Clear Corneal Incision Architecture Research Articles

Comparison of Three-Dimensional Surgical System Versus Binocular Microscope for Clear Corneal Incision in Cataract Surgery.

IntroductionTo compare surgical outcomes of 2.2 mm clear corneal incision (CCI) between a three-dimensional (3D) visualization system and traditional binocular microscope (BM) for phacoemulsification and intraocular lens implantation surgery.MethodsIn this randomized controlled clinical study, 60 eyes with age-related cataracts were divided into two groups receiving cataract surgery using either a 3D vision system (n = 30 eyes) (3D group) or a binocular microscope (n = 30 eyes) (BM group). We recorded and statistically analyzed surgical parameters and pre- and postoperative ocular parameters. Primary outcomes included the change in endothelial cell density (ECD) and CCI architecture, and secondary outcomes comprised other ocular parameters and surgical parameters. All procedures complied with the tenets of the Declaration of Helsinki.ResultsOf the 60 eyes randomly assigned between January 5, 2021, and May 9, 2021, 55 (26 eyes in the 3D group and 29 eyes in the BM group) were analyzed. The ECD loss rate was 8.1% in the 3D group and 12.3% in the BM group, but the difference was not statistically significant. Local detachment of Descemet’s membrane was seen in 50% (13 eyes, 3D group) and 51.6% (15 eyes, BM group), wound gaping at the endothelial side in 15.4% (four eyes, 3D group) and 10.3% (four eyes, BM group), gaping at the epithelial side in 11.5% (three eyes, 3D group) and 6.9% (two eyes, BM group), and misalignment of the incision in 3.4% (one eye, BM group) 1 day after surgery. These abnormalities improved with time. There was no difference between the 3D group and BM group in terms of other ocular parameters or surgical parameters before and after surgery.ConclusionsUsing the 3D surgical system for phacoemulsification and IOL implantation surgery seems to result in similar ECD and CCI conditions as using a conventional binocular microscope.Trial RegistrationThe protocol was registered on ClinicalTrials.gov (NCT04839250).

Architecture evaluation of the main clear corneal incisions in femtosecond laser-assisted cataract surgery by optical coherence tomography imaging.

PurposeTo assess the stability and reliability of femtosecond laser-assisted cataract surgery (FLACS) incisions design and dimensions using anterior segment optical coherence tomography (AS-OCT) imaging.SettingRenato Ambrósio Ophthalmologic Study Center from Hospital Oftalmológico de Brasília, Brasília, Brazil.DesignProspective nonrandomized controlled case series.MethodsEyes undergoing FLACS with triplanar main temporal clear corneal incision (CCI) were evaluated at the end of the case. Eyes that required any incision hydration, surgical complications or lacked follow-up were excluded. The AS-OCT was performed after femtosecond delivery; at the end of the case; at 1 day and at 30 days after surgery. Data of pachymetry, endothelial and epithelial gaps, Descemet detachment and CCI architecture were compared.ResultsEleven eyes from 11 patients completed follow-up. Corneal thickness was statistically different between after femtosecond delivery and the end of the case (P-value <0.05), but without difference compared to 30 days evaluation. There was an increase of Descemet detachments (P-value <0.05) and endothelial gaps (P-value =0.0133) at the end of the case compared to post-femtosecond delivery. As for the architecture of the CCI, significant difference was found between the parameters of entry angle and exit angle measured with AS-OCT and the programmed.ConclusionThe AS-OCT was capable of visualizing changes in the cornea at the CCI. Despite the stress caused by manipulation, results indicated good stability of incision and reproducibility of tunnel length.SynopsisDifference of corneal thickness at the CCI between after femtosecond and after phacoemulsification measurements (P-value <0.05), with increase of endothelial gaps (P-value =0.0133) and Descemet detachments (P-value <0.05).

The Effect of Eye Patching on Clear Corneal Incision Architecture in Phacoemulsification: A Randomized Controlled Trial.

To investigate the effects of postoperative eye patching on clear corneal incision architecture in phacoemulsification. A single-center, randomized controlled trial. A total of 132 patients with uncomplicated phacoemulsification were randomly allocated to the intervention or control group. The intervention group received postoperative eye patching for approximately 18 hours, whereas the control group received eye shield. The clear corneal incision architecture was examined postoperatively at 2 hours, 1 day, and 7 days after surgery using optical coherence tomography. Epithelial gaping was significantly reduced on postoperative day 1 in the intervention group (52.4%) compared with control (74.2%) (P = 0.01). No differences were found for other architectural defects. Descemet membrane detachment was associated with lower intraocular pressure on postoperative day 7 (P = 0.02). Presence of underlying diabetes mellitus did not seem to influence architectural defects. Postoperative eye patching facilitated epithelial healing and reduced the occurrence of epithelial gaping on postoperative day 1. It may play a role in protecting and improving corneal wounds during the critical immediate postoperative period.

Clear Corneal Incision Architecture Imaging after Torsional Phacoemulsification of Hard Nuclear Cataract through a 2.2 mm and a 3.0 mm Large Tunnel

Purpose: To compare the morphological characteristics and the wound edema degree of clear-cornea microincisions and small-incisions for hard cataract removal.Setting: The Eye Hospital of Wenzhou Medical College.Design: Prospective randomized study. Methods: Fifty eyes from 36 consecutive patients with hard cataract were included. They were randomized to have phacoemulsification through a clear-cornea microincision (2.2 mm, n=25) or small-incision (3.0 mm, n=25). Anterior segment optical coherence tomography evaluation was performed preoperatively and postoperatively, including wound architecture and incisional corneal thickness (ICT).Results: Endothelial gaping was more common in the 2.2 mm group than in the 3.0 mm group at 2 hours (48 vs 12%) and 1 week (28 vs 12%) postoperatively, although the statistical difference was significant only at 2 hours. There was no statistically significant difference between the two groups in the incidence of epithelial gaping, local detachment of Descemet’s membrane, loss of coaptation, and posterior wound retraction. At 2 hours and 1 week after surgery, the mean ICTd was slightly higher in 3.0 mm group (52.1±12.5% and 46.4±12.3%, respectively) than in 2.2 mm group(51.4±11.6% and 40.6±15.1%, respectively), with no statistically significant differences. On the contrary, the ICTd was statistically higher in 3.0 mm group than 2.2 mm group at 1 month (16.8±10.0% vs 10.2±5.8%, P = 0.007) and 3 months (12.1±8.1% vs 6.0±4.5%, P = 0.002).Conclusion: In hard cataract phacoemulsification, microincisions increase the risk of endothelial gaping in the early postoperative period, compared to small incisions. However, they induce a lower amount of corneal edema.

Analyse architecturale des incisions cornéennes par OCT Visante ® au cours des endophtalmies aiguës après chirurgie de la cataracte

To analyze the architecture of clear corneal incisions after acute endophthalmitis following cataract surgery using anterior segment OCT (AS-OCT). Fourteen eyes of 14 patients followed at the Quinze-Vingts National Ophthalmology Hospital for acute endophthalmitis following cataract surgery, between April and November 2008, were included in this study. All patients had a complete biomicroscopic examination and a Visante-OCT (Carl Zeiss Meditec AG) analysis of the corneal incision. The length, size (width), location, angle, architecture, and anatomic imperfections of the incisions were analyzed. Symptoms occurred 4+/-2.4 days after cataract surgery. The location of the incision was superior in 71.43% of cases, temporal in 21.43% and nasal in 7.14%. Incision size (width) was 3.2 mm in 42.86% of cases, 2.75 mm in 35.71%, and 3 mm in 21.43%. Two incisions were sutured (14.28%). Using AS-OCT, the mean incision length was 1.42+/-0.25 mm and the mean incision angle was 39+/-10.62 degrees . Three-step incisions were found in 35.71% of cases and endothelial gaping was found in 42.86 % of cases. A reduced incision length and inappropriate construction seemed to be determinant risk factors of endophthalmitis following cataract surgery. Other studies using a greater number of patients with an architectural analysis of clear corneal incisions are necessary to confirm these preliminary results.

Corneal Wound Architecture and Integrity After Torsional and Mixed Phacoemulsification: Evaluation of Standard and Microincisional Coaxial Techniques

To compare the effects of torsional and mixed ultrasound on clear corneal incision architecture, wound integrity, and apposition using standard (2.75 mm) and microincisional (2.2 mm) coaxial phacoemulsification. Twenty human cadaver eyes (4 groups of 5 eyes) underwent simulated coaxial phacoemulsification for 45 seconds of ultrasound time (group 1 = 2.75 mm, 100% torsional; group 2 = 2.2 mm, 70% torsional; group 3 = 2.2 mm, 100% torsional; group 4 = 2.2 mm, mixed ultrasound). All phacoemulsification settings were kept constant across each group. Following phacoemulsification, intraocular pressure (IOP) was cyclically raised and lowered from 0 to 125 mm Hg. Two eyes from each group had India ink placed over the wound and were observed for leakage and for histopathologic examination. Eyes not exposed to India ink (three eyes of each group) were examined using anterior segment optical coherence tomography (OCT) and scanning electron microscopy (SEM). Wound leakage was evident in one eye from group 1 and no eyes from the other three groups. Histopathologic examination revealed no India ink penetration in any of the eyes studied. Anterior segment OCT showed good wound apposition in each group. SEM demonstrated partially compromised endothelium and Descemet's membrane in all eyes studied from each group. No differences in corneal wound architecture and integrity were observed. Torsional and mixed ultrasound settings do not appear to induce any adverse effects on corneal wound architecture and integrity in standard and microincisional coaxial phacoemulsification techniques.

Optical coherence tomography of the effects of stromal hydration on clear corneal incision architecture

To evaluate the effects of stromal hydration on clear corneal incision (CCI) architecture immediately after surgery using anterior segment optical coherence tomography (AS-OCT). Department of Ophthalmology, Royal Berkshire Hospital, Reading, United Kingdom. Clear corneal incisions in adult eyes were examined using a Visante AS-OCT imaging system within 1 hour of surgery. Half the CCIs had stromal hydration with a balanced salt solution and half did not. Incisions were made with a 2.75 mm steel keratome. Intraocular pressure (IOP) was measured within 90 minutes after surgery. The CCI length and corneal thickness at the CCI site were measured using software built into the AS-OCT system. Thirty CCIs were evaluated. Stromal hydration significantly increased the measured CCI length (P<.05, t test); this was the result of a trend toward increased corneal thickness at the CCI site with hydration (P<.1, t test). The mean CCI length was 1.69 mm +/- 0.27 (SD) (range 1.31 to 2.32 mm) with hydration and 1.51 +/- 0.23 mm (range 1.30 to 1.95 mm) without hydration. The mean IOP was 20.9 +/- 8.18 mm Hg and 15.8 +/- 8.20 mm Hg, respectively. The IOP tended to be higher with hydration (P<.1, t test). Local detachment of Descemet membrane was more likely with stromal hydration (63%) than without (25%). Stromal hydration significantly increased CCI length and tended to leave the eye with a higher early postoperative IOP, showing the importance of taking stromal hydration into account when designing similar OCT studies of CCI architecture.

In vivo architectural analysis of clear corneal incisions using anterior segment optical coherence tomography

To use anterior segment optical coherence tomography (AS-OCT) to analyze the in vivo architecture of clear corneal incisions after phacoemulsification using different techniques. Department of Ophthalmology, Quinze-Vingts National Ophthalmology Hospital, Paris, France. This prospective observational study analyzed clear corneal incisions used in phacoemulsification. All wounds were evaluated 1 day and 8 days postoperatively by AS-OCT (Visante). Incision architecture and pachymetry at the wound level were analyzed. Thirty-five clear corneal incisions were analyzed. Six eyes had 2.75 mm coaxial phacoemulsification, 19 had 2.20 mm microincision coaxial phacoemulsification, and 10 had 1.30 mm bimanual microincision phacoemulsification. The 1.30 mm incision had a straight-line configuration. The 2.20 mm and 2.75 mm incisions had an arcuate configuration. The angles of incidence of 1.30 mm incisions were greater than those of 2.20 mm incisions (P<.001). All incisions had slight corneal edema limited to the incision area. The edema was slightly greater around 1.30 mm incisions (mean pachymetry 1143 microm +/- 140 [SD]) than around 2.20 mm incisions (mean 1012 +/- 101 microm) (P = .001). Bimanual procedures had satisfactory endothelial apposition in the enlarged areas, where stromal edema was less than that surrounding the unenlarged 1.30 mm incisions. The 3 phacoemulsification techniques induced gaping of the endothelial edge, minor inadequate endothelial apposition, and mild stromal edema in the area of the clear corneal incisions. Bimanual microincision sleeveless phacoemulsification may alter the wound slightly more than coaxial 2.75 mm and microcoaxial 2.20 mm sleeved-tip phacoemulsification.

Optical coherence tomography of clear corneal incisions for cataract surgery

To study the architecture of clear corneal incisions for phacoemulsification cataract surgery using optical coherence tomography (OCT). Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA. This prospective study comprised 20 eyes of 20 patients 1 month after cataract surgery performed by 1 of 2 experienced surgeons. Temporal clear corneal single-plane incisions were made with 3.0 mm metal keratomes. Each eye was scanned before and 1 month after surgery with a prototype high-speed anterior segment OCT system (Carl Zeiss Meditec, Inc.). The OCT scans were repeated 3 times during the same visit. The length of the corneal incision, thickness of the cornea, and position of the incision (distance from external wound edge to scleral spur) were measured using a computer caliper. The angle of the incision relative to the corneal surface was then calculated. The mean corneal incision length was 1.81 mm +/- 0.27 (SD), the mean corneal thickness at the incision was 747 +/- 67 microm, and the mean distance between the incision and the scleral spur was 1.46 +/- 0.24 mm. The mean angle of the incision was 26.8 +/- 5.5 degrees. The measurements were repeatable to within +/-0.072 mm (pooled standard deviation) for the incision length, +/-11 microm for the corneal thickness, and +/-0.042 mm for the position of the incision. Optical coherence tomography allowed excellent evaluation of corneal incisions in cataract surgery postoperatively. Measurements of wound dimensions using OCT were highly repeatable.

Clear corneal incision architecture in the immediate postoperative period evaluated using optical coherence tomography

Clear corneal incision architecture in the immediate postoperative period evaluated using optical coherence tomography

Clear corneal incision architecture in the immediate postoperative period evaluated using optical coherence tomography

To investigate clear corneal incision (CCI) architecture in the immediate postoperative period using optical coherence tomography (OCT). Prince Charles Eye Unit, King Edward VII Hospital, Windsor, United Kingdom. Thirty-four CCIs in 34 adult eyes were examined prospectively using the Carl Zeiss Visante anterior segment OCT imaging system within 1 hour of uneventful phacoemulsification cataract surgery. The CCIs were created using 4 widths of stainless steel blades (2.20 mm, 2.50 mm, 2.75 mm, and 3.20 mm). Immediately afterward, a Seidel test, an inverse Seidel test, and intraocular pressure (IOP) measurements were performed independently. The OCT images were randomized and masked before evaluation. Approval was obtained from appropriate research and ethics committees. The mean CCI length was 1.61 mm +/- 0.26 (SD) (range 1.10 to 2.25 mm). The mean incision angle was 40.7 +/- 9.43 degrees (range 24 to 56 degrees). Five CCI architectural features were noted with the following frequencies: epithelial gaping (12%), endothelial gaping (41%), endothelial misalignment (65%), local detachment of Descemet's membrane (62%), and loss of coaptation (9%). A reduction in wound apposition up to 20% was caused by endothelial gaping and up to 25%, by loss of coaptation, in a bidimensional image. The mean postoperative IOP was 16.1 +/- 9.02 mm Hg (range 3 to 46 mm Hg). The IOP was lower with local detachment of Descemet's membrane (P<.1). Other CCI architectural features varied predicatively with IOP, but not with blade width. Optical coherence tomography architectural features of endothelial gaping and loss of coaptation theoretically reduce CCI structural integrity in the immediate postoperative period. These features appeared to be more common at low IOP and could represent significant risk factors for endophthalmitis.

Corneal wound architecture and integrity after phacoemulsification: Evaluation of coaxial, microincision coaxial, and microincision bimanual techniques

To compare the effects of microincision bimanual phacoemulsification, standard coaxial phacoemulsification, and microincision coaxial phacoemulsification on clear corneal incision architecture and wound integrity.Department of Ophthalmology, Duke University, Durham, North Carolina, USA.A prospective study of 15 human cadaver eyes (3 groups of 5 eyes) ranging 1 to 4 days postmortem had simulated phacoemulsification by bimanual phacoemulsification (1.2 mm incision), standard coaxial phacoemulsification (2.75 mm), or microincision coaxial phacoemulsification (2.2 mm). All phacoemulsification settings were kept constant across each group. After phacoemulsification, intraocular pressure (IOP) was cyclically raised and lowered from 0 to 125 mm Hg. Two eyes in each group had India ink placed above the wound, and the IOP was varied as above. Entry of India ink into the wound or aqueous leakage from the wound was recorded. The same 2 corneas in each group were removed for histopathologic review of India ink penetration. Scanning electron microscopy was used to evaluate wound architecture in 1 eye in each group.Spontaneous wound leakage was evident in all 5 eyes having bimanual phacoemulsification, in 1 eye (20%) having standard coaxial phacoemulsification, and no eye having microincision coaxial phacoemulsification. India ink penetration was grossly evident in 2 of 2 eyes having bimanual phacoemulsification, 1 of 2 eyes having standard coaxial phacoemulsification, and neither of the 2 eyes having microincision coaxial phacoemulsification. Scanning electron microscopy showed increased endothelial cell loss and greater compromise to Descemet's membrane with bimanual phacoemulsification than with standard coaxial phacoemulsification or microincision coaxial phacoemulsification.Results in this experimental setting suggest microincision coaxial phacoemulsification and standard coaxial phacoemulsification induce less wound stress and alteration of wound morphology leading to wound leakage than microincision bimanual phacoemulsification.

In vivo architectural analysis of 3.2 mm clear corneal incisions for phacoemulsification using optical coherence tomography

To analyze in vivo the architecture of clear corneal incisions (CCIs) for phacoemulsification using optical coherence tomography (OCT). Anterior Segment Department, Asociacion Para Evitar la Ceguera en Mexico, Hospital Dr Luis Sanchez Bulnes, Mexico. A prospective masked study analyzed 20 unsutured CCIs placed superiorly and created in a uniplanar fashion with a 3.2 mm slit-angled metal keratome. All wounds were evaluated with a retinal OCT model 1, 3, and 30 days postoperatively. Intraocular pressure (IOP) and incision leakage were checked. The architecture was described according to the angle of incidence, apposition of the epithelial and endothelial margins, and wound sealing. No leakage was detected. The angle varied from 33 to 85 degrees; angles greater than 75 degrees were done by a surgeon in training. Wound apposition at the epithelial margin was achieved in all cases. In contrast, imperfect apposition of the endothelial margin was seen in 45% of incisions on day 1 and in 15% on day 30. Incomplete sealing of the wound was seen by OCT in 25% of cases at 24 hours and persisted in 10% of all cases at 1 month. This gaping occurred on the endothelial side and never translated to the epithelial margin. No statistical correlation was found between gaping and the angle of the incision, IOP variations, or surgeon experience. Although in vivo CCIs caused minor anatomic imperfections, they were clinically stable independent of incision angle, IOP variation, and surgeon experience. Incision stability may be related to careful wound construction, epithelial viability, stromal edema, and efficient endothelial pumping.