TP53 mutations identify high-risk events for peripheral T-cell lymphoma treated with CHOP-based chemotherapy

Nodal peripheral T-cell lymphomas (PTCL), the most common PTCLs, are generally treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based curative-intent chemotherapy. Recent molecular data have assisted in prognosticating these PTCLs, but most reports lack detailed baseline clinical characteristics and treatment courses. We retrospectively evaluated cases of PTCL treated with CHOP-based chemotherapy that had tumors sequenced by the Memorial Sloan Kettering Integrated Mutational Profiling of Actionable Cancer Targets next-generation sequencing panel to identify variables correlating with inferior survival. We identified 132 patients who met these criteria. Clinical factors correlating with an increased risk of progression (by multivariate analysis) included advanced-stage disease and bone marrow involvement. The only somatic genetic aberrancies correlating with inferior progression-free survival (PFS) were TP53 mutations and TP53/17p deletions. PFS remained inferior when stratifying by TP53 mutation status, with a median PFS of 4.5 months for PTCL with a TP53 mutation (n = 21) vs 10.5 months for PTCL without a TP53 mutation (n = 111). No TP53 aberrancy correlated with inferior overall survival (OS). Although rare (n = 9), CDKN2A-deleted PTCL correlated with inferior OS, with a median of 17.6 months vs 56.7 months for patients without CDKN2A deletions. This retrospective study suggests that patients with PTCL with TP53 mutations experience inferior PFS when treated with curative-intent chemotherapy, warranting prospective confirmation.

Update of a phase II, multicenter study of high-dose chemotherapy with autologous stem cell transplant followed by maintenance romidepsin for T-cell lymphoma

7533

Background: Peripheral T-cell lymphomas (PTCL) have suboptimal outcomes with conventional chemotherapy. Autologous hematopoietic stem cell transplant (AHCT) is a therapeutic strategy for patients in first complete or partial remission (CR1 or PR1), with median progression-free survival (PFS) after AHCT of 36-48% by intent to treat (d’Amore et al JCO 2012, Reimer et al JCO 2009). Romidepsin (romi) is a histone deacetylase inhibitor approved for treatment of relapsed/refractory T-cell lymphoma. We present updated data of the first multicenter study to evaluate PFS of patients (pts) receiving maintenance therapy with romi after AHCT. Methods: This was a phase 2, open-label, investigator-initiated study (expected PFS 45%, desired PFS 70%; success achieved if 15 or more pts out of 25 were progression-free at 2 years post-AHCT). 26 pts transplanted in CR1 or PR1 were evaluable for the primary endpoint of 2-year PFS (Cohort 1, Table). An exploratory cohort (Cohort 2, n=7) enrolled pts either transplanted ≥ CR/PR2 (n=5) or with high risk histologies (n=2). Pts underwent AHCT with carmustine, etoposide, cytarabine and melphalan (BEAM) conditioning. Maintenance romi 14 mg/m2 started days 42-80 post AHCT; every other week through 6 mon, every 3 weeks through 1 year and every 4 weeks through 2 years post AHCT. PFS was estimated by Kaplan-Meier. Results: 47 pts consented; 13 did not receive romi (no AHCT, n=2; relapse before romi, n=3; cardiac comorbidity, n=3, patient declined, n=5). 1 consented pt did not have PTCL. 15 out of the first 25 pts in Cohort 1 were progression free after 2 years; median follow up of 31 mon (21 - 36 mon). Estimated 2-year PFS was 62% (45-83%, 95% CI); median PFS 30 mon (12.0- NA, 95% CI). In Cohort 2, estimated 2-year PFS was 43% (18 – 100, 95% CI); median follow up of 30 mon (range, 24 – 37 mon); median PFS 14 mon (5 – NA, 95% CI). Across cohorts, 5 pts required dose reduction. The most common toxicities (≥10% of pts, all grades) were fatigue (n=24, 73%), decreased platelets (n=16, 48%) and anemia (n=16, 48%). Conclusions: While the study did not meet its desired primary efficacy endpoint, maintenance romi was well-tolerated with an estimated 2-year PFS of 62%, greater than historical data. A larger, randomized study would be needed to determine the superiority of this approach. Clinical trial information: NCT01908777. [Table: see text]

Initial results of a multicenter, investigator initiated study of MRD driven time limited therapy with zanubrutinib, obinutuzumab, and venetoclax

8006

Background: Venetoclax (Ven)-Obinutuzumab (O) is approved for chronic lymphocytic leukemia (CLL) achieving frequent undetectable minimum residual disease (uMRD; Fischer NEJM 2019). Ven-Ibrutinib is synergistic with frequent uMRD but with grade >3 neutropenia in 33-48% patients (pts; Tam ASH 2019; Jain NEJM 2019). Zanubrutinib (B) is a highly specific BTK inhibitor that demonstrated 100% occupancy in lymphoid tissues, so may be preferred to combine with OVen. We hypothesize that treatment (tx) with BOVen using an MRD driven discontinuation strategy will achieve frequent uMRD and durable responses. Methods: In this multicenter, investigator initiated phase 2 trial (NCT03824483), eligible pts had previously untreated CLL requiring tx per iwCLL, ECOG PS <2, ANC >1, PLT >75 (ANC >0, PLT >20 if due to CLL). BOVen was administered in 28D cycles: B 160 mg PO BID starting D1; O 1000 mg IV D1 or split D1-2, 8, 15 of C1, D1 of C2-8; Ven ramp up initiated C3D1 (target 400 mg QD). Tx duration was determined by a prespecified uMRD endpoint (min 8 cycles). MRD was assessed in peripheral blood (PB; flow cytometry, sensitivity >10−4) starting C7D1 then every 2 cycles. Once PB uMRD was determined and confirmed in bone marrow (BM), tx continued 2 additional cycles. Adverse events (AE) were assessed per CTCAE v5. Median (med) time to uMRD (primary endpoint) was estimated using the Kaplan-Meier method. Results: The study accrued 39 pts (3-10/19): med age 59 years (23-73), 3:1 male, CLL IPI >4 26/39 (67%), unmutated IGHV 28/39 (72%), 17p del/ TP53 mutated 4/39 (10%), all pts were evaluable for toxicity with 37 evaluable for efficacy. At a med follow up of 8 months (mo; 3-10), 25/37 (68%) pts achieved PB uMRD. Med time to PB uMRD is 6 mo (4-8+). Another 8/37 (22%) had PB MRD < 0.1%. Of 25 with PB uMRD, 19 had BM uMRD with 10/19 completing 2 additional cycles and discontinued; 3 had BM MRD (all <0.02%); 3 pending. The most common tx emergent AEs were neutropenia (49%), infusion related reaction (41%), bruising (39%), and diarrhea (39%). Grade ≥3 AEs in ≥5% pts were neutropenia (13%), thrombocytopenia (5%), rash (5%), and pneumonia (5%). Of 17 pts at high risk for TLS on C1D1, 2 cycles of BO reduced TLS risk to low/medium at Ven initiation in 15 (88%). No pts had laboratory/clinical TLS (Howard). Conclusions: BOVen is well tolerated and achieves rapid uMRD: currently 68% PB uMRD and 51% BM uMRD with limited follow up (to be updated on presentation). Ten (27%) have discontinued treatment thus far. The value of MRD directed treatment duration will be evaluated with continued follow up. Clinical trial information: NCT03824483 .

Early data from a phase II trial investigating the combination of pembrolizumab (PEM) and entinostat (ENT) in relapsed and refractory (R/R) Hodgkin lymphoma (HL)

e20018

Background: Histone deacetylase (HDAC) inhibitors have single agent activity in various types of lymphoma. They have been shown to restore antigen-specific immune recognition in cancer cells and to downregulate PD-1 expression in circulating T lymphocytes. In preclinical studies, the combination of HDAC inhibitors and anti-PD-1 antibodies acts synergistically against various tumor models in mice. Accordingly, we investigated the safety and efficacy of the novel combination of the HDAC inhibitor ENT and the PD-1-blocking antibody PEM in patients with R/R HL. Methods: Patients with R/R HL received ENT 5-7 mg orally once weekly and PEM 200 mg intravenously once every three weeks. The primary objective is overall response rate (ORR) and 12-month progression-free survival (PFS). Multiplexed serum cytokine analysis of 20 pro-inflammatory cytokines and chemokines was performed on sera from peripheral blood samples collected at baseline and at 21 days on treatment. Results: At data cutoff on 2/5/20, 14 patients with HL have been enrolled. Out of 13 evaluable patients, 12 responded (92% ORR), including 3 who progressed on prior anti-PD-1 therapy. With a median duration of follow-up of 176 days (21-632), 9 patients are currently receiving treatment on study, 2 discontinued due to toxicity, 1 for progression, and 2 for consolidation with transplant or radiation. After 21 days on treatment, there was a decrease in median serum levels of eotaxin (-39%, p = 0.002), eotaxin-3 (-56%, p = 0.04), MDC (-78%, p = 0.025), MIP1a (-60%, p = 0.025), and TARC (-98%, p < 0.001) and a 3-fold increase in median levels of IFNγ (p = 0.032). There was an association between extent of tumor reduction and greater decrease in the cytokines eotaxin-3 (-62%, p = 0.064), MDC (-90%, p = 0.064), and MIP1a (-85%, p = 0.064), which trended towards statistical significance. Out of 22 total patients enrolled in this study (including 8 patients with follicular lymphoma), 62% had grade ≥3 adverse events (AE), which were predominantly hematologic, including neutropenia (48%), thrombocytopenia (19%), and anemia (10%). Immune-related AEs included 3 cases of hypothyroidism, 2 cases of hepatitis and 1 case of pneumonitis. Four patients who experienced serious AEs due to pericarditis (n = 2), hemophagocytic lymphohistiocytosis, and bullous dermatitis were taken off study. Conclusions: Early results from this ongoing phase II clinical trial suggest that the combination of PEM and ENT is safe with encouraging responses in HL. Clinical trial information: NCT03179930 .

Pilot study of gemcitabine, nab-paclitaxel, PEGPH20, and rivaroxaban for advanced pancreatic adenocarcinoma: An interim analysis

405

Background: PEGPH20 (P) degrades hyaluronan (HA), a key component of pancreatic adenocarcinoma (PDAC) tumor microenvironment, leading to reduction of tumor interstitial pressure, decompression of tumor blood vessels and improvement in delivery of chemotherapeutics. A prior study of P with chemotherapy in PDAC (HALO-202) found an increased risk of thromboembolic (TE) events, 43%, effectively reduced with subcutaneous enoxaparin treatment. Rivaroxaban (R) is a safe and effective oral anticoagulant for treating cancer-related TE. Methods: 28 patients with advanced PDAC, KPS ≥ 70 and without prior TE were enrolled from January to June 2017. Patients received treatment with PAG (P; 3 µg/kg IV 2x/wk x 3 wks in C1, then 1x/wk x 3 wks in C2+, plus AG) every 28 days, with R (15 mg twice daily for 21 days, followed by 20 mg once daily). Primary endpoint is symptomatic TE event rate; secondary endpoints include PFS, OS, major bleeding rate and RR. Results: All 28 patients are evaluable for efficacy and safety. Key patient characteristics: age = 62 (range 45-76), M/F = 15/13, stage III/IV = 4/24, KPS 70/80/90 = 1/13/14. Median follow-up is 5.4 mo. No symptomatic and one grade 2, asymptomatic TE event (DVT) occurred (1/28 = 3.6%). Two grade 3 GI hemorrhages occurred. Best responses: partial response 11 (39%), stable disease 13 (46%), progressive disease 4 (14%), and overall disease control rate of 86%. Median PFS and OS have not been reached. Conclusions: Interim analysis shows R is safe and effectively prevents TE events in patients receiving PAG. Responses and disease control rate are encouraging in this tumor HA-level unselected patient population. Updated safety and efficacy data will be reported. Clinical trial information: NCT02921022.

A dual role for the RhoGEF Ephexin5 in regulation of dendritic spine outgrowth

The outgrowth of new dendritic spines is closely linked to the formation of new synapses, and is thought to be a vital component of the experience-dependent circuit plasticity that supports learning. Here, we examined the role of the RhoGEF Ephexin5 in driving activity-dependent spine outgrowth. We found that reducing Ephexin5 levels increased spine outgrowth, and increasing Ephexin5 levels decreased spine outgrowth in a GEF-dependent manner, suggesting that Ephexin5 acts as an inhibitor of spine outgrowth. Notably, we found that increased neural activity led to a proteasome-dependent reduction in the levels of Ephexin5 in neuronal dendrites, which could facilitate the enhanced spine outgrowth observed following increased neural activity. Surprisingly, we also found that Ephexin5-GFP levels were elevated on the dendrite at sites of future new spines, prior to new spine outgrowth. Moreover, lowering neuronal Ephexin5 levels inhibited new spine outgrowth in response to both global increases in neural activity and local glutamatergic stimulation of the dendrite, suggesting that Ephexin5 is necessary for activity-dependent spine outgrowth. Our data support a model in which Ephexin5 serves a dual role in spinogenesis, acting both as a brake on overall spine outgrowth and as a necessary component in the site-specific formation of new spines.

Phase I/II trial of vorinostat with rituximab, cyclophosphamide, etoposide and prednisone as palliative treatment for elderly patients with relapsed or refractory diffuse large B-cell lymphoma not eligible for autologous stem cell transplantation

The standard treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL) in frail elderly patients has not been established. A variation was made on rituximab (R), cyclophosphamide (C), etoposide (E), procarbazine and prednisone (P), substituting vorinostat (V) for procarbazine. Patients ≥aged 60 years with relapsed/refractory DLBCL, not candidates for autologous stem cell transplantation, were treated R-CVEP [R 375 mg/m(2) intravenously (IV), day 1; C 600 mg/m(2) IV days 1, 8: E 70 mg/m(2) IV day 1, 140 mg/m(2) days 2, 3 orally (PO); V (300 vs. 400 mg) PO and P 60 mg/m(2) PO days 1-10] every 28 d for six cycles. Quality of life (QoL) was assessed in addition to response. Thirty patients (median age 76 years, 69-88) were enrolled (one died before treatment). Maximum tolerated dose (MTD) for V was 300 mg. For 23 patients at MTD (six phase I + 17 phase II), two were discontinued for toxicity, one withdrew consent, eight achieved complete response (35%), five achieved partial response (22%) and seven progressed (25%). Median overall survival was 17·5 months. Median progression-free survival was 9·2 months. Nine patients are alive. QoL declined during treatment but improved above baseline for patients who completed treatment. In conclusion, R-CVEP was tolerated at MTD and produced durable responses with improved QoL.

Final results of phase I/II trial of vorinostat in combination with cyclophosphamide, etoposide, prednisone, and rituximab (R-CVEP) for elderly patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL)

8054

Background: Standard treatment of relapsed/refractory DLBCL in elderly patients who are not candidates for autologous stem cell transplantation (auSCT) has not been established. Cyclophosphamide (C), etoposide (E), prednisone (P) and procarbazine (CEPP) has been used by many clinicians based on limited data (Blood 76: 1293-98, 1990). Vorinostat (V) is a histone deacetylase inhibitor that is approved for relapsed cutaneous T-cell lymphoma and has activity in B-cell lymphomas. This trial defined the maximum tolerated dose (MTD) of V added to standard therapy and determined the response rate of this combination. Methods: Patients ≥age 60 with relapsed/refractory DLBCL not candidates for auSCT were enrolled on R-CVEP (R 375mg/m2 IV, d1; C 600mg/m2 d1 and 8, E 70mg/m2 IV d1, 140mg/m2 d2 and 3; V PO and Pred 60mg/m2 PO d1-10) every 28 days for 6 cycles. In the phase I component V was administered at doses of 300mg/d or 400mg/d for 10 days. The phase I was a 3 + 3 design and the phase II a two stage design requiring 8/20 complete responses (CR) for expansion. Assessment of response utilized end-of-treatment positron emission tomography (PET) (JCO 25: 579-86, 2007). Quality of life (QOL) was measured with the FACT-Lym v.4. Results: 27 pts. were enrolled. 1 died before treatment. For 26 pts: median age 76 yrs. (69-88), 14 females and 12 males, baseline PS (ECOG) 1 (0-2). Median follow-up for survivors: 9.2 mo. Phase I: 6 pts. at 300mg/d (no dose-limiting toxicity-DLT), 6 pts. at 400mg/d (2 grade 3 neutropenia = DLT). MTD 300mg/d x 10d. For 20 pts. at V 300mg/m2 (6 phase I + 14 phase II): 2 off study for toxicity, 1 withdrew consent, 6 CR (30%), 5 partial response (PR) (25%), 6 progressed (30%). Phenotypic overall responses (OR): germinal center (GC) 4/8 (2 CR), non-GC 6/10 (3 CR), transformed CLL 1/2 (1 CR). Median progression-free survival: 10 mo. QOL results will be presented. Conclusions: OR rate for V added to conventional chemotherapy and R was 55% (CR 30%, PR 25%) in relapsed/refractory DLBCL in elderly pts. not candidates for auSCT. This could provide a baseline for comparison with future clinical trials in this understudied population.

Diabetic retinopathy--an historical review

Diabetic macular changes in the form of yellowish spots and extravasations that permeated part or the whole thickness of the retina were observed for the first time by Eduard Jaeger in 1856. This was only possible as a result of the newly developed direct ophthalmoscope that was first described in 1855. Jaeger's findings were controversial at the time and Albrecht von Graefe openly claimed that there was no proof of a causal relationship between diabetes and retinal complications. It was only in 1872 that Edward Nettleship published his seminal paper "On oedema or cystic disease of the retina" providing the first histopathological proof of "cystoid degeneration of the macula" in patients with diabetes. In 1876, Wilhelm Manz described the proliferative changes occurring in diabetic retinopathy and the importance of tractional retinal detachments and vitreous haemorrhages. In the early years of the 20th century, the debate continued whether macular changes were directly related to diabetes or whether they were due to hypertension and arteriosclerosis. It was not until the second half of the century that the work of Arthur James Ballantyne in Glasgow provided more evidence that suggested that diabetic retinopathy represents a unique vasculopathy.

Phacoemulsification versus extracapsular cataract extraction in patients with diabetes

OBJECTIVE

To compare phacoemulsification with extracapsular cataract surgery in patients with diabetes and to identify determinants of postoperative visual acuity.

DESIGN

Prospective, randomized, paired-eye trial.

PARTICIPANTS

Forty-six patients with diabetes and bilateral cataract.

INTERVENTION

Patients were allocated to phacoemulsification surgery with silicone intraocular lens to one randomly determined eye, and extracapsular cataract surgery with 7-mm polymethylmethacrylate intraocular lens to the other.

MAIN OUTCOME MEASURES

Logarithm of minimum angle of resolution visual acuity (logMAR VA), incidence of clinically significant macular edema (CSME), retinopathy progression, indices of anterior segment inflammation, and incidence of capsulotomy.

RESULTS

Compared with eyes undergoing phacoemulsification, eyes managed with extracapsular surgery had more anterior chamber cells (P = 0.0004) and flare (P = 0.007) 1 week after surgery and a higher incidence of posterior synechiae (P = 0.04) and intraocular lens deposits (P < 0.0005) in the first postoperative year. The need for posterior capsulotomy was greater in eyes undergoing extracapsular surgery (16 of 46 vs. 5 of 46, P = 0.01). No difference in incidence of postoperative CSME, progression of retinopathy, or development of high-risk proliferative retinopathy was identified between techniques (P = 1.0, 0.8, and 0.2). Median 1-year logMAR VA was worse in eyes undergoing extracapsular surgery (0.08 vs. 0.06, P = 0.02), especially in those with retinopathy (0.14 vs. 0.08, respectively; P = 0.01). The presence or absence of CSME at the time of surgery was the most significant determinant of 1-year logMAR VA in regression models for both extracapsular (P = 0.0004, R2 = 0.45) and phacoemulsification groups (P < 0.00005, R2 = 0.46).

CONCLUSIONS

Phacoemulsification is associated with better postoperative VA, less postoperative inflammation, and less need for capsulotomy than extracapsular cataract surgery in patients with diabetes. However, with both techniques, the principal determinant of postoperative VA appears to be the presence or absence of CSME at the time of surgery. Early intervention, reducing the risk that unrecognized CSME is present at the time of surgery, may be more critical to outcome than choice of surgical technique.

Micropulse laser in the treatment of diabetic macular edema

The micropulse laser is a new development in laser therapy. Micropulsing is frequent short pulses of subthreshold intensity applied to retinal lesions. It has been shown to be effective in diabetic macular edema, branch vein occlusion, and drusen. Although the initial landmark studies showed it to be effective, the exact parameters have not been established. This article illustrates the current state of its use.

Ocular manifestations of diabetes mellitus

The ocular complications of diabetes mellitus are numerous and include retinopathy, cataract, uveitis, and neurophthalmic disorders. A review of the current literature shows that the emphasis has changed from the laser and surgical management of pre-existent retinopathy to the development of cohesive multidisciplinary screening and education programs, and to a better understanding of the cellular and molecular mechanisms that underlie disease. The role of associated and potentially modifiable systemic factors is also now recognized. Early intervention with systemic and local therapies may soon provide hope for the better management of diabetic eye disease.

Panretinal photocoagulation during cataract extraction in eyes with active proliferative diabetic eye disease

PURPOSE

Cataract surgery in the presence of active proliferative diabetic eye disease carries a high risk of progression of retinopathy and neovascular glaucoma. Lens opacities may prevent panretinal photocoagulation (PRP) before surgery, and applying PRP in the immediate post-operative period can be difficult. The purpose of this study is to report results of cataract extraction combined with per-operative indirect laser PRP in a group of these patients.

METHODS

Nine eyes of 9 diabetic patients with active retinal or iris neovascularisation in which lens opacities prevented adequate pre-operative PRP underwent cataract surgery combined with indirect laser PRP after cortex aspiration and before intraocular lens implantation.

RESULTS

Regression of neovascularisation with this combined procedure alone was achieved in 5 eyes, 3 responded to further PRP, and 1 developed neovascular glaucoma. Visual acuity improved in all eyes, 4 achieving > or = 6/12. Four patients developed increased post-operative uveitis. One developed clinically significant macular oedema.

CONCLUSIONS

The method described has definite practical advantages over PRP attempted in the immediate post-operative period, when many factors can prevent its application or reduce its effectiveness, and when neovascularisation may be progressing rapidly. In addition, adjunctive per-operative indirect laser PRP appears to improve the outcome of cataract surgery in eyes with active proliferative diabetic eye disease.

Clinical applications of the MicroPulse diode laser

PURPOSE

To evaluate the efficacy of the Iris Oculight MicroPulse 810 nm diode laser in the treatment of macular oedema secondary to either branch retinal vein occlusion (BRVO) or diabetic maculopathy and in the treatment of proliferative diabetic retinopathy. The specific advantages of this type of laser delivery are greater retinal pigment epithelial specificity and less damage to the inner retina, thus preserving visual field and colour contrast sensitivity.

METHODS

Fifty-two eyes of 33 consecutive patients were treated over a 6-month period. Thirteen eyes had proliferative diabetic retinopathy and 39 had macular oedema secondary to BRVO or diabetic maculopathy. Panretinal and grid pattern photocoagulation were performed using the micropulse mode with the laser on for 100-300 microseconds and off for between 1900 and 1700 microseconds repeatedly in a pulse envelope of 0.1-0.3 s duration. Microaneurysms were not treated directly. Patients were assessed clinically and angiographically at 3 and 6 months.

RESULTS

Ten eyes (77%) with proliferative disease showed some regression of new vessels at 6 months. Twenty-two eyes (57%) showed resolution of macular oedema at 6 months. Visual acuity was maintained in 27 eyes (69%) and improved in 11 eyes (28%).

CONCLUSION

Diode laser in micropulse mode is effective in the management of diabetic and occlusive macular oedema and proliferative diabetic disease.

The natural history of macular edema after cataract surgery in diabetes

OBJECTIVE

To determine the natural history of macular edema after cataract surgery in diabetes to provide a rational basis for laser therapy.

DESIGN

Prospective clinical and angiographic trial.

PARTICIPANTS

Thirty-two patients with diabetes undergoing cataract surgery.

INTERVENTION

Phacoemulsification surgery with intraoperative fluorescein angiography, and postoperative clinical and angiographic assessment without macular laser therapy for 1 year after surgery.

MAIN OUTCOME MEASURES

Clinically significant macular edema, postoperative macular and optic disc hyperfluorescence relative to the intraoperative angiogram, and logarithm of the minimum angle of resolution (LogMAR) visual acuity.

RESULTS

In the first postoperative year, macular fluorescence remained at its intraoperative level in 2 (6%) of 32 eyes and increased in 30 (94%) of 32 eyes, returning to its intraoperative level within 1 year of surgery in 13 (43%) of 30 eyes. Optic disc fluorescence remained at its intraoperative level in 2 (6%) of 32 eyes, was not graded in 3 (9%) of 32 eyes, and increased in 27 (84%) of 32 eyes, returning to its intraoperative level within 1 year of surgery in 19 (70%) of 27 eyes. Clinically significant macular edema was identified in the first postoperative year in 18 (56%) of 32 eyes, being present at the time of surgery in 5 eyes and arising de novo within 1 year of surgery in 13 eyes. It resolved spontaneously within 1 year of surgery in 0 of 5 eyes in which it had been present at the time of surgery and in 9 (69%) of 13 eyes in which it arose in the first 6 months after surgery (P = 0.05). Angiographic and clinical resolutions of macular edema were less likely in eyes with more severe retinopathy at the time of surgery (P = 0.03, 0.005). One-year LogMAR acuity of 0.3 or less (> or = 20/40) was achieved in 27 (84%) of 32 eyes. Clinically significant macular edema at the time of surgery was associated with poorer 1-year visual acuity in multivariate analysis (P = 0.005, r2 = 0.5).

CONCLUSIONS

Clinically significant macular edema present in diabetic eyes at the time of cataract surgery is unlikely to resolve spontaneously, but clinically significant macular edema arising after surgery commonly resolves, particularly if retinopathy is mild. These findings have implications for the timing of cataract surgery in diabetes and postoperative macular laser therapy. Ophthalmology 1999;106:663-668

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.

Partial laser ablation of massive peripapillary subretinal neovascularization

BACKGROUND

Although peripapillary subretinal neovascular membranes (PSRNs) are less common and often larger than neovascular complexes arising near the fovea, they may lead to severe visual loss. Very large (massive) PSRNs (MPSRNs) are 3.5 disc areas or greater in overall size, are even less common, and may contain a significant occult component, leading to slow and unpredictable growth. Such massive lesions may begin at the nasal margin of the disc and do not become symptomatic until they have extended around the disc toward the macula, threatening central vision. Although complete laser ablation has been used for symptomatic PSRNs with variable success, the optimal treatment of MPSRNs remains controversial.

METHODS

The authors reviewed the clinical course of 12 eyes of seven patients with MPSRNs. Ten eyes received laser treatment, which was limited to the temporal portion of the subretinal neovascular complexes only and two received no treatment.

RESULTS

Of the ten eyes receiving laser treatment, six showed stabilization of visual acuity, whereas in four the neovascular membrane progressed beneath the fovea with severe visual loss. In the two untreated eyes, the subretinal neovascular membrane progressed beneath the macula with the loss of central vision.

CONCLUSIONS

In contrast to the small symptomatic PSRNs, which are usually treated by complete laser ablation, MPSRNs may stabilize with only partial laser treatment. However, both types of lesions may remain stable for long periods of time without any treatment and require treatment only if progression toward the fovea occurs.

The venous closing pressure in central retinal vein obstruction

OBJECTIVE

To assess the rate of change in the central retinal venous closing pressure in central retinal vein obstruction over time, and its relationship to visual acuity improvement and the development of rubeosis iridis.

METHODS

Fifty patients presenting with central retinal vein obstruction of less than three months' duration, between the ages of 40 and 80 years, were reviewed prospectively. The central retinal venous closing pressure was measured by digital ocular compression. Patients were discharged from the study after the six-month visit.

RESULTS

All patients had elevated venous closing pressure at presentation, whereas at six months only 24 patients had persistent elevation. Of 16 patients with lowering of the venous closing pressure within four months of onset of central retinal vein obstruction, 11 (69%) had two or more lines of visual acuity improvement. Only two of 10 patients (20%) developing lowering of the venous closing pressure thereafter had visual improvement. No patient developed rubeosis iridis after the venous closing pressure lowered.

CONCLUSION

The central retinal venous closing pressure is raised in central retinal vein obstruction to about central retinal arterial diastolic pressure, and is its pathognomonic sign. This sign is easily elicited via digital pressure on the eyelid, and has prognostic significance for visual acuity improvement and the development of rubeosis iridis.

Extracapsular cataract surgery with and without intraocular lens implantation in Fuchs heterochromic cyclitis

PURPOSE

To compare the surgical and postoperative complications and visual outcome of extracapsular cataract extraction (ECCE) with and without intraocular lens (IOL) implant in Fuchs heterochromic cyclitis.

METHODS

The records of 77 patients with Fuchs heterochromic cyclitis who had undergone ECCE were reviewed. Of a total of 77 eyes, a posterior chamber IOL (PC IOL) was implanted in 43 eyes, whereas 34 eyes did not receive an implant.

RESULTS

In the pseudophakic group, 40 (93%) eyes achieved 20/40 or better. This level also was achieved in 29 (85%) eyes not receiving an implant. Intraoperative anterior chamber hemorrhage was documented in 18 eyes but there was no correlation with preoperative gonioscopic findings. A temporary or permanent elevation of intraocular pressure was noted in five of eight eyes that had marked anterior chamber hemorrhage. Severe postoperative uveitis occurred in ten eyes and was more common in patients with glaucoma who had PC IOL implantation, but this did not adversely affect the visual outcome. Of 40 eyes with PC IOL implant, severe postoperative uveitis developed in 7. In six of these seven eyes, the implant was a three-piece lens with polypropylene haptics. Severe postoperative uveitis developed in 6 of 16 eyes with preoperative glaucoma. Five of these six eyes had a PC IOL implant. Of the 34 aphakic patients, 10 (29%) were intolerant of contact lens correction. There was no difference in the incidence of postoperative uveitis, cystoid macular edema, and development of glaucoma between the two groups.

CONCLUSION

Implantation of PC IOLs in ECCE in patients with Fuchs heterochromic cyclitis appears to a safe procedure, but careful postoperative follow-up of intraocular pressure, particularly in patients with intraoperative hemorrhage or postoperative uveitis, is indicated.

Is the first day postoperative review necessary after cataract extraction?

BACKGROUND

In current ophthalmic practice day-case surgery cataract patients are conventionally discharged and then reviewed the following morning thus limiting the advantages of what 'true' day-case surgery strives to achieve. The aim of this study was to see if there was a difference in outcome between 'true' day-case cataract surgery and non-day-care surgery.

METHODS

A total of 387 consecutive cataract operations were followed, comprising 122 local anaesthetic day-cases, 149 local anaesthetic non-day-cases, 63 general anaesthetic non-day-cases, and 53 general anaesthetic day-cases.

RESULTS

Although not randomised the groups were comparable with respect to age, operator grade, sex, presence of diabetes, anaesthetic type, pre and postoperative visual acuities, and time to first planned outpatient visit. There were 10 early postoperative complications in the day-case group (5.71% of total) and 14 in the non-day-case group (6.6% of total), the commonest complications in both groups were raised intraocular pressure, corneal oedema, and wound leaks. One patient in each group had an early complication that necessitated attending the casualty department. The visual outcomes in both groups were comparable.

CONCLUSIONS

These findings suggest that there were no preventable complications within the constraints of the number of operations studied and that no additional risk is attached to 'true' day-case surgery relative to non-day-case surgery.

Influence of myosin isoforms on tension cost and crossbridge kinetics in skinned rat cardiac muscle

1. In attempting to consolidate the role of ventricular isomyosins in regulating the contractility of the myocardium, actomyosin ATPase and crossbridge kinetics were obtained at 24 degrees C in chemically skinned isometrically contracting cardiac muscles containing V1 and V3 isomyosins. 2. The ATPase activity was measured at various levels of Ca2+ activation by the enzymatic coupling of ATP hydrolysis with the conversion of NADH to NAD+. The crossbridge kinetics were inferred from small-amplitude perturbations of muscle length and muscle tension, and characterized by the frequency-domain parameter fmin. 3. The ATPase rates of V1 and V3 muscles obtained at various levels of Ca2+ activation were plotted against the corresponding proportional tensions. The ATPase vs tension plots were linear with slopes of 4.92 nmol/min-1 per mm per mN and 1.98 nmol/min-1 per mm per mN, respectively for, V1 and V3 muscles. Individual calculations of ATPase-to-tension ratios (nmol/min-1 per mm per mN) gave corresponding averages of 4.98 +/- 0.12 (s.e.m., n = 12) and 2.16 +/- 0.12 (s.e.m., n = 10). The myosin isoform induced proportional change in tension cost was accompanied by a similar change in fmin (4.1 +/- 0.1 Hz and 1.95 +/- 0.03 Hz, means +/- s.e.m., for V1 and V3 muscles, respectively). 4. The observations and other published kinetic data are discussed in the context of models of crossbridge cycling. It is suggested that the tension economy of V3 muscle arises principally from an increase in the fraction of time, during the crossbridge cycle, when the crossbridge is exerting force.

Clinical comparison of semiconductor diode versus neodymium: YAG non-contact cyclo photocoagulation

AIMS

The advent of diode lasers has allowed their use in transscleral cyclo photocoagulation for refractory glaucoma. A trial was performed to compare the ocular hypotensive and inflammatory effects of cyclo photocoagulation using a continuous wave diode (810 nm) and a free running neodymium:yttrium aluminium garnet (Nd:YAG) laser (1064 nm).

METHODS

Forty patients with refractory glaucoma were randomised to receive either diode or Nd:YAG therapy. The intraocular pressure (IOP) and inflammatory response to treatment were monitored over 3 months.

RESULTS

There was no significant laser related difference in the effect on IOP after one treatment. There was, however, a difference in effect in retreatments with the IOP lowering effect significantly less, but equally sustained in diode retreatment patients. Severe postoperative complications such as hyphaema or fibrinous anterior uveitis only occurred in the Nd:YAG group.

CONCLUSION

The degree and duration of the ocular hypotensive response to cyclo photocoagulation appears to be related to the available power output of the system used, and the extent of tissue damage.

Visual acuity following extracapsular cataract extraction in diabetes: a meta-analysis

Although pre-operative retinopathy severity appears to be a major factor in determining the visual outcome of diabetic extracapsular cataract extraction, its precise relationship to post-operative visual acuity is ill defined. A meta-analysis was therefore carried out, and studies were included if pre-operative maculopathy and retinopathy status was sufficiently defined to permit discrimination of visual outcome between subgroups. Weighted mean proportions of eyes achieving a post-operative visual acuity > or = 6/12 were as follows: no retinopathy, 87%; non-proliferative retinopathy with no maculopathy, 80%; quiescent proliferative retinopathy with no maculopathy, 57%; non-proliferative retinopathy with maculopathy, 41%; quiescent proliferative retinopathy with maculopathy, 11%; active proliferative retinopathy, 0. Differences in visual outcome between groups were significant (chi 2 = 119.9, p < 0.0005), attributable mostly to the trend across groups (chi 2 for trend = 115.4, p < 0.0005). Logistic regression indicated that maculopathy was a more potent predictor of post-operative visual acuity < or = 6/12 (odds ratio 6.4, 95% CI 4.13-9.94, p < 0.0005) than quiescent proliferative retinopathy (odds ratio 3.33, 95% CI 2.04-5.42, p < 0.0005). The severity of retinopathy and maculopathy prior to cataract surgery in diabetics are the major determinants of post-operative visual acuity. Further study of the relationship between pre-operative retinopathy severity and the incidence of post-operative complications, progression of retinopathy and maculopathy is required to optimise the management of cataract in diabetes.

Diode laser photocoagulation for diabetic macular oedema

AIMS

This study aimed to investigate whether diode laser irradiation, which is poorly absorbed by haemoglobin, can induce closure of leaking retinal microvascular lesions in the treatment of diabetic macular oedema.

METHODS

Thirty three eyes with clinically significant diabetic macular oedema were treated with a diode laser. Fundus evaluation before and after treatment included visual acuity, stereoscopic biomicroscopy, colour photographs, and fluorescein angiography.

RESULTS

At a mean period of review of 6 months macular oedema had completely or partially resolved in 27 eyes. Visual acuity improved in three, deteriorated in one, and was unchanged in 29 eyes.

CONCLUSION

Preliminary data suggest that diode laser therapy induces closure of leaking retinal microaneurysms and is effective in the treatment of diabetic macular oedema.

Posterior capsule opacification following diabetic extracapsular cataract extraction

Review was performed of extracapsular cataract extraction with posterior chamber lens implantation in 90 diabetic patients and 263 non-diabetic patients. There was a higher incidence of posterior capsular opacification as judged by the requirement for Nd:YAG posterior capsulotomy in patients with non-proliferative (12/35, 34%) or quiescent proliferative diabetic retinopathy (8/18, 44%) than in non-diabetic patients (48/263, 18%) (Mantel-Haenszel p = 0.04). Although subgroup analysis showed a higher incidence of posterior capsule opacification in diabetics with non-proliferative or quiescent proliferative retinopathy than in diabetics without retinopathy, this was not statistically significant (Mantel-Haenszel p = 0.19 and p = 0.07, respectively). Following cataract surgery in diabetics with retinopathy, frequent review and prompt management of posterior capsular opacification is recommended, to maintain adequate fundus visualisation at a time when deterioration of retinopathy is likely.

Adult Coats' disease in branch retinal vein occlusion

We report a case of adult Coats disease secondary to a branch retinal vein occlusion. Angiograms show the relationship of the peripheral telangiectasis, aneurysm formation and vascular incompetence to the peripheral retinal ischaemia. The possible role of vascular remodelling in the pathogenesis of this uncommon complication of a common condition is discussed.

Color contrast sensitivity and pattern electroretinographic findings after diode and argon laser photocoagulation in diabetic retinopathy

The retinal depth at which photocoagulation is maximal varies with wavelength. We compared visual function of eyes undergoing photocoagulation by the near-infrared diode laser to the argon green laser. We treated 14 patients with diabetic retinopathy requiring bilateral panretinal photocoagulation with the diode laser on the right eye and the argon system on the left eye. Before and after treatment visual acuity, central and peripheral color contrast sensitivity, and pattern electroretinograms were recorded. No difference was noted in the clinical response or visual acuity outcome, but a tendency was observed for less decline in color contrast sensitivity and pattern electroretinogram recordings after diode laser photocoagulation. Although P values (.05 to .5) did not reach significance, a mean of 8.4 of 14 patients per test had better test results after diode laser treatment. Diode laser photocoagulation seems to be a viable alternative to argon laser treatment and may be a more gentle mode of treatment.

Immunofluorescence analysis of B-1 cell ontogeny in the mouse

In order to further understand the developmental aspects of B-1 cells, we characterized the ontogeny of this B cell population in the spleen and peritoneal cavity of BALB/c mice. Although there are B-1 cells in the spleen within the first 1-3 weeks after birth, they do not at any stage represent the majority of splenic B cells. Splenic B-1 cells reach peak levels at approximately 9 days after birth. The mesenteric lining that covers the small intestine of 7-day-old mice contains a population of IgM+ B cells, while at the same age, there are few lymphoid cells in the peritoneal cavity. Between 7 and 8 days after birth there is an influx of B cells into the peritoneal cavity. At 8 days, the first detectable peritoneal B cells appear to be of the B-1 type based on expression of IL-5 receptor and CD5. However, these peritoneal B-1 cells do not express Mac-1. This antigen is not expressed by the majority of peritoneal B-1 cells until 3 weeks. This study indicates that the majority of early splenic B cells are not B-1 cells and it suggests that the mesenteric tissues surrounding the gut contain B lymphocytes which traffic into the peritoneal cavity where they then reside.

Effects of IgM allotype suppression on serum IgM levels, B-1 and B-2 cells, and antibody responses in allotype heterozygous F1 mice

IgM allotype heterozygous F1 mice were independently suppressed for Igh6a or Igh6b to evaluate the contribution of B-1 and B-2 cells to natural serum IgM levels and Ab responses. B-2 B cells expressing IgM of the suppressed allotype were evident in the spleens of suppressed mice 4 to 6 weeks after cessation of the suppression regimen, whereas B-1 B cells of the suppressed allotype were undetectable for up to 9 months. Although serum IgM of the suppressed allotype was initially depleted in mice suppressed for either allotype, by 7 months of age, there were detectable levels of IgM of the suppressed allotype in the serum; however, the levels were significantly below that found in nonsuppressed mice. When mice were immunized with either the T-independent or T-dependent form of phosphorylcholine, those suppressed for either allotype, and consequently depleted of B-1 B cells of that allotype, did not respond with phosphorylcholine-specific IgM of the suppressed allotype. In contrast, when mice were immunized with alpha 1-3 dextran, the Igh6a allotype-suppressed mice were able to produce dextran-specific IgM of that allotype. These results show that allotype-bearing B-1 cells of both allotypes can be effectively suppressed by this suppression protocol and this produces long-lasting effects on B-1 cell levels and serum IgM of the suppressed allotype. These observations reflect the derivation of the majority of B-1 cells from fetal-neonatal precursors, which cannot be replaced by newly emerging B-2 cells of adult origin. Their ablation by antibody treatment results in permanent alterations to the adult B-cell repertoire.

Orbital ultrasound in the ocular ischaemic syndrome

The ocular ischaemic syndrome illustrates well the effects of hypoperfusion of the globe and is a useful model for studying disorders of the orbital circulation. Recent advances in orbital ultrasound techniques have provided a non-invasive method of examining flow velocities in the orbital vessels, particularly the ophthalmic artery. Orbital ultrasound studies were performed on 3 cases of the ocular ischaemic syndrome. Continuous or intermittent reversal of blood flow in the ophthalmic artery was seen in all cases. How this phenomenon relates to the symptoms and signs in affected patients, and the role of orbital ultrasound in the investigation of the ocular ischaemic syndrome, are discussed.

No-needle one-quadrant sub-tenon anaesthesia for panretinal photocoagulation

Panretinal photocoagulation (PRP) is tolerated well by most patients using topical anaesthesia alone, though there are a significant number of patients who experience pain. Additional local anaesthesia alternatives for these patients include retrobulbar, peribulbar or subconjunctival injection. Deep introduction of a sharp needle may rarely cause damage to orbital structures, whereas no-needle sub-Tenon irrigation of local anaesthetic solution to the posterior Tenon's space theoretically avoids these risks. A one-quadrant, inferior-nasal, sub-Tenon delivery of 1.5-2 ml plain 2% lignocaine was administered and PRP performed on 12 eyes of 12 patients who were previously intolerant of PRP by topical anaesthesia alone. To assess the efficacy of anaesthesia, patients were asked to score pain, using a visual analogue score chart graded from 0 to 10. If patients were unable to see the chart, or read the accompanying text, a verbal explanation and description of the scoring chart was performed. Where PRP was performed with topical amethocaine 1% alone, pain scores were graded as median 8, mean 8.5 and range 6-10. The administration of sub-Tenon anaesthesia was well tolerated with a median pain score of 1.5, mean 1.9 and range 0-5. PRP after sub-Tenon administration was successfully completed in 11 of the 12 patients with a median pain score of 1.5, mean 1.8 and range of 0-9. The range was wide due to one patient with a high pain score who was intolerant of PRP in spite of the sub-Tenon delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of diode laser trabeculoplasty for primary open-angle glaucoma and ocular hypertension

BACKGROUND

Initial studies of laser trabeculoplasty using infrared energy (810 nm) emitted by diode semi-conductor lasers have been encouraging. A 2-year study of diode laser trabeculoplasty (DLT) in the control of primary open-angle glaucoma (POAG) and ocular hypertension has been completed.

METHODS

Patients with uncontrolled POAG or ocular hypertension were treated with DLT to one half of the trabecular meshwork using a trabeculoplasty lens. Spot size was 100 microns, exposure time was 0.2 second, and mean power was 1096 mW (+/- 46.5 mW). The desired endpoint was a mild blanching of the meshwork only.

RESULTS

Twenty-five eyes of 16 patients were treated. Mean intraocular pressure reduction was 9.24 mmHg (+/- 3.4 mmHg) at 6 weeks, 9.32 mmHg (+/- 3.6 mmHg) at 3 months, 9.34 mmHg (+/- 3.8 mmHg) at 6 months, 8.42 mmHg (+/- 2.62 mmHg) at 12 months, 8.14 mmHg (+/- 3.42 mmHg) at 18 months, and 7.9 mmHg (+/- 3.63 mmHg) at 24 months. No pressure peaks (> 5 mmHg) were recorded after therapy. Inflammation and discomfort were minimal after laser treatment. Of 16 eyes examined at 2 years, there were no peripheral anterior synechiae. During the course of the study, six eyes became uncontrolled, despite one session of DLT. Four eyes regained control with a further session of DLT, but two required trabeculectomy.

CONCLUSION

Diode laser trabeculoplasty is an effective form of therapy in POAG and ocular hypertension. Hypotensive effects and success rates are comparable with argon laser trabeculoplasty (ALT). Reduced inflammation after laser treatment may be due to reduced absorption of infrared energy by the melanin of the anterior segment. The portable nature of these lasers may allow for laser delivery in developing countries and remote situations.

[Comparative use of diode and argon laser for panretinal photocoagulation in diabetic retinopathy]

The recently introduced semiconductor diode laser is portable, more compact, and cheaper to maintain than other laser systems. It is unclear whether its wavelength characteristics in the near infrared (810 nm) lead to different clinical results of retinal photocoagulation. In a prospective study ten diabetics (3 type I and 7 type II) ranging in age from 26 to 72 years with bilateral proliferative or severe nonproliferative diabetic retinopathy and visual acuity better than 6/18 in both eyes underwent panretinal photocoagulation. One eye was treated with the diode laser, the fellow eye with argon green (514 nm). Follow-up was documented by best-corrected visual acuity, fundus photography and fluorescein angiography. Mean duration of follow-up was 12 months. In neither group was there a significant difference in the response of retinopathy and neovascularization to the treatment, or in the course of visual acuity. Fluorescein angiography revealed the more profound effects of the diode laser in the choroid. Compared to argon laser treatment, patients found diode laser treatment more painful, but appreciated the absence of bright flashes during therapy. Photocoagulation for diabetic retinopathy using the diode laser was as effective as using the argon system in this initial pilot study.

Displaced intraocular lens repositioning using a reversed 10-0 straight polypropylene needle lasso technique

Images

Photocoagulation of choroidal neovascular membranes with a diode laser

Nine eyes with parafoveal choroidal neovascular membranes due to age-related macular degeneration or angioid streaks were treated with a diode laser and were followed up to 40 weeks (mean 26 weeks). Angiographically proved closure of the membrane was achieved in seven eyes. Four lesions needed a second treatment for growth of subretinal neovascular tissue. Post-treatment visual acuity ranged from 6/9 to 6/60. Two eyes developed subfoveal membranes resulting in poor visual acuity. The morphology of the diode laser lesions differed from that of the argon green laser and was more similar to that of the krypton laser, producing a 'black hole' on the fluorescein positive print. In one particular eye fluorescein angiography revealed subfoveal choroidal non-perfusion next to the site of the diode lesion suggesting choroidal vascular closure.

Factors influencing the natural history of diabetic retinopathy

Despite recent improvements in the management of blood glucose control and in modern technology such as laser treatment and vitreoretinal surgery, diabetes mellitus is the major systemic cause of blindness in the Western world. The study of the natural history of diabetic retinopathy is difficult because of the variability of the disease, and the numerous factors that may influence its course and outcome. In the many studies available of the natural history of diabetic retinopathy, there is a failure to identify these factors. This article tries to identify and to classify the influences that may modify the outcome and the natural course of diabetic retinopathy, and gives some advice on how to deal with them. They can be subdivided into external, internal and ocular factors. Any future studies of the natural history of diabetic retinopathy are marred by the fact that effective treatment is now established and the guidelines for when to commence treatment and the techniques of treatment are well documented.

Encephalitis and chorioretinitis associated with neurotropic African horsesickness virus infection in laboratory workers. Part II. Ophthalmological findings

Four laboratory workers developed uveitis-chorioretinitis, associated with encephalitis in 3 cases. The retinitis was characterised by haemorrhages and areas of retinal oedema, most marked over the posterior polar regions, and was associated with exudative retinal detachments. The lesions progressed over weeks and showed a severe retinal arterial vasculopathy with arteriolar narrowing, ghost vessel formation and the development of optic atrophy. The picture in 2 of the patients resembled that of the acute retinal necrosis syndrome (ARN). Antibodies to African horsesickness (AHS) virus were detected. The serology for AHS virus was positive in all 4 patients as well as in 5 of 15 laboratory workers from the same facility who were clinically and ophthalmologically normal. This is to our knowledge the first description of subclinical and probable clinical neurotropic AHS virus infection in man. AHS is a hitherto-unrecognised possible cause of viral retinitis and the ARN syndrome.

Transient vessel wall sheathing in acute retinal vein occlusions

Three cases are reported which had features similar to, and evolved in a pattern consistent with central retinal vein occlusions and a fourth case is reported which behaved as a hemispheric vein occlusion. However, they differed from classic retinal vein occlusions by having prominent sheathing of the retinal venous vasculature at presentation, which in all four cases resolved within three weeks. There was no evidence for any of these cases having an inflammatory vasculitis. The significance of this transient sheathing is uncertain.

Extracapsular cataract extraction in diabetics with rubeosis iridis

We reviewed thirteen operated eyes (twelve diabetic patients) with rubeosis iridis who underwent extracapsular cataract extraction and intraocular lens implantation. Prior to surgery five had active proliferative retinopathy (APR), and eight had non-proliferative retinopathy (NPR), either quiescent proliferative retinopathy (QPR) or background retinopathy (BR). No case with APR was visually improved by surgery. Three cases with NPR achieved a visual acuity of 6/12. After surgery, vitreous haemorrhage or progression of proliferative retinopathy occurred in three cases with APR. Early postoperative fibrinous uveitis was severe in eyes with APR, resulting in permanent fibrin membrane formation in four. We suggest a significant prognostic indicator in diabetic cataract extraction with rubeosis iridis is the status of the underlying retinopathy. With NPR, postoperative visual acuity may be good and early postoperative complications less severe. In the presence of APR the visual outcome is poor, progression of retinopathy likely and early postoperative fibrinous uveitis may be severe enough to prevent postoperative panretinal photocoagulation. Maximum preoperative panretinal ablation is essential in these cases.

Macular oedema and retinal neovascularisation in juvenile diabetics

Thirteen young diabetic patients with peripheral capillary non perfusion who presented with symptoms of mild maculopathy were reviewed retrospectively. In this group, peripheral retinal ischaemia was often overlooked and a rapidly progressive proliferative retinopathy developed. Fluorescein angiography of the peripheral retina showed capillary closure, but with preservation of arterioles and venules. In this series, half of the eyes lost vision. In seven eyes where the peripheral ischaemia was treated by pan retinal photocoagulation, the maculopathy resolved without any specific laser treatment to the macula. In young diabetics presenting with maculopathy, the peripheral retina should be examined for ischaemia, and if present, pan retinal laser photocoagulation should be performed. Focal treatment for the macular disease can be delayed until after the peripheral photocoagulation, as the maculopathy may remit.