Intraocular Illumination Research Articles

Randomized trial comparing the effects of a 3D head-up system and microscope eyepiece-assisted simulated vitrectomy with intraocular illumination on the ocular surface of an operator

BackgroundTo compare the effects of a 3D head-up system and microscope eyepiece-assisted simulated vitrectomy intraocular illumination on the ocular surface of an operator.MethodsThis was a prospective randomized controlled study. According to the application system, thirty ophthalmic operators (60 eyes) were randomly divided into 3D and eyepiece groups. Under different intensities of intraocular illumination, operators in both groups viewed the fundus model through a 3D display screen or microscopic eyepiece for 2 h. Objective examinations and a subjective symptom questionnaire were used immediately after the test to evaluate the ocular surface of the operators. Objective examinations included nonintrusion tear meniscus height (NIKTMH), nonintrusion break-up time (NIKBUT), and bulbar redness and strip meniscometry tube (SMTube) measurements. Statistical analyses were performed by using SPSS 26.0 software.ResultsAfter the test, the NIKTMH, NIKBUT and SMTube measurements decreased; however, the degree of change varied among the groups of different systems. The differences between the 3D group and the eyepiece group in NIKTMH measurements, SMTube measurements, subjective symptom scores (eye dryness, difficulty focusing, and cervical pain), and light intensity reaching the ocular surface of the operators were statistically significant (P < 0.05). All of the objective and subjective tests showed that the 3D group had fewer effects on the NIKTMH and SMTube measurements, and the subjective comfort of the 3D group was greater.ConclusionFor both 3D screens and eyepieces, simulated vitrectomy with intraocular illumination for two hours can lead to discomfort and abnormalities in the operator’s ocular surface; however, these abnormalities are less severe in the 3D group.Trial registrationThis trial was registered on December 22, 2022, at the Chinese Clinical Trials Registry with NO. ChiCTR2200066989.

Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oil-filled eyes.

To evaluate scleral buckling (SB) surgery using a non-contact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil (SO)-filled eyes. Totally 9 patients (9 eyes) with retinal detachment in SO-filled eyes were retrospectively analyzed. All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination. SO was removed at an appropriate time based on recovery. The patients were followed up for at least 3mo after SO removal. Retinal reattachment, complications, visual acuity and intraocular pressure (IOP) before and after surgery were observed. Patients were followed up for a mean of 8.22mo (3-22mo) after SO removal. All patients had retinal reattachment. At the final follow-up, visual acuity showed improvement for 8 patients, and no change for 1 patient. The IOP was high in 3 patients before surgery, but it stabilized after treatment; it was not affected in the other patients. None of the patients had infections, hemorrhage, anterior ischemia, or any other complication. This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes.

Cost-Effectiveness Analysis of Cataract Surgery for the Beginners Using Intraocular Illumination

Purpose: To evaluate the cost-effectiveness of cataract surgery for the beginners using intraocular illumination compared to the case of using microscope illumination.Methods: A Markov model was constructed for cost-effectiveness analysis. Hypothetical Korean men and women over 50 years of age were set as a cohort, and cataract surgeons were limited to beginners with less than 2 years of experience. Cataracts were classified as severe cataracts requiring surgery and mild cataracts that did not require surgery. Cataracts was assumed to progress to severe cataracts in 10% of each year. A cost-effectiveness analysis was performed based on the difference in the complications of surgery according to intraocular and microscope illumination. For the cost, data from the National Health Insurance Corporation were used, and a micro cost calculation method was used. In the utility analysis, data from previous studies were used for utility in each cataract and complication status. Sensitivity analysis was performed to evaluate the uncertainty of the results.Results: The surgery using microscope intraocular illumination showed the cost of 3,168,895 won, and the quality-adjusted life years of 16.4 years. The surgery of intraocular illumination showed the cost of 3,200,552 won and the quality-adjusted life years of 16.5 years. the incremental cost-effectiveness ratio of intraocular illumination was 1,675,630 won compared to microscope illumination. In the sensitivity analysis to, the utility of postoperative state without complication had the greatest influence on the results.Conclusions: For beginners with less than 2 years of surgical experience, the incremental cost-effectiveness ratio was 1,675,630 won, which is acceptable in Korea's health care system, when comparing the case of using intraocular illumination to the case of using conventional microscope illumination.

Fundus examination using a wide-angle viewing system and intraocular illumination through the corneal incision during cataract surgery: a case series.

To report a new technique for fundus examination using a wide-angle viewing system combined with intraocular illumination without accessing the vitreous cavity. Retrospective case series METHODS: Consecutive patients with atopic dermatitis-related cataracts who underwent standard cataract surgery and the novel fundus examination technique were included. After phacoemulsification, the anterior and posterior chambers were filled with ocular viscoelastic devices. A 27-gauge endo-illumination probe was inserted into the anterior chamber through a corneal incision made for cataract surgery. The fundus examination was performed with a wide-angle viewing system and scleral indentation. If any retinal breaks/detachments were detected, they were treated simultaneously. Finally, an intraocular lens was implanted. Ten patients (13 eyes) were included (mean age 26.8 years; 9 men). Retinal breaks were detected in 5 eyes (38%); 2 of the 5 had rhegmatogenous retinal detachment (RRD) (15%). Intraoperative cryopexy was performed for 3 eyes with retinal breaks, while 2 eyes with RRD underwent a scleral buckling procedure (SBP) during the same surgery. There were no intra- or postoperative complications, including posterior capsule damage. The average surgical time was 22minutes for cases requiring only fundus examination and about 28 and for eyes with cryopexy and 80minutes for SBP. The described technique may reduce the disadvantages of creating scleral incisions and provide comparable visibility to inserting the illuminator into the vitreous cavity.

Opticon Vitrectomy System

The Opticon vitrectomy system is a safe and efficient unit used for anterior and posterior segment surgical procedures. The device is designed to perform phacoemulsification, irrigation/aspiration, anterior and posterior vitrectomy, making air/silicone tamponade, intraocular illumination and bipolar diathermy coagulation procedures.

Determination of Correlated Color Temperature in Ex Vivo Porcine Eyes during Intraocular Illumination.

(1) Background: In ophthalmic surgery, white light is mostly applied to illuminate the intraocular space, and ophthalmologists are comfortable working with it. Diaphanoscopic illumination changes the spectral composition of light, resulting in a change in the correlated color temperature (CCT) of the intraocular illumination. This color change makes it difficult for surgeons to recognize the structures in the eye. CCT during intraocular illumination has not yet been measured before, and it is the aim of this study to perform such measurement. (2) Methods: CCT was measured inside ex vivo porcine eyes during diaphanoscopic illumination and endoillumination using a current ophthalmic illumination system with a detection fiber inside the eye. By applying pressure on the eye with a diaphanoscopic fiber, the dependency of CCT on pressure was examined. (3) Results: The intraocular CCT values during endoillumination were 3923 K and 5407 K for the halogen and xenon lamps, respectively. During diaphanoscopic illumination, a strong unwanted red shift was observed, resulting in 2199 K and 2675 K for the xenon and the halogen lamps, respectively. Regarding different applied pressures, the CCT did not differ considerably. (4) Conclusions: This red shift should be compensated for in the development of new illumination systems since surgeons are used to white light illumination, which also simplifies the identification of retinal structures.

Intraocular illumination assisted scleral buckling for the treatment of simple rhegmatogenous retinal detachment

Objective To evaluate the efficacy of 25 G intraocular illumination assisted scleral buckling in the treatment of simple rhegmatogenous retinal detachment. Methods Retrospective case analysis. Total of 37 eyes of 37 cases with simple rhegmatogenous retinal detachment from Feb. 2016 to Oct. 2018 in Zhengzhou Second People’s hospital were included in the study. All cases underwent 25 G intraocular illumination assisted scleral buckling. The follow-up period ranged from 6 to 12 months. Results Retinal reattachment occurred in 35 eyes (94.59%) after first operation. Preoperative visual acuity ≥0.4 in 2 eyes (5.41%) increased to 12 eyes (32.43%) postoperatively. The difference was statistically significant (χ2=8.810, P=0.003). Conclusion 25 G intraocular illumination assisted scleral buckling has unique advantages.Compared with traditional scleral buckling, the surgical operation is more intuitive and accurate for the treatment of simple rhegmatogenous retinal detachment. Key words: Detachment, retinal, rhegmatogenous, simple; Buckling, scleral; Illumination, intraocular

Higher Risk of Light-Induced Retinal Damage Due to Increase of Intraocular Irradiance by Endoillumination.

IntroductionAll applied illumination systems are validated according to a standard that measures in an experimental setup the direct radiation intensity on a surface in an aqueous solution, not involving an eyeball. Due to various factors, multiple intraocular light-tissue interactions could occur and lead to retinal irradiation intensities that are higher than the irradiation caused by direct illumination. The aim of this work is to investigate the hypothesis that intraocular and technical reference irradiance is different.MethodsUsing an illumination system and a calibrated optical fiber, the irradiance in porcine eyes was measured at the posterior pole (macula) and compared with reference measurements. We compared two endoilluminators (spotlight and wide-angle) at a total of nine porcine eyes with a brown iris and five porcine eyes with a blue iris.ResultsThe intraocular irradiance was always significantly higher compared to reference measurements (p < 0.001). Between eyes with a blue or brown iris, no significant difference was observed.ConclusionA significantly higher irradiance could be measured compared to a reference measurement with the same illumination setup. The intraocular illumination increased between 30 and 60%, dependent on the distance of the distal end of the light fiber (4–12-mm distance to the retina). This leads to the assumption that the so far allowed “safe” exposure times for illumination systems are overestimated and the potential hazard to the retina is higher.

An intraocular micro light-emitting diode device for endo-illumination during pars plana vitrectomy.

Development of a new, fiber-free, single-use endo-illuminator for pars plana vitrectomy as a replacement for fiber-based systems with external light sources. The hand-guided intraocularly placed white micro light-emitting diode is evaluated for its illumination properties and potential photochemical and thermal hazards. A micro light-emitting diode was used to develop a single-use intraocular illumination system. The light-source-on-tip device was implemented in a prototype with 23G trocar compatible outer diameter of 0.6 mm. The experimental testing was performed on porcine eyes. All calculations of possible photochemical and thermal hazards during the application of the intraocular micro light-emitting diode were calculated according to DIN EN ISO 15007-2: 2014. The endo-illuminator generated a homogeneous and bright illumination of the intraocular space. The color impression was physiologic and natural. Contrary to initial apprehension, the possible risk caused by inserting a light-emitting diode into the intraocular vitreous was much smaller when compared to conventional fiber-based illumination systems. The photochemical and thermal hazards allowed a continuous exposure time to the retina of at least 4.7 h. This first intraocular light source showed that a light-emitting diode can be introduced into the eye. The system can be built as single-use illumination system. This light-source-on-tip light-emitting diode-endo-illumination combines a chandelier wide-angle illumination with an adjustable endo-illuminator.

25G intraocular illumination aided scleral buckling for treatment of rhegmatogenous retinal detachment

Objective To evaluate the effectiveness and safety of 25G illumination aided scleral buckling surgery for treatment of rhegmatogenous retinal detachment (RRD). Methods This is a retrospective case control study. Fifty-seven RRD patients (57 eyes) were enrolled in this study. There were 35 males (35 eyes) and 22 females (22 eyes). The patients were randomly divided into ophthalmoscope group (29 patients, 29 eyes) and illumination group (28 patients, 28 eyes). There was no differences in the data of gender, age, onset time, logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity(BCVA) and information of retinal tears between the two groups (P>0.050). The patients in the ophthalmoscope group received operation of conventional scleral buckling with binocular indirect ophthalmoscope. The patients in the illumination group received scleral buckling surgery with the aid of intraocular illumination and noncontact wide-angle viewing system. The follow-up was ranged from 6 to 12 months. The BCVA, intraocular pressure, fundus examination and complications were observed and recorded. Results The difference of operation time between two groups was significant (t=2.124, P=0.031). In the ophthalmoscope group, 26 eyes (89.7%) achieved retinal reattachment, 3 eyes (10.3%) failed in retinal reattachment. In the illumination group, 26 eyes (92.8%) achieved retinal reattachment, 2 eyes (7.2%) failed in retinal reattachment. There was no difference of retinal reattachment rate (P=1.000). Five eyes failed in retinal reattachment, 3 eyes received sclera buckling surgery, 2 eyes received vitrectomy with silicone oil tamponade. The final reattachment ratios were both 100%. BCVA increased in both groups compared with pre-surgery BCVA (t=4.529, 5.108; P<0.001). The difference of BCVA between two groups was not significant (t=0.559, P=0.458). There was no significant difference of intraocular pressure and complications before and after surgery in both two groups (t=−1.386, −1.437; P=0.163, 0.149). The difference of intraocular pressure between two groups was not significant (t=0.277, P=0.730). Subretinal hemorrhage occurred in 1 eye in the ophthalmoscope group. There was no iatrogenic retinal break, choroidal hemorrhage and endophthalmitis in the two groups. Conclusion 25G intraocular illumination aided buckling surgery for treatment of RRD is fast, safe and effective. Key words: Retinal detachment/surgery; Scleral buckling

Transscleral LED illumination pen.

Existing light sources for intraocular illumination are often bulky and expensive and pose a risk for the patient, because light guides are inserted in the eye through incisions and if the tip of these light guides get too close to the retina, the retina can be damaged photochemically within minutes or even seconds. Therefore a new, safe and simple device for intraocular illumination is developed and evaluated for its thermal and photochemical risks to the patient. It consists of a white LED which is integrated into a pen like holder. This device is pressed against the sclera by the physician who seeks for illumination during surgery or for diagnostic purposes. The LED light is transmitted through the sclera without the need for an incision. Considering the relevant standards, the device poses no harm to the patient, and in tests with the authors' own eyes a sufficient intraocular illumination is reached. The proposed device is quite simple but easy to handle and very gentle for the patient.

Outcomes of scleral buckling using chandelier endoillumination.

To report the results and complications of scleral buckling for the treatment of rhegmatogenous retinal detachment (RRD) using 25-gauge chandelier endoillumination. A total of 61 patients (61 eyes) with RRD were treated with scleral buckling. For the sclera buckling procedure, a 25-gauge chandelier was inserted through the pars plana for intra-ocular illumination, and retinal tears were identified and treated with episcleral cryotherapy under surgical microscope. On postoperative days 1, 3 and 7, the intra-ocular pressure was measured by a non-contact tonometer. On postoperative months 1 and 3, ultrasound biomicroscopy was used to examine the pars plana incision. In the surgical procedure, there was no lenticular or retinal damage due to the chandelier insertion. There was no conjunctival bleb formation at pars plana incision and no incidence of endophthalmitis after surgery. The mean intra-ocular pressure was 15.74±2.98, 15.83±2.76 and 16.14±2.52mmHg on postoperative days 1, 3 and 7, respectively. The one-time retinal reattachment rate was 93.4%. No visible vitreous incarceration was found in the incision of the pars plana. There was no complication found due to the chandelier insertion in early postoperative period. Chandelier endoillumination is a feasible method for retinal visualization under surgical microscope during scleral buckling.

Scleral buckling with a noncontact wide-angle viewing system in the management of rhegmatogenous retinal detachment.

To introduce a modified scleral buckling surgery using noncontact wide-angle viewing system and intraocular illumination in the treatment of rhegmatogenous retinal detachment (RRD) without proliferative retinopathy. A modified scleral buckling surgery using noncontact wide-angle viewing system with a 25-G optic fiber through sclerotomy site was performed in 22 eyes of 22 patients with RRD. Twelve women and 10 men were included. The mean age was 49.23 ± 15.19 years. The mean refraction of myopia was -4 D (range -3 to -7 D). The mean duration of RRD was 6.64 ± 3.14 days. The preoperative best-corrected visual acuity (BCVA) ranged from 0.02 to 0.8. Mean follow-up was 9.59 ± 2.24 months. Proliferative retinopathy was grade A in 8 eyes and grade B in 14 eyes. This surgery was performed successfully and retinal attachment was achieved in all eyes at the final follow-up. The postoperative BCVA increased in all eyes. No complication was encountered related to this technique. This modified scleral buckling surgery brings a panoramic and upright view and easy surgical maneuvers. It may be an additional approach for the management of RRD.

FBG-based sensorized light pipe for robotic intraocular illumination facilitates bimanual retinal microsurgery.

In retinal surgery, microsurgical instruments such as micro forceps, scissors and picks are inserted through the eye wall via sclerotomies. A handheld intraocular light source is typically used to visualize the tools during the procedure. Retinal surgery requires precise and stable tool maneuvers as the surgical targets are micro scale, fragile and critical to function. Retinal surgeons typically control an active surgical tool with one hand and an illumination source with the other. In this paper, we present a "smart" light pipe that enables true bimanual surgery via utilization of an active, robot-assisted source of targeted illumination. The novel sensorized smart light pipe measures the contact force between the sclerotomy and its own shaft, thereby accommodating the motion of the patient's eye. Forces at the point of contact with the sclera are detected by fiber Bragg grating (FBG) sensors on the light pipe. Our calibration and validation results demonstrate reliable measurement of the contact force as well as location of the sclerotomy. Preliminary experiments have been conducted to functionally evaluate robotic intraocular illumination.

Endoscopic vitrectomy

To update on the recent developments and surgical applications of intraocular endoscopy, and highlight its role in the modern era of microincision vitreoretinal surgery. Recent progress in our understanding of the unique intraocular illumination properties of endoscopy, specifically the use of reflected (coaxial) versus conventional transmitted (dissociated) light, is redefining its role in vitreoretinal surgery. Indications for endoscope-enabled intraoperative viewing during pars plana vitrectomy include posterior segment disease with significant anterior segment opacity, difficult-to-access retroirideal diseases involving the sclerotomy, pars plana, pars plicata, ciliary sulcus, ciliary body, or peripheral lens, and complex anterior retinal detachments, particularly in diseases in children. The recent introduction of 23-gauge endoscope that works with standard microcannulas increases its utility. Endoscopic vitrectomy, particularly with the recent advent of 23-gauge technology, expands our surgical armamentarium, making it a useful complement to conventional viewing systems.

Endoscopy-guided vitreoretinal surgery

Vitreoretinal surgery has recently undergone remarkable developments. The introduction of micro-incision vitrectomy surgery using 25- and 23-gauge techniques has led to minimally invasive, faster, safer, and more accurate surgeries. Similarly, intraocular illumination and observation systems have advanced from light pipes to chandelier illumination, slit illumination, wide-angle viewing systems, and intraocular endoscopes. Compared to observation via the cornea and optic media, vitreous surgery using an endoscope is extremely useful, as the endoscope is inserted directly into the eye, circumventing the difficulties of corneal clouding and small pupil diameters. Furthermore, there are no blind spots after surgery. We here discuss the advantages of intraocular endoscope use, the current state of endoscopy-guided vitreoretinal surgery, and its future prospects.

A Newly Developed Video-Meibography System Featuring a Newly Designed Probe

To demonstrate the usefulness of a video-meibography system featuring our newly designed probe. This study utilized a newly designed probe featuring an obliquely inclined, T-shaped head containing 16 windows in the portion of the probe applied for emitting infrared light. The transilluminated structure of the meibomian gland is conducted to a highly sensitive, infrared charge-coupled device video camera and recorded digitally. The utility of the new probe was compared with the intraocular illumination probe traditionally used for meibography, both being applied to the eyelids of ten healthy volunteers and ten patients with meibomian gland dysfunction. The results were then analyzed. The newly designed probe facilitated eyelid eversion and transilluminated the meibomian gland structure effectively. Moreover, subjects experienced no irritation and only limited invasiveness when the new probe was applied. Our meibography system featuring the newly designed probe provided greater ease of use, an improved visualization of the meibomian gland structure, and increased comfort for patients during the examination.

Vitrectomy for severe proliferative diabetic retinopathy: a comparison of optical fiber free intravitreal surgery system with traditional vitrectomy

To compare the optical fiber free intravitreal surgery system with traditional vitrectomy in eyes with severe proliferative diabetic retinopathy (PDR). 22 eyes of 18 patients with extensive fibrovascular proliferation associated with PDR were undergone vitrectomy using optical fiber free intravitreal surgery system (OFFISS) with bimanual technique, peeling of epiretinal membrane and/or internal limiting membrane, intraocular laser coagulation, air-fluid exchange, tamponading of air and expansive gases or silicon oil were performed according to the condition of diseases. 22 eyes with similar severity of fibrovascular proliferation treated with traditional vitrectomy were served as control. The operations were finished successfully in both different vitrectomy systems, but fundus cannot be visualized during fluid-gas exchange in phakic eyes, and intraocular illumination had to been used again in OFFISS group. Postoperatively, retina was fully attached in all eyes, best-corrected visual acuity of 19 eyes had improved two lines and more in OFFISS group, and 17 eyes in control group. No significant difference in surgical complications was found between OFFISS and traditional vitrectomy group. Mean duration of peeling membrane was less in OFFISS group than control group. The efficacy of vitrectomy using different system for severe PDR both are satisfactory and comparable. We consider vitrectomy using OFFISS more safe and effective during complicated surgical manipulations than using traditional vitrectomy system.

New approach to managing vitreous loss and dislocated lens fragments during phacoemulsification

I performed a one-port pars plana vitrectomy during phacoemulsification to manage vitreous loss with and without posterior dislocation of lens fragments in nine consecutive cases. I used a 1 mm vitrectomy instrument with an infusion sleeve for the vitrectomy; the coaxial light of the microscope and an infusion contact lens held on the cornea provided intraocular illumination. Eight of the nine cases achieved a visual acuity equal to or better than 20/25 after a mean follow-up of 5.7 months. One patient's visual acuity was 20/70 because of severe background diabetic retinopathy.

In vivo cannulation of retinal vessels.

In vivo cannulation of retinal blood vessels has not been reported but would be useful in exploring local vascular parameters and new treatment modalities. We developed a microsurgical technique for cannulating rabbit and cat retinal vessels, using glass micropipettes with curved shanks made from standard capillary tubing. The micropipette was held by a micromanipulator, which was fitted with a fiberoptic sleeve for intraocular illumination and for micropipette tip protection during insertion through the sclera. Direct aspiration from and injection into retinal blood vessels were possible.