Robotic Assisted-Intravitreous Light Pipe Illumination for Cataract Surgery in Eyes with Corneal Opacity: Case Reports

Abstract

Introduction

In cataract surgery for eyes with corneal opacity, reduced intraoperative visibility remains a major surgical challenge. To enhance intraoperative visualization, OQrimo, a robotic medical device approved in Japan, was used to hold a light guide. Outcomes of 3 eyes from 2 cases are reported.

Case Presentation

Case 1: A 48-year-old man developed bilateral corneal opacity from graft-versus-host disease following umbilical cord blood transplantation for acute myeloid leukemia. At age 45, he underwent penetrating keratoplasty in the right eye but declined surgery in the left eye. Bilateral cataract surgery under general anesthesia was performed. Due to poor visibility under the surgical microscope in both eyes, a 25-gauge light pipe was inserted into the vitreous cavity and stabilized using OQrimo, thereby improving intraoperative visibility and enabling successful cataract surgery in both eyes. Case 2: A 74-year-old man had previously undergone pterygium excision with conjunctival autograft transplantation for a lesion involving the pupillary area of the left eye. Residual central corneal opacity remained, and cataract surgery was performed 6 months later. Due to poor microscopic visibility, a 25-gauge light pipe was inserted into the vitreous cavity and held using OQrimo. While visualization improved, the weight of the OQrimo arm caused ocular deviation, preventing stable positioning and necessitating its discontinuation.

Conclusions

OQrimo effectively enhanced intraoperative visibility in cataract surgery for eyes with corneal opacity, although stable positioning was occasionally challenging.

Introduction

Cataract surgery is 1 of the most commonly performed ophthalmic procedures worldwide and has evolved significantly with advances in surgical techniques and intraocular lens (IOL) technology [1]. The standard approach, phacoemulsification, allows for rapid recovery and excellent visual outcomes in most cases. However, in patients with corneal opacities, intraoperative visualization can be markedly impaired, rendering the procedure technically challenging [2]. Poor visibility may increase surgical risk and lead to suboptimal refractive outcomes. To address these challenges, various adjunctive techniques have been explored to enhance visualization, including brilliant blue G (BBG) staining, endoscope, endoillumination, intraoperative optical coherence tomography (iOCT), 3D monitor, combined keratoplasty, and other light-assisted devices [3–9]. These methods have several limitations, including the inability to adjust the angle, high cost, and limited availability.

OQrimo (Riverfield Inc, Tokyo, Japan) is a robotic-assisted surgical device designed to support intraocular procedures by holding and manipulating instruments such as intraocular endoscope or light pipe [10, 11] (Fig. 1a). It has received regulatory approval in Japan as a Class I medical device. The system is controlled via a foot pedal controller, enabling hands-free adjustments by the surgeon during ophthalmic surgery [11]. This design enhances ergonomic efficiency and minimizes hand tremor, allowing for improved stability and safety during delicate intraocular maneuvers [12–14]. By securely holding an intraocular light pipe or endoscope within the vitreous cavity (Fig. 1b), OQrimo provides illumination and visualization of intraocular structures, facilitating safer and more efficient surgery (Fig. 1c). Additionally, the device incorporates safety features such as force sensors to prevent excessive pressure on ocular tissues, and its compact design allows seamless integration into standard ophthalmic operating environments without disrupting surgical workflow.

Fig. 1.

Cataract surgery assisted with the OQrimo system. a The OQrimo arm is designed to hold and stabilize either a light pipe or an endoscope. It can be controlled via a foot switch, allowing anterior-posterior and lateral movements, as well as 360-degree rotation. b A screen allows the surgeon to select either a light pipe or an endoscope according to the surgical needs. c The intraoperative display shows the position of the instrument within the eye. d A 25-gauge light pipe is inserted through the pars plana from the inferotemporal quadrant, and the OQrimo arm stabilizes it in position. e After placement of the light pipe, intraocular illumination is applied.

In this report, we present 3 eyes from 2 patients of cataract surgery in the presence of corneal opacity, in which the OQrimo system was used to enhance intraoperative visibility. We also discuss the surgical outcomes and the practical considerations associated with this approach.

Case Reports

Surgical Technique

All procedures were performed using the Centurion (Alcon Laboratories, Inc., Fort Worth, TX, USA) and the OPMI Lumera 700 microscope (Carl Zeiss Meditec AG, Jena, Germany). After topical anesthesia (1% Xylocaine) under sub-tenon, a 25-gauge trocar was placed in the outer inferior (right eye at 8 o’clock and left eye at 4 o’clock). The OQrimo endoscope-holding robot was used with a 25-gauge light pipe (18,271–0,325, Alcon Laboratories, Inc., Fort Worth, TX, USA) (Fig. 1d, e). The optimal position of the light pipe was adjusted using the OQrimo foot pedal. After creation of the side port, the anterior capsule was stained with BBG, and continuous curvilinear capsulorhexis (CCC) was performed. Following the creation of the main incision, hydrodissection was carried out, and phacoemulsification with IOL implantation was performed using the divide-and-conquer technique. After removal of the surgical instruments, the incision was closed with an 8-0 Vicryl suture (online suppl. Video; for all online suppl. material, see https://doi.org/10.1159/000553027).

Case 1 was a 48-year-old man who developed corneal opacity in both eyes due to graft-versus-host disease (GVHD) following umbilical cord blood transplantation for acute myeloid leukemia at age 27. At the age of 30, the patient developed corneal opacity due to Pseudomonas aeruginosa infection in the right eye (Fig. 2a). At the age of 43, the patient was referred to our department for evaluation with the intent of undergoing corneal transplantation. At the age of 45, he underwent penetrating keratoplasty in the right eye but declined surgery in the left eye (Fig. 2b, c). Bilateral cataract surgery under general anesthesia was performed. Due to poor visibility under the surgical microscope in both eyes (Fig. 2e, g), a 25-gauge light pipe was inserted into the vitreous cavity and held in place using OQrimo (Fig. 2d, f). This improved intraoperative visualization, enabling successful phacoemulsification and IOL insertion in both eyes (Fig. 2g). BCVA (logMAR) was improved from H.M. to 0.40 in the right eye and 1.0 to 0.70 in the left eye. No significant postoperative complications were observed.

Fig. 2.

Preoperative and intraoperative photographs of Case 1. a Right eye at initial presentation, showing corneal opacity due to Pseudomonas aeruginosa infection obscuring the pupillary area. b Right eye after penetrating keratoplasty. c Left eye at initial presentation, showing mild stromal opacity with neovascularization. d Intraoperative view of the right eye during cataract surgery, with adequate visualization using a light guide stabilized by OQrimo. e Intraoperative view of the right eye without the light guide, showing poor visualization. f Intraoperative view of the left eye during cataract surgery, with adequate visualization using a light guide stabilized by OQrimo. g Intraoperative view of the left eye without the light guide, showing poor visualization.

Case 2 was a 74-year-old man who underwent pterygium excision and conjunctival autograft transplantation for a lesion involving the pupillary area in the left eye. Despite surgery, residual central corneal opacity remained. Six months later, cataract surgery was attempted (Fig. 3a) with Sub-Tenon’s local anesthesia with 1% lidocaine. Due to poor intraoperative visibility with the microscope alone, a 25-gauge light pipe was inserted into the vitreous cavity and held using OQrimo (Fig. 3b). The surgical field remained well-visualized by the light guide with OQrimo up to the completion of CCC and midterm of phacoemulsification (Fig. 3c, d). The weight of the OQrimo arm caused ocular deviation outside, making stable positioning difficult and necessitating discontinuation of its use. The surgery was completed with IOL insertion without any complications (Fig. 3e). BCVA (logMAR) was improved from 1.05 to 0.70. No significant postoperative complications were observed.

Fig. 3.

Cataract surgery in Case 2 with postoperative corneal opacity following pterygium excision. a Intraoperative view before insertion of the light guide. b Insertion of a light guide stabilized by OQrimo, enabling clear visualization. c Continuous curvilinear capsulorrhexis (CCC) performed in the area of corneal opacity with adequate visualization. d Intraoperative view during phacoemulsification. e IOL implantation. The surgery was completed without complications.

The characteristics of the 3 cases are summarized in Table 1. The OQrimo device was used in 2 patients (3 eyes), with a mean operative time of 36 min. A 25-gauge light pipe was used in all eyes. In 2 eyes, it was utilized throughout the entire procedure. In 1 eye, the device was used only until completion of the CCC, after which it was discontinued due to globe deviation caused by the weight of the arm, and phacoemulsification was performed without the device.

Table 1.

Summary of 3 cases

​	Age, years	Eye	Causes	Operation time (min)	OQrimo arm location(o’clock)	preVA (logMAR)	postVA (logMAR)
Case 1	48	Right	GVHD, Post PKP	42	8	HM	0.40
Case 1	48	Left	GVHD	27	4	1.0	0.70
Case 2	74	Left	Pterygium surgery	41	4	1.05	0.70

GVHD, graft-versus-host disease; PKP, penetrating keratoplasty; VA, visual acuity; HM, hand motion.

Discussion

Cataract surgery in patients with corneal opacity poses significant challenges both intraoperatively and postoperatively [2]. One of the most critical issues is reduced intraoperative visibility due to corneal clouding. This hampers the surgeon’s ability to clearly visualize anterior chamber structures, making key steps including capsulorhexis, nucleus disassembly, and cortical cleanup technically demanding. Consequently, the risk of intraoperative complications such as zonular dialysis, posterior capsule rupture, and incomplete lens removal increases.

Moreover, eyes with corneal opacity often have underlying systemic or ocular comorbidities, such as prior infections, trauma, or immune-mediated diseases (e.g., GVHD), which further complicate surgical planning and postoperative recovery. In some cases, simultaneous or staged corneal transplantation may be indicated; however, this approach carries additional risks, including graft rejection, delayed visual recovery, suture-induced astigmatism, and increased surgical complexity.

To address poor intraoperative visualization, various adjunctive technologies have been explored, including BBG staining, endoscope, endoillumination, iOCT, 3D monitor, combined keratoplasty, and other light-assisted devices [3–9]. Although BBG staining is highly effective and widely used for anterior capsule visualization, it does not facilitate 3D observation during phacoemulsification. Endoscopy provides only a narrow and localized field of view, making it difficult to maintain global spatial awareness and depth perception within the anterior chamber. iOCT offers high-resolution cross-sectional images; however, it is less suitable for capturing rapidly changing intraoperative events. In addition, metallic instruments, dense nuclei, and corneal opacities can cause shadowing artifacts, thereby reducing image interpretability. Performing corneal transplantation concurrently with cataract surgery introduces additional surgical steps, increases the risk of complications such as infection or astigmatism, and often prolongs operative time. In our cases, use of the OQrimo system in combination with a 25-gauge intraocular light pipe provided enhanced illumination, significantly improving visualization during key surgical steps. The greatest advantage of OQrimo is that the light pipe can be moved 360° in all directions using a foot switch, allowing fine adjustment of the illumination angle and position. In this study, the technique was applied to different types of corneal opacity, including GVHD-related, penetrating keratoplasty, and post-pterygium opacity. These results suggest that the approach may be applicable to a variety of corneal opacities. In our opinion, this technique can potentially be used for any condition in which the pupil can be visualized through the opacity using a slit-lamp microscope. This approach might enable safe completion of cataract extraction in eyes in which visualization with the operating microscope alone was insufficient. The cost of OQrimo is approximately 10 million Japanese yen, and the setup requires about 10 min. Regarding the learning curve, the foot switch used for horizontal and vertical movements is similar to that of a surgical microscope, allowing surgeons to become familiar with it quickly. Forward and backward movements are controlled by a separate switch; however, it is similar to adjusting the focus of a microscope, and we believe that users can adapt to it rapidly. OQrimo is placed according to the procedure described in the manual. The direction of trocar insertion is the same as that used in vitreoretinal surgery, and the light guide is similarly inserted before being controlled with the foot switch. Therefore, surgeons experienced in vitreoretinal surgery can use the system without significant difficulty, which secures repeatability and reproducibility.

However, as demonstrated in Case 2, the use of external robotic devices such as OQrimo introduces additional variables, including the need for stable eye positioning and adequate mechanical support. In this case, the weight of the device’s arm induced ocular deviation, necessitating discontinuation of its use. The difficulty was not caused by ocular movement under local anesthesia interfering with adjustment of the robotic arm. Rather, fixation became difficult because the direction of trocar insertion differed from the vector of tension applied by the robotic arm. This observation highlights the importance of carefully evaluating the mechanical setup and ergonomics considerations when implementing such systems. Moreover, preventing injury to the posterior capsule or retina is critically important. Because the 25-G vitreoretinal light pipe is relatively long, we are developing an attachment that enables the robotic arm to hold chandelier illumination in order to establish a safer surgical technique.

In the 3 eyes of the 2 cases reported in this study, posterior infusion was not used, and no significant issues were observed with anterior chamber stability or lens position. Therefore, posterior infusion may not be necessary. However, in elderly patients who are more prone to vitreous liquefaction and in whom anterior chamber stability is compromised, there may be cases in which the use of posterior infusion is beneficial. Further studies with a larger number of cases are needed to clarify this issue.

Overall, while cataract surgery in eyes with corneal opacity remains challenging, OQrimo as an intraoperative visualization technology may improve surgical safety and outcomes. Although further studies are warranted to optimize the use of such devices and to establish standardized protocols for complex anterior segment surgery, OQrimo shows the future possibility to be a useful adjunct in cases with compromised intraoperative visibility, including cataract surgery in eyes with corneal opacity. As robotic technologies continue to evolve, devices such as OQrimo may represent a step toward greater precision and consistency in ophthalmic surgery, especially in complex or high-risk cases.

The CARE Checklist has been completed by the authors for this case report and is attached as online supplementary material.

Conclusions

The use of OQrimo in cataract surgery for eyes with corneal opacity improved intraoperative visibility. However, further investigation is required to determine the optimal setup conditions and ensure device stability.

Acknowledgments

We would like to express our sincere gratitude to Mr. Hiroshi Watanabe of Riverfield Inc. and Mr. Kenichi Fujimoto of Nipro Corporation for their invaluable support in enabling the use of the OQrimo device.

Statement of Ethics

Human participants were included in this study. This study was approved by the Institutional Review Board of Juntendo University Hospital (Approval No. E24-0089-H01) and was conducted in accordance with the ethical standards of the Declaration of Helsinki. Written informed consent was obtained from all participants for participation in the study and for publication of the details of their medical cases and any accompanying images. This prospective interventional case series included 3 eyes of 2 patients who underwent cataract surgery at Juntendo University Hospital in October 2024 and January 2025.

Conflict of Interest Statement

Shintaro Nakao: consulting fee by Boehringer Ingelheim, Chugai Pharmaceutical, Kowa, Novartis, Riverfield; travel reimbursements and speaker fees from Alcon, Boehringer Ingelheim, Bayer Pharma, Canon, Chugai Pharmaceutical, JFC Sales Plan, Kowa, Mitsubishi-Tanabe pharma, Machida, MSD, Nipro, Novartis, Novo Nordisk Pharma, Otsuka, Santen Pharmaceutical, Senju Pharmaceutical, and Wakamoto Pharmaceutical. Kenta Ashikaga: travel reimbursements and speaker fees from Machida. All other authors have no conflicts of interest to declare.

Funding Sources

This work was supported by the Juntendo University Department of Ophthalmology Alumni Fund. This study was also supported by grants from Alcon Japan Ltd (S.N.), AMO Japan K.K. (S.N.), HOYA Corporation and Santen Pharmaceutical Co., Ltd. (S.N.).

Author Contributions

All authors attest that they meet the current ICMJE criteria for authorship. Masahiro Yamaguchi: writing – original draft, investigation, data curation, and conceptualization. Yuta Umemoto and Kenta Ashikaga: investigation and data curation. Shintaro Nakao: writing – original draft, writing – review and editing, supervision, and conceptualization.

Funding Statement

This work was supported by the Juntendo University Department of Ophthalmology Alumni Fund. This study was also supported by grants from Alcon Japan Ltd (S.N.), AMO Japan K.K. (S.N.), HOYA Corporation and Santen Pharmaceutical Co., Ltd. (S.N.).

Data Availability Statement

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.