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At least 19 recordsLinked to original sources
PubMed2003

Vertical cup-to-disc ratio: agreement between direct ophthalmoscopic estimation, fundus biomicroscopic estimation, and scanning laser ophthalmoscopic measurement.

PURPOSE: Ophthalmoscopic estimation of the vertical cup-to-disc ratio (VCDR) of the optic nerve head is important in the management of patients with glaucoma or who are glaucoma suspects. The purpose of this study was to compare the accuracy of estimation of VCDR obtained with direct ophthalmoscopy with that obtained with fundus biomicroscopy through undilated pupils. Measurements of VCDR obtained with the Heidelberg Retina Tomograph (HRT), a confocal scanning laser ophthalmoscope, were used as a standard. METHODS: Thirty young, healthy adults had their optic discs photographed and then imaged and analyzed with the HRT. Due to HRT software limitations, the VCDR could not be calculated automatically, and so a validated VCDR measurement was derived. This was used as the standard against which ophthalmoscopic estimations were compared. Two months later, the subjects had their VCDRs estimated using direct ophthalmoscopy and fundus biomicroscopy performed in random order after varying time intervals. Agreement between ophthalmoscopic VCDR estimation and HRT-derived VCDR measurement was assessed by means of bias plots and the weighted kappa statistic. RESULTS: Compared with the HRT-derived VCDR measurement, both ophthalmoscopic techniques tended to underestimate VCDR. The bias with direct ophthalmoscopy was statistically significant. There were also wide variations in VCDR estimation with direct ophthalmoscopy and fundus biomicroscopy, which were more pronounced with direct ophthalmoscopy. The weighted kappa statistic indicated moderate agreement between fundus biomicroscopy and HRT-derived VCDR measurement. There was poor to fair agreement between direct ophthalmoscopy and HRT-derived VCDR measurement. The level of disagreement was independent of HRT-derived VCDR, optic nerve head size and pupil size for both direct ophthalmoscopy and fundus biomicroscopy. CONCLUSIONS: Fundus biomicroscopy enables more accurate, less variable VCDR estimation than direct ophthalmoscopy. The clinician should record which method they used to examine the optic nerve head so that subsequent clinical decisions are not influenced by apparent VCDR changes.

Adult↗
PubMed1993

Confocal laser scanning ophthalmoscope. Reproducibility of optic nerve head topographic measurements with the confocal laser scanning ophthalmoscope.

BACKGROUND: Glaucoma is an optic neuropathy in which changes in the appearance of both the optic nerve head and the surrounding tissues are important in both diagnosing its presence and progression. Accurate methods to objectively document the appearance of the optic nerve are necessary. The confocal laser scanning ophthalmoscope (Zeiss) is a new prototype instrument that may have the capability to accurately perform this function. METHODS: The authors performed a prospective pilot study evaluating the ability of the confocal laser scanning ophthalmoscope to reproduce three-dimensional optic nerve images. Each retinal image contained 600,000 bytes of information. Thirty discrete images of the right optic nerves of 19 visually normal volunteers were obtained. Depth measurements were compared from the same 100 x 100 micron areas (neighborhoods). RESULTS: Image comparisons found the variability of depth measurements for the entire image were within 102 microns (95% confidence interval). Sixty percent of the depth measurements were reproducible within 100 microns. Variability of the depth measurements was greatest where the neuroretinal rim sloped at the edge of the optic cup and lowest in the peripapillary area. CONCLUSION: The confocal laser scanning ophthalmoscope has the potential to be a safe, rapid, and reproducible method of imaging ocular structures.

Adult↗
PubMed1992

Comparison of photocoagulation with the argon, krypton, and diode laser indirect ophthalmoscopes in rabbit eyes.

PURPOSE: The purpose of this study is to compare photocoagulation with the argon green, krypton red, and diode infrared laser indirect ophthalmoscopes in an experimental setting. METHODS: Photocoagulation was performed with each of the laser indirect ophthalmoscopes in a grid pattern within one sector of the same eye of 14 Dutch-belted rabbits. Treatment was performed either with or without scleral depression. Measurements of the retinal burn diameters were performed after hemisecting the globes, and the burns were examined with light microscopy. RESULTS: Variation in burn intensity and diameter (10% to 28%) was common with all 3 laser indirect ophthalmoscopes. Five times more output energy was required to make equivalent burns with the diode laser indirect ophthalmoscope than with the argon or krypton laser indirect ophthalmoscopes. Choriovitreal hemorrhages only occurred during scleral depression. Histopathologically, the argon green laser indirect ophthalmoscope burns spared the choroid and inner sclera, while the intense krypton and diode burns had full-thickness choroidal involvement and even thermal injury to the inner sclera. Scleral depression reduced the mean energy required to create equivalent burns with all three laser indirect ophthalmoscopes. There was a 10% to 40% reduction in the mean retinal burn diameter with scleral depression (argon green, P < 0.0005; krypton red, P < 0.0005; and diode, P < 0.025). CONCLUSION: Photocoagulation with the argon green, krypton red, or diode infrared laser indirect ophthalmoscopes is a safe and effective method of retinal ablation. Decreasing the posterior nodal distance of the eye with scleral depression will produce a smaller spot on the retina with the laser indirect ophthalmoscope.

Animals↗
PubMed1994

Differences between pattern-evoked electroretinograms obtained by a scanning laser ophthalmoscope and by a mechanical mirror system.

Pattern electroretinograms were studied in response to stripe patterns of different spatial frequencies and intensities in the pattern-onset and reversal mode by means of a scanning laser ophthalmoscope and a mechanical mirror system (maxwellian view). The stimulus conditions in both procedures were as close as possible: 31 degrees square field, 633-nm wavelength and the same equipment for recording. The remaining differences between the two methods were the line and pixel structure in the scanning laser ophthalmoscope and the buildup speed (40 ms in the scanning laser ophthalmoscope and less than 1 ms in the mirror system). This difference was reflected in the response peak times of the pattern electroretinogram, which were up to 10 ms in the scanning laser ophthalmoscope measurement. The pattern-related onset response was smaller with the scanning laser ophthalmoscope, indicating a strong sensitivity to the slow build-up speed, while the offset and reversal responses showed no differences in amplitudes. All differences were found only with the use of high luminances. The results suggest that responses evoked with patterns displayed on a television screen could be faster and larger if stimulators faster than the conventional television standard were used. Because of the smallness of onset amplitudes, the pattern-reversal mode might be better for stimulation in a clinical study when the scanning laser ophthalmoscope is used.

Adult↗
PubMed1984

An optimized zoom ophthalmoscope.

An indirect ophthalmoscope that could provide higher magnification (up to 15X) would offer definite advantages in fundus diagnosis. If it could also supply an erect fundus image, it could advantageously replace the surgical microscope in vitrectomy operations. The surgical microscope requires the use of a contact lens, which restricts the surgical techniques and may damage the corneal epithelium, and it reduces image brightness when the magnification is increased. In contrast, an indirect ophthalmoscope does not require a contact lens and keeps the image brightness constant regardless of magnification. Increased magnification can be obtained in an indirect ophthalmoscope by incorporating telescopes in the ophthalmoscope oculars. The possible use of two telescopic systems, Keplerian and Galilean, and the problems of stereopsis and image inversion are discussed. A new, optimized ophthalmoscope is described, with Keplerian telescopes, that provides a range of magnifications from 2X to 15X as well as options for an erect or inverted fundus image.

Humans↗
PubMed1998

Indocyanine green videoangiography of occult choroidal neovascularization: a comparison of scanning laser ophthalmoscope with high-resolution digital fundus camera.

PURPOSE: To compare the indocyanine green (ICG) angiographic findings of occult choroidal neovascularization (O-CNV) taken by scanning laser ophthalmoscope and high-resolution digital fundus camera. METHODS: We examined 100 eyes of 100 consecutive patients with ICG angiographic evidence of CNV secondary to age-related macular degeneration. All patients were diagnosed with O-CNV based on fluorescein angiography. Indocyanine green videoangiography was carried out using the scanning laser ophthalmoscope and high-resolution digital fundus camera at the same session. RESULTS: Indocyanine green videoangiography revealed well-defined vessel structure of the O-CNV in 28% of eyes examined by scanning laser ophthalmoscope and in 8% of eyes examined by digital fundus camera. Well-defined focal spots were demonstrated in 37% of eyes examined by scanning laser ophthalmoscope and in 52% of eyes examined by digital fundus camera. Plaques (well-defined) were found in 13% and 35% of eyes examined by scanning laser ophthalmoscope and digital fundus camera, respectively. CONCLUSION: Indocyanine green videoangiography with scanning laser ophthalmoscopy seems to be superior to the digital fundus camera in delineation of the vessel architecture of O-CNV. Focal spots and plaques are best detected by digital fundus camera.

Aged↗
PubMed1995

Agreement between clinicians and a confocal scanning laser ophthalmoscope in estimating cup/disk ratios.

PURPOSE: We assessed agreement between cup/disk ratio measurements obtained by glaucoma expert evaluation of stereoscopic photographs of the optic disk and those obtained with a confocal scanning laser ophthalmoscope. METHODS: Three glaucoma experts estimated vertical and horizontal cup/disk ratios from stereoscopic photographs of 15 normal subjects and 15 patients with glaucoma. These estimates were compared to vertical, horizontal, and area cup/disk ratios measured with a confocal scanning laser ophthalmoscope. Intraobserver and interobserver agreements were also estimated. RESULTS: Agreement between clinicians and the confocal scanning laser ophthalmoscope varied by clinician. Agreement was moderate to substantial for vertical cup/disk ratio and fair to moderate for horizontal cup/disk ratio; kappas ranged from 0.57 to 0.72 and from 0.21 to 0.55, respectively. The mean confocal scanning laser ophthalmoscope area cup/disk ratio measurements were smaller than each clinician's mean vertical and horizontal cup/disk ratio estimates; differences ranged from 0.10 to 0.24 and from 0.06 to 0.16, respectively. Differences were smaller between clinician estimates and instrument measurements of horizontal and vertical cup/disk ratios of patients with glaucoma than normal subjects. CONCLUSIONS: These results demonstrate good agreement between confocal scanning laser ophthalmoscope measurements and clinician estimates of the vertical cup/disk ratios from stereoscopic photographs, particularly of patients with glaucoma. However, as differences between clinician and instrument estimates of cup/disk ratios were found, new quantitative criteria must be established for characterizing a disk as glaucomatous using confocal scanning laser ophthalmoscopy.

Adult↗
PubMed2003

Characteristics of visual loss by scanning laser ophthalmoscope microperimetry in eyes with subfoveal choroidal neovascularization secondary to age-related macular degeneration.

PURPOSE: To evaluate the effects of subfoveal choroidal neovascularization secondary to age-related macular degeneration on functional parameters obtained by scanning laser ophthalmoscope microperimetry. DESIGN: Retrospective observational case series and cross-sectional study. METHODS: At the Doheny Retina Institute and Wilmer Eye Institute a consecutive series of 179 eyes of 175 patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration was studied. The onset of visual symptoms, best-corrected visual acuity, fluorescein angiography, evaluation of fundus microperimetry and fixation pattern using the Rodenstock scanning laser ophthalmoscope were obtained for each patient. The main outcome measures were central retinal sensitivity and fixation pattern (fixation location and fixation stability) in eyes with subfoveal choroidal neovascularization and their relationship to the length of disease, type and characteristics of choroidal neovascularization, and visual acuity. RESULTS: Of 179 eyes, 135 (75%) had central fixation, 27 (15%) had poor central fixation, and 17 (9%) had predominantly eccentric fixation. Seventy-six eyes (42%) had stable fixation, 70 eyes (39%) had relatively unstable fixation, and 33 eyes (18%) had unstable fixation. In 50 eyes (28%) a dense central scotoma was noted. Eighty-nine of 100 eyes (89%) with length of symptoms of less than 3 months had predominantly central fixation and 58 (58%) had stable fixation; 14 of 34 eyes (41%) with length of symptoms of more than 6 months had predominantly central fixation, and 5 eyes (15%) had stable fixation. In 15 eyes of patients who elected not to receive treatment, successive scanning laser ophthalmoscope microperimetry were obtained over time (follow-up of 18 months after onset of symptoms). Three months or less after the onset of symptoms, 13 eyes (87.7%) had predominantly central fixation and 9 eyes (60%) had stable fixation. More than 3 months and 6 months or less after the onset of symptoms, 10 eyes (66.7%) had predominantly central fixation and 7 eyes (46.7%) had stable fixation. This trend was further demonstrated in eyes more than 6 months after the onset of symptoms. CONCLUSIONS: We conclude that the sequence of events leading to visual function deterioration appears to involve an initial mild decrease in central retinal sensitivity and visual acuity followed by progressive fixation instability and, ultimately, development of an absolute central scotoma with totally eccentric fixation. Increased length of disease is associated with worse fixation pattern and retinal sensitivity deterioration as assessed by scanning laser ophthalmoscope microperimetry. A better understanding of the characteristics of visual loss assessed by fixation pattern evaluation and microperimetry in age-related macular degeneration may help optimize timing, patient selection, and treatment options in eyes with this condition.

Aged↗
PubMed1995

[From otoscope to ophthalmoscope and back. The interwoven history of their invention and introduction into medical practice. Pictures from the history of otorhinolaryngology, illustrated by instruments from the collection of the Ingolstadt German Medical History Museum].

Friedrich Hofmann, medical officer in Burgsteinfurt, Westphalia, Germany, in 1841 described a concave mirror with a central aperture in it as the ideal instrument that allowed reflecting and focussing light into the external auditory canal and simultaneously inspecting the tympanic membrane without obstructing either the light or the view. He recommended his device also for the inspection of other concealed regions of the body. His invention was referred to by Martell Frank in his textbook of otology in 1845, but otherwise attracted no attention. Hermann Helmholtz, physiologist in Königsberg, East Prussia, devised his ophthalmoscope in 1850-51 in order to study the phenomenon of glowing eyes. With this instrument he was the first to see the retina of a living human. As means of illumination he used small panes of glass similar to cover-glasses which were introduced into the common visual axis of the observer and the subject at such an angle that light from a lamp was reflected into the subject's eye while the observer inspected the subject's retina through the glass and an appropriate lens. He recommended this type of illumination also for otoscopy. His invention was at once acclaimed throughout the world and opened completely new opportunities in ophthalmology. The slanting panes of glass, however, were not the ideal solution for illumination. It was only one year later that Ruete in Göttingen replaced them with a concave mirror with a central aperture, and there is every indication that Frank's report on Hofmann's mirror had suggested this technique to him. During the following two years quite a number of other modifications of the ophthalmoscope were constructed, all of them using the concave mirror with a central aperture, which soon became synonymous with the ophthalmoscope as such. Von Tröltsch, otologist and ophthalmologist in Würzburg, presented a concave mirror with a central aperture for otoscopy in Paris in 1855-56. His instrument was obviously derived from the already well known ophthalmoscope by adapting the diameter and focal distance to this special application. His primary concern was to use daylight instead of artificial light for otoscopy. Von Tröltsch did not know Hofmann's publication, but later did not hesitate to acknowledge Hofmann's priority. It was von Tröltsch who popularized the concave reflector with a central aperture as the instrument of choice in otoscopy, and subsequently also for rhinoscopy and laryngoscopy. Further modifications were devised to have the hands free for operations. Thus the reflector was fixed to the forehead by strap and buckle or a vulcanite band, or it was provided with a handle that was to be held between the teeth, or it was attached to a spectacle frame. The details of this interwoven history are related and highlighted by numerous quotations and historical illustrations.

Ear↗
PubMed1997

[Ophthalmoscopic assessment of the size of the optic nerve papilla].

PURPOSE: To examine whether the optic disc size can be measured with common ophthalmoscopic lenses. PATIENTS AND METHODS: The horizontal and vertical disc diameters in 125 eyes of 65 patients were measured ophthalmoscopically using a commercial slit lamp with adjustable length of the beam and a Volk 60 diopters lens or a Volk Superfield lens. The refractive error of the subjects ranged between -7.25 D and +3.25 D (mean +/- S.D.: -0.34 +/- 1.77). Based on these measurements we calculated the optic disc area by applying a modified formula for an ellipse, where area = horizontal diameter x vertical diameter x pi/4. Additionally, we measured planimetrically the horizontal and vertical diameters of the optic disc on color stereo disc photographs after correcting the ocular and camera magnification according to Littmann's method. RESULTS: The values of the horizontal and vertical disc diameters evaluated on the photographs were by factors of 1.0 and 1.5 larger than those values measured with the Volk 60 D lens, and the Volk Superfield lens, respectively. Taking into account these constant linear correction factors, the optic disc diameters as measured by the Volk 60 D lens and the Volk Superfield lens varied by 0.11 +/- 0.09 mm (5.9 +/- 5.1%), and 0.11 +/- 0.09 mm (5.9 +/- 4.9%), respectively, from the values measured on the photographs. The error for the ophthalmoscopic measurement of the disc diameters decreased slightly with increasing disc size. With highly myopic eyes excluded, it was independent of the refractive error. CONCLUSION: For clinical purposes, the optic disc and other structures of the posterior fundus can be determined by ophthalmoscopy using a slit lamp and commonly used ophthalmoscopical lenses.

Adult↗
PubMed1995

Laser indirect ophthalmoscope photocoagulation and scleral depression for rhegmatogenous retinal detachment.

BACKGROUND: Transconjunctival cryotherapy or laser photocoagulation with simultaneous Eisner funnel scleral depression has been used to treat selected cases of rhegmatogenous retinal detachment. There are no studies to date reporting the use of the laser indirect ophthalmoscope coupled with scleral depression for treating retinal detachment. METHODS: 16 consecutive patients (18 retinal detachments in 17 eyes) were enrolled in a prospective, uncontrolled clinical trial using the laser indirect ophthalmoscope with scleral depression as the sole treatment for retinal detachment. The region immediately surrounding the break where subretinal fluid was present was directly treated rather than demarcated. All patients were treated with local anesthesia in an outpatient setting. RESULTS: Complete retinal reattachment was initially achieved in 14 (78%) of 18 eyes after scleral depression and laser alone. Significant postoperative complications of scleral depression with laser indirect ophthalmoscope photocoagulation included macular pucker (2 eyes), late recurrent rhegmatogenous retinal detachment without proliferative vitreoretinopathy (1 eye), and late recurrent rhegmatogenous retinal detachment with proliferative vitreoretinopathy (2 eyes). Failure of initial treatment to flatten the retina, late recurrent retinal detachment, macular pucker, or proliferative vitreoretinopathy led to scleral buckling and/or vitrectomy in 6 (86%) of the 7 eyes with clinical detachment and 3 (30%) of the 10 eyes with localized detachment. Final retinal reattachment at the last follow-up examination was achieved in all 17 eyes with subsequent surgical procedures. CONCLUSION: Although scleral depression with laser indirect ophthalmoscope photocoagulation is a noninvasive outpatient surgical procedure that is capable of flattening selected retinal detachments, its use cannot be recommended because of the relatively high rate of postoperative complications requiring further surgical procedures.

Adult↗
PubMed2004

Panoptic versus conventional ophthalmoscope.

BACKGROUND: The 'ease of use' and accuracy in measurement of the vertical optic cup/disc ratio (VCDR) was compared between the conventional direct ophthalmoscope (CO) and Panoptic direct ophthalmoscope (PO) in a group of 'naïve' first year medical students to determine which would be more suitable for non-ophthalmologists. METHODS: In this quasi-randomized method comparison study, eight students received an introductory session on ophthalmoscopy then examined 18 eyes (9 left, 9 right) with each ophthalmoscope in a private practice. The subjects were the eight students themselves plus two other subjects. Each subject (n = 10) had one eye dilated. Students determined a VCDR and a subjective score of 'ease of use' on a scale of 1 (difficult) to 10 (easy). A consultant ophthalmologist (GAG) determined the benchmark VCDR for each eye with each ophthalmoscope. RESULTS: Of 288 eye examinations, there were 111 measurements of VCDR using the CO (47 undilated, 64 dilated), and 140 measurements using the PO (75 undilated, 65 dilated). Differences in the students' estimated VCDR and the benchmark were similar for the CO and PO (P = 0.67). 'Ease of use' was scored in 288 eyes and the median score was higher in the PO overall (CO: median 8, IQR 6-9; PO median 9, IQR 8-10; P < 0.0001), and within each session (P < 0.0001 for each session). CONCLUSIONS: Medical students found the PO much easier to use, with accuracy of rating the VCDR similar to the CO. This comparison would support the wider use of the PO amongst medical students, general practitioners and other primary care providers.

Adolescent↗
PubMed2003

Transpupillary diode laser retinopexy in dogs: ophthalmoscopic, fluorescein angiographic and histopathologic study.

OBJECTIVE: To evaluate the ophthalmoscopic, fluorescein angiographic and light microscopic effects of diode laser retinopexy application in the tapetal and nontapetal fundus in the dog, and to ascertain appropriate laser power settings for production of photocoagulative lesions in these two regions. ANIMALS STUDIED: Three adult female Beagle dogs. PROCEDURES: Laser burns were applied to selected areas in the fundus with an indirect headset delivery system using settings varying from 100 to 200 milliWatts (mW) and from 100 to 600 milliSeconds (mS) with total delivered energy ranging between 15 and 100 milliJoules (mJ). The dogs were then monitored by ophthalmoscopic examination and fluorescein angiography at regular intervals for 7-28 days. Histopathologic studies were performed at 7, 14 and 28 days after laser application. RESULTS: The diode laser produced ophthalmoscopically visible lesions in the nontapetal fundus with all laser settings used, and the appearance of these lesions corresponded to the energy levels used, and degree of pigment in the lased region. Gray-white colored lesions with minimal subsensory retinal edema were seen with settings as low as 100 mWatts/150 mSeconds. In the tapetal fundus, laser burns were more difficult to produce, less repeatable, and required higher energy levels. Laser burns appeared as bronze, dark green or black discolorations of the tapetum with varying degrees of subsensory retinal edema. Lesions were more reproducible and were achieved with lower settings in the tapetal area of the tapetal/nontapetal junction. Ophthalmoscopically, depigmentation and repigmentation of the RPE (nontapetal fundus) and degenerative changes in the overlying retina (tapetal fundus) developed in the laser burns over the 28-day study period. Fluorescein angiographic studies showed disruption of the blood-retinal barrier at the level of the RPE and fluorescein leakage into the subsensory retinal space was seen in most lesions at 24 h, was minimal at 3 days, and had resolved by 7 days. Histologically, grayish-white lesions in the nontapetal fundus, and bronze to small black lesions in the tapetal fundus were typically characterized by outer retinal necrosis and RPE migration. Gliosis was considered minimal, was confined to the retina, and no inflammatory cells were seen. Peripheral intense white lesions (nontapetum) and lesions with a black center (tapetal fundus) were characterized by more extensive panretinal and choroidal necrosis. Most of the nontapetal lesions and a few in the tapetal fundus showed the formation of a central retinal detachment. CONCLUSIONS: The diode laser effectively produces lesions suitable for retinopexy in both the nontapetal, pigmented fundus and the tapetal fundus, although variably so in the latter region. Initial laser settings of 100-150 mW/200 mS for the pigmented fundus, and 150 mW/200-300 mS for the peripheral tapetal fundus are recommended, and the clinician should gradually increase time interval settings to achieve a grayish-white lesion in the nontapetum, and a bronze to slightly black lesion in the tapetal fundus. If possible, retinopexy should be applied to the peripheral tapetal area or tapetal/nontapetal junction.

Angiography↗
PubMed1993

The scanning laser ophthalmoscope and retinal assessment in diabetes.

In order to evaluate the Scanning Laser Ophthalmoscope as a method of assessing diabetic retinopathy, 57 consecutive patients with diabetes were examined through undilated pupils using laser ophthalmoscopy followed by pupillary dilatation and direct ophthalmoscopy. Results of laser scanning were recorded on videotape and analysed independently. Scanning (both eyes) took under 5 minutes per patient. For the 113 eyes studied, the two techniques gave concordant results in 73/113 (65%). Where there was discordance, laser ophthalmoscopic severity was greater than direct ophthalmoscopy in 36/40 (90% of discordant results). In 4/40 eyes conventional ophthalmoscopic appearances were judged more severe than those seen with the laser. The laser ophthalmoscope may have value as a method of assessing diabetic retinopathy, but further work is required to evaluate its efficacy as a screening tool in patients with moderate to severe retinopathy.

Diabetic Retinopathy↗
PubMedDate not supplied

Treatment of retinoblastoma with indirect ophthalmoscope laser photocoagulation.

INTRODUCTION: The indirect ophthalmoscope laser photocoagulation delivery system is relatively new and is potentially applicable for treating selected small retinoblastomas. There has been very little reported on the results achieved with this laser delivery system in the treatment of retinoblastoma. METHODS: We reviewed all patients with retinoblastoma managed by indirect ophthalmoscope laser photocoagulation on the Ocular Oncology Service between July 1, 1991 and July 1, 1994. The individual tumor size, location, and proximity to the optic disc and foveola, as well as the laser power, duration, and number of sessions ,were recorded. We assessed the tumor response to treatment and the visual outcome of the patients. RESULTS: There were 30 retinoblastomas in 20 eyes of 18 patients managed with indirect ophthalmoscope laser photocoagulation over the 3-year period. The mean tumor base was 2.1 mm (range: 1 mm to 8 mm); the mean tumor thickness, 1.2 mm (range: 0 mm to 3 mm). The tumor margin was a mean of 6.5 mm (range: 0 mm to 19 mm) from the foveola, and 7.7 mm (range: 0 mm to 22 mm) to the optic disc. In general, it required a power of approximately 350 mW and a continuous duration lasting 1 to 4 seconds to obtain satisfactory obliteration of feeding blood vessels. The tumor responded in one to three sessions (mean: 1.9 sessions per tumor). Complete regression occurred in 21 tumors (70%) and local recurrence in nine (30%). The recurrent tumors were successfully treated with plaque radiotherapy in seven cases and cryotherapy in two cases. The central vision was minimally distorted due to foveal traction from the laser treatment in three cases. CONCLUSION: Indirect ophthalmoscope laser photocoagulation is an effective conservative method to manage selected small retinoblastomas. Tumors treated by this technique should be followed closely due to the moderate risk for local recurrence.

Child, Preschool↗