Leber’s hereditary optic neuropathy (LHON) is the most frequent mitochondrial disease and was the first to be genetically defined by a point mutation in mitochondrial DNA (mtDNA). A molecular diagnosis is achieved in up to 95% of cases, the vast majority of which are accounted for by 3 mutations within mitochondrial complex I subunit–encoding genes in the mtDNA (mtLHON). Here, we resolve the enigma of LHON in the absence of pathogenic mtDNA mutations. We describe biallelic mutations in a nuclear encoded gene, DNAJC30 , in 33 unsolved patients from 29 families and establish an autosomal recessive mode of inheritance for LHON (arLHON), which to date has been a prime example of a maternally inherited disorder. Remarkably, all hallmarks of mtLHON were recapitulated, including incomplete penetrance, male predominance, and significant idebenone responsivity. Moreover, by tracking protein turnover in patient-derived cell lines and a DNAJC30 -knockout cellular model, we measured reduced turnover of specific complex I N-module subunits and a resultant impairment of complex I function. These results demonstrate that DNAJC30 is a chaperone protein needed for the efficient exchange of complex I subunits exposed to reactive oxygen species and integral to a mitochondrial complex I repair mechanism, thereby providing the first example to our knowledge of a disease resulting from impaired exchange of assembled respiratory chain subunits.

Purpose: To evaluate the effects of repeated intravitreal dexamethasone implant (IDI) (Ozurdex®) in eyes with macular edema (ME) due to retinal vein occlusion (RVO). Methods: We reviewed the charts of patients with RVO-related ME, who received repeated Ozurdex IDI (0.7 mg) on an ‘as-needed’ basis. Main outcome measures included changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), retreatment interval, and incidence of side effects. Results: A total of 33 eyes were included for analysis. Retreatment with Ozurdex was judged necessary after 4.7 ± 1.1 months from the first IDI (1st IDI) and 5.1 ± 1.5 months from the second IDI (2nd IDI). Baseline BCVA was 0.65 ± 0.43 logMAR; it significantly improved to 0.50 ± 0.42 logMAR after 1.4 ± 0.7 months from the 1st IDI (peaking efficacy) (p < 0.001) and to 0.48 ± 0.44 logMAR after 1.8 ± 0.8 months from the 2nd IDI (peaking efficacy) (p < 0.001). CMT decreased from 636 ± 217 µm (baseline) to 300 ± 114 µm, 1.4 ± 0.7 months after the 1st IDI (p < 0.001), and to 298 ± 91 µm, 1.8 ± 0.8 months after the 2nd IDI (p < 0.001). A rebound effect was recorded in 7 eyes after the 1st IDI (mean 168 ± 158 µm) and in 4 eyes after the 2nd IDI (mean 215 ± 199 µm). All eyes with a rebound effect improved again after a 2nd intravitreal Ozurdex injection. No serious adverse events were observed; 12 eyes developed a transient IOP increase, and cataracts were extracted in 2 eyes. Conclusion: Repeated intravitreal Ozurdex on an ‘as-needed’ basis, with a retreatment interval <6 months, may produce long-term clinically meaningful benefits in the treatment of ME due to RVO, without other significant side effects than expected after intraocular corticosteroid treatment.

Intravitreal ranibizumab and IVB are effective in the treatment of subfoveal myopic choroidal neovascularization. Intravitreal ranibizumab achieved greater efficacy than IVB in terms of the mean number of injections administered.

AimsTo evaluate longitudinal retinal ganglion cell inner plexiform layer (GC-IPL) and macular retinal nerve fibre layer (mRNFL) thickness changes in acute Leber's hereditary optic neuropathy (LHON).MethodsSix eyes of four patients with LHON underwent SD-OCT (optical coherence tomography) at month 1, 3, 6 and 12 after visual loss. In two eyes, the examination was carried out in the presymptomatic stage. The relationship and curves for area under the receiver operator characteristic (AUROC) were generated to assess the ability of each parameter to detect ganglion cell loss.ResultsSignificant longitudinal thinning of GC-IPL and mRNFL was detected in LHON. GC-IPL thinning was detectable in the deviation map during the presymptomatic stage in the inner ring of the nasal sector and then it progressively extended following a centrifugal and spiral pattern. Similarly, mRNFL thinning began in the inferonasal sector and it progressively extended. No further statistically significant changes were detected after month 3. The highest level of AUROC values at 1 month were detected in the nasal sectors and inferonasal mRNFL thickness reached AUROC value=1. All the parameters were equally able to detect ganglion cell loss from month 2 to 12.ConclusionsThe natural history of GC-IPL thinning follows a specific pattern of reduction, reflecting the anatomical course of papillomacular fibres. Month 6 represents the end of GC-IPL loss. GC-IPL and mRNFL thinning is detectable before onset of visual loss. These observations can help future therapeutic approaches for both LHON carriers at high risk of conversion and patients with acute early LHON.

Purpose: To evaluate the effects of a single injection of Ozurdex over 6 months in eyes with persistent diabetic macular edema (DME). Methods: In this retrospective interventional study, 9 patients with decreased visual acuity, as a result of persistent DME, received Ozurdex (intravitreal dexamethasone implant 0.7 mg). Main outcome measures included changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Results: Nine eyes of 9 patients (5 males, 4 females; mean age 58 years) were included in the analysis. The mean duration of DME was 49.9 months (range 24–85). All patients had undergone previous treatments for DME (intravitreal injection of anti-vascular endothelial growth factor, steroids or laser photocoagulation) before entering the study. At baseline, the mean BCVA was 0.74 ± 0.33 logMAR, and the mean CRT was 502 ± 222.16 µm. The mean BCVA was unchanged on the third day (0.74 ± 0.38 logMAR, p = 0.5), improved to 0.62 ± 0.32 logMAR (p = 0.02), 0.59 ± 0.26 logMAR (p = 0.02) and 0.63 ± 0.38 logMAR (p = 0.6) after the first, third and fourth months, respectively, and decreased again to 0.73 ± 0.35 logMAR (p = 0.4) at 6 months. The mean CRT improved to 397 ± 115.31 µm (p = 0.17), 271 ± 99.97 µm (p = 0.007), 325 ± 133.05 µm (p = 0.03) and 462 ± 176.48 µm (p = 0.36) on the third day and after 1, 3 and 4 months of follow-up and then increased again to 537 ± 265.42 µm (p = 0.33) at 6 months. Eight patients needed retreatments in the sixth month. One eye developed a transient intraocular pressure (IOP) increase 1 month after injection, which was successfully managed with topical IOP-lowering medication. Conclusion: In eyes with persistent DME, Ozurdex produces improvement in BCVA and CRT as soon as the first days after the injection. Such improvement is maintained until the fourth month.

Significant peripapillary miscrovascular changes were detected over the different stages of LHON. Studying the vascular network separately from fibres revealed that microvascular changes in the temporal sector preceded the changes of RNFL and mirrored the GC-IPL changes. Measurements of the peripapillary vascular network may become a useful biomarker to monitor the disease process, evaluate therapeutic efficacy and elucidate pathophysiology.

Leber’s hereditary optic neuropathy (LHON) is typically characterized by vascular alterations in the acute phase. The aim of this study was to evaluate choroidal changes occurring in asymptomatic, acute and chronic stages of LHON. We enrolled 49 patients with LHON, 19 with Dominant Optic Atrophy (DOA) and 22 healthy controls. Spectral Domain-Optical Coherence Tomography (SD-OCT) scans of macular and peripapillary regions were performed in all subjects, to evaluate macular and peripapillary choroidal thickness, and retinal nerve fiber layer (RNFL) thicknes. Macular and peripapillary choroidal thicknesses were significantly increased in the acute LHON stage. On the contrary, macular choroidal thickness was significantly reduced in the chronic stage. Furthermore, peripapillary choroidal thickness was decreased in chronic LHON and in DOA. Both RNFL and choroid had the same trend (increased thickness, followed by thinning), but RNFL changes preceded those affecting the choroid. In conclusion, our study quantitatively demonstrated the involvement of the choroid in LHON pathology. The increase in choroidal thickness is a feature of the LHON acute stage, which follows the thickening of RNFL. Conversely, thinning of the choroid is the common outcome in chronic LHON and in DOA.

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