Conventional Panretinal Photocoagulation Research Articles

Retinal Oxygenation With Conventional 100-ms Versus Short-Pulse Pan-Retinal Laser Photocoagulation.

Conventional (100 ms) pan-retinal photocoagulation (PRP) laser burns are larger than short-pulse (10 ms to 20 ms) PRP burns. This study investigates the effect of PRP burns of different sizes on retinal oxygenation. A mathematical model using COMSOL Multiphysics 6 was used to create a three-dimensional abstraction of the coupled biology of the choroid, photoreceptor, and retinal tissues. Laser burn sizes were varied in the model, specifically considering burn diameters of 500 μm, 250 μm, and 125 μm, while keeping the total burn area constant. Total increase in retinal oxygenation was the same for different burn sizes, but the oxygen distribution differed. Smaller burns resulted in a more even lateral oxygen distribution but with reduced penetration into the inner retina. Conventional and short-pulse PRP may affect retinal oxygenation differently, even when total burn area is the same. Further investigation into optimum burn size and pattern is required. [Ophthalmic Surg Lasers Imaging Retina 2024;55:40-45.].

Comparative Study between Targeted Retinal Photo coagulation With and Without Single Intravitreal Bevacizumab Injection Versus Conventional Panretinal Photocoagulation for Proliferative Diabetic Retinopathy Treatment

Comparative Study between Targeted Retinal Photo coagulation With and Without Single Intravitreal Bevacizumab Injection Versus Conventional Panretinal Photocoagulation for Proliferative Diabetic Retinopathy Treatment

Conventional and Pattern Scanning Pan-Retinal Photocoagulation Laser in Diabetic Patients' Visual Field.

Introduction: In this study, we aimed to compare visual field defects in two different laser methods, namely conventional pan-retinal photocoagulation (PRP) and pattern scanning PRP, in patients with either proliferative diabetic or very severe non-proliferative diabetic retinopathy. Methods: This study was a randomized, single-blind, prospective clinical trial. Twenty patients with either proliferative or very severe non-proliferative diabetic retinopathy were enrolled in this study. Notably, only those patients with the same severity scores in both eyes were included. One eye underwent the conventional PRP laser and another eye underwent the pattern scanning PRP laser simultaneously. Swedish interactive threshold algorithms (SITA) standard perimetry was performed at baseline and one month after the treatment, and visual field defects were evaluated. Results: The pattern standard deviation (PSD) significantly increased in both the pattern and conventional PRP laser groups after one month. The change of the PSD at baseline and after the treatment was not significant between the groups. The mean deviation (MD) level significantly decreased in the conventional group after one month. The change in the MD level at baseline and after the treatment was not significant between the pattern and conventional groups. The change in the mean best corrected visual acuity (BCVA) between the groups was not significant. Conclusion: Changes in visual acuity and visual fields of the patients between the pattern and conventional PRP laser methods showed no significant difference; however, the pattern PRP method caused a smaller reduction in overall sensitivity in the patient's visual field.

Macular pigment optical density after panretinal photocoagulation

ABSTRACT Clinical relevance Panretinal photocoagulation, an important treatment method in diabetic retinopathy, can affect macular pigment optical density, which has protective and antioxidant properties. As a result of this effect, the retina may become more sensitive to high‐energy visible light. Background The current study assesses the effect of panretinal photocoagulation treatment on macular pigment optical density, which has essential functions for the retina. Methods In this prospective clinical study, the colour perimetry method was used to measure macular pigment optical density. Thirty‐six eyes of 36 participants with severe non‐proliferative diabetic retinopathy without macular involvement were included in the study. Conventional panretinal photocoagulation treatments were applied at baseline, one month, two months, and at three months to the participants who clinically required this treatment. Macular pigment optical density and retinal thickness measurements were performed at baseline, months one, two, three and six. Results The mean macular pigment optical density reduction in the fovea over the six-months was 0.02 ± 0.02 logarithmic units (p < 0.001). Similarly, the pericentral areas declined by 0.04 ± 0.03 logarithmic units (p < 0.001). Mean central macular thickness and foveal thickness increased by 5.03 ± 5.02 μm and 2.78 (interquartile range 2–4) μm, respectively. In this study, correlation analysis shows that the laser energy applied was significantly and strongly correlated with reductions in macular pigment optical density (for the fovea and pericentral area respectively: r = −0.855, p < 0.001; r = −0.895, p < 0.001). Further, there were significant and strong correlations between the applied laser energy, and central macular thickness and fovea thickness (r = 0.751, p < 0.001; ρ = 0.718, p < 0.001, respectively). Conclusion Panretinal photocoagulation may potentially cause a decrease in macular pigment density in proportion to the laser energy applied.

Analysis of choroidal thickness in patients with proliferative diabetic retinopathy by optical coherence tomography angiography.

Objectives:This study aimed to evaluate the changes in choroidal thickness at different parts in patients with stage IV-V diabetic retinopathy (DR) treated by Panretinal Photocoagulation (PRP) or its combination with anti-vascular endothelial growth factor (VEGF) therapy using optical coherence tomography angiography (OCTA).Methods:Patients with proliferative DR (stage IV-V) diagnosed in Shijiazhuang People’s Hospital between January 2016 to January 2020 were selected and treated with conventional PRP or combined with anti-VEGF therapy. OCTA was performed before treatment and one three and six months after treatment to observe and compare subfoveal choroidal thickness (SFCT), perifoveal choroidal thickness at 500 um (M500) and 1500 um (M1500).Results:A total of 76 patients (133 eyes) were included. Six months later, re-examination showed effective treatment in 122 eyes (91.72%) and ineffective treatment in 11 eyes. Before treatment and one week, three months and six months after treatment, the choroidal thickness was observed and compared by OCTA. SFCT, M500 and M1500 increased one week after treatment, were significantly thinner 3 months after treatment than those before treatment, and further decreased six months after treatment.Conclusion:OCTA presents a good evaluation of perifoveal choroidal thickness in patients with proliferative DR. It provides a basis for treatment selection and efficacy determination of proliferative DR.

Changes of visual fields in treatment of proliferative diabetic retinopathy: a systematic review.

The aim of this systematic review was to compare certain side-effects [visual fields (VF), dark adaptation, colour vision (CV) and contrast sensitivity (CS)] of conventional panretinal photocoagulation (PRP) with those of other treatments in proliferative diabetic retinopathy (PDR). A systematic literature search was conducted on 30 November 2018 in PubMed and Embase. The search comprised the keywords 'proliferative diabetic retinopathy', 'laser', 'treatment' and 'anti-vegf'. We included prospective studies and randomized controlled trials that investigated certain side-effects (VF, dark adaptation, CV, CS) in treatment of PDR (primary outcome). In total, 1867 articles were screened, and 10 studies were included (2176 eyes of 2086 patients examined in the VF studies and 1360 eyes of 1360 patients examined in the CV and CS studies). Visual fields (VF) were investigated in 10 studies, CV in one study and CS in one study. Treatment modalities included conventional PRP, other modalities of laser treatment and vascular endothelial growth factor (VEGF) inhibitors. Four studies demonstrated a worse VF impact of PRP than VEGF inhibitors. Seven studies reported of an overall worsening in VF after laser with no differences between different laser approaches. No differences were found in CV or CS. Overall, we found a trend, confirmed in four large studies, towards VEGF inhibitors causing less harm to VF compared to conventional PRP. Whilst VF was generally depressed after laser, it did not differ between different treatment approaches. Furthermore, it was not possible to make certain conclusions of CV or CS, with only one study in each field.

COMPARATIVE EVALUATION OF ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY, ULTRASOUND BIOMICROSCOPY, AND INTRAOCULAR PRESSURE CHANGES AFTER PANRETINAL PHOTOCOAGULATION BY PASCAL AND CONVENTIONAL LASER.

To compare intraocular pressure, anterior segment optical coherence tomography, and ultrasound biomicroscopy parameters over 3 months after panretinal photocoagulation (PRP) for proliferative diabetic retinopathy after 1 of 2 sittings by conventional laser (half PRP) and a single sitting of Pattern Scan Laser (PASCAL) PRP. This was a prospective, randomized, interventional study. All tests were performed at baseline, and at 1, 6, and 24 hours, and 1, 4, 8, and 12 weeks after PRP. The intraocular pressure at 1 hour and 6 hours after PRP was significantly raised in both groups. Mean intraocular pressure was 21.17 ± 4.01 mmHg after PASCAL and 17.48 ± 3 mmHg after conventional laser at 1 hour, P < 0.001. On anterior segment optical coherence tomography, conventional laser PRP caused a more significant narrowing of angle-opening distance (AOD750) and trabecular-iris space area (TISA 500), P = 0.03 and 0.04, respectively, on Day 1. Ultrasound biomicroscopy showed a significantly narrow angle in both groups on Day 1. A significant increase in ciliary body thickness was observed in both groups, with 57.1% of PASCAL and 100% of conventionally treated eyes showing ciliary effusion on Day 1 that decreased but persisted for the next 3 months. Performing PRP in sittings, prescribing previous glaucoma medications in patients at risk, and recording intraocular pressure an hour after the PRP could decrease complications.

Long-term effects of pattern scan laser pan-retinal photocoagulation on diabetic retinopathy in Chinese patients: a retrospective study.

To evaluate the long-term effects of pattern scan laser (PASCAL) pan-retinal photocoagulation (PRP) on diabetic retinopathy (DR) in Chinese patients. In this retrospective study, we evaluated clinical data of 29 patients (53 eyes) with severe non-proliferative DR (SNPDR) or proliferative DR (PDR) who received PRP and follow-up at our hospital from 2008 to 2013. Sixteen patients (29 eyes) received PASCAL PRP and 13 patients (24 eyes) received 100-ms conventional laser PRP. After long-term follow-up (mean, min-max days: 719.8, 290-1666 for PASCAL PRP vs 743.5, 240-1348 for conventional PRP, P=0.569), patients receiving PASCAL PRP required fewer photocoagulation sessions than the conventional PRP group (2.6±1.0 vs 3.9±0.9, P<0.01). Best corrected visual acuity (BCVA) was reduced slightly in PASCAL PRP group while reduced significantly in conventional PRP group. At last visit, 24 eyes in the PASCAL group (88.9%) and 21 eyes in the conventional group (91.7%) were improved or stable. Two eyes in PASCAL PRP group (7.4%) and 3 eyes in the conventional PRP group (12.5%) developed vitreous hemorrhage or vitreous fibrovascular proliferation. PASCAL PRP is as effective and may be more conducive to maintaining visual acuity with less treatment sessions for DR treatment compared to conventional laser PRP.

PASCAL Laser Produces Less Pain Responses Compared to Conventional Laser System During the Panretinal Photocoagulation

Background: Majority of patients experience pain during complete the panretinal photocoagulation (PRP). Laser photocoagulation delivery progressed with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and choroidal penetration are believed to reduce pain during laser treatment. Objective: The purpose of this study was to assess pain response in patients with proliferative diabetic retinopathy (PDR) who underwent either PASCAL or conventional laser. Subjects and Methods: Eighty eyes with newly diagnosed proliferative diabetic retinopathy were randomly divided in to two groups each composed of 40 eyes: group (A) in which patients were received standard argon laser panretinal photocoagulation and group (B) in which patients were received pattern scan multispot panretinal photocoagulation. Results: Mean pain scores were 0.515 ±0. 834 in the PASCAL laser and 0.128 ±...1 in the conventional laser group. Numerical pain score was statistically significant higher in conventional group than in PASCAL group (p<0.001). Conclusion: It could be concluded that pattern scan multispot laser PRP was associated with more patient comfort compared to conventional PRP.

PASCAL Laser Produces Less Pain Responses Compared to Conventional Laser System During the Panretinal Photocoagulation

Background: Majority of patients experience pain during complete the panretinal photocoagulation (PRP). Laser photocoagulation delivery progressed with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and choroidal penetration are believed to reduce pain during laser treatment. Objective: The purpose of this study was to assess pain response in patients with proliferative diabetic retinopathy (PDR) who underwent either PASCAL or conventional laser. Subjects and Methods: Eighty eyes with newly diagnosed proliferative diabetic retinopathy were randomly divided in to two groups each composed of 40 eyes: group (A) in which patients were received standard argon laser panretinal photocoagulation and group (B) in which patients were received pattern scan multispot panretinal photocoagulation. Results: Mean pain scores were 0.515 ±0. 834 in the PASCAL laser and 0.128 ±...1 in the conventional laser group. Numerical pain score was statistically significant higher in conventional group than in PASCAL group (p<0.001). Conclusion: It could be concluded that pattern scan multispot laser PRP was associated with more patient comfort compared to conventional PRP.

Comparative study between single session pattern short pulse laser and conventional pan-retinal photocoagulation regarding efficacy and macular thickening in patients with diabetic retinopathy

Aim: The aim of this study is to compare the effect of pan-retinal photocoagulation (PRP) using short-pulse laser (SPL) performed in a single session and conventional laser, regardless of the number of spots, in terms of their effect on the progression of diabetic macular edema (DME) and efficacy of regression of signs in patients with proliferative and high-risk nonproliferative diabetic retinopathy (NPDR). Methods: A prospective comparative case series was carried out, in which eyes with a similar degree of severe nonPDR or high-risk PDR underwent four-session PRP using a conventional laser in one eye (Group a) and a single session SPL in the other eye (Group b). After the session, colored photographs were taken to show immediate laser reaction. A follow-up visit was scheduled at 6 weeks to detect any complication. Finally, fluorescein angiography and optical coherence tomography were repeated at 3 months to assess the efficacy of laser treatment and the remeasure the macular thickness. Best-corrected visual acuity (BCVA) was remeasured after 12 weeks and compared to the prelaser VA. Results: The 20 patients included had a mean age of 53.4 ± 6.4 years. All patients had hemoglobin A1c (HBA1c) ranging from 7.2 to 8.4 with a mean of 7.7 ± 0.5. Before PRP initiation, there was no statistically significant difference between the two groups as regards mean age, duration of DM, and mean HBA1c. The mean power of laser was 198.7 ± 13.26 mW and 393.2 ± 17.7 mW (P

Extended targeted retinal photocoagulation versus conventional pan-retinal photocoagulation for proliferative diabetic retinopathy in a randomized clinical trial.

To determine the clinical efficacy of extended targeted retinal photocoagulation (ETRP) compared to conventional panretinal photocoagulation (CPRP) in proliferative diabetic retinopathy (PDR). In a single-masked randomized clinical trial, 270 eyes of 234 patients with naïve early or high-risk PDR were randomly assigned to receive either CPRP or ETRP (135 eyes, each treatment arm). Best-corrected visual acuity (BCVA) measurement, fundus examination, wide-field fluorescein angiography (WFFA) and optical coherence tomography were carried out before and 3months after retinal photocoagulation. Primary outcome was early PDR regression, specified as reduction in retinal neovascularization based on WFFA at 3months. Secondary outcomes were BCVA and central macular thickness (CMT) changes. There were significantly more high-risk PDR eyes in ETRP group compared to CPRP (109 and 94 eyes, respectively, P=0.04). Early PDR regression occurred in 71.9 and 64.4% of eyes in the ETRP and CPRP groups, respectively (P=0.19). The mean number of applied laser spots in the ETRP was significantly fewer than CPRP (1202 vs. 1360, respectively, P<0.001). Mean BCVA at baseline and 3months post-laser were 0.37±0.26 and 0.47±0.19 logMAR in the ETRP arm, respectively. In the CPRP arm these values were 0.40±0.27 and 0.47±0.24 logMAR, respectively. Although mean BCVA decreased significantly in both treatment arms (ETRP P<0.001, CPRP P=0.009), the difference was not significant between arms (P=0.68). CMT increased significantly in both groups (ETRP 41.08μm, P<0.001, CPRP 33.31μm, P<0.001). Nevertheless, the difference between the groups was not significant (P=0.26). ETRP with fewer number of laser spots may be an appropriate alternative to CPRP in PDR regression at least through 3months. NCT01232179.

Factors Associated with Worsening Proliferative Diabetic Retinopathy in Eyes Treated with Panretinal Photocoagulation or Ranibizumab

To compare rates and identify predictive factors for events that represent worsening of proliferative diabetic retinopathy (PDR) in eyes treated with panretinal photocoagulation (PRP) or ranibizumab. Randomized clinical trial (55 United States sites). Three hundred ninety-four study eyes from 305 adults with PDR, visual acuity (VA) 20/320 or better, and no history of PRP. Panretinal photocoagulation or intravitreous ranibizumab injections (0.5 mg/0.05 ml). Time from randomization to a composite PDR-worsening outcome defined as the first occurrence of vitreous hemorrhage, retinal detachment, anterior segment neovascularization, or neovascular glaucoma. Through 2 years, the cumulative probability of worsening PDR was 42% (PRP) versus 34% (ranibizumab; hazard ratio [HR], 1.33; 99% confidence interval [CI], 0.90 to 1.98; P= 0.063). Worse baseline levels of diabetic retinopathy severity (Early Treatment Diabetic Retinopathy Study scale) were associated with increased risk of worsening PDR, regardless of treatment group (64% [high-risk PDR or worse] vs. 23% [moderate PDR or better]; HR, 3.97; 99% CI, 2.48 to 6.36; P < 0.001). In the PRP group, eyes receiving pattern scan versus conventional single-spot PRP also were at higher risk for worsening PDR (60% vs. 39%; HR, 2.04; 99% CI, 1.02to 4.08; P= 0.008), regardless of the number of spots placed or the number of sittings to complete the initial PRP. Eyes in both groups with vision-impairing (VA 20/32 or worse) center-involved diabetic macular edema (DME) at baseline were required to receive ranibizumab for center-involved DME. Therefore the composite outcome was compared by treatment in the subgroup of eyes that did not have vision-impairing center-involved DME at baseline. For these eyes, the rate of PDR-worsening was greater with PRP than ranibizumab (45% vs. 31%; HR, 1.62; 99% CI, 1.01 to 2.60; P= 0.008). In eyes with PDR, ranibizumab resulted in less PDR worsening compared with PRP, especially in eyes not required to receive ranibizumab for center-involved DME. Although anti-vascular endothelial growthfactor therapy requires a more frequent visit schedule than PRP, these findings provide additional evidence supporting the use of ranibizumab as an alternative therapy to PRP for PDR, at least through 2years.

Ranibizumab for High-Risk Proliferative Diabetic Retinopathy: An Exploratory Randomized Controlled Trial

Purpose: To compare the efficacy and safety of intravitreal ranibizumab (IVR) in monotherapy or associated with panretinal photocoagulation (PRP) versus conventional PRP, for high-risk proliferative diabetic retinopathy (PDR) without vitreoretinal traction. Procedures: Multicenter randomized trial, with 3 treatment arms: PRP versus IVR alone and PRP + IVR combined treatment. Follow-up was performed at months 3, 6 and 12. Results: Thirty-five subjects were randomized and 32 used for analysis. Complete regression of neovessels elsewhere occurred in 100% (PRP + IVR), 75% (IVR) and 69.2% (PRP) and for neovessels of the disk in 44.4% (PRP + IVR), 37.5% (IVR) and 30.8% (PRP). During the 1-year duration of treatment, there was no need for laser rescue treatment in IVR-treated eyes. Conclusions: This trial suggests that the use of IVR is safe and may have a beneficial effect in the treatment of eyes with high-risk PDR. Message: Ranibizumab appears to have a place in the treatment of PDR.

A Comparative Study of Retinal Function in Rabbits after Panretinal Selective Retina Therapy versus Conventional Panretinal Photocoagulation.

Purpose. This study evaluates functional changes in electroretinographic findings after selective retina therapy (SRT) compared to panretinal photocoagulation (PRP) in rabbits. Methods. The right eyes of 12 Chinchilla rabbits received 200 laser treatment spots. The right eyes of six rabbits received SRT (SRT group), whereas the other six animals were treated using PRP on the right eye (PRP group). The eyes were investigated using full-field ERG 1 hour and 3 weeks after treatment. Histologic exam to assess the tissue response of lasers was performed on 3 weeks. Results. No significant changes in the mean ROD or CR b-wave amplitudes of the SRT lesions were evident, compared to baseline, 1 h after laser treatment (p = 0.372 and 0.278, resp.). In addition, the OPs and 30 Hz flickers of the SRT lesions were not significantly altered (p = 0.17 and 0.243, resp.). At 3 weeks, similar results were found. Comparing the two groups, the ROD b-wave amplitude was reduced in the PRP and SRT groups to 60.04 ± 4.2% and 92.32 ± 6.43% of baseline (p < 0.001). Histologically, there was no visible photoreceptor alterations on week 3. Conclusions. SRT in rabbit eyes induced less functional loss than PRP in both rod-mediated retinal function and cone-mediated retinal function. In addition, SRT irradiated eyes had no functional loss compared to its control.

Pan retinal photocoagulation for proliferative diabetic retinopathy

Diabetic retinopathy is the leading cause of visual impairment in working-age adults worldwide. Pan retinal photocoagulation (PRP) has provided an effective treatment to decrease the risk of severe vision loss in patients with proliferative diabetic retinopathy for the past four decades. Pattern scan laser (PASCAL) was developed to minimize the side effects of PRP. The purpose of this review is to discuss the differences between the traditional argon laser and the PASCAL. PASCAL can achieve comparable results with the conventional argon PRP in the treatment of patients with diabetic retinopathy. The PASCAL delivery system creates well aligned arrays of retinal lesions in a shorter period. PASCAL provides amore comfortable profile when compared to the argon laser. The PASCAL is now being substituted for the conventional argon laser for PRP in many clinics. Ophthalmologists should keep in mind that adjusting the PASCAL settings (including the duration, number, and size of laser burns) might become necessary to maintain regression and eliminate recurrence of neovascularization in patients with proliferative diabetic retinopathy. Further studies are needed to determine the parameters for optimal safety and efficacy on the PASCAL.

Changes in peripapillary retinal nerve fiber layer thickness after pattern scanning laser photocoagulation in patients with diabetic retinopathy.

PurposeTo examine the effects of panretinal photocoagulation (PRP) using a pattern scanning laser (PASCAL) system on the retinal nerve fiber layer (RNFL) thickness in patients with diabetic retinopathy.MethodsThis retrospective study included 105 eyes with diabetic retinopathy, which consisted of three groups: the PASCAL group that underwent PRP with the PASCAL method (33 eyes), the conventional group that underwent conventional PRP treatment (34 eyes), and the control group that did not receive PRP (38 eyes). The peripapillary RNFL thickness was measured by optical coherence tomography before, six months, and one year after PRP to evaluate the changes in peripapillary RNFL.ResultsThe RNFL thickness in the PASCAL group did not show a significant difference after six months (average 3.7 times, p = 0.15) or one year after the PRP (average 3.7 times, p = 0.086), whereas that in the conventional group decreased significantly after six months (average 3.4 times, p < 0.001) and one year after PRP (average 3.4 times, p < 0.001).ConclusionsThe results of this study suggest that the PASCAL system may protect against RNFL loss by using less energy than conventional PRP.

Pain score of patients undergoing single spot, short pulse laser versus conventional laser for diabetic retinopathy

To compare pain score of single spot short duration time (20 milliseconds) panretinal photocoagulation (PRP) with conventional (100 milliseconds) PRP in diabetic retinopathy. Sixty-six eyes from 33 patients with symmetrical severe non-proliferative diabetic retinopathy (non-PDR) or proliferative diabetic retinopathy (PDR) were enrolled in this prospective randomized controlled trial. One eye of each patient was randomized to undergo conventional and the other eye to undergo short time PRP. Spot size of 200 μm was used in both laser types, and energy was adjusted to achieve moderate burn on the retina. Patients were asked to mark the level of pain felt during the PRP session for each eye on the visual analog scale (VAS) and were examined at 1 week, and at 1, 2, 4 and 6 months. Sixteen women and 17 men with mean age 58.9 ± 7.8 years were evaluated. The conventional method required a mean power of 273 ± 107 mW, whereas the short duration method needed 721 ± 406 mW (P = 0.001). An average of 1,218 ± 441 spots were delivered with the conventional method and an average of 2,125 ± 503 spots were required with the short duration method (P = 0.001). Average pain score was 7.5 ± 1.14 in conventional group and 1.75 ± 0.87 in the short duration group (P = 0.001). At 1 week, 1 month, and 4 months following PRP, the mean changes of central macular thickness (CMT) from baseline in the conventional group remained 29.2 μm (P = 0.008), 40.0 μm (P = 0.001), and 40.2 μm (P = 0.007) greater than the changes in CMT for short time group. Patient acceptance of short time single spot PRP was high, and well-tolerated in a single session by all patients. Moreover, this method is significantly less painful than but just as effective as conventional laser during 6 months of follow-up. The CMT change was more following conventional laser than short time laser.

Comparison of the Effects of Patterned and Conventional Panretinal Photocoagulation on Diabetic Retinopathy

Purpose: To compare the therapeutic effects and complications after panretinal photocoagulation (PRP) and discomforts of patients using patterned PRP versus conventional PRP for diabetic retinopathy. Methods: Eighty patients who required PRP due to diabetic retinopathy were enrolled in a prospective randomized controlled study. The patients were randomly divided into two groups: a patterned PRP group in which PRP was performed with a short laser exposure time (0.02 seconds) and a conventional PRP group with a long exposure time (0.2 seconds). At the 1-year follow-up visit, the progressions of diabetic retinopathy, best-corrected visual acuity, and central macular thickness were evaluated. All patients were questioned about the grade of pain during PRP. In addition, the complications after PRP were investigated. Results: There were no statistical differences in clinical characteristics between both groups. The progression of diabetic retinopathy was not different in both groups at the 1-year follow-up visit. The best-corrected visual acuities at 1, 2, 4, and 8 weeks after PRP were decreased in both groups and, in the conventional PRP group, the decrements of visual acuity were greater than in the patterned PRP group. The increments of central macular thickness were also greater in the conventional PRP group than the patterned PRP group. Conclusions: When patterned PRP is performed using a short laser exposure time, the efficacy in the treatment of diabetic retinopathy is similar to that of the conventional PRP using a longer laser exposure time. Moreover, patterned PRP is less painful, and fewer complications.

Ultra Wide Field Fluorescein Angiography Guided Targeted Retinal Photocoagulation (TRP)

We report two cases in which ultra wide field fluorescein angiography was used to direct targeted retinal photocoagulation (TRP) to areas of retinal capillary non-perfusion in an attempt to cause regression of diabetic neovascularization. By providing up to a 200 degree field of view, accurate delineation of retinal capillary non-perfusion and precise application of photocoagulation was possible. The application of TRP successfully led to the regression of the retinal neovascularization in our patients. Complications of conventional panretinal photocoagulation (PRP) such as visual field loss and macular edema may have been avoided. When TRP is used in conjunction with ultra wide field fluorescein angiography, preservation of functional retina may be possible while minimizing the amount of laser treatment that is applied to the retina.