Macular Photocoagulation Study Research Articles

Clinicopathological correlation in exudative age related macular degeneration: histological differentiation between classic and occult choroidal neovascularisation

AIMSTo analyse the histopathology of classic and occult choroidal neovascular membrane surgical specimens in age related macular degeneration.METHODS35 membranes, from a consecutive series of surgically removed choroidal neovascular membranes in...

Transpupillary thermotherapy of occult subfoveal choroidal neovascularization in patients with age-related macular degeneration

Objective To evaluate the efficacy of transpupillary thermotherapy for the treatment of occult subfoveal choroidal neovascularization (CNV) in patients with age-related macular degeneration. Design A retrospective, noncomparative case series. Participants Sixteen eyes of 15 consecutive patients who presented with occult subfoveal choroidal neovascularization secondary to age-related macular degeneration. Intervention After informed consent was obtained, 16 eyes of 15 patients were treated with transpupillary thermotherapy. All patients underwent pretreatment fluorescein angiography and were deemed untreatable by the Macular Photocoagulation Study standard. Transpupillary thermotherapy was delivered using a diode laser at 810 nm. A variable spot size of 1.2 mm, 2.0 mm, or 3.0 mm was used depending on the size of CNV. The diode laser was delivered through a contact lens, and treatment was initiated in one spot for 60 seconds’ duration at a power range between 360 and 1000 mW. The end point was an area of no visible color change to a light-gray appearance. Main outcome measures In all eyes, outcome was assessed by Snellen chart visual acuity and clinical examination. In 10 of 16 eyes, preoperative and postoperative fluorescein angiography and optical coherence tomography were available. In the remaining 6 of 16 eyes, exudation was measured by postoperative clinical examination alone. Results Three eyes (19%) showed a two-or-more-line improvement in visual acuity over a period of 6 to 25 months. Mean follow-up was 13 months. Visual acuity remained stable (no change or one-line improvement) in nine treated eyes (56%). The remaining four eyes (25%) showed a decline (equal to one-line worsening or greater) in visual acuity. Fifteen eyes (94%) demonstrated decreased exudation on fluorescein angiography, optical coherence tomography, and/or clinical examination. Conclusions Transpupillary thermotherapy shows no deleterious side effects in treating occult subfoveal choroidal neovascularization. A randomized, prospective study is necessary to evaluate treatment efficacy.

Enlargement of atrophy and visual acuity loss in the geographic atrophy form of age-related macular degeneration

Objective To describe the progression of geographic atrophy (GA) from age-related macular degeneration (AMD) with respect to visual acuity (VA) loss and enlargement of atrophy. Design A prospectively observed case series. Setting Tertiary retinal referral center. Participants One hundred twenty-three patients with GA due to AMD who completed at least 1 year of follow-up (median follow-up, 3 years) were examined annually. Methods At each examination, a protocol best-corrected VA of each eye was measured, a clinical examination was performed, and color fundus photographs were taken. The areas of atrophy were drawn and measured. Main outcome measures Visual acuity loss and enlargement of total and central atrophy. Results At baseline, median VA was poorer with larger areas of atrophy, but there was wide variation related to sparing of the fovea. Thirty-one percent of all study eyes suffered a three-line VA loss from baseline by 2 years, and 53% had a three-line loss by 4 years. Those eyes with VA better than 20/50 had the highest rate of acuity loss; 27% of these eyes had acuities of 20/200 or worse at 4 years. Visual acuity loss in the GA study eye was similar in patients with bilateral GA and in those with choroidal neovascularization in the fellow eye. Total atrophy enlarged a median of 1.8 Macular Photocoagulation Study disc areas (DA) at 2 years; atrophy within a 4-DA circle centered on the fovea enlarged a median of 0.9 DA. Two (22%) of nine patients with GA in one eye and only drusen without advanced AMD in the fellow eye developed GA in the fellow eye at 2 years. Conclusions Geographic atrophy is associated with a significant decline in VA over time in many eyes. Areas of atrophy continue to enlarge over time, even when already large at baseline. The combination of reduced VA with enlargement of atrophy, occurring bilaterally in most patients, can lead to significant impairment of visual function.

Long term results of radiotherapy for subfoveal choroidal neovascularisation in age related macular degeneration

BACKGROUND/AIMSRadiotherapy has been proposed as an alternative treatment for patients with subfoveal choroidal neovascularisation (CNV) that is untreatable according to macular photocoagulation study guidelines. This prospective study was designed to...

Surgical removal of subfoveal choroidal neovascularization in age-related macular degeneration

Objective To assess the results of surgical excision of subfoveal choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD). Design Retrospective, interventional, noncomparative case series. Participants and intervention Sixty-four consecutive patients undergoing surgical removal of AMD-related subfoveal CNV were studied. The surgical method included a small retinotomy, subretinal tissue plasminogen activator (t-PA), perfluoro-n-octane, and air-fluid exchange. Main outcome measures Final visual acuity was the main outcome measure; surgical complications and recurrence rates were also assessed. Results Preoperative visual acuity ranged from 20/100 to 1/200, with a mean of 20/400. Average follow-up was 19 months. The best acuity achieved after surgery ranged from 20/20 to hand motions, with a mean of 20/200. Final visual acuity ranged from 20/50 to light perception, with a mean of 20/400. Final acuity was improved 3 or more lines in 19 eyes (30%) (median, 5 lines), stable in 27 eyes (42%), and 3 or more lines worse in 18 eyes (28%) (median, 4 lines). Factors associated with greater visual improvement included poorer initial acuity, larger CNV size, and smaller subretinal hemorrhage. Analysis of groups similar to Macular Photocoagulation Study subgroups A through D showed an average improvement of 1 line for group C (visual acuity, 20/200 or worse; CNV larger than 2 disc areas). Other preoperative, intraoperative, and postoperative factors, including recurrence and retinal detachment, did not have a significant effect on final visual outcome. Conclusions After surgical excision of AMD-related subfoveal CNV, vision improved or stabilized in the majority of patients. Surgery may be of greatest value for patients with poorer vision, larger subfoveal CNV, and minimal hemorrhage. Further evaluation of this technique should be accomplished via completion of a controlled, randomized multicenter study.

Radiation therapy of occult choroidal neovascularisation (CNV) in age-related macular degeneration (AMD)

Occult choroidal neovascularisation secondary to age-related macular degeneration cause severe visual loss due to exsudation, hemorrhage and fibrovascular scarring. So far, no efficient treatment of this condition could be established. Recently, some publications described an improved prognosis after low-dose radiation therapy of the neovascular membranes. Patients with occult choroidal neovascularisation as defined by the Macular Photocoagulation Study were inclosed in our study. Irradiation with Photons (10 to 12 MeV) in fractions of 5 x 2 Gy were administered. At three-month follow-up intervals visual acuity a complete ophthalmological examination including visual acuity, fluorescein- and ICG-angiography as well as fundus photography was performed. In our study 64 patients (74 +/- 7 years) with occult CNV secondary to AMD were included. Follow-up was between 3 and 39 months (14.5 +/- 10). Compared to studies who investigated the natural history of this disease, the visual acuity measured in our study did not differ significantly from the natural course. Our results do not support the general use of radiation therapy in patients with occult choroidal neovascularisation secondary to AMD. However, the controlled multicenter studies might provide a better basis for a general recommendations.

Krypton Laser Photocoagulation of Peripapillary Choroidal Neovascular Membrane

The Macular Photocoagulation Study criteria require that at least 1.5 clock hours of temporal peripapillary retina be spared when treating choroidal neovascular membrane in that location. The authors successfully treated peripapillary choroidal neovascular membrane involving temporal 180 degrees with the krypton laser without any loss of visual acuity and central field.

Surgical removal of extensive peripapillary choroidal neovascularization associated with presumed ocular histoplasmosis syndrome

Objective This study aimed to report the visual outcome of surgical removal of extensive peripapillary choroidal neovascularization (CNV) due to presumed ocular histoplasmosis syndrome (POHS). Design Retrospective review of the records of all patients seen at the Barnes Retina Institute who underwent surgical removal of extensive peripapillary CNV associated with POHS and who had at least 12 months of follow-up. Participants Seventeen consecutive eyes (in 14 patients) undergoing surgical removal of extensive peripapillary CNV associated with POHS were studied. Intervention Pars plana vitrectomy and surgical removal of CNV were performed. Main outcome measurements Best-corrected Snellen visual acuity, funduscopic examination, and intravenous fluorescein angiography were obtained before surgery and at regular intervals after surgery. Results In 14 of 17 eyes, the peripapillary CNV was subfoveal, and in 3 eyes, it was extrafoveal. All three eyes with extrafoveal CNV were not eligible for laser treatment according to Macular Photocoagulation Study guidelines because treatment would have spared less than 1.5 contiguous clock-hours of retina temporal to the optic disc. Follow-up ranged from 17 to 57 months, with a median of 32 months. In eyes with subfoveal CNV, best-corrected preoperative Snellen visual acuity ranged from 20/25 to counting fingers at 2 feet with a median of 20/200, and best-corrected final Snellen visual acuity ranged from 20/25 to 20/200 with a median of 20/40. In 7 (50%) of 14 eyes, a final Snellen acuity of 20/40 or better was achieved, and in all cases except 1, visual acuity improved or did not change with surgery. In the three eyes with extrafoveal CNV, best-corrected preoperative Snellen visual acuity ranged from 20/20 to 20/400 with a median of 20/200, and best-corrected final Snellen visual acuity was 20/20 in all cases. In addition, visual acuity improved with surgery. Conclusions The data from this small retrospective study suggest that surgical removal may provide visual benefit in selected cases of extensive peripapillary CNV due to POHS.

Idiopathic juvenile macular sub-retinal neovascularization: to treat or not to treat

Juvenile macular sub-retinal neovascularization is an exceedingly rare condition. It occurs in patients under the age of 20. Subretinal neovascularization is so rare in patients less than twenty years of age, that the macular photocoagulation study presents data only for patients 18 years of age or older. This poster describes a 17-year-old female with a foveal hemorrhage secondary to idiopathic juvenile macular sub-retinal neovascularization in one eye. Although the patient was given the treatment option of laser, she refused, and opted for close observation instead. In this case the hemorrhage resolved spontaneously and left the patient with 20/80 vision. The rationale for and against laser treatment is discussed. The significance of the Macular Photocoagulation Study is reviewed with respect to this case.

Age-related macular degeneration and risk factors for the development of choroidal neovascularization in the fellow eye.

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the world. Most of the severe vision loss associated with AMD is due to the development of choroidal neovascularization (CNV). The specific causes of AMD and in particular, its neovascular phase, remain uncertain. During the past two decades a number of large prospective clinical trials, observational epidemiologic studies, and population-based cohort studies have furthered our understanding of this blinding ocular condition. The Macular Photocoagulation Study has received praise for its many contributions in the laser treatment of neovascular complications of AMD; however, these trials have made other significant contributions by helping to better define the natural history of AMD, and in particular, risk factors for the development of CNV in eyes with non-neovascular disease. This type of information may provide significant clues for researchers regarding disease pathogenesis and identify a high-risk group in whom to target new treatment strategies. For patients currently diagnosed with macular degeneration, this information can lead to a better understanding of their condition and a more accurate prognosis of their ocular health and vision status. This article reviews information from a variety of sources to investigate incidence rates and risk factors for the development of CNV in the fellow eye of patients with AMD and unilateral neovascular maculopathy.

External beam radiation therapy for choroidal neovascularization

This study aimed to determine the effect of external beam radiation therapy on choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). The study design was a nonrandomized clinical trial with an historic control group. A total of 91 patients were treated with external beam radiation. These patients were compared retrospectively to the 119 patients in a control group. Patients with subfoveal CNV who did not meet the criteria for laser treatment defined by published reports from the Macular Photocoagulation Study Group or who did not want laser treatment were considered for radiation therapy in a nonrandomized, prospective clinical trial. Additional entry criteria for this prospective study included visual acuity better than or equal to 20/320 on the Early Treatment Diabetic Retinopathy Study chart and a lesion size less than 12 disc areas. The patients were treated with 5 fractions of 200 cGy 6 MV external beam photons. The visual acuity measured at baseline was compared to the visual acuity after 1 year of follow-up. The mean baseline visual acuity of the 91 patients entered into the Radiation Study was 20/80. After 1 year, 83 patients (91.2%) completed follow-up, and their mean visual acuity dropped to 20/200. By comparison, the mean baseline visual acuity of the control patients also was 20/80, and after 1 year, the control subjects had a mean visual acuity of 20/125. At 1 year of follow-up, 49.4% of patients treated with radiation and 38.1% of the control subjects lost 3 or more lines of visual acuity (P = 0.16). This study found that external beam radiation using 1000 cGy in 5 fractions, a dose similar to that used in previous studies, was not effective in the treatment of CNV secondary to AMD. These results suggest that patients should not be treated with this dose of external beam radiation for CNV secondary to AMD.

Treatment of age-related subfoveal choroidal neovascularization by low-dose external radiation: A preliminary study

We applied low dose external beam radiation (6 MV) to 17 eyes of 17 patients (Mean age 70.9 years, range 58 approximately 85) who had subfoveal choroidal neovascularization associated with age-related macular degeneration. None of the cases were suitable for photocoagulation according to the Macular Photocoagulation Study protocol, and no feeding vessels underlying choroidal neovascular membrane could be detected. Corrected visual acuity ranged from 0.02 to 0.6 before treatment. The patients were divided into two groups. One group of 11 eyes was treated with 10 Gy and the other group of 6 eyes with 21 Gy. Mean follow up period was 347 +/- 89 (mean +/- standard deviation) days in the 10 Gy group and 312 +/- 100 days in the 21 Gy group. We evaluated the outcome as "effective' if no progression in neovascular membrane was found by ophthalmoscopic and angiographic examination. Only 3 eyes (21%) of patients in the 10 Gy group and 2 eyes (33%) in 21 Gy group showed any effect. Although the rate of progression in choroidal neovascular membrane was significantly smaller in the 10 and 21 Gy group than in the controls, the corrected visual acuity in the treated group was not improved over that of the controls. No serious complications were seen. Only one case showed a stabilized neovascular membrane in the control group of 7 patients. Although the present results seem to be worse than those in previous reports, the efficacy of this treatment still needs to be evaluated because no beneficial strategies in the treatment of subfoveal neovascularization have been established.

Histological characterization and classification of surgically excised choroid neovascular membranes

This study was undertaken in order to histologically characterize surgically-excised choroidal neovascular membranes and to correlate theses histologic findings with the fundus and fluorescein angiographic appearance. Surgically-excised subfoveal choroidal neovascular membranes submitted in the time period from November 1994 to July 1996 were included in this study. The membranes were processed and evaluated by light and transmission electron microscopy. Some membranes were oriented by the surgeon and marked on their inner surface with India ink and the configurations of these membranes were recorded and correlated with the fundus and fluorescein angiographic features. Sixty-two choroidal neovascular membranes were available for this study. In 74% age-related macular degeneration was the underlying disease. Retinal pigment epithelium and endothelial lined vascular channels were present in over 87.5% of cases. Basal laminar (linear) deposit was only present in membranes excised from patients with age-related macular degeneration. In six cases with Gass Type II choroidal neovascular membranes the histologic-clinical-fluorescein angiographic correlation showed well-defined (classic) neovascular membranes according to the criteria of the Macular Photocoagulation Study. Two membranes were not surrounded by retinal pigment epithelium and were classified as Type IIa membranes. Four membranes were surrounded by retinal pigment epithelium and classified as Type IIb membranes. Choroidal neovascular membranes represent a stereotypic, non-specific wound repair response to a specific stimulus. Retinal pigment epithelium may proliferate around and attempt to wall off choroidal neovascular membranes. We propose a new classification of surgically-excised choroidal neovascular membranes as Types I, IIa, and IIb.

The Application of the Macular Photocoagulation Study Eligibility Criteria for Laser Treatment in Age-Related Macular Degeneration

To analyze the application of the Macular Photocoagulation Study eligibility criteria for laser photocoagulation of choroidal neovascularization, in view of the expansion of these criteria in recent years. The authors prospectively analyzed 50 eyes of 47 consecutive patients with exudative age-related macular degeneration (AMD) to determine their suitability for treatment. Fifteen eyes (30%) were found to be suitable for laser photocoagulation. Patients eligible for treatment were more likely to have experienced visual symptoms for a months or less (P = .006), to have a visual acuity of 20/200 or better (P = .009), and to be younger in age (P = .02). Visual symptoms experienced for a month or less were more prevalent in extrafoveal exudative lesions compared with the subfoveal type (P = .01) Despite recent advances, laser photocoagulation still can be applied only to a minority of the patients with neovascular AMD. Prompt ocular examination following the onset of visual symptoms is essential.

Phase [formula omitted] study of proton beam irradiation for the treatment of subfoveal choroidal neovascularization in age-related macular degeneration: Treatment techniques and preliminary results

Purpose : Age-related macular degeneration is the prevalent etiology of subfoveal choroidal neovascularization (CNV). The only effective treatment is laser photocoagulation, which is associated with decreased visual acuity following treatment in most patients. This study assessed both the response of subfoveal CNV to proton beam irradiation and treatment-related morbidity. We evaluated preliminary results in patients treated with an initial dose of 8 Cobalt Gray Equivalents (CGE) using a relative biological effectiveness (RBE) of 1.1. Methods and Materials : Twenty-one patients with subfoveal CNV received proton irradiation to the central macula with a single fraction of 8 CGE; 19 were eligible for evaluation. Treatment-related morbidity was based on Radiation Therapy Oncology Group (RTOG) criterai; response was evaluated by Macular Photocoagulation Study (MPS) guidelines. Fluorescein angiography was performed; visual acuity, contrast sensitivity, and reading speed were measured at study entry and at 3-month intervals after treatment. Follow-up ranged from 6 to 15 months. Results : No measurable treatment-related morbidity was seen during or after treatment. Of 19 patients evaluated at 6 months, fluorescein angiography demonstrated treatment response in 10 (53%); 14 (74%) patients had imporved or stable visual acuity. With a mean follow-up of 11.6 months, 11 (58%) patients have demonstrated improved or stable visual acuity. Conclusion : A macular dose of 8 CGE yielded no measurable treatment morbidity in patients studied. Fluorescein angiography demonstrated that regressed or stabilized lesions were associated with improved visual acuity as compared with MPS results. In the next phase, a dose of 14 CGE in a single fraction will be used to further define the optimal dose fractionation schedule.

Radiation Therapy for Subfoveal Choroidal Neovascular Membranes in Age-Related Macular Degeneration: A Pilot Study

• Background: The natural course of the visual acuity of age-related subfoveal choroidal neovascularisation (CNV) membranes is poor. Laser photocoagulation of subfoveal CNV is recommended if the patient is willing to accept a large decrease in visual acuity immediately after treatment. A large proportion of patients with subfoveal CNV do not meet the Macular Photocoagulation Study Group (MPS) guidelines for laser photocoagulation. The fact that so few patients meet these criteria makes further research into new treatment techniques warranted. Ionising radiation may prevent the proliferation of endothelial cells of newly formed subretinal capillaries and may induce obliteration of the aberrant new vessels. • Methods: In this study, the effect of radiation therapy on subfoveal CNV membranes was evaluated. Four groups of ten patients were treated with external beam radiotherapy (16-MV photons) on an area of 1 cm2 (macular region) using a lens-sparing technique and total doses of 8–24 Gy. The first group received 8 Gy in one fraction. The second, third and fourth groups received 12 Gy in 2 fractions, 18 Gy in three fractions and 24 Gy in four fractions respectively. The studied parameters included best-corrected visual acuity and membrane size and leakage on the fluorescein angiogram. we included 17 occult and 23 classic CNV membranes as defined by the MPS, with a duration of less than 5 weeks at presentation. Complete ophthalmic examination including fluorescein angiography was performed before and 3, 12 and 18 months after radiation treatment. We analysed the angiogram using a standard over-projection sheet. The results concerning the visual acuity and fluorescein angiography (FA) were compared with the extensively published, natural course data. • Results: The first group (including three cases of occult CNV) received 8 Gy in a single fraction. In this group only four of ten patients had stable visual acuity and stable FA appearance after 21 months follow-up. The visual acuity and FA remained stable after 13.6 months follow-up in seven of the patients in group 2 (12 Gy in two fractions, four occult CNV). The third group (18 Gy in three fractions, seven occult CNV) contained six patients with stable visual acuity, although two of them had CNV deterioration on the FA (11.1 months follow-up). In the last group (24 Gy in four fractions, three occult CNV), with a short follow-up of 5.6 months, eight patients had stable visual acuity and FA appearance. We did not note any regression of the CNV membrane on the angiogram. The visual acuity in groups 2, 3 and 4 decreased to 0.1 or worse in only three cases, three cases and one case respectively after at least 6 months follow-up. • Conclusion: Comparison of these findings with the natural history data of subfoveal age-related CNV suggests a beneficial effect of radiation therapy with a total dose of 12 Gy or more on the progression of CNV To date no negative side effects have been observed.

Laserkoagulation der altersabhängigen, feuchten Makuladegeneration

Age-related macular degeneration (AMD) is a common disease in ophthalmology. The current status of knowledge in subretinal neovascularisations concerning epidemiology and treatment based on the findings of the macular photocoagulation study is shown. Most important parameters in treatment of subretinal neovascularisations in AMD are exact localization of the membrane in fluorescein angiography, its size and the visual acuity. The treatment of extra-foveal, well demarcated membranes can be recommended. Moreover recent results in the treatment of subfoveal, well demarcated membranes show some benefit for the patient as long as the size of the membrane is lower than 2 discs areas and the actual visual acuity is taken into account. Indocyanin-Green-(ICG)-angiography is recommended in occult subretinal membranes. Guidelines for the treatment are given.

The Digital Indocyanine Green Videoangiography Characteristics of Well-defined Choroidal Neovascularization

To evaluate the digital indocyanine green (ICG) videoangiography characteristics of well-defined choroidal neovascularization (CNV). The authors retrospectively reviewed all ICG angiograms performed at the New England Eye Center over a 2-year period. Included in this study were all patients with the clinical and fluorescein angiographic diagnosis of well-defined CNV according to the Macular Photocoagulation Study Group criteria. Of the 25 eligible patients, 18 (72%) had a well-demarcated area of ICG hyperfluorescence that was observed either both early and late (6 patients = 24%) or only late (12 patients = 48%) on the ICG angiogram. Five patients (20%) showed only poorly demarcated late hyperfluorescence on ICG angiography. Two patients (8%) had type II occult CNV associated with classic CNV as per the Macular Photocoagulation Study Group criteria. Both patients showed a late, well-demarcated area of ICG hyperfluorescence greater than the area imaged with fluorescein angiography. Choroidal neovascularization which is well-defined on fluorescein angiography has variable ICG appearances. When there is late leakage associated with a well-defined CNV on fluorescein angiography (type II occult CNV), ICG angiography may more completely delineate the extent of the lesion.

The impact of the macular photocoagulation study results on the treatment of exudative age-related macular degeneration.

To determine the percent of cases with all primary forms of exudative age-related macular degeneration that are eligible for treatment by the Macular Photocoagulation Study (MPS) guidelines in a retina clinic serving both as a primary care center and as a referral center. Fluorescein angiograms of patients with age-related macular degeneration examined at the Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, during a 5-year period (1985 to 1990) were randomly selected and reviewed. Angiograms showing all forms of exudative age-related macular degeneration were eligible. The first 100 eligible angiograms identified constituted the study series and were classified into four groups: active choroidal neovascularization (CNV), pigment epithelium detachment, hemorrhage, and disciform scars. The active CNVs were further divided into three subgroups: classic (well defined), occult (poorly defined), and combined. Eligibility for laser treatment was determined exclusively with use of the published MPS recommendations for treatment of extrafoveal, juxtafoveal, and subfoveal membranes. There were 10 cases in the pigment epithelium detachment group, 11 cases in the hemorrhagic group, and 16 cases with disciform scars. All of these 37 cases were ineligible for treatment by MPS guidelines. Sixty-three eyes had active membranes; 37 were classic CNVs (eight extrafoveal, seven juxtafoveal, and 22 subfoveal). All extrafoveal and juxtafoveal CNVs were found to be eligible for laser treatment. Eleven membranes of the subfoveal group were larger than 2 disc areas, a size for which the MPS did not demonstrate benefit from laser treatment. There were 19 membranes in the strictly occult CNV subgroup, all of them untreatable by MPS criteria. Seven cases had both occult and classic CNV, and all were larger than 3.5 disc areas and therefore ineligible for treatment. Overall, 26 cases were eligible for treatment by strict MPS criteria; these constitute 26% of the whole series and 41% of the active CNV cases in the series. Our results indicate that the MPS guidelines for laser treatment are applicable only to a minority of the cases with exudative age-related macular degeneration presenting to our clinic. Further studies should be conducted to identify additional treatment modalities for this common eye disease.

Treatment of Subfoveal Choroidal Neovascularization-Reply

In reply We thank Dr Tiedeman for his careful reading of our article and his thoughtful comments. As we emphasized in our discussion, advising whether a particular patient should be treated with laser photocoagulation involves consideration of both short- and long-term effects of the treatment and characteristics of the patient such as the condition of the fellow eye. We and Dr Tiedeman are in agreement that the reason that group B patients are good candidates for immediate treatment is the reduced risk for severe loss of vision that begins at 12 months after treatment and endures for at least 3 additional years. This sustained period of lower risk for loss of vision outweighs, in our opinion, the period of increased risk immediately following treatment. Members of the Macular Photocoagulation Study Group are listed in the April issue of theArchiveson page 482.