Diode versus argon-green laser panretinal photocoagulation in proliferative diabetic retinopathy: a randomized study in 44 eyes with a long follow-up time

A clinical randomized study using argon-green (532 nm) and diode (810 nm) lasers was carried out on 44 eyes (34 patients) affected by proliferative diabetic retinopathy (PDR), with the aim of evaluating the long-term effects of diode panretinal photocoagulation. Of the total 44 eyes, 22 were randomized to argon laser treatment (ALT) and 22 to diode laser treatment (DLT). The mean follow-up time was 25 +/- 5 months in the ALT group versus 24 +/- 4 months in the DLT group. In the ALT group 20 eyes (91%) showed regression of PDR whereas 2 eyes (9%) deteriorated. In the DLT group regression of neovascularization was observed in 22 eyes (100%). These results show that the long-term efficacy of diode laser PRP in the treatment of PDR is similar to that of argon-green laser PRP.     

Visual fields at different stages of diabetic retinopathy

Available studies on visual field disturbances in diabetic retinopathy have shown conflicting results, obtained with different and often non-comparable techniques. We have studied visual fields at different stages of diabetic retinopathy with modern sensitive computerized technique taking precautions to limit disturbing effects of random field variation and lack of perimetric experience. Sixty-three diabetic patients, insulin-dependent and non-insulin dependent, were each subject to three test sessions using the 30-2 full threshold program of the Humphrey perimeter. Retinopathy levels ranged from 10 to 65 in the ETDRS Final scale. In eyes without retinopathy or with very mild and mild disease (levels 10-35) mean deviation values exceeding the p < 5% level occurred in only 4% of eyes in trained sessions, and the number of test points with significantly reduced sensitivity did not exceed that expected in normal eyes. In moderate and moderately severe diabetic retinopathy (level 43-47) and in severe non-proliferative and proliferative retinopathy (levels 53-65) there was clear evidence of field loss, however, with significantly reduced mean deviation values in 44% of the eyes and 6.5% of tested points showing reproducible loss of sensitivity. Thus, there was no evidence of field loss in eyes with mild disease, but clear field defects in eyes with more advanced disease. Significantly reduced sensitivity was often correlated with retinal non-perfusion and there was seen a tendency towards more correlation in the midperiphery than paracentrally.     

High serum lipoprotein(a) levels in Korean type 2 diabetic patients with proliferative diabetic retinopathy

OBJECTIVE: To examine the possible association between serum lipoprotein(a) [Lp(a)] concentration and proliferative diabetic retinopathy (PDR) in Korean patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 412 Korean outpatients with type 2 diabetes were examined. Diabetic retinopathy was determined by an ophthalmologist using fundoscopic examination. Serum Lp(a) levels were measured by two-site sandwich enzyme-linked immunosorbent assay. RESULTS: The patients with PDR had higher serum Lp(a) levels than those with no diabetic retinopathy or with nonproliferative diabetic retinopathy (NPDR). Multiple logistic regression analysis showed that high serum Lp(a) levels and the presence of diabetic nephropathy were independent variables having a statistically significant association with PDR. CONCLUSIONS: Korean type 2 diabetic patients with PDR had higher serum Lp(a) levels versus those with no diabetic retinopathy or with NPDR. Although these results suggest that Lp(a) might play a role in the occlusion of retinal capillaries leading to PDR, further prospective studies are required to prove the causal relationship.     

Resting ECG changes in long term survivors after carotid endarterectomy

PURPOSE: The aqueous flare intensity and pupillary size were studied before and after instillation of 10% phenylephrine and 4% pilocarpine in eyes with diabetes mellitus (DM). METHODS: Twenty-three patients with DM type I were compared with 30 age-matched controls, and 25 patients with DM type II were compared with 30 age-matched controls. Patients with DM were divided into two groups: 1) with mild-moderate nonproliferative diabetic retinopathy (NPDR), and 2) with advanced diabetic retinopathy (DR) which includes moderate-severe, severe NPDR and proliferative DR. The aqueous flare intensity and the horizontal diameter of the pupil were measured before and 60 minutes after topical instillation of 10% phenylephrine and 60 min after topical administration of 4% pilocarpine. RESULTS: Degree of induced mydriasis after phenylephrine instillation was not significantly different between diabetic groups and controls. Significantly less pronounced miosis was observed after stimulation of cholinergic receptors by pilocarpine in eyes with mild-moderate NPDR with DM type II and in eyes with advanced DR with DM type I and type II when compared to controls (p<0.05). Phenylephrine decreased flare intensity in all groups without a significant difference between groups. Pilocarpine instillation increased flare intensity in all groups as compared to flare intensity before any treatment. Also, a significantly smaller increase in flare intensity in eyes with advanced retinopathy in both DM type I and type II was found when compared to controls (p<0.05). CONCLUSION: Pharmacological response to cholinergic stimulation on pupil size and flare intensity is weaker in advanced stages of DR.     

Full panretinal photocoagulation and early vitrectomy improve prognosis of florid diabetic retinopathy

BACKGROUND: Florid diabetic retinopathy (FDR) is a rare form of proliferative diabetic retinopathy (PDR) that is characterized by a bilateral rapidly progressive, very severe ischemic retinopathy. Florid diabetic retinopathy was reported to carry a high risk of blindness. This study was conducted to determine whether visual prognosis of FDR can be improved by appropriate photocoagulation and surgical management. METHODS: The authors retrospectively studied 20 patients (40 eyes) who were treated from October 1978 to February 1994. Systemic risk factors, visual acuity, complete ocular examination, and fundus findings, as well as fluorescein angiography, were analyzed with respect to photocoagulation and surgical management. Mean follow-up was 3.6 years. RESULTS: All patients had poorly controlled type I diabetes (mean duration, 13.5 years), which often was associated with systemic complications. Mean initial visual acuity was equal to or better than 20/40 in 32 eyes (80%). During the course of the study, high-risk PDR was observed in 38 eyes (95%) and vitreous hemorrhage occurred in 26 eyes (65%). Extensive full subconfluent panretinal photocoagulation was performed completely in 37 eyes (92.5%). Vitrectomy was necessary in 15 eyes (37.5%). Macular edema was present in 30 eyes (75%). Major complications included retinal detachment that required surgery (2 eyes, 5%) and neovascular glaucoma (2 eyes, 5%). However, final visual acuity was equal to or better than 20/40 in 23 eyes (57.5%) and less than 5/200 in only 4 eyes (10%). CONCLUSION: These results suggest that aggressive treatment of FDR with extensive panretinal photocoagulation and early vitrectomy, when necessary, may result in a much better prognosis than has been reported previously.     

Extracapsular cataract extraction in diabetic eyes. The role of YAG laser capsulotomy

Cataract surgery may exacerbate preexisting diabetic retinopathy. Especially diabetics with active retinal neovascularisation are at high risk of rubeosis iridis after intracapsular cataract extraction. Thirty-five eyes previously treated with panretinal photocoagulation underwent extracapsular cataract extraction with posterior chamber lens implantation. Twenty-eight eyes with retinal neovascularisation required further Argon laser PRP after surgery. Fourteen eyes required YAG-laser capsulotomy. From the group of eyes without YAG-laser capsulotomy none developed neovascular glaucoma. From the YAG laser capsulotomy group six eyes developed rubeosis iridis and neovascular glaucoma. Our results indicate that eyes in which PRP has been performed, have an excellent prognosis after ECCE with posterior chamber lens implantation only if YAG Laser posterior capsulotomy is not performed.     

Risk factors for high-risk proliferative diabetic retinopathy and severe visual loss: Early Treatment Diabetic Retinopathy Study Report #18

PURPOSE: To identify risk factors for the development of high-risk proliferative diabetic retinopathy (PDR) and for the development of severe visual loss or vitrectomy (SVLV) in eyes assigned to deferral of photocoagulation in the Early Treatment Diabetic Retinopathy Study (ETDRS). METHODS: Multivariable Cox models were constructed to evaluate the strength and statistical significance of baseline risk factors for development of high-risk PDR and of SVLV. RESULTS: The baseline characteristics identified as risk factors for high-risk PDR were increased severity of retinopathy, decreased visual acuity (or increased extent of macular edema), higher glycosylated hemoglobin, history of diabetic neuropathy, lower hematocrit, elevated triglycerides, lower serum albumin, and persons with mild to moderate nonproliferative retinopathy, younger age (or type 1 diabetes). The predominant risk factor for development of SVLV was the prior development of high-risk PDR. The only other clearly significant factor was decreased visual acuity at baseline. In the eyes that developed SVLV before high-risk proliferative retinopathy was observed, baseline risk factors were decreased visual acuity (or increased extent of macular edema), older age (or type 2 diabetes), and female gender. CONCLUSIONS: These analyses supported the view that the retinopathy-inhibiting effect of better glycemic control extends across all ages, both diabetes types, and all stages of retinopathy up to and including the severe nonproliferative and early proliferative stages and the possibility that reducing elevated blood lipids and treating anemia slow the progression of retinopathy.     

Retinal arteriovenous shunt at the arteriovenous crossing

OBJECTIVE: The purpose of the study was to demonstrate that the arteriovenous shunt at the arteriovenous crossing could occur in major retinal vascular diseases other than Takayasu disease. DESIGN: Clinical review of consecutive case series. PARTICIPANTS: The authors studied 1885 eyes with retinal vascular diseases such as diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, central retinal artery occlusion, Leber's miliary aneurysms, Eales disease, Beh?et disease, and systemic lupus erythematosus retinopathy. INTERVENTION: Fluorescein fundus angiography using a wide-field fundus camera (60 degrees) was performed. MAIN OUTCOME MEASURES: Dye transit from artery to vein through sequential angiography. RESULTS: The arteriovenous shunt at the arteriovenous crossing was found in 8 eyes with proliferative diabetic retinopathy, 27 eyes with branch retinal vein occlusion in the chronic stage, 2 eyes with central retinal vein occlusion, 2 eyes with central retinal artery occlusion, and 2 eyes with miliary aneurysms. The arteriovenous shunt was formed by a direct inflow from artery to vein, showing vasodilation and hyperpermeability, followed by obliteration peripheral to the shunts. The pattern of initial inflow was classified into axial flow and laminar flow, and the inflow became wider and more rapid in the advanced stage. CONCLUSIONS: These findings indicate that the arteriovenous shunt at the arteriovenous crossing is not a unique phenomenon in Takayasu disease but rather is a basic pattern of retinal vascular reaction pathologic states.     

Long-term results after drainage of premacular subhyaloid hemorrhage into the vitreous with a pulsed Nd:YAG laser

OBJECTIVE: To investigate the effects of drainage of premacular subhyaloid hemorrhage into the vitreous with an Nd:YAG laser in a large series of patients with long-term follow-up. METHODS: A retrospective review was conducted on 21 eyes with a circumscribed premacular subhyaloid hemorrhage of various causes. These eyes were treated with a pulsed Nd:YAG laser to drain the entrapped blood into the vitreous. The period of review ranged from 12 to 32 months (mean, 22 months). RESULTS: In 16 eyes, visual acuity improved within 1 month. Four eyes had persistent, dense, nonclearing vitreous opacity for at least 3 months and finally required vitrectomy. One clotted hemorrhage did not drain into the vitreous. Final visual outcome was determined by the underlying diagnosis, such as Valsalva retinopathy (7 eyes), diabetic retinopathy (7 eyes), branch retinal vein occlusion (4 eyes), and retinal macroaneurysm, Terson syndrome, or blood dyscrasia (1 eye each). Eyes with Valsalva retinopathy fared the best. Complications included a macular hole in 1 eye and a retinal detachment from a retinal break in a myopic patient. CONCLUSIONS: Drainage of premacular subhyaloid hemorrhage into the vitreous with an Nd:YAG laser is a viable treatment alternative for eyes with recent bleeding. However, a macular hole and a retinal detachment were observed as complications. Thus, to establish Nd:YAG laser treatment as a routine procedure, the risks and benefits have to be weighed in a randomized trial and compared with those of deferral of treatment or primary vitrectomy.     

Occurrence of changes in the eye in diabetic retinopathy with significant myopia

The optic disc and retinal neovascularization are less prominent and less frequent in myopic eyes in patients suffering from diabetes mellitus. The exact mechanisms of this phenomenon are not well known, but there is some evidence that there is a reduced blood flow in myopic eyes which is associated with less damaged microcirculation in eyes of patients with diabetes mellitus. The aim of our study was to evaluate the correlation between myopic refractive error and degree of diabetic retinopathy. We conducted a retrospective study in a group of randomized patients, divided into the following groups according to their refractive error: emmetropia (30 eyes), myopia simplex (30 eyes) and high myopia, over -6.5 dsph (21 eyes). Among patients with high myopia, seven had monocular myopia. All patients suffered from non insulin dependent diabetes mellitus for more than ten years, and their average age was 52.37-3.48 years. We did not observe patients with rubeosis iridis and neovascular glaucoma or patients with myopia less than -2.0 dsph. Our results indicated that there was no significant difference in the appearance of fundus between the studied groups. In all patients the incidence rate of non proliferative and proliferative diabetic retinopathy was the same as well as the absence of retinopathy (Fisher's test). The only exception were the patients with monocular myopia over -13.o dsph who had no signs of diabetic retinopathy in myopic eye, while the other, emmetropic eye, showed various stages of retinopathy, from severe non proliferative to proliferative. Some of the risk factors which influence the incidence rate of ocular complications in diabetic patients are well known, as are duration of diabetes mellitus, blood sugar level, blood pressure, ocular pressure and eye perfusion. On the other hand, it is also known that amblyopia, optic atrophy, low blood pressure in central retinal artery and retinitis pigmentosa are ocular conditions which are not associated with proliferative diabetic retinopathy. It was also noticed that complications of diabetes in high myopic eyes are less prominent than in emmetropic eyes. This finding is in harmony with our results. Sultanov et al. observed diabetic changes in the retina in 40.9% of myopic refraction patients, 65.2% of emmetropia cases and 70.4% of hypermetropia cases. The severity of involvement was less in myopia than in other types of refraction. In medium severe myopia, no proliferative diabetic retinopathy was observed, and in high myopia (10 eyes) no diabetic involvement of the fundus oculi was found. In anisometropia diabetic symptoms on the myopic side were either absent or poorly manifest. The possible cause of such findings could be the changes in retinal perfusion in myopic eyes and eyes in patients with diabetes mellitus. In 1973 a lower blood flow was detected in the retina and the choroid, proportionally to the degree of myopia. In 1982, Perkins indicated that the circulation time and pulsation rate in the central retinal artery in myopic eyes were reduced proportionally to the degree of myopia. In cases with early diabetic retinopathy Coscas detected a lesser blood flow in retinal veins. On the other hand, it has been found that high blood pressure increases the risk of diabetic retinopathy. These data suggest that the reduced blood flow in high myopia is a protective factor regarding the occurrence of complications in diabetes. Anisometropia and amblyopia in cases with monocular myopia, which presents a particular group in our study, could be factors which also prevent the occurrence of proliferative diabetic retinopathy. Instead of conclusion, we would like to point out that pathophysiologic mechanisms of these phenomena are not discussed enough. It is, nevertheless, important to appropriately examine the fundus in patients with high myopia and diabetes mellitus, because if the complications appear, they may be disastrous and must be treated immediately.     

Absence of foveal avascular zone demonstrated by laser scanning fluorescein angiography

We present laser scanning fluorescein angiograms of abnormal foveal capillary patterns in a healthy subject and an insulin-dependent diabetic patient with mild diabetic retinopathy. In both subjects capillaries were seen to cross the central foveal area where capillaries are usually absent. The flow pattern of the foveal capillaries, which were visualised with the use of a laser scanning ophthalmoscope, was indistinguishable from that of the more peripheral capillaries, indicating that foveal vessels are functionally normal retinal capillaries. The two cases demonstrate that identification of abnormal capillary patterns induced by retinal disease such as diabetic retinopathy is made difficult by the marked interindividual variation in capillary anatomy. In prospective studies, however, the method may be capable of detecting subtle changes in early diabetic retinopathy with a high degree of sensitivity.     

Macular edema caused by contraction of the posterior hyaloid in diabetic retinopathy. Surgical treatment of a series of 22 cases

We have observed some patients with diabetic macular edema who did not respond to grid laser treatment and who improved with spontaneous posterior vitreous detachment or vitrectomy. These cases have a taut and glistening vitreo-macular interface. Three such cases are presented in detail. Pars plana vitrectomy with separation of the posterior hyaloid was performed in 22 cases. All of them had proliferative diabetic retinopathy, previously treated by panretinal photocoagulation. Fourteen cases had an ineffective macular grid laser treatment. Postoperative visual acuity was improved in 19 eyes and was unchanged in three eyes. The macular edema disappeared in 12 eyes and decreased in 10. Complications included a vitreous hemorrhage in 6 eyes, a paramacular tear in 1 eye, a reghmatogenous retinal detachment in 1 eye and cataract formation in 2 eyes. Vitreous surgery can improve the visual prognosis in cases of diabetic macular edema associated with a pathological vitreo-macular interface.     

The topographic distribution of the first sites of diabetic retinal neovascularization

PURPOSE: To examine the topographic distribution of the origin of diabetic retinal neovascularization. METHODS: The eyes of 3,121 patients with background diabetic retinopathy were investigated. These patients were volunteers in systemic medical therapy experiments. Color stereo photographs were obtained annually. The first retinal neovascularization sites were identified and the distances from the optic nerve measured. RESULTS: In 1 year, neovascularization originated in 282 eyes. The superotemporal quadrant, at 6 mm from the optic disk, was the most frequent initial site. CONCLUSIONS: The first retinal neovascularization sites cluster around specific anatomic foci. This information should influence retinopathy monitoring protocols.     

Ocular arterial flow hemodynamics in patients with diabetes mellitus

The purpose of this study was to investigate ocular blood flow hemodynamics in patients with diabetes mellitus. We used color Doppler sonography, in 22 normal subjects and 52 patients with (n = 25) or without (n = 27) diabetic retinopathy, to determine blood flow velocities and the resistive index of the central retinal artery. The resistive index of the central retinal artery in patients with diabetic retinopathy (0.85 +/- 0.09) was significantly greater (P < 0.01) than that in normal subjects (0.72 +/- 0.08) and in patients without diabetic retinopathy (0.81 +/- 0.09). The resistive index of the central retinal artery in the patients without diabetic retinopathy was also significantly greater than that of normal subjects (P < 0.01). The resistive index of ocular arterial flow was increased in the patients with diabetes mellitus and further increased in the presence of retinopathy. Increased resistance in the peripheral ocular vascular bed contributes to diabetic retinopathy, and this change is present before the appearance of overt diabetic retinopathy.     

Cost-effective screening for diabetic retinopathy using a nonmydriatic retinal camera in a prepaid health-care setting

OBJECTIVE: To assess the efficacy of using a nonmydriatic Polaroid retinal camera as a method for screening diabetic patients for treatable diabetic retinopathy. RESEARCH DESIGN AND METHODS: All 522 diabetic patients followed in a health maintenance organization-affiliated diabetes program had retinal photos taken. Compliance with the routine referral to one of two retinal specialists (the examiners) was 74%. The results from the examiners were compared with the results of the reader of the retinal photos. RESULTS: Sensitivity was 100% and specificity was 82% for the diagnosis of serious diabetic retinopathy (preproliferative or proliferative retinopathy or macular edema) by the examiners compared with the diagnosis of any diabetic retinopathy by the reader. No patient had serious diabetic retinopathy inside or outside the photographic field that was missed because all patients with serious diabetic retinopathy showed some diabetic retinopathy within the photographic field. The reader tended to underrate the severity of the diabetic retinopathy, but when the reader diagnosed serious diabetic retinopathy, it was always present on exam. CONCLUSIONS: The nonmydriatic retinal camera is easy to use, inexpensive, and can be used as part of a general diabetes exam, independent of a physician, in patients who should, but may not, be referred to an ophthalmologist. Any patient with abnormal findings on photos should be referred to an ophthalmologist, and any patient with findings of serious diabetic retinopathy on the photos should be referred immediately for possible laser therapy.     

Activated eosinophils in esophagitis in children: a transmission electron microscopic study

OBJECTIVE: To describe the interval between first appearance of mild nonproliferative diabetic retinopathy (NPDR) and first appearance of neovascularization (NV) in type I diabetes. SETTING: A longitudinal study of 269 patients followed up annually. PARTICIPANTS: Participants had insulin-dependent diabetes and were free of proliferative diabetic retinopathy in both eyes at the baseline visit. MAIN OUTCOME MEASURE: Stereoscopic color fundus photographs of each eye at each study visit, graded for features of retinopathy. RESULTS: Among the 305 eyes for which the duration of diabetes at the first appearance of mild NPDR could be determined, NV developed in 28 by the end of the study. Survival analysis showed that the later the onset of mild NPDR was, the shorter the time from onset of mild NPDR to onset of NV (relative hazard for each additional year to onset of mild NPDR, 1.22; 95% confidence interval, 1.10-1.35). Adjustment for systolic and diastolic blood pressure, proteinuria, and glycosylated hemoglobin (Hgb A10) levels did not change the relative hazard estimate for onset of mild NPDR. Higher levels of Hgb A10 were associated with a shorter time from onset of mild NPDR to onset of NV (relative hazard, 1.26; 95% confidence interval, 1.05-1.51 [after adjusting for time at onset of mild NPDR]), as were higher levels of diastolic blood pressure, although not significantly (relative hazard for 10-mm Hg increase in diastolic blood pressure, 1.52; 95% confidence interval, 0.82-2.83 [adjusting for onset of mild NPDR, Hgb A10 level, systolic blood pressure, and proteinuria]). Neither proteinuria nor systolic blood pressure had an effect on time from onset of mild NPDR to onset of NV, after adjustment for time at onset of mild NPDR, Hgb A10 level, and diastolic blood pressure. CONCLUSION: Later onset of mild NPDR is not necessarily associated with delayed development of NV in patients with type I diabetes. Caution must therefore be used in assessing the value of interventions that delay the onset of mild NPDR without evidence of delayed onset of NV.     

Vitrectomy for traction macular detachment in diabetic retinopathy

BACKGROUND: A small number of eyes with proliferative diabetic retinopathy develop massive central fibrovascular membranes characterized by vitreoretinal tractions along the arcades and optic disk and retinal traction lines extending through the macula. The aim of our study was first to present the results of vitrectomy for removal of these central membranes and second to determine the correlation between preoperative parameters and postoperative visual outcome. SUBJECTS AND METHODS: We treated 28 eyes with severe central fibrovascular diabetic membranes by a modified bi-manual en bloc excision technique during vitrectomy. Preoperative examination included general status, visual acuity, slit-lamp investigation, binocular funduscopy, ultrasound investigation and visual evoked potentials (VEP). Further, we analyzed intraoperative complications and postoperative anatomic and functional outcomes. RESULTS: The retinas of 27 eyes with central traction retinal detachments were reattached by surgery. With a minimum of 6 months' follow-up, the macula remained attached in 24 eyes, while the retinas were completely attached in 22 eyes. Preoperative visual acuity was defective light perception to 0.1; an increase in visual acuity to maximal 0.1 was seen in 50% of the patients postoperatively. Preoperative visual acuity of light perception was associated with no functional improvement. Preoperative ultrasound investigation gave information about the real anatomic situation of the retina, especially if funduscopy was not possible. The other preoperative parameters could not predict correctly the functional outcome of vitrectomy in diabetics with severe central fibrovascular membranes because of the damage of the optic nerve and the retina. CONCLUSIONS: The high rate of anatomical reattachment after vitrectomy in diabetic eyes with severe central fibrovascular membranes is associated with a slight improvement of function; only preoperative visual acuity of hand motions or better was associated with an improvement of function.     

Microperimetry of localized retinal nerve fiber layer defects

The aim of this study was to determine the sensitivity of retinal areas involved in a localized retinal nerve fiber layer (RNFL) defect and to assess correlations between microperimetry and the standard full threshold central 30 deg visual field test. Twenty-five patients with focal RNFL defects, evaluated by means of Argon-blue scanning laser ophthalmoscopy (SLO), underwent an automated 30 deg central visual field examination and a microperimetry with SLO. Microperimetry was performed according to standard procedures (infrared laser for fundus imaging; HeNe laser for 10 candles/m2 background illumination, fixation aid and generation of stimuli; manual fundus tracking). The size of stimuli was Goldmann III with 0.1 sec duration. In eyes with focal RNFL defects a deep microperimetric scotoma of at least 5 dB was found in 12 cases and a mild scotoma (1-4 dB) in 13 cases. These scotomas were mainly located throughout the whole defect or grouped in the temporal or nasal sides of the defect and were characterized by sharp and well-defined borders. With automated perimetry, a scotoma, defined by a single point depression of at least 10 dB or a depression of at least 5 dB in two or more contiguous points corresponding to the RNFL, defect, was found in only 14 out of 25 eyes with microperimetric defect. Focal RNFL defects correspond to localized areas of depressed retinal sensitivity as evaluated by microperimetry. The close correspondence between structural and microperimetric findings suggests that, in hypertensive eyes also, localized RNFL defects correspond to visual dysfunction possibly associated with substantial atrophy of ganglion cells.     

Longer-term visual outcome of eyes with retinopathy of prematurity treated with cryotherapy or diode laser

AIMS: Visual outcome of 66 eyes in 37 patients who had undergone treatment with either cryotherapy or diode laser for threshold retinopathy of prematurity was assessed. METHODS: 17 patients, representing 30 eyes treated with cryotherapy, were examined at between 56 and 98 months corrected age (median 68 months). 20 patients representing 36 eyes treated with diode laser, were examined at between 30 and 66 months corrected age (median 51 months). Structural outcome was categorised as: optimal--flat posterior pole; suboptimal--macular ectopia, optic nerve hypoplasia, retinal fold involving the macula, and retinal detachment involving the macula. RESULTS: Optimal structural outcome was, in the absence of amblyopia, associated with optimal visual acuity (of 6/12 or better) in all cases, with most eyes achieving a visual acuity of 6/9 or 6/6. Suboptimal structural outcome was invariably associated with suboptimal visual acuity. Amblyopia was present in eight out of 20 cryotherapy treated eyes and in five out of 26 laser treated eyes with an optimal structural outcome. Refractive errors were significantly less in laser treated eyes as was the incidence of anisometropic amblyopia. CONCLUSION: Eyes treated with either cryotherapy or diode laser for threshold retinopathy of prematurity with optimal structural outcome are associated with development of optimal visual acuity--that is, 6/12 or better. Treatment with either cryotherapy or laser does not in itself reduce the visual potential of these eyes.     

The role of vitrectomy for diabetic retinopathy

BACKGROUND: Diabetic retinopathy is an important cause of severe vision loss. The risk of vision loss from diabetic retinopathy is substantially reduced by intensive control of diabetes and appropriate laser surgery for proliferative diabetic retinopathy and diabetic macular edema. METHODS: The Diabetic Retinopathy Vitrectomy Study (DRVS) helped identify the indications and most propitious time for performing diabetic vitrectomy for nonresolving vitreous hemorrhage. The DRVS also highlighted the risks and potential complications of vitrectomy surgery. RESULTS: Diabetic persons with severe vision loss from severe proliferative diabetic retinopathy are candidates for vitrectomy after vitreous hemorrhage and severe fibrous changes in the retina. CONCLUSION: In cases in which vision loss occurs, pars plana vitrectomy frequently can restore useful vision, and reduce the risk of vision loss from traction retinal detachment.