach for the development of a disposable paper based POC ocular biosensor strip. A grafted poly(styrene)-block-poly(acrylic acid) (PS-b-PAA) and graphene platelet composite with contour based μ-electrodes design (CBμE) exhibit a highly sensitive platform to perform electrochemical immunosensing technique to study clinical samples that have small volumes like tear fluid. Samples used in this study were collected clinically from subjects undergoing therapeutic anterior chamber paracentesis. The proposed biosensor reports the level of AA concentration on an electronic screen, making the results easy to read, efficient, and reliable.

Wound stability and surgically induced corneal astigmatism after transconjunctival single-plane sclerocorneal incision cataract surgery

PURPOSE

To compare intraocular pressure (IOP) immediately after cataract surgery, and surgically induced corneal astigmatism (SIA) and corneal shape changes between eyes with transconjunctival single-plane sclerocorneal incisions (TSSIs) and eyes with clear corneal incisions (CCIs).

METHODS

Bilateral eyes of 64 patients undergoing phacoemulsification were randomized to undergo 2.4-mm temporal TSSI or CCI. IOP was measured preoperatively, and in the immediate postoperative periods. SIA was determined using vector analysis, and corneal shape changes and irregular astigmatism were evaluated using a videokeratography preoperatively, and in the early postoperative periods.

RESULTS

Wound hydration was performed in 23 eyes (35.9 %) of the TSSI group and in 60 (93.8 %) of the CCI group (P < 0.0001). Mean IOP was significantly higher in the TSSI group than in the CCI group at 30, 60, and 120 min postoperatively (P ≤ 0.0179). SIA tended to be smaller in the TSSI group than the CCI group, but the difference was not significant. The higher order irregular astigmatism was smaller in the TSSI group than in the CCI group at 2 days (P = 0.0312). The videokeratography revealed a wound-related flattening postoperatively in both groups; this change disappeared within 4 weeks in the TSSI group, whereas it persisted until 12 weeks in the CCI group.

CONCLUSION

IOP was significantly higher immediately after TSSI than after CCI and required less wound hydration, suggesting better stability with TSSI. Higher order irregular astigmatism and wound-related corneal flattening were smaller after TSSI than after CCI in the early periods, suggesting that fewer corneal shape changes with TSSI.

Cataract surgery and methods of wound closure: a review

Clear corneal incisions are routinely used in cataract surgery, but watertight wound closure may not always be achieved, which can increase the risk for anterior chamber fluid egress or ocular surface fluid ingress. A new US Food and Drug Administration-approved ocular sealant appears to have good efficacy in sealing clear corneal incisions; its use may be indicated when wound integrity is in question.